newbvetteguy

I'm really interested in modern engine technology that can be applied to a TPI or "Alternative Long-runner Port Intake" to extend power and MPG further than from the factory...

In my opinion TPI is super interesting as a technology as it allowed for a car to FEEL considerably more powerful than what came immediately before it AND it made big strides in fuel economy. -It just gives you a vehicle with a wide "dynamic range" from efficient highway cruise fuel economy to fun torque when you get on it. -The OEM TPI was super air-flow limited but all the various aftermarket experiments documented on this site show that the air flow limits have been significantly improved upon over the decades, too.

One thing that continually comes up in the 400+ HP TPI engines is that these engines quickly run into 92 or 93 octane knock limits. It's easy for a well-built TPI engine to exceed 100% VE around the torque peak (RCS Racing Engine's FIRST TPI-based crate engine reaches 120% VE at it's torque peak) and this combined with around 10.0:1 static CR and an appropriately sized cam -means you reach the limits of pump gas.


I've found a few items that, with a modern ECU controlling a high performance TPI engine, I think can make small contributions to pushing that "dynamic performance range" of a TPI engine further, and I'd love a conversation on these items and any other modern technologies that can help potentially extend the fuel efficiency at highway cruise or power at WOT a bit further, even if they're just small gains in the right direction.

Tech that helps a modern TPI engine's "dynamic range":

• Sequential injection: Sequential injection might not make any more WOT power and won't actually be working at high RPMs, but it does help bring small fuel economy gains and is a technology that can be easily introduced to a TPI engine controlled by modern EFI systems and can help tame the idle and lower RPM performance of a more aggressive modern cam that can make more power.
• Open Valve Injection: This strategy, IMO, has GREAT application to a TPI engine as it can significantly decrease the tendency to knock, with everything else being the same. Open Valve Injection involves combining much higher capacity fuel injectors (Sized for 20%-30% duty cycle vs. 85%) that have good low pulse-width characteristics with sequential port injection timed to occur so that fuel is only injected when the intake valve is open AND overlap is over. This results in more cooling occurring in the combustion chamber AND cools the incoming air charge and often also brings single digital increases in WOT performance. Avoiding any fuel being introduced into the cylinder before overlap is complete at highway cruise also means small gains in fuel economy

• Fine Atomization Fuel Injectors: Modern fuel injectors can finely atomize fuel, which helps with idle and transitions and can help an engine with a more aggressive modern cam to be "better behaved" at low RPMs and might also help with tiny gains in fuel economy. Denso or Delphi 12 hole fuel injectors (2000-2004 Toyota Tundras had 12 hole Denso injectors @ 250cc which are very close to a stock 24 lb/hr 350 TPI injector flow rate) have an initial droplet size of 50 micrometers, which is approaching half the droplet size of the CIII 4 hole injectors that came out in 1996, which were way better than the injectors that came out in the TPI era. These newer injectors can support much higher fuel pressures, which also drive further improvements to droplet sizes.
• Modern, aggressive roller cam designs: Many of the high HP TPI, modified TPI, and aftermarket TPI engines dynoed in the magazine articles we've all ready and some of the better TPI engine builds on this site have used much more modern, and aggressively-ramped cam lobes to help ensure that the wave tuning characteristics are still maintained with the seat-to-seat durations of the cam, while throwing the valve open faster and farther to fill the cylinder and continue making power at higher RPM. Modern ECUs are not as sensitive to vacuum as low vacuum as the GM TCMs that TPI cars came with, allowing additional flexibility
• Improved Ignition System & Spark Plugs: MOST Any aftermarket ECU or even a retrofitted LS ECM that supports sequential multiport can also support Coil-Near Plug LS-style ignition coils, which can reduce misfires but can also provide more firing voltage and energy reliability which allows for larger plug gaps that form a larger initial flame kernel that requires less ignition advance via faster combustion events. -This results in tiny torque and energy efficiency gains that also improve fuel economy (TINY gains). Larger gaps also support leaner cruise AFRs, if emissions / NOX is not a concern. Faster combustion also reduces the available time for pre-ignition to form.
• Piston oil squirters: I haven't seen piston oil squirters utilized in a TPI engine build but easy retrofit kits are are available for SBCs and significantly reduced piston and combustion temps -a knock thresholds result when they're combined with oil coolers. -Piston oil squirters+ Open Valve Injection should result in a pump gas TPI engine that can support a surprising amount of compression / cylinder pressure without detonation on pump gas.
• Modern Heads: Nothing helps the "dynamic range" more than the best modern head designs, probably. Amazing flow for the area means high speed flow that generates more torque and more HP- the air speed helps prevent reversion and sluggishness at low RPM and it also helps increase VE around the torque peak with a "paired" cam that continues to stuff the maximum amount of air into the cylinder as the piston is moving back up the bore. -Those compact chambers help combustion happen faster -even on our lowly 23 deg heads which helps give pre-ignition less time to happen so indirectly supports slightly higher cylinder pressures and not having to pull ignition timing around our TPI engine's knock-prone torque peaks... (The AFR 195cc race heads and Chad Speier Racing's 205cc Sfactor "Street" head are true modern marvels that are a wonderful addition to a high performance 383 - 406 with a desired 5,500 - 6,000 RPM torque peak.)

