I'm sure this comes up quite a bit.. but what are all the pros and cons of superchargers and turbochargers?

------------------
89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

This has been brought up COUNTLESS times on several boards. Please do a search at www.camaroz28.com for the huge discussions on turbos vs. blowers...

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

when it comes down to it turbo is for high rpm's and lots of speed. superchargers kick in at lower rpms and dont have to wiat for the exhaust to speed up. i'd rather run a supercharger just my .02

------------------
1991 RS LO3
mods: 14" chrome air cleaner, straight-piped after cat exhaust with one chrome dual tip on the left side.
future mods: headers, removing smog equipment, and as many cheap mods as i can find
aol s/n: budman8503

 

Please use the search tool and check the archives.

As for high or low rpm, I disagree. I see full boost at 2000 rpms, while a supercharged car will only see full boost at redline.

Super is better since there are bolt-on kits out there, turbo is better since they generally makes more power (at same boost).


------------------
Andris Skulte
Skulte Performance Designs
Z28tt-89 IROC T56 DFI Twin Turbo
http://www.skulte.com

 

Andris is correct. Despite popular beliefs, the following is CORRECT:

1) Turbos produce less heat.
2) Turbos reach max boost SOONER.
3) Blowers rob horsepower (belt).
4) Turbos give n/a fuel economy out of boost.
5) Turbos are less harsh on internal components.
6) Turbo boost levels are infinitely adjustable (I run 15 psi on pump gas, and with race gas I run 25 psi. I just push a button!).

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

"3) Blowers rob horsepower (belt)."

Are we to imply that turbos do not rob the engine of any horsepower then? If that is true, then I must have misunderstood some of the most fundamental laws of Physics in High School and College, the most obvious being you never get something for nothing. Turbos use exhaust to spool up. That generates backpressure. That robs horsepower (much in the same way a restrictive exhaust robs horsepower). Bottom line, turbos consume horsepower just as superchargers do, how much is another question, but your statement, while technically correct, is also just as technically misleading, unless of course there is some critical detail I'm missing.

 

You are correct that turbos rob horsepower. However, compared to blowers, its orders of magnitude less, hence it wasn't mentioned.

A.

 

Without quantifying the differences, you are making a very misleading statement. A more appropriate claim would be that turbos rob less horsepower then superchargers.

I think it's also important to point out that you (askulte) are using a twin turbo setup. A single turbo would not provide max boost at 2k rpm.

Over the years I've driven a number of turbo and supercharged vehicles in 'daily driver' environments, and the two are inherently different beasts. I've driven a turbo GMC Syclone (my brother in laws prized possession), a turbo pontiac Sunbird, my uncle's blown 76 corvette, and the Pontiac Grand Prix GTP.

In on-off throttle driving, the supercharger provides a far superior feel. It's power is there without delay. In my eyes that is it's biggest advantage. In a strictly WOT situation that advantage obviously evaporates (and perhaps a twin-turbo setup also eliminates that advantage, but I've never had the opportunity to experience the feel first-hand) In my experience, superchargers are more streetable and provide a better feel in on-off throttle situations.

 

jRaskell,
The turbo cars you've driven have had higher boost smaller displacement engines, which naturally take quite a bit more time to spool up.

I just didn't feel like expanding on this conversation since everything we (yourself, me, and GMI_fast) discussed here has been said countless times and can be found in the archives. You seem knowledgeable about both superchargers and turbos, and the topic was started by Enkil, who is new to this. Those are my last few cents on this

Andris, groggy from percoset and !teeth mod

PS-Where in NH are you? If you're ever in Boston or NY, drop me a line and we'll go for a drive sometime

[This message has been edited by askulte (edited February 12, 2001).]

 

Maybe not, but my friends single turbo hit peak boost @ 2800 rpms,(17 psi) which is about 3k faster at producing peak output than an equivelant blower for his setup. It was on a 90 302 Mustang.

Blowers are much more gradual than a turbo setup. A turbo car will have an SOTP which will seem much faster than most centrifical blower cars, since it hits much harder and sooner.. A roots style blower will also make its boost faster than a centrifical.

