QwkTrip

iTrader: (22)

The time being talking about is time it takes for fuel to get carried from injector to cylinder. ECM software usually treats that in terms of crank turn angle. But TPI is batch fire so kind of a moot point. Really everything that defines what is a TPI from other engines are the things you'll end up ditching.

Kingtal0n

Lets Think of what we are saying. Injector data doesnt add HP. Injector data is negligible at WOT. You dont need injector data to tune WOT, .2 or .15ms at WOT is negligible when wot spray is 12 to 24ms. Injector data only makes the injector act more linear at low speeds, 400-1200rpm ranges.

The reason it picked up power with 'injector data' is because the injector data wizard automatically moved the EOIT injector spray which resulted with increase KE to the cylinder, more power.

Its very easy to see if you tune hundreds of engines. I guess you are new to tuning or don't understand how the data works or what it does. Thats fine, I will teach you. Focus carefully now, you can only change 3 things to make more power on the curve: A/F, timing, And EOIT. And it wasn't A/F or Timing , so process of elimination. He was using closed loop wideband so there is no target A/F adjustment and .2ms is negligible.

That 400hp engine picks up around 15% or 50hp from EOIT injector timing. I've seen +100hp between 2500-4000rpm on various 3L to 6L Engines making just 500-600rwhp. It is a powerful tool when used correctly. And actually it is MORE important and MORE Powerful, the larger the injectors are.

I will elaborate since I said I will teach you. When the injector is very small it will approach duty cycle of 70% to 80% perhaps 90% 100% even. This means the injector is open most of the time, which means it will spray through overlap at some point, and spray leading up to overlap period, before overlap. When this happens there is a power loss and fuel loss to the exhaust, as it will inhibit KE to the cylinder, and some fuel is also lost to the runner/plenum which will reduce air density above the valves, causing further power loss with the smallish injector.
This is why many people only see ~1% power difference from injector phasing; they are using too small of an injector to get the entire window of fuel into the cylinder post overlap after EVC (exhaust valve close) and more to PPV (peak piston velocity) at WOT, so whatever is gained by phasing retarded EOIT is lost once the spray period interferes with overlap, making EOIT MOOT/pointless on the graph. It's why we hear commonly reports of incredible gains in the mid-range (low % duty cycle regions) but no gains on the big end (peak power high % duty). In other words, if I am 90% duty cycle at WOT it won't matter where my EOIT Is because I'm basically spraying constantly.

When the injector is very large, say 1000cc injector and I'm only making 500rwhp on gasoline. Now I can fit the entire injector spray at WOT between EVC and PPV, through PPV. This will keep fuel out of the plenum increasing air density (1 to 3% power gain). It will keep fuel from leaving the exhaust valve during overlap (3 to 10% economy increase). It will also work with cylinder KE (Kinetic energy) and add to the airflow velocity/KE Entering the cylinder during such a short, powerful spray with low duty cycle (another 5 to 10% power increase is available).

Another issue is the turbulence of fluid when velocity is high and ports are small, a late powerful injector spray won't add much KE Induced power if there is alot of turbulence because so much energy is being lost just moving fluids into the cylinder, the spray KE is obfuscated. Thus a large open port with twin valves like a modded 2jz engine is going to gain more rwhp peak using late EOIT than a small port high velocity/turbulent intake engine such as single valve Chevrolet using a small runner head/intake. To summary, Ports that are great for daily drivers are also good for mid-range retarded EOIT but won't see much rwhp increase peak due to turbulence and energetic losses at high turbulent velocity. On the other hand, Ports/valves that are **** for daily drivers, low velocity, high flow, will gain alot more rwhp peak from retarded EOIT all in between EVC and PPV because the fluids are moving more slowly and gain energy, take advantage from the KE of sharp powerful injector spray.