There's a ton of other technologies that should be able to help make small advances, but I'm particularly interested in the opportunities that a modern EFI system running an open valve injection strategy could take advantage of. OVI and TPI seem like they just belong together.


-The only other thing I'd truly love to see would be a high compression, solid roller TPI engine running on 100% methanol. I think the torque per cube would be HILARIOUS. .


Adam

newbvetteguy

And as long as I'm "What If?-ing": A ZF 8HP50 or 8HP51 transmission would also be a "perfect pairing" to increase the "dynamic range".

In my version of history the TPI's lower RPM powerband was combined with low rear gears like the 3.08 and the 700r4 with it's torquey first gear-to make it FEEL fast, and it's overdrive and a lockup TC to get the highway cruise RPMs down.

The 8HP50's gear spread is just MONSTEROUS from a 5.0 1st gear to a .64 8th gear, but it's shifts are insanely fast, and these things can stand up to lots of torque for a LOOONG time.

The 8HP50 also automatically physically disconnects the gears when it detects that you're coasting, so it's like coasting with the clutch in in a manual transmission car and it again helps with that dynamic range of great fuel economy and great performance when you demand it.

(There's already bell-housing adapters available to an SBC as the 350Z / 370Z drift guys swap to SBCs for drifting...) The TCU is a problem...

Adam

newbvetteguy

My priority is getting my FIRST TPI-based high-tech Holley HP-controlled engine just back in my car and running, in a normal sequential strategy with my Bosch 4 injectors, but I plan to test out OVI and likely with a 550cc ish Denso 12 hole injector (unless I can find the rare 698cc injector) after that.

I don't really have the dynamic compression where I'll benefit from it, though (8.13 DCR on aluminum heads), and my cool Seattle air temps also mean I'll have difficulty generating knock to see much anti-knock benefit, but I'll lug it up a big hill in OD and see what I can do...


Adam

Fast355

iTrader: (2)

I am at 11:1 with my 383 that has a 6,500 lbs van wrapped around it and frequently tows a 6,000 lbs travel trailer. My cranking compression is 225 psi. I run 31° total timing at 3,600 rpm and it has 24° by 2,600 rpm. 91+ pump gas and I run 34° on E85 with 34° by 2,600. It loves the corn syrup. I am also well over 100% VE. I run tight quench at 0.041", 6" rods which slightly lower DCR, a 218/228 @ 0.050, 108 LSA cam on a 106 ICL, 1.7 rockers for 0.578 lift and Rhoads V-Max lifters that take away about 20° @ 0.050 off that cam at low rpm.

newbvetteguy

WOW. Outstanding. I've actually heard a few people across a few different forums reference your build now.

I did NOT know that you were running 11:1 static CR. -What is your DCR? Do you have your ADV or seat-to-seat cam specs? -I'm super happy to see someone with a tight 108 LSA on a TPI build finally!

You running an aftermarket ECU? Or do those Rhodes lifters and your 3.75" stroke provide just enough vacuum that you can run a tuned stock ECM? Your ADV durations are in the upper 270s - low 280s range?

