Confuzed1

iTrader: (4)

And all I can say is....WOW!!!
I had an issue with the blower only making about 2 pounds of boost with a 3.6" pulley at WOT. Even though the car was pretty darn quick with only 2 pounds, I really didn't feel I was getting the most bang for my buck with the blower.

So.... I decided to call the tech reps at Magnuson and they recommended going down to a 3" pulley which they said in theory should give me 6-7 pounds of boost.

Just got done installing the new pulley and test driving it......I'm not sure I'm getting 7 pounds of boost because I'm unable to look at the gage long enough because I need to focus on the road ahead!! It made a HUGE difference in power to say the least!!

I'm not posting this to gloat whatsoever about how much power my car is making at all. My intent is to let everyone know what I've experienced with this E Force blower, and to tell all you guys considering installing one of these blowers on your thirdgen... - DO IT - You won't regret it.

I intend to get this car up on a chassis dyno real soon for additional A/F and timing adjustments - and to see what this thing is putting out!

90 L98 TransAm

iTrader: (3)

Enjoy your "new" car!

2 psi of boost doesn't seem like it would be worth the trouble and expense. A boost gauge with a peak boost hold function might be helpful for monitoring your boost.

I'll be doing just the opposite with my Vortech V-3 tomorrow.

I'm going from a 3.48" 6-rib SC pulley to a 3.60". Was getting 10-11
psi peak boost while the original kit for '88-'92 F bodies (that uses a
V-1 or V-2 and no bypass valve) is only supposed to put out 6-8 psi.

Confuzed1

iTrader: (4)

Just a quick update...I went to a 3.0" pulley, and I ended up with 5 pounds of boost, even though the tech at magnuson said it should be making 6-7 pounds with that pulley. I think it would maybe make 6 pounds of boost on a 350, but not on a 400. But -It made even more of a difference in power. Traction is even more of a factor now, and the torque on the car feels unreal!

So - I had to get it on a chassis dyno just to see what the car is actually making, and I got a dose of reality.... I didn't make the numbers I was hoping for, but the guys doing the dyno were impressed enough and said I should be smiling. They also said with a couple more pounds of boost, I should easily get the numbers I'm looking for. So - I'm going down to the smallest pulley available, which is 2.8" diameter. Hopefully I'll end up with 7 pounds of boost!

sleepybu

details man...

Confuzed1

iTrader: (4)

OK then...I had 2 runs on a Mustang chassis dyno. The first run was cut short due to detonation around 4800 RPM's. So it only recorded from 2595 to 5300 RPM's. Results were:

Max Torque (Ft-Lb) = 465
Max Power (HP) = 362

-Average of both didn't take due to detonation. Max AFR was 15.3, Min was 10.0 - average = 12.4

The tech said he likes to see 11:1 AFR on a blown engine, so he went up 2 jet sizes on both primaries and secondaries and backed off the max timing (it was too high at 40 degrees) -Now set at 12 initial and 28 total.

2nd run was recorded from 2547 to 5916 RPM's and results were:
Max Torque (Ft-Lb) = 492
Max Power (HP) = 375
Max boost = 5.7 PSI

Average Torque = 421
Average Power = 342

AFR stayed pretty much at 11:1

So there's the details! I just installed a 2.8" diameter pulley today, and it looks like I'm getting at least 6 pounds of boost now. I would have posted up the dyno sheet, but no idea how.

sleepybu

Try to get your hands on a WBo2.

Confuzed1

iTrader: (4)

That would be nice for my own personal tuning, but it's set at 11.0:1 right now - which is where it should be....any comments out there about the more important details?

Confuzed1

iTrader: (4)

Well, still on the quest for even more power. I took my Pro-Systems 750 carb out of storage, drilled the needed holes and plugged the ports so I'll run a bigger carb which is what I think it needs.

Let me tell you, the pucker factor is high when you're drilling into a carb you paid a little over 700 bucks for!! But at least now the power valve is manifold referenced as it should be to work as intended.