Moral of the story is two fold, and I will share an additional tuning secret I learned from 20 years of doing this. In the old days we went for the smallest injectors possible because back then 20 years ago injectors were kinda crap, hard to control a large injector, tough to idle and such. However all of that is different now, we have 2000cc injectors that can idle like stock in a 2.0L Engine now. There are MANY gains possible using such a large injector in modern times. When I size injectors for a build now I always shoot for a max of around 50% duty cycle- nearly twice the injector than necessary. This not only gives us the option of EOIT to increase power as discussed above, it will also keep the injector drivers in the ECU cool, and the injector solenoids cool, allowing the vehicle to make power for extended periods without fear of injector or ECU driver issues, which are quite common at constant output with high percentage duty cycles, its why they always say try not to exceed 85% duty cycle or whatever- the drivers get hot, the injectors get hot, failure is an option.

Bishopts

I'm actually talking about air travel time. Mainly referring to time from filter to valve to roughly determine how much heat is obtained in the air once it is in the intake system. If the air is from the filter to the intake valve in less than a second how much did it increase in temperature in less than a second.

Bishopts

Then with that knowledge determine steps to improve it. I.e plastic runners or thermal wrap the metal ones or even think outside the box and cover exposed metal intake parts with rubberized bed liner for an insulation

Kingtal0n

Almost all engines have a nearly negligible heating at WOT because air moves too quickly to absorb much heat.

At idle and cruise however there is plenty of time to heat the air, which the factory always wants/wishes for various reasons. Plastic intakes for example, are modern insulators. Plastic engine covers, underhood covers/blanket-like materials and such.
The OEM will insulate as much as possible to conserve the heat energy. The hotter an engine, and more heat is conserved, the more efficiency will be, higher economy. Its also easier to tune and control the a/f ratio if the IAT remains somewhat constant/unchanging. The heat also help evaporate fuel quickly. There are many reasons to conserve the heat energy done by OEM.


Throwing away heat is fine when fuel waste is no concern, or when engine demands protection from high temps and is willing to sacrifice economy.
In a daily driver application you never want to throw away any heat, no hood venting, use extra insulation, maintain the power plant at highest temperature possible.
All power plants no matter whether gasoline or otherwise will become more efficient at higher temperature.

In Forced induction applications we use intercooling, which pulls heat from airflow obviously. This will reduce KE of intake airflow, which costs power. Thus intercooling will always reduce power output, it takes out energy. But we need it because high temp air is deadly to an engine at wide open throttle where compression is increasing beyond acceptable limits for the given fuel at some temp T. In other words, fuel choice is the largest factor in IAT (intake air temp) heating. On gasoline you will want to throw away as much heat energy as possible at WOT to keep the engine safe, the extra 2hp 'hidden' in hot air so critical for cruise economy isn't worth exploding the engine over.
When using alcohol fuels however, such as ethanol or methanol, some people don't even use an intercooler. There are 2000hp engines out there using 200*F IAT on alcohol fuels. This is because the high IAT does not present a danger to engines equipped with low compression and racing fuels as alcohol, thus throwing away the heat energy and Kinetic energy by intercooling isn't necessary and would only rob power.

Summary: Hot air good for economy, bad for power. A daily driver needs both; you want to trash the heat at WOT and conserve it for cruise/idle to save fuel. The way you do this is... well... Just look at my setup. Shielding, blankets (there is additional blanket you don't see I keep over the engine, under the hood), reflective (Infrared reflectors) thin aluminum, insulating wrap and turbo blankets, etc... anything you can do to trap the heat is powerful motivator to economy and fuel efficiency. On the other hand I have an oversized intercooler for WOT which can limit IAT to approx 100*F~ at outputs approaching 620rwhp on gasoline which is how you know it working as intended. IAT of approx 120*F+ Is where I draw the line on gasoline forced induction, but many will run with 130 or 140iat which eventually results with detonation and destruction on gasoline at some point, its really not a good fuel in the first place and the high temp is it's bane.