My build right now is a 10.2:1 .40 thou squish, FIRST intake, 350 build, with an aggressive Mike Jones roller (278/280 adv on a 110 LSA because my C3 Corvette uses vacuum for EVERYTHING, .600" lift on the intake with 1.6 rockers, 195cc /64cc Profiler heads). I'm dreaming about a DART SHP 406 short block, though and pushing the compression further in v.Next...

I understand why everyone told Richard (RacProps) to contact you now... Two TPI towing vans both trying hard to avoid pre-ignition / detonation.

Adam

Fast355

iTrader: (2)

271/284 @ 0.006

Hard to get a DCR since it varies but somewhere north of 8.5.

I am running a P59 LS PCM tuned with HP Tuners. 2005 GMT800 L31 350 Mexican truck base file.

Wish I had built a 427 using a 1 piece rear seal factory roller compatible 350 main, 400 bore SHP myself.

newbvetteguy

What do you mean by DCR varying? You mean between the various online calculators? (or "varying" because of the Rhodes lifters?) -My understanding is that the Rhodes lifters wouldn't effect the seat-to-seat durations and therefore wouldn't impact the DCR, but actual cylinder filling WOULD vary by RPM in the engine "dynamically". (DCR is the dumbest term ever...)

4.030 bore x 3.75 stroke, 6" rod
64cc chamber?
piston to deck -11 thou + 30 thou head gasket = 0.041" quench
5 or 5.5cc piston valve reliefs

=11.01:1 static CR and with 271 adv duration, a 108 LSA with 2 deg advance = a DCR of 9.0:1!

I know my cam has +4 deg of seat to seat duration vs the .006" #s so if calculating off of an estimated seat-to-seat of 275, that's still a DCR of 8.88:1!

Wow. I assume a cold air intake, what temp thermostat?

-Wait.. There's no TPI intake in that picture, but you ARE running an OEM TPI?
I'm surprised it doesn't ping around the torque peak, but I guess if you pulled timing there until it didn't ping.

Seriously cool build.
Anything you attribute the lack of knock to? -The good quench obviously helps.



Adam

Fast355

iTrader: (2)

The Rhoads lifters bleed off up to 20° of duration at 0.050, but they also change seat to seat. With straight lifters mine cranks 210 psi. With Rhoads the way mine are adjusted for street use it cranks 225 psi. They can actually be adjusted to help prevent detonation as well but it minimizes the added low speed torque and idle smoothing feature.

I don't have a TPI on this one, but my iron Vortec head 383 in my G20 was run with stock LTR TPI runners prior to swapping to siamese ported SLP runners. That 383 had 5.7 rods at 10.5:1. The truck cross ram L31 intake has long straight runners and also has a tuned effect. My torque peak is about 3,600 rpm. Timing has to be retarded a bit around peak torque.

170°F thermostat and runs about 178°F.

Careful tuning on the lack of detonation, shape of the combustion chamber helps too. On the LS style PCMs you can control injection timing as well to coincide with intake valve events. The only time I have seen detonation on my fairly conservative tune was when the PCM killed the fuel for the rev-limit at 6,200 rpm.

newbvetteguy

Having your tuned RPM be above your torque peak definitely helps with knock there. I'm pretty sure you'd have more issues with knock with a TPI intake on this combo.
-Sometime I'll look into how the LS PCMs and HP Tuners deals with injection timing... Holley has you select the crank degree at which you want to STOP injecting fuel- you set how many degrees before the intake valve close event you want to stop spraying and then as it calculates the required duty cycle it just injects backwards from there. I haven't looked at how any other ECMs or EFI systems do it, but this makes the most sense to me -then when you're at low pulse width with an appropriately sized injector you're spraying after overlap and before the valve closes, but as the pulse width needs to increase you start squirting in fuel during overlap and then eventually when you start running out of time spraying on a closed intake valve anyway.

Again thanks for sharing your build. Really love it. That complete sleeper 5,000 lb van at a stop light must get you some crazy looks; it would be so hard not to mess with people with it; lol!

Thanks for clearing up the Rhodes lifters and the impact on the seat-to-seat durations; it just won't sink in that as they're bleed down, they're not going to start opening the valve for a while after the lifter is on the ramp and on the way up. "Lifter Lag". I just keep thinking that all they do is reduce the lift and then as the lift reduces the durations at each of the higher lift points is also reduced, but they also introduce what only makes sense to me to call "lifter lag" -kinda like a solid lifter valve train taking up the lash (so hard to think of a hydraulic valve train behaving like this...).