I've also went down to the smallest pulley size I can get - a 2.6" diameter. They say that "should" get me around 7 pounds of boost.

Next step is to remove my CAT and replace it with a 3" test pipe, and back to the dyno again. I'm hoping to squeeze 400 RWHP or better out of it this time around... I hope.

And then.......drum roll please......after 6 years of goofing around with the engine, drivetrain etc., It's going to the body shop over this winter and FINALLY getting painted. I decided on the same color as Elenor (sp) on the movie "Gone in sixty seconds" - except I'll do bright silver ground FX and hockey stripes down each side.

3rd gen Will

iTrader: (8)

Good stuff man, that is a TON of torque! definitely has to put your butt firmly planted into the seat. Def sounds fun and makes me want to get my blower on asap.

I can tell you why you make less boost than they are telling you that it should with the pulley size. A 400 is able to move more air than a 350 due to larger cylinder volume. Don't get hung up so much on the boost psi. The amount of air, CFM, your blower moves is what makes more power. On a 305 the boost would probably be around 8-9 psi because the smaller cylinder volume. The 400 can move air easier, which in turn actually means more power at the 5.7 your are getting than if your boost was to actually at 7 psi with that pulley since the blower isn't having to force the air in as hard.

Confuzed1

iTrader: (4)

Thanks 3rd gen Will - but along with the torque comes traction issues, which I have big time, and I'll continue to work on. You make a valid point when it comes to an engine using boost. The blower I have was tested on a 350 SBC, and it made 8 pounds of boost using the bigger pulley I originally had in my kit. Since I have a 400, I have bigger cylinders to fill and it probably flows a little better than your average 350 cube engine.

Even the instructions that came with the blower tell you not to worry too much about lower than advertised boost levels, since a good breathing engine is actually using the boost instead of stacking it up in the intake. A lesser flowing engine would actually see higher boost levels. Heads, intake, cam and exhaust also have a big part to play in how it'll flow.

All that being said, I think there's more power to be had with my setup, and since my blower is now "maxed out", I'm hoping the couple pounds of added boost, bigger carb and removing the CAT will allow the engine to make a bit more power. Guess I'll find out !!

3rd gen Will

iTrader: (8)

I hear ya, my old 3rd gen made over 500ft/lbs on the bottle, it was basically pointless to hit it unless I had the ET streets bolted up. Did some WICKED burn out's by my old apartment though. haha

Right on man, bigger carb and a better flowing exhaust will only help move that air through it. Exactly what you said, higher boost psi means the extra air is in you intake and not in the cylinders. Make sure you post up when you get that stuff done so we can see how your numbers improve!

BTW my *** probably would have eaten a huge hole in my shorts drilling into a $700 carb!

OUTATIME GTA

iTrader: (2)

Sounds like you're having some fun swapping pulleys and playing with torque.

Keep in mind your dyno #'s could seem less than expected due to using a Mustang dyno. Dynojets tend to give more boasted #'s, but either can be manipulated.

Either way, don't get too focused on the #'s as a dyno is meant to be a tool and the real test is at the track!

3rd gen Will

iTrader: (8)

I didn't even catch that you were on a mustang dyno. I have been told that the mustang dyno's are supposed to be more or less "actual" numbers where the dynojets are #'s are a bit more forgiving.

Yes the proof is definitely in the pudding when you get that timeslip.

Damon

Sounds like it's coming along nicely. Bigger motors definitely "eat" more boost. My 383 is a VERY mild combo but it only made about 3 PSI with the stock pulleys supplied with the Weiand 142 blower. I swapped out the crankshaft pulley for the larger 7" unit (stock is 6") and got it up to 5 PSI, where I stopped. The only step up left is a smaller 2.85" top pulley (vs. 3.07" stock) and that is a belt-slipping nightmare the last time I tried it with the stock 6-rib.