Bishopts

That's a topic I've wanted to do some of my own research on. Turbo input temp to output temp, turbo output temp to intercooler output temp, intercooler output temp to throttle input temp. Vs a no intercooled short pipe setup. I would like to see a lot of different aspects of that. Maybe I will just put a turbo on the tpi and test it until I put the rods through the block

Kingtal0n

I appreciate your enthusiasm for experimentation however it isn't necessary these days, very easy to calculate performance and temperatures (IAT, EGT) using calculators online.
For example basic turbo outlet temp calcs
https://www.stealth316.com/2-turbotemp.htm

Another one
https://racingcalcs.com/turbo-boost-...re-calculator/

My favorite calc is matchbot, because it sizes turbo blades to engine not just temp calcs
https://www.borgwarner.com/matchbot/

The matchbot has been proven to be able accurately estimate turbocharger selection to an engine, any engine,
including temp rise in the exhaust and intake manifold

newbvetteguy

When I watch that video, I hear him saying that he had the wrong "injector categorization" data -the latency vs. volts vs. PWM % open time "injector categorization" for his injectors at his fuel pressure. -I think those first gains were just from him imputing the correct "injector categorization" for the injectors that were actually in the engine, and then the jump from 394 rwhp to 408 rwhp was from playing with the injection end angle.

Adam

newbvetteguy

Good tips. I found the Holley IEA XLS calculator and read some of the threads on it.

I also saw something from Bosch + Toyota that makes me think that Toyota's strategy is now to do OVI even in idle conditions but they dynamically control the pressure from the fuel pump so that it's running at 6 bar when the engine starts and until it warms up and then drops it down to 3 bar on their newest advanced port injection implementations. They seem to have gotten the idle good enough with 12 hole injectors and high pressure to keep spraying on an open valve even at idle.

Adam

newbvetteguy

Interesting thought!

I like your guess about the injector spray pattern being a challenge; I think that you're supposed to have a pretty narrow cone spray pattern injector aimed right at the valve, right? It would make sense if injecting around the time that air velocity through the port is at it's highest would help carry the fuel where it needs to go better if your injector spray pattern isn't ideal for OVI.


Adam

Kingtal0n

It is clear to me that you have no broad tuning experience, that is not meant as an insult. THere is no way to add power just from adding injector data. Latency vs volts vs Manifold pressure is a finite adjustment for low speed, idle-2500rpm operation useful for controlling injectors at low pulse widths. It has nothing to do with power.

Here are the adjustments which influence power:
Air fuel ratio
Timing
Injector Phase

If you don't change a/f ratio (its closed loop wideband, so it didnt)
and you don't adjust timing

BY process of elimination the only thing left is EOIT injector phase. That is where the power came from. The wizard for the injector automatically moved the EOIT without Matt either knowing or caring or maybe he wanted to hide the fact since its esoteric and the fewer people that know it the more money a tuner can make by showing how much extra power is available by them tuning the engine.

Kingtal0n

Here is a thread which may contain (probably) all of the answers to your question
https://forum.hptuners.com/showthrea...l=1#post470537

And even then we may not discuss such things as injector spray pattern. Its not as much of a topic tuning as the port to wall impact factor, or boiling time for fuel as pressure changing within the manifold. In other words poor spray patterns don't matter if you inject to a hot closed intake valve, and poor spray patterns matter even less if the injector is positioning in a particular manifold to spray directly or mostly onto the port wall before it can enter the valve. Some injectors have very narrow sprays and other very wide. These are all reasons why EOIT is done experimentally using a dynometer after some initial calculations on spreadsheets.

newbvetteguy

Another interesting subject! I REALLY love the electronic thermostats that a lot of the modern BMW engines have now that let the engine run warmer at highway cruise for improved fuel economy and then switch to running cooler when higher loads are demanded. (Not sure exactly what strategy they use.)

I know it's POSSIBLE to use a Holley PWM output and a table to control a PWM capable electric water pump to do this kind of thing. -Davies Craig is an Australlian MFGR of water pumps and their controller does this and I know some folks have used their aftermarket ECUs to control the Davie's Craig water pumps this way.