Turbos do rob some horsepower due to the exhaust spinning the turbo, but the S/C will take away much more h.p. from having to spin off the crank.. I have heard a couple guys who tune sick setups with both S/C and turbo on dynos say it might take as much as 100 crank h.p. to spin a YS blower to max boost, vs around 70 percent less horsepower to spin a turbo with the same output. Spinning off the crank also puts more load and stress on internal engine parts, promoting more wear.
I run an S/C on my car, but if I didnt have to get custom headers made and make a custom kit for my car, i would have gotten a turbo in a heartbeat over an S/C. As mentioned earlier, there are complete easy kits for the S/C out there, which since I am lazy, I choose to go that route.
Hands down I think a turbo is more efficient than a blower, and will make more overall power.

 

Turbos are efficient but they are also complicated as hell to put in and expensive. A good intercooled centrifugal supercharger such as a procharger is easily installed in one day, cheap, and you dont have to retard your timing or any of that other crap you have to do with other superchargers.

 

Don't have to retard timing? Yes you do, if you want to make some big boost!

No need to jump all over my statement. I stand firm behind it. I said they "rob horsepower", and they do! My friend's YS-trim Vortech requires approximately 70+ horsepower to run the unit. Damned right that's robbery! As far as power lost to turn a turbo, I disagree. Of course there is some minute power needed to turn a turbine wheel...duh. But here is a simple example of the power needed. Hold a pinwheel and blow on it. Oooh, that was difficult. Now strap on a rubber band and turn a pulley to make it spin. Hmmm. The turbine wheel also creates a scavenging effect when spinning, not unlike putting your hand on the back of an electric fan. Once the exhaust gases overcome inertia of moving the turbine wheel, the horsepower loss is almost nothing. The spinning wheel will help pull more exhaust through it.The supercharger belt is always on, and always is robbing power.

The examples of vehicles you have had experience with is downright staggering. Thank you for your eager pounce on my single statement. Here is a list of vehicles we have had experience with, and also dyno-tested. Some were turboed after being previously supercharged. Guess what? Even with SMALLER turbo units replacing superchargers, at same boost pressures the turbos always made more horsepower and same or better torque...

Single turbo 306" 1986 Mustang SVO
Single turbo 2.3L 11-sec. SVO
Single turbo 351" 1993 GT Conv't
Twin turbo 1988 Saleen Conv't.
Vorteched 1992 GT
Vorteched, nitroused 1988 GTA
Vorteched 1989 Formula 383"
Vorteched 1989 Formula 350
ProCharged 1988 383" IROC
Vorteched 1995 C1500 4X4
Oh, yeah, and these, too:
Twin turbo Donzi Off-Shore Boat
Countless 4-cylinder turbo imports
Bazillion Supras, 300ZX's, RX-7's
Tons of Turbo/EFI motorcycles
Champion Turbo/NOS 6-sec. Funnybikes

Okay, I'm done.
Have a nice day.


------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

Thanks for all the responses. Now for another question..

What are necessary mods to the engine to run a turbo/super? I've heard that since supers put stress on the engine that getting forged parts wouldn't be a bad idea.

Does the same hold true for a turbo?

 

I meant no offense in my original post GMI Fast. I just wanted to point out that turbos also consume horsepower to generate boost, and I have no intention of arguing against the fact that superchargers are less efficient.

Once again, however, your example is a little misleading. Take the pinwheel and attach it to a compressor, then blow on it enough to generate 15psi of boost into an engine that is at the same time sucking air into it. I'll repeat that I am not disputing the fact that turbos are more efficient, I'd just like to see some concrete and solid tests that provide real world numbers. I'm sure they are out there somewhere, if you could point me in the right direction I would in fact be very thankful. I'm curious as to where this 70hp figure came from, and I'm curious to hear what the respective figure for a turbo is, and where that number came from also.

As for my 'experience' with forced induction vehicles, I meant that only with respect to daily driven activities. I have NEVER driven a forced induction vehicle in any sort of race, though I hope to change that with my own vehicle someday. I also have NO practical experience when it comes to actually installing either a custom built, or aftermarket kit, system, or any tuning and tweaking that follows such an installation.

Andris was also correct in pointing out that the turbo vehicles I've driven are relatively old with small displacement engines. But that's just the experience I have to draw upon. I'm certainly not trying to refute anybody elses experience, but for me the proof is always in the pudding. It's not that I don't want to take anybody's word on anything, I just prefer to see all the data for myself and draw the same conclusions on my own. Maybe sounds inefficient, but I learn a lot more that way. The last thing I want to do is step on any feet that can possibly help me out down the road when I do get my own system (which at this time will likely be a kit SC simply because I don't have the resources to do anything custom. My preference, fyi, would definitely be a twin turbo setup) No hard feelings intended, was just trying to participate in an intelligent debate, which I seem to have gone about all wrong.