I will add, however, that any carburetor restriction (too small a carb, throttles not getting fully open) will drop STRIAGHT TO THE BOTTOM LINE in terms of boost and power. A little restriction above the blower is less air for it to grab onto a stuff into the motor (and it's NOT a 1:1 relationship- it's worse than that). I did some checks of the vacuum under the carb on my setup and I'm pulling almost 1.5" of vacuum at the top of the RPM range, wide open. Means I'm basically using everything my 800 CFM Qjet is capable of providing without becoming a restriction. Don't be afraid to go big. Well tuned, obviously, but big. Remember your carb is feeding more HP than is produced at the end of the crank- the engine also has to make additional power just to drive the blower. And that's probably considerable- consider how much power it takes to slip a 6-rib serpentine blower belt and it's probably easily 30-40HP on to of the 450-500 showing up at the end of the crank.

With roots blowers it's not just the boost pressure, it's the fact that it's basically a one-way valve into the engine. There is effectively NO back-flow possible like in a N/A, centrifugal or turbo application. Does wonders for packing in the air just before the intake valve closes. Great for making torque in the low to mid RPMs.

Get some traction. Roots blowers, especially efficient little ones like your Magnuson, make BRUTAL low end torque. There's not much you can to do to harness it on street rubber. Can't remember your drivetrain combo but there is absolutely NO need for steep rear gears- they only make the problem worse. I have 2.73s in the back of my Malibu and it can't hook up on street tires anywhere in 1st gear, even from a roll. I tried a set of borrowed DRs and it made a WORLD of difference, even on the street. Still spins them off the line but from a 25 MPH roll they (mostly) stick and acceleration is radically different than spinning all through 1st and waiting for 2nd gear to hook up. The giggle factor is huge- you can FEEL things twisting around under/in a chassis that was NEVER designed to harness that kind of power (78 Malibu, original engine: 120 HP).

I'm putting 390 to the rear wheels with my setup, but that's DynoJet numbers. On a Mustang dyno your 375 is already making more power than mine in the real world. I have no doubt you'd be making over 400 on a DynoJet.

Confuzed1

iTrader: (4)

Thanks for the replies guys. I visited the web site I dynoed my car at, and got the following general info on their Mustang Dyno:
I don't have a clue how all that works....I do know it even comes with a Pro tree and you can simulate 1/4 mile times on the dyno. How accurate it is, I don't know.

OUTATIME GTA - Thanks for the advice. I'm trying not to focus too much on dyno numbers, I just know there's a little more power to be had from this blower. I've put my 750 carb on it, and it feels a little stronger still.

Damon - I'm running the smallest drive pulley now, they don't offer a bigger crank pulley with this blower, so I've reached it's limitation. Luckily I've had no slippage at all on the 6 rib belt yet.

Too late for the gearing in the car...I have 3.70:1 rear gears in it. That coupled with the 5 speed, and traction is bad - most any car will get me off the line because of my traction issues.

I'll get some decent shocks and some drag radials like you mentioned and see if it'll help.

3rd gen Will

iTrader: (8)

Sticky tires will definitely help! Your 10 bolt will hate you. LOL

I don't even bother with the nitrous in my LS1 M6 T/A unless I have my DR's on, It will roast street tires through 3rd gear EASILY, Spinning at 100 mph is scary ****.

Confuzed1

iTrader: (4)

My 10 bolt won't even whimper since I don't have one...

3rd gen Will

iTrader: (8)

I am internet retarded sometimes, I see it says moser 9" in your side bar.

<---- Envious!

bm87ta

iTrader: (5)

a trip to WIR is in order

anesthes

iTrader: (12)

What was the rough cost of the magnacharger?

-- Joe

Confuzed1

iTrader: (4)

Wow, they've raised the price since I got mine. I paid 700 dollars less when they first came out a year and a half ago. It also appears Trickflow Specialties sells them now along with Edelbrock. They're all the same Magnuson MP-122 blowers. Here's a link: http://www.summitracing.com/parts/TF...4/?image=large