I'd LOVE to do it with a more traditional electric water pump like a Meziere; I contacted Meziere to see if their pumps could be safely controlled with a PWM signal and if so, what the recommended control frequency was but couldn't get a response to save my life. (I think temp + TPS would be a good enough 2D table in Holley to send to the PWM output to try this, IF I could find a standard-style SBC electric water pump that could be PWM controlled I don't want to burn up a $300-$500 water pump cycling it on/off way too fast; and I have a LOT of experience blowing up SSRs and things controlled by SSRs and I'm very tired of blowing up expensive things that way; lol!) -You have to wire an SSR to control the actual load as the Holley PWM outputs only support like 2 amps, but it would make a really fun weekend experiment! (or two)

Adam

newbvetteguy

Thanks.

100% true. -I'm TRYING to get prepared to tune my engine, but the learning curve has been STEEP and of course, I can't do anything the simple way, so I want to play with injector end-angle timing because I'm hoping it helps me to stay out of detonation / pull less timing. (Pipemax is estimating that 95 octane is required to avoid pulling timing around my torque peak, but Washington State premium is 92, so I'll take any / all help I can get.)

What you say makes complete sense, as soon as you say it.


Adam

Kingtal0n

My recommendation is always keep it simple. Don't try PWM water pump or even fan controls. You are better off simply switching off and on the fans to control temperature of coolant rather than fooling with potentially unreliable electric water pump. The less electric crap you depend on the better, In General.

If you want a reliable engine, you will use mostly OEM style parts, including water pump and PCV system stuff.

Here is a discussion about home-made fan controller using Arduino we had on Supraforums recently
https://www.supraforums.com/threads/.../post-13985104

I am a TA for engineering college freshman, we use arduino to control various 'robots' in some basic ways, obstacle avoidance, line tracking, IR and ultrasonic sensors and servos.
If you are interested to control theory using PWM and SSR Then I would recommend the arduino as a 'play toy' to learn on before trying anything with 'real' or expensive hardware. If you PM me I can mail you a free arduino and some sensors and stuff, I get it from school for being a TA, I don't mind sharing. I have limited supply so maybe 2 or 3 people max.

newbvetteguy

I've used pre-packaged SSR / PWM controllers in my electric brewing hobby for over a decade and am roughly familar with Arduino and Raspberry PI devices (19 year Microsoft employee), but I hate having to maintain and update devices in my hobbies in my old age now.

I do like to fiddle and experiment, though and that includes with my car / engine. I break something or it doesn't work, I just consider it my "education fees" (I WISH the IRS agreed, that they were "unreimbursed education expenses", but they don't see it that way; lol!).


Adam

Bishopts

I don't do any tuning but I do quite a bit of diagnostic and repair 1.4 chevy cruze engine has a electric thermostat that is a very simple design you could probably integrate into your car and most of the 3 and 5 series bmws in the mid to late 2000s have an electric waterpump that I do believe is pwm controlled. With very generic pipe fittings

Bishopts

I'm a big fan of those thermostats because I can command them to 100 percent and burp the system pretty quickly and then do a final test drive to move on to the next car.

newbvetteguy

I meant to and thought I did reply to this a lot sooner. Apologies for the long delay.
Although, from the few before and after dyno results I've seen, I've seen a 1-2% increase in max WOT power (but per the above maybe they just weren't tuned optimally), the reason I see a lot of potential on these higher HP TPI combos is open valve injections ability to reduce combustion temps and help prevent knock when you're octane-limited.

The PHD Thesis paper linked to below is a "study of studies" on advanced port fuel injection techniques; one of it's findings was that Open Valve Injection reduced exhaust gas temperatures by 30-40 degrees Celcius! This is almost certainly because a lot of the evaporative cooling is happening in the combustion chamber vs. in the intake port; just like Direct Injection gives us the advantage that all the evaporative cooling is happening in the chamber and we see a jump in the cylinder pressures that can be supported by the same octane fuel, OVI seems to accomplish similar things, but to a lesser degree. -Bosch's current page on their state-of-the-art OEM port injection system includes a section on Open Valve Injection that states that they've found that they can run a 0.5 - 1.0 higher compression ratio with the same fuel and avoid knock.