Oh, and thanks for reminding me of that TT RX-7 I drove once. I forgot about that one. It was a 5 minute cruise a few years ago. Heh, so take that. (j/k)

[This message has been edited by jRaskell (edited February 13, 2001).]

 

The 70 hp figures were given to us by Vortech! The figure was actually closer to 100 hp, but we have changed the pulley arrangement and achieved lower amounts of parasitic drag. Regardless of boost pressure, exhaust pulsing through a turbine will never cause the power loss a belt-driven blower does. I never mentioned it in my original reply because the power loss is sooooo minimal. I also never stated that there was NO power loss with a turbo, just a bazillion times less than a blower. On the same vehicle, we have seen 50 horsepower gains when replacing the blower with a similarly-sized turbo. Just real-world dyno-proven experience, there for ya! If you need to learn more, read Corky Bell's book on turbocharging...

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

Damn, I got baited into posting again

The turbo will take quite a bit of force to spin. Freewheeling doesn't take much hp, but compressing the air does. Figure a 350 at 6000 rpms and perfect cylinder filling inhales 607 cfm = (350 / 12^3 * .5 * 6000), and 14.7 lbs of boost has a pressure ratio of two.

CFM * 0.015(Ratio^.29-1) = 29 horsepower

It takes 29 horsepower to compress the air, not counting innefficiency. Don't look at it as a direct 29 hp off the crank like a supercharger. The turbo gets most of its energy from the heat of the exhaust and expanding the gas in the turbine. Backpressure is the only HP penalty you pay (at roughly 1 to 2x boost pressure) but it only affects the amount of time air flows through the intake valve... Yes, it is a penalty, but very small compared to the free hp you get (otherwise all that heat would just get out of the tailpipe). Of the fuel you burn, 1/3 of the energy goes to spinning the crank, another third gets removed by the cooling system, and the final third goes out the exhaust. If you're curious about the thermodynamics of turbos and engines in general, feel free to ask questions. I've got a great bunch of books for further reading.

Andris

 

When you say similarly sized turbo, are you referring to the amount of boost provided? ie replacing a supercharger setup generating 12psi of peak boost with a turbo setup that also generates 12psi of boost?

And a couple more questions on how turbos generate boost, just making sure I understand what you're stating. When you talk about the heat expansion, are you referring to the further expansion of the gases within the header pipes, or the expansion of the intake air as it is being compressed (given that the compression of air generates heat, and hot air expands, is this actually a compounding effect, some of the measured compression actually coming from the rise in temperature of the intake air?)

Formulas:
I got the cfm calculation figured out, but for the second formula I keep getting 14.8, which is just over half 29. (And that's when I use 1-.29 and not .29-1, if I use .29-1 I end up with 5.5) I'm replacing ratio with 2, assuming that's what you meant when you said 14.7 lbs of boost has a pressure ratio of two. Is that value gotten from some table, or another formula?

 

This has been talked abgout before.Turbos and centrificals have their place,one makes more power in certain situation and the situation it is suited for.I know superchargers use hp,so do turbos,how much Ill never know ,no one post on this,but I know In life nothing is a free lunch.Maybe it uses half the hp a centrifical does maybe not.As for street situations ,centrifical is the hands down winner,cheaper,easier install.From what I see in the Mustang classes the turbos are not that far ahead,some classes are still dominated by centrificals.As for the roots,the most inefficent blower you could use is the top choice by the top classes.They probably draw in the highhundreds of hp,maybe close to 1000 or more just to be turned on a top fuel car,but they work,and inefficent as they are they make a lot of hp.Centrificals and turbos would never be able to live in such situations because this type of performance is way out of there league.Certain situations call for different power adders,to say one is the best over all is a gross understatement.