->Running a bit more compression and cylinder pressure and not having to pull timing out around the torque peak seems very useful to a high perf TPI engine and higher compression / cylinder pressure also helps out at part throttle highway cruise with fuel economy -although tiny gains.

My thinking is that OVI in a modern high perf TPI build, just helps a TPI to do what it does better -more cylinder pressure more of the time on pump gas (more power at peak) AND improved fuel economy. -Every little gain that can increase efficiency makes a better TPI, IMO.


-I'm definitely going to play with it on mine, anyway. Right now PipeMax is telling me I need between 95 - 99 octane and Washington Premium is only 92 octane so I need all the help I can get.
I'll start out running normal sequential on my Holley HP with my 36 lbs Bosch injectors that don't support OVI very well / very long -and I'll induce knock lugging up hill (I've got a knock sensor that I'll get tuned in to have good log data), then I'll switch injectors to something much bigger and play with the end of injection and see what it takes to get it to knock and see if I can add any timing around the torque peak.

I've got a 4L60e and PLENTY of pretty good hills in the Seattle area to lug the engine and generate some knock counts to play with it anyway.
It'll be a fun experiment either way.https://www.researchgate.net/profile...e_Redacted.pdf



Adam

Kingtal0n

I do inject to open valve in my setup

however there is one major potential pitfall doing this,

IF the cylinder/IAT is not fully warmed up (hot enough together), then liquid from injectors will hit the cylinder wall and wash out the oil film , causing excess wear and tear

modern Gen4+ OEM GM ecu (05+?) Always include an ECT (coolant temp) adjustment for Injection angle to help you keep from injecting to a cold cylinder

but you have to actually be aware of the issue and tune around it otherwise it could wind up eating up the cylinders/rings especially with a large powerful injection spray and double especially when using alcohol fuels which can cool the cylinder so much that even under power it can start to condense and wash the cylinder walls

Orr89RocZ

iTrader: (20)

nowhere did i say that? What reading comprehension class did you take lol

alll that proves is the base tune with wrong data was wayyyy wrong for the car.

Injector data doesnt include end angle timing. Typically data means on off times, and battery voltage pulsewidth correction. My holley end angle timing does not change its value simply by changing injector type. The table or single value is a user controlled input. So again i wonder what exactly was different by switching the brand injector.

if he had started with the correct injectors woth the correct data, THEN play with injector timing you see he only gained a tiny bit of power.

Kingtal0n

He used a wizard. Load the base holley tune and inspect injector angle. Then, use injector wizard to implement injector data and check the injector angle, the wizard moves the injection angle.

I agree data is just offsets. So why would that give any extra power? Its impossible. Process of elimination here, it isn't the injector data or delay causing increased power. .1 or .2ms at WOT is negligible effect on anything- injector data is for idle and low rpms where .1 .2 ms matters.

Orr89RocZ

iTrader: (20)

I have a 2000 hp turbo bbc…i know how to tune.
lmao did you even watch the video you posted?? The guy explained the CHanges.

yes wideband has a air fuel target!!!! He changed it and it picked up power.

please stay off the forums you give bad advice

Orr89RocZ

iTrader: (20)

i never said data did make power or didnt. But something happened if all he did was change injector type and made power. If he used a wizard, then clearly it calculated a bad value which means the tune was bad to begin with. That doesnt prove injector timing is 50-70 hp on a na motor. Something was wrong.

Kingtal0n

yawn. you can lead a horse to water

Orr89RocZ

iTrader: (20)

Again, at 6:15 in video he phase injector to cam shaft and went from 390’s hp to 408

Orr89RocZ

iTrader: (20)

As an engineer your data analysis skills need improvement. its easy to make a crap tune show low power then put correct tune in and all a sudden see big gains and think it implies something it doesnt lol

i could duck up my tune by putting wrong end angle timing and then put in right value and see big numbers but that’s because it was way out left field to begin with. Thats basically what he did by garbage data input to the wizard and getting a wrong value. You should know better. You manipulated data to make a point when its clearly not correct.

we tune a lot of cars and you dont see that much on na motors of that power level. A shotty tune compared to a good tune does not imply something worked. It was simply wrong to begin with

Kingtal0n

THat is the second or third time he moved the injection angle. It moved first with injector data and again later when he fine tuned it past the wizard pre-set value. I can easily tell this because an engine can only pick up power due to one of those 3 things and he didnt move timing or a/f so... process of elimination

Have you ever tuned a carb and dist before? Try to think like a mechanical aspect forget about the computer.

Also you should stop slinging mud, it is unbecoming
I never insulted you and yet you constantly insult me

newbvetteguy

VERY NICE Tip! Much appreciated.

I've heard of several ECUs / ECMs that don't do OVI injection at IDLE and I was thinking it was just because it ran crappy at idle; I didn't think about washing down the cylinder walls with fuel at that time. -Now I'm curious if Holley can do this, too or does it by default.

I remember a conversation with someone attributing a longer time between rebuilds on EFI cars partially to the lack of fuel spray washing down the cylinders at startup vs. a carb -OVI at startup seems potentially far worse there.


Adam

newbvetteguy

WHY ARE MOMMY AND DADDY FIGHTING?!? ;-)

Had to...

Adam

Kingtal0n

Something I think that never occurs to people is the beginning of injection settings are often not the worst to begin with. The spread between the worst possible setting and the best possible setting is something like 20 to 40% difference in some cases, for example

https://www.hindawi.com/journals/jc/2016/6501462/
80 torque to 120 torque - what percentage increase is that?

40 is half of 80 so there was a 50% increase in torque due to injection timing possible. And notice it is ACROSS THE BOARD.

But when you initially get the ECU and start tuning- the EOIT isn't automatically adjusted to the worst possible position.
So when you finally adjust it slightly and see a gain of 1% or 2% power- you aren't getting 2% power from EOIT. You are getting 2% on top of whatever was already provided from not starting off in the worst possible place.

That is why the engine in the dyno video from sloppy mechanics likely picks up much more power than people are used to seeing. It happened to start off in a 'very bad' place and then picked up 15% or whatever along the way. it also happened to have large enough injectors to get most of the fuel in at WOT post overlap which many smaller injectors can never do. Other setups won't be starting in the 'worst possible place' especially if they used the wizard to automatically adjust the EOIT To some basic initial starting value before ever trying to dyno tune the car in the first place. For example if he adjusted the injector data with the wizard before even putting the car on the dyno- we would never have seen the initial increase in power provided from some arbitrary EOIT adjustment, only the later fine tuning of the EOIT which gave the 2% or whatever was added late in the game.

If you truly want to see what Injection angle is WORTH you need to first find the WORST possible angle, and then the BEST possible angle, and compare them. You can't only compare a 'nearly perfect already' angle with the 'actual perfect angle' and say it was only worth 2%

Bill Chase

A short fill to the water pump holes coupled with a high flow pump, higher system pressure, and a GOOD oil cooler, along with piston squirters would probably allow the gen 1 block and heads to run higher scr/dcr that has most of the benefits of the lt1 reverse cooling. Ceramic coatings in the intake coolant ports, as well as intake plenum and runners would help too. The next big one would be a reverse dome piston that is painstakingly matched to the combustion chamber. But it begs the question why do it when you can do a 6.0 with truck manifold, direct injection and contr it all with a 1500 dollar terminator x ecu and have all these benefits, plus a hell of a lot less money invested in the project. I love the gen1 23° too, but you are essentially talking about applying 2022 technology to a 1985 engine, it's not cheap, and the end result will fall short of a low mileage junkyard pullout. I mean you can buy a 525 hp ls3 and the suggested ecu that's tuned already as a package for 10-12 grand, how much money do you think it will cost to do this stuff to the gen1 by the time you buy the raised cam tall deck block, all the coatings, pay for cfd designed plastic tpi like intake etc there are easier ways to get where you are wanting to go is my point. Unless you are a engine builder and can get the coatings, exotic parts at cost. Just accept the limits of the gen1 architecture, or install a modern engine, save the money and have a better end result.

newbvetteguy

double post

newbvetteguy

Very good point. If someone wants a "modern equivalent" to a TPI motor that has incredible driveability, fantastic highway MPG, and DRAMATICALLY improved performance, a 5.3 direct inject L83 Gen V swap gets you there WAY faster, easier, and cheaper.
-A cathedral port LS build with the Holley Sniper dual plenum cross-ram is another good option that gives up quite a bit of fuel economy vs. an L83, but another good option.