 

J-
I forgot to add atmospheric pressure to the formula:

CFM * atmospheric pressure * 0.015(Ratio^.29-1) = 29 horsepower

It's ratio to the power of 0.29

CFM * 14.7 * 0.015(Ratio^.29-1) = 29 hp
607 cfm * 0.015 * 14.7 = 134
Ratio of 2^0.29=1.223
134 * (1.223-1) = 29 hp

Superchargers have the same hp draw to compress air as turbos, and the other half is the efficiency of the gear drive mechanism. I've heard 75+ for Vortech's and ATI's on our <600hp street applications. As for the roots style - they're hugely innefficient, but they have instant response, and at the rate the top fuel dragsters accelerate (4 sec pass) the turbos can't respond quick enough. The only free lunch is nitrous (/me ducks! opening another can of worms)

I love the whole design and engineering side of engines, and do my best to learn about it. I just have first-hand experience with my own setup, and get most of the knowlege from other list guys and books. I'm just trying to keep misinformation from spreading.

Andris, going to go work on the car now...

 

When I say "similarly-sized", I am talking about the maximum cfm of airflow of the compressor. Say 1200 cfm vs. 1200 cfm at X amount of boost. Turbo wins hands down. While each power adder uses horsepower to compress air, horsepower used to turn the actual compressor wheel is exponentially greater in a centrifugal blower. Just look at simple things like power gained from removing belt-driven items such as a/c units and smog pumps, power steering, etc. Lose the belt on the blower, gain horsepower. Period. You guys have fun with whatever power adder you choose. Enjoy my taillights!

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

ATI prochargers are intercooled so no you do not have to retard your timing unless you go over 15psi of boost. If you have a supercharger such as vortech it is not intercooled that is why if you have more than 6psi boost you have to retard your timing and use water injection to prevent your engine from getting damaged and your engine is still exposed to detonation. And to who ever said you have to retard your timing if you want a lot of boost 15psi is a lot of boost in a daily driver with no mods. Also a procharger itself runs cooler than a turbo so an intercooled procharger will produce more power than an intercooled turbocharger at the same boost level. So the fact that it is cheaper and way easier to install makes it the winner in my book.

 

LOL Sorry I highly disagree with this.. I dont know anyone who runs that much psi and doesnt have a custom chip or manual boost box.. it would be foolish to not retard timing with that much boost. tuning is the key in making the most out of your setup, and running no retard is like putting blinders on, and crossing your fingers.

I never ran water injection with 10 psi of boost on my Vortech. Water injection is far from "necessary" on a non intercooled setup. I did get an Aftercooler after awhile, but tuning is the key in any setup. I know guys running 11 psi on stock motors non intercooled and lasting a long time.. Once again tuning is the key.

That is once again very far from the truth... Where are you getting your info from anyway??
From dealing with Second Street in Pa. and Turbo People in Ny. and seeing dyno results from many different setups, let alone messing with a few myself,
Turbos make the most overall power in almost every situation in comparison to boost and cfm on the cars I have seen.



[This message has been edited by Kevin G (edited February 14, 2001).]

 

89 Iroc,
Who told you the Prochargers run cooler than turbos? The intake charge is heated up for 3 reasons.

1. Compressing air heats it (feel your bicycle floor pump after pumping a road race tire to 120 psi). I can give you standard formulas for this amount of heat. This is constant for everything.

2. Efficiency of the pump. The turbo I have is 78% efficient, so 78% of the energy goes into compressing the air, the other 22% heats it up additionally. AFAIK, the superchargers were not that efficient since they have a broader operating range. If you can show me a supercharger compressor map with efficiency, CFM, and RPM, I'd love to see it. All the supercharger companies claim they're the best, heat the least, etc, so the maps have been pretty secretive. It'll show what is really going on.

3. Heat by conduction - If your supercharger/turbocharger etc is hot, the air passing through it will get slightly heated. This is the reason for icing the intake.

Your argument saying the IC'd procharger is cooler than an IC'd turbo is completely false. There are many variables, such as the efficiency of the compressor and intercooler. The intercooler I chose has an efficiency of 81% at the CFM I need with only a 0.6 psi drop in pressure. I seriously doubt the smaller and thicker ATI intercooler can match those numbers. Again, the only way to compare it is to know what is going on - for air:air IC cores, you need to know the thickness, length, speed of ambient flow (air going through it to cool), what fin arrangement it has, thickness of fins, and end tank design), or a map showing efficiency + pressure drop vs flow rate and ambient air speed.

If you want to run 15 psi on your stock motor+timing, intercooler or not, it will break. Maybe not this week, but within 5000 miles for sure. I'm running 7 psi non-intercooled, and after I finish the http://www.skulte.com/intercooler.html intercooler install, I will probably turn the boost up to 10-12 psi. I don't expect the motor to last, since the stock internals were not designed for this level of power.