I like the challenge of taking a GEN1 SBC and particularly one with a long-runner intake and using those limitations to make the most average power and fuel economy possible. -I like the surprise / shock factor of someone seeing a smog-era GEN1 SBC with a TPI-looking intake sitting up top making 25 mpg on the highway and making mid 400 hp at the crank; both are loathed and derided as being impossible to make power with, but you can take a mostly stock bottom-end L82, bolt on some $1000 heads, and a roller cam, a FIRST intake and some modern EFI control and make power that surprises a lot of people. -Beyond that, there's quite a few opportunities to find small 1%-2% gains that can add up. Find enough of those little gains to add up to 10% and all of a sudden you're making an extra 40-50 HP, that's a fun game by itself.

Consider it a form of "class racing" and the "Class Rules" require a GEN1 SBC, a Long-runner TPI style intake, and pump gas. -The restrictions make more of a challenge and require more learning; no challenge, no fun in my opinion. This is my hobby so I'm going to have fun with it and finding all the tiny opportunities to make small improvements that add up.

I've already got my ceramic thermal barrier coated FIRST intake, rebuilt L82 bottom end (stock except for a 1.2mm ring pack from total seal with spacers), retro roller cam, and Holley HP, LS Truck ignition coils, 58x trigger wheel.. -So taking advantage of it, especially with things like the engine tune is now my current goal. But I DO like to think about the art of what's possible with an eye to a future build.

-Bill, I am curious what you think a partial fill of the block would gain you. I thought you'd have better cooling with no block fill at all.


Adam

Bishopts

Taking a stock TPI and just running a new pcm that will convert it to SFI using stock injectors not trying to get any more than stock power. Could you get 30 mpg highway?

Bill Chase

Higher pressure coolant flow through the heads, more stable cylinder bores. It would force it to scrub more heat from the upper cylinder wall and heads. Let the oil cooler take care of the oil. Easier to have finite control of combustion chamber temperature, if approached right would offer a wider tuning window and not be as octane limited.

TTOP350

iTrader: (8)

I once got 27 mpg in my 89 formula 350. it had the SLP setup, tfs heads and couple small things done to it. Going 85mph with ac and 4 people

Bill Chase

Did you have absorbent coating on the outsides of the plenum and runners, and reflective on the outside? Siamese the runners to focus power at a higher rpm? Curious if you had yours modified, then extrude honed prior to having ceramic coatings applied to it?

I picked up a first performance tpi over the winter and am seriously considering installing it in my 91 c4, but it needs port work before that. The miniram is good, but for no more time than it spends above 4000 rpm I feel the longer runner setup will make the car more enjoyable to drive. It's higher operating range coupled with the 13 pound flywheel makes it a little high strung for street use, it is very drivable, but another 35-45 foot pounds of torque down low will be better for my intended use. I will say this though, if I were drag racing I wouldn't change a thing, very pleased with the way it turned out just want more usable power off idle without having to open the throttle so much. The best way to describe it would be to compare it to a two stroke dirt bike, nothing, then when it gets on the pipe it gives you everything. Blowing the tires off at highway speeds is fun, but not very predictable. I do agree with your thoughts on making the sbc more modern. Amazed nobody has CFD modeled a plastic long runner efi intake for the sbc, I have a hunch it would sell very well.

newbvetteguy

Sorry for the delay, Bill, I either missed the notification on this thread or I've got them turned off for this thread somehow.
I had the whole intake outside and inside coated in thermal barrier coating (largely because I'm both vain, and like "shiny" and because I can't bare to have to polish the dang thing all the time to keep it looking good; so maybe not the ultimate choice for maximum thermal performance but, good for maintenance-free "shiny").

I had Ken from FIRST open up the base to a Felpro 1206 to match my heads. My heads have a slightly raised intake runner so I took a rubbing of them and send that to him and he went above and beyond and not only matched the .015" raised intake port but he then hand-ported the port on the intake side up a good 5-6 inches -as far as his burr would reach so that it was a smooth transition with no lip. (I didn't even ask him to, he just did it and it looked spectacular.) -I made a small mistake because I moved to Felpro .015" shim gasket and this made the intake sit up higher on the heads, like getting a head or deck milled does -I put an endoscope in it and noticed it on assembly, it was a tiny mis-match, but I hate mis-match so I touched up the top of the intake ports to make sure it was a perfect match.

-I used sandpaper flapper wheels on my dremel to smooth the entry to the throttle body, I killed the EGR bump at the rear of the throttle body and a couple inches into the plenum and I just smoothed out the entry to the runners on the plenum side in a few places. Then I dropped it off at the ceramic coaters. I also added a DIY oil splash shield to the bottom and coated it with a teflon spray that I'm hoping will help it to shed oil -my fabrication skills are non-existent so I installed it slightly off-center, but the good news is I never have to look at it again; lol! -The coater did NOT mask off all the coolant port threads and the threads on my front-facing coolant port are REALLY screwed if I ever try to remove the fitting, but I'm hoping that I never have to remove it...

I'd LOVE to see a plastic or ANY type of dual plenum cross-ram for an SBC. The SNIPER dual plenum intake for LS1-7 engines is just a work of art and has a ton of great modern touches -properly CFD designed plenums -pretty straight runners with some taper. And the dyno results are just fantastic, too. -My dream intake for the SBC would be a dual plenum intake with runners that are the same 21" ish total length (including the heads) where the plenums just kind of sit up on top of the opposite side valve covers like the ultra long runner Chrysler Max Wedge intakes. They'd looks super bad-*** and have way STRAIGHTER runners vs. a TPI -get proper taper in those things and a modern plenum shape with dual throttle bodies, you'd have the same wave tuning as a TPI with way better flow characteristics and better cylinder to cylinder distribution. Front mounted mirror image turbos dumping into those plenums would just be the most awesome LOOKING engine with torque for days and the ability to do water / meth or nitrous injection ahead of the throttle bodies with the the cylinder to cylinder distribution issues solved. (Removable runners to allow for different targeted peak RPMs, as long as I'm dreaming...)

BadSS and his copy of EA Pro say that I've got slightly more intake port area than I need for my 350 cubic inches and HP peak RPM so no need for me to port the runners and no desire to siamese and change the tuned RPM. If I ever move to my dream 406, that would change, but it's fully in "Dream" stage, despite me having a list of very specific parts for it... ;-)

-There WAS a kid on the CorvetteForum who was CFD designing an improved TPI plenum and I think runners for a TPI, but then he abandoned the project and got an LS. He had a bunch of models that I was HOPING he'd release on ThingiVerse so SOMEONE could take his model and get it printed or at least build upon the work he already did, but he never posted it. I've followed up with him twice and I think the project is abandoned forever...


Adam

newbvetteguy

My pictures should be on this public Facebook album:
Just don't judge me for some of my financially stupid decisions: Is a 1.2mm ring pack worth the cost on an engine with a 5,800-5,900 RPM peak? -Probably not.
Does anyone need a Jomar stud girdle on a 5,900 RPM SBC? -Probably not.
PAC 1219x beehive springs when dual springs are probably half the price?!?
LS ignition coils necessary on a 5,900 RPM engine?!? Really?!?

A weak-*** 4L60e transmission that requires a computer just so you can have paddle shifters on a C3 Corvette?!?
(Although keeping the stock rod bolts WAS stupid and I DO regret that... The rest of it was intentional choices.)

I've heard it all already...

Adam