There are no winners since everything always is a compromise. Before you start talking about numbers, efficiency, temperature rise, etc, get some hard numbers to back it up. Thanks.

Andris

 

ok, listen. i'm going not to get involved in this arguement which will never end because some know what they are talking about and others are just assuming with what knowledge they already have and I AM NOT GOING TO NAME NAMES. i have posted two good things in the past and will post them here. one post is about which is better: Turbo, super, or juice. the other post is about this topic here: the result loss of supers and turbos.

well, i truly believe that if you do your homework right that any combo may it be turbo, blower, or juice will all get you your goal. take for example pro street. bob rieger runs a 427sm with twin 76s and runs 6.50s and tony christian has a big block and a whole lot of juice and runs very close to the same. Also, look at the NMRA and Pro 5.0 The two fastes racers as of last season were Jim Summers and John Gullet. Guess what, Jim has a Procharger D-3R and John Gullet has a 100mm turbo, now guess what their times were.
Gullet: 7.25 @ 192
Summers: 7.26 @ 193

-i am not really sure how much blowers take away from the motor. it will vary upon boost level, rpm's, and whether it is a cog drive or serpentine set-up. I DO KNOW that the biggest D-3M at about 30psi takes about 200hp to turn!
-to pugs, yes turbos to take a little power to turn. one reason other reason why it is so little power wasted and why turbos are usually more efficient than ANY SUPERCHARGER, except for a roots with teflon coated blades, is because as you should already well know; all the energy of combustion IS NOT USED. if it was, then technially there would be no exhaust needed because everything would combust. Second, that which is not combusted still has energy, energy that is turned into a vehicle's exhaust. THIS ENERGY helps to turn the turbine of the turbocharger (which takes a little horse too) which in turn, turns the compressor wheel. i am no expert but to read alot and this is what i have come to know.


so there you have it. like i said...i'm no expert but this is what i have read about and know at this point in time. I hope what i have said might help others concerning these questions and i have also learned some from Andris and GMI FAST, so take it as knowledge and learn from it.



[This message has been edited by 89ProchargedROC (edited February 14, 2001).]

 

89Pro - Close, just about all the air/fuel mixture is combusted. It is the HEAT of combustion that motivates a piston. All of the heat energy is not extracted by the engine from combustion, and is dumped out of the exhaust.

 

Just one thing to note. The small displacement guys have a huge weight advantage over the big block Pro Street guys. They are allowed to run lighter, so the h.p levels are not the same from the 2 you mentioned My buddies stopped running in Pro Street and went with another class for this reason. But seeing how much damn power a small block makes with those guys is amazing.

 

Kevin G when you say in your experience turbos make more power than superchargers did both cars have the same engine? were they both intercooled? an did they both have the same boost?

 

I got a ton of my info from the guys I mentioned who build and tune 1000 hp+ cars for a living. One customer switched from a D1 to a turbo and got good gains, motor and boost being the same. I didnt need to ask for dynos or graphs and charts. I went off of their opinion.. I have built 3 S/C cars before, one which appeared in 99 Hot rod mag.. 580RWHP T/A..and put together one turbo car before.I have a couple friends who went from S/C to turbo and love it. Like a guy I know Steve Cs stock suspended 10 inch slicked 306 cu single turbo Mustang that runs 7.79@172. I dont have definitive proof, because I never doubted the people I talked to or personally know who run different setups. But feel free to call around shops local to you who deal with high output blown and turbo setups, and get their opinion. Feel free to post the "you do not need retard until 15 psi" on other boards such as CCZ28 and see what others think.
I would still like to know where your info came from where you stated the ATI makes more power. Or where you need to run water injection on non inter/aftercooled Vortech setups.
Everyone does things differently. If you want to run 15 psi and no retard, more power to you. If you want to believe an ATI will make more power..thats great. I have no problems with that. I got my opinion based from my own projects, friends projects, and some of the best tuners on the east coast for EFI.




[This message has been edited by Kevin G (edited February 14, 2001).]

 

see, like i said we are all learning. know i know more. thanks

 

uh....actually the SBC guys w/ twin turbos dont have that good a weight break. they actually made Rieger weigh 200lbs more than Christian. so you are right small block guys have the weight break over the big block guys, but not any SBC with twins. LOOK AT ANY CLASS YOU WANT AND TWIN TURBO CARS WHETHER FORD OR CHEVY HAVE THE WORST STANDARD WEIGHT PENALTY. Why do you think the NMRA and Pro 5.0 guys all run single turbos instead of twins????? car can weigh less.

 

I ran across this the other day:
http://www.vortechsuperchargers.com/tech/



[This message has been edited by Dan W (edited February 14, 2001).]

 

Ok, some of the responces here are good, however really dont help anyone choose what is better, so here are a couple of descriptions of how each one act. Oh and for a side note this is all experience with Mustangs and Camaro's.

Roots style charger = Low end big block torque feel from a small block. Awsome low end torque, full boost by 1500-2000 rpms.
Heat up intake air charge more so than the others, smaller kits designed for street cars dont make the higher horsepower numbers. Also generally boost levels are lower. Generates a flat Torque Curve, Horsepower is fairly flat also, not as peaked as the others. Plus general Hp lost because of belt.

Centr. Blower = Not the same low range power of the roots, but do have good mid range torque, more upper Horsepower than roots. Produce torque peaks higher, Dyno graphs are more peaked. Do not heat up intake air charge as much as roots style. Street kits and general bolt on kits can produce higher boost levels than the roots.

Turbo's... These I know because I have built one, building a second, and have helped build 2 other Turbo cars. All of which are Mustangs.

Turbo's do not have instant off idle power. However how bad, is effected by a number of things. Fuel maps, timing Maps, size of the turbo exhaust housing side vs the amount of exhaust being moved by the engine into that housing. Other effects on how a Turbo responds is by engine load. The more load, the quicker the boost will build. For instance holding 2500 rpms on a flat road will usually produce no boost, hold that same rpm pulling a hill and the turbo will produce pressure. The type of transmission you run has a great effect on how a turbo responds. With an automatic, the stall effects the turbo responce. Needless to say, turbos have more variables to consider than the others.

On a Turbo car loosing power from having to build MAP is no different then a Blower having to build that same pressure. There are many other variables on just how much power a Turbo robs. Not only the passing of the exhaust makes the turbine spin, heat expansion also does. So with that depending on how close the Turbo is to the exhaust outlet is going to effect power loss. If the turbo is really the right size for that engine. And in all reality, as soon as exhaust passes through the turbo it is already spinning, so its not starting from a dead stop. Other effects would have to do with vain pitch and such. In any event loss of power is not really a measurable effect with the turbo.

As for the Top Fuel reasoning, not true either. NHRA Does not allow Turbos due to the fact they can not regulate them the way they can with chargers.

My car was a 93 GT Stock 302, TrickFlow heads, Cobra Intake, 70mm throttle body, 215/224 @.50 .533 lift cam. T4 Turbo (which is small. A Turbocoupe Thunderbird with a 2.3 4cyl runs a T3) producing 15psi. With a C4 and a bad torque converter (The motor overpowered the converter) hit 126mph hitting a 6000 rpm revlimiter 100' before the end of the 1/4. The car would reach full 15psi by 2800-3000 Rpms.

NMRA, I have helped Steve Cascio with 2 of his Mustangs, both of which where Super Street Outlaw class. The first one was a 90 LX with a T76 ceramic bearing (the bearing is another effect on power loss) The car ran 9.35@144 weighing in at 3000 pounds. The car was not dynoed. On the street the car had lots of lag. However if you are able to build boost from a dead stop, generally using the right stall converter and a trans brake, lag is no longer a factor.

The new car is a 85 Coupe, with a T100. At 28psi this car produced 1160 rwhp. The car ran a best of 8.20@170 mph spinning the slicks the first 90 feet of the track. Also on the 1-2 shift the car broke the tires loose again.

A car with close to the same setup owned by Job Spetter Jr, made a little less power, but with better traction has run 7.87@179mph.

These both are NMRA cars, And many Pro 5.0 Cars also run Turbos. However NMRA had many complaints from Superchargers guys and NOS guys that the Turbo cars were to fast. NMRA then put limits on the turbo cars such as size and boost controlers. Twin Turbo cars had to weigh 200 more pounds than single power adder cars.

Basically to end all of what I am saying, Turbo cars will make more power.
However how you intend to use the car, how you want the car to feel are what should really make up your mind on what type of power adder to choose.

Oh and dont bother with NOS, I have run that too. While the power is awsome, its a pain in the butt. Bottle pressures, filling the bottle... Trust me it gets old. But I must say a 200hp shot is totally awsome in the way it feels when its right.

[This message has been edited by Cobra R (edited February 14, 2001).]

 

True, dat! Hear that, boys? 9.30's with a T76. Hmmm...

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Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

yes i did dan....but he said the car weighed 3000lb. You better put you and the car on a diet for that to happen....

BTW, i think that guy is lying about the T-100, at those boost levels that car should be making more hp.....are you trying to trick us??? hey just joking that is impressive. One thing i will say that has me the most impressed is Mike Murillo's new motor. 302 w/ T-100 making 1750hp flywheel. Truly unbelievable. he also ran in the 7s, 7.96 @ 181 with a lift i believe. those stangs can really fly. TRULY AMAZING AND I HOPE IT BREAKS INTO THE 7S MORE YOU.i myself is going big thumper

------------------
Big Thumper 400 started!
91mm Turbo
GM raised runner heads
more as money allows
Always a cool place visit
www.mfba.org

 

I think it has nothing to do with weather NHRA can regulate them or not,it has to do with if they can last the run or not.Seems they melt the heads practically after every run ,since the Roots sits on top of the motor I dont think it would survive the heat.You talking about a motor making in excess of 7000hp,not a 2000hp turbo motor.Since the fastest turbos are not even out of the 6 second range I still think anything but the roots could survive and maybe a big enough centrifical(doubt it though),I just dont think the turbo could take the heat.Good discussion though,but I still like my D1.When somone comes up with a kit(turbo),let me know. Im not spending money on research.GMI fast,cant you use your kit as a reference to build other 3rd gen kits?Do you guys get calls on the idea?Or just intrested folks,with no money to spend

 

Interested folks with no money...

3000#, little motor, T76 = 9.35

3600#, 400" motor, T76, NOS =

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

GMI fast,I guess you didnt get my post,you told me before that you had people bother the crap out of you for a turbo kit(IE,Caviler kit)and after developing hardly anyone bought it.
I dont understand your posting of those times,explain?

 

Oh my bad , thats right, it is considered 2 power adders. I guess from what I heard from some guys who were running against him that day at Maple Grove when he busted everyone up. Some were complaining he had a weight advantage.. Or maybe they made him add more weight after that day I saw him run, due to the fact he was mopping everyone up all the time. LOL

 

PROCHARGED89Z: What "times" are you referring to? As far as the Cavalier turbosystem goes, yes. We had a number of people tell us they wanted a kit. When asked to put down a $100 deposit, only one guy did so.

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

yeah, that would **** me off too. think about it, you have a BUILT RACE CAR, and hear comes this non-aerodynamic bel aero 57 chevy that weighs more than almost everyone esle and still kicks the crap out of everyone...yeah i would be mad too, espeicially since i hear rieger is a ***** in real life.

 

i hear ya...but you know what? i'm starting to believe that cubic inches has little to do with power when you put a HUGE turbo on the car. my new hero (dont hate me everyone) is mike murillo.
-just a little ford 302
-100mm turbo
-about 1750hp

7.96 @ 180 with slight lift and true 10.5" tire. simply amazing

 

It depends on what your car's purpose is. Small motors rock with big turbos. They can also be less streetable than big motors with smaller turbos. I have chosen to run a large-inch small-block with a good-sized turbo. But mine is not a drag-only car. My goal is to run 9's, pull over 1.0G on a skidpad, run 200 mph and cruise around town with the t-tops off and the stereo bumping...

We have successfully held the most Funnybike and Streetbike records for so many years in a row it isn't funny. All done with a big turbo on an surprisingly stock 1100cc engine that runs 6-second ET's. But on our streetbikes, we run a smaller turbo, which spools great with some more cubes.

------------------
Old: 1989 Formula, 383", DFI, built 700R4, TFS heads, Mini-Ram, Vortech S-trim 15 psi, 3.70 gears
Best ET: 10.796 @ 125.8 mph

New: 1989 T/A, 400" CNC Bow-Tie Tall-Deck, Accel Pro-Ram, DFI, AFR heads, HRC T76 Turbo, NOS 150-hp dry kit, TH400 w/GV overdrive, 12-bolt w/3.70 gears, 8-pt. S&W rollbar, Spohn suspension, 18" wheels, Baer brakes
Best ET: Spring 2001

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association www.mfba.org

 

In the NMCA Super Street class, they impose a higher pound-per-cubic inch rule on the turbocharged cars. Is this the same in the mustang classes? I hate when they do sh_t like that. They did the same thing to Buddy Ingersol in the mid eighties. After that didnt work, they banned turbochargers from NHRA Pro Stock and created a separate class just turbo cars (I believe it was call AA/Altered Turbo, it didnt last long). Oh well, life is NEVER fair!

If you cant beat them, join them.

TURBO FAN FOR LIFE!!!

[This message has been edited by JAYDUBB (edited February 17, 2001).]

 

....streetable.....what's that
hehehe, that is ok. you'll have the street car and i'll have the race car. either way...we will dominate the club minus maybe one who runs a 'glide you know who i mean. oops, forgot about that elgin car too. mfba all the way

 

For the NMRA classes, Renegade only will allow a INCON Turbo kit, a kit that really wont make major power. In that class the superchargers seem to do a little better. As far as Outlaw and Pro 5.0 Turbo's did the best last year. So this year the NMRA put a restriction on the turbo size to a 90 and wont allow boost controllers. Basically with out the boost controller the cars will be hard to controll off the line. So now alot of the fastest turbo cars have dropped out of the NMRA due to the rule changes.

 

actually, they are only limiting turbo size to 91mm in the Super Street Outlaw class, since no one could touch those cars with a 100mm. i mean come-on, if mike murillo would have competed all season turbos would have been 1,2,3. dont know the order but would have been Job Spetter Jr, Mike Murillo, and John Urist.
Actually, the NMRA has never allowed electric boost controllers in any class because it would give them yet another advantage over blower cars.
here is what the rules say:
ENGINE: POWER ADDERS
Turbochargers ¡X A maximum of one turbocharger is permitted. Single turbochargers are permitted a maximum of a 101 MM (3.976-inch) measured inducer (inlet) diameter. The "inducer" is defined as the tip-to-tip measurement of the impeller blades on the inlet side of the compressor wheel. Dual turbochargers are prohibited.(for Pro 5.0)
Turbochargers ¡X A maximum of one turbocharger is permitted. Single turbochargers are permitted a maximum of a 91.5 MM (3.602-inch) measured inducer (inlet) diameter. The "inducer" is defined as the tip-to-tip measurement of the impeller blades on the inlet side of the compressor wheel.(for Super Street Outlaw)
here is rule for boost controllers:
Boost Controllers ¡X Electronic or automated boost controllers of any type are prohibited on any forced induction vehicle. Manual (non-electronic, and non-automatic) wastegate controls are required for turbocharged combinations. Entire fixed system including control and tubing must be located in engine compartment and be self-contained.
The NMRA has always only allowed manual boost controllers mounted in the engine compartment only.




[This message has been edited by 89ProchargedROC (edited February 19, 2001).]

 

Yea I just realized today that I had included Pro in that statement, and that is incorrect on my part.

Ok so no boost controllers allowed but they can have a progressive NOS controller... That makes total sense. Oh well, I guess somebody has to cry about someone being better.

 

i didn't mean to make you look stupid here, i just wanted to let everyone know the actual rules so dont be mad at me. on the other hand i think that the NOS progessive controllers doesn't make much sense either, but the main goal of every racing association is to make exciting and close racing. if you know who is going to win all the time then who is going to enter or even go watch? that is why they made rieger add 200lb to his bel air to help others get closer to him. personally, i know i would not like to see the rules changed but you need to improvise to make exciting racing. i think they have it done in Pro 5.0 since as i posted above both a blower car and turbo car are within 1mph and .01 of each other. hopefully the same will happen in Super Street Outlaw. i will say that i am mad that i didn't get to see a 7 second pass on true 10.5" tire.....but even with a 91mm low 8s are possible. lee howie ran a best of 8.30 with a PTE 90mm and that was with DOT's not slicks so we will wait and see

 

Not mad at all. Job Spetter did go 7's on True 10.5"

I do see what you are saying about keeping it close. However it seems that NOS cars get more breaks. I dont suppose that would have to do with NOS paying alot of the bills would it?

 

yup, he did it like 6 different times. he did it five times in canada at a non-nmra event and his best was 7.87 @ 180 and officially at an NMRA event he went 7.97. Mike Murillo also did it too....7.96 @ 180. Both were running 100mm turbos

no i dont think it is because the money NOS gives....just something the rule makers have to do to keep it all competitive.

[This message has been edited by 89ProchargedROC (edited February 19, 2001).]