Adam

Orr89RocZ

iTrader: (20)

I like the idea of increased tech and efficiency.

Having had batch fire stock efi and sequential via ls1 pcm on same engine i do like how nice the sequential felt. Seemed smoother running.

a good aftermarket efi system utlizing individual cyl tuning is a great way to go. But expensive. Multiple wideband and or egt helps balance the system out.

drill heads to not run coolant thru intake manifold to try help keep some heat out of the intake charge would be interesting. Running engine water as cool as possible always helps

a high compression tpi with e85 is the hot ticket. That be a fun car. But yeah timing at low rpm peak torque def needs to be looked at. Cant always ramp in max timing that soon. Tpi seems to like a bit less around there when approaching max trq on pump gas with compression

a modern thin ring package piston, lightened crank, tight bearing clearance with very low viscosity weight oils…. Run vacuum pump. Heads with thin valve stems, conical springs for control with less pressure. Coatings. Etc all add up in efficiency. Heat and power.

Orr89RocZ

iTrader: (20)

The injector end angle timing does help, typically with idle quality, emissions and smell. Some cars have large overlap and get fuel smell on idle. Lot of raw fuel goes out the exhaust. Playing with injector spray timing def cleans that up. I have the holley table set up that way for various rpm and loads, the end angle changes.

now i have heard ppl say theres power there with adjusting the spray interval. Its minor tho it seems. On my buddies turbo car he tried my table vs just using bottom dead center timing and it didnt seem to do anything at the track but it was hard to tell and my table at high rpm gets closer to bottom dead center anyway

Fast355

iTrader: (2)

Just use a LT1 with its factory reverse cooling system. Cool the heads first then warm up the bores with that water. Less heat in the heads and less bore friction, win all around. Lingenfelter had an intake base at one time to run a SuperRam TPI style intake on.

Fast355

iTrader: (2)

Biggest difference I noticed was throttle response and the fact I had to pull 6-8% fuel in the lower throttle angles. Made a small mpg improvement. This was altering injector timing on a L31 with an 0411 and small GM 395' Marine cam.

Bishopts

I've wondered how the tpi setup would feel if the injectors were in the throttle body and not at the valves. Like a sideways tbi type of setup with long intake runners. Seems like it would be better since tpi is bank fire so it's spraying fuel on closed valves. And tbi is basically the same spray sequence but it's spaying into a central "plenum" area giving it a little more of a chance to follow the airflow and not pool up on a closed valve .

Komet

TPI was designed to be a dry manifold. Fuel distribution would be worse compared to port injection; there's a reason you're only supposed to spray up to 150hp through a tpi fogger plate.

Bishopts

How would the fuel distribution be worse?
obviously their are far better systems out there.
but spraying fuel into a central located plenum so it can pool up with its friends seems just as inefficient as spraying it into a closed valve 3 times only to spray it again when the valve actually opens.

Fast355

iTrader: (2)

Richard Holdener tried to run one with a carb. Manifold has terrible wet flow distribution. I bet it would run well on CNG or Propane though.

Fast355

iTrader: (2)

Sprying on the back side of a closed valve is actually ideal at low rpm and low load. Liquid fuel does not combust and the heat on the back side of the valve helps boil the fuel into vapor.

Bishopts

I could see that in theory. But that would make for a very big difference from a cold engine to a hot engine.

Bishopts

I've had my car for about 2 weeks now. I just got it running last week. I haven't driven it or really even let it run for very long. I've been on the fence of getting the tpi to work the way it's supposed to or pulling the whole thing out and putting a 5.3 in it.

Kingtal0n

I've seen and heard of over +100hp from injector timing adjustments, both NA and turbo applications

https://forum.hptuners.com/showthrea...l=1#post686907

+1 vote for 5.3
I used 5.3L engine for 5 years now, 600rwhp on the stock 5.3 is no issue, very reliable, my only car, I put 40k miles on it so far
I don't know why people bother modifying their random (V8 or otherwise) engine when the stock 5.3L for $300 from a salvage yard will 500-600rwhp all day when setup properly
The key to reliability is, excellent tuning obv, but also superior air filtration, crankcase pressure monitoring (PCV system is the key) and heat control strategy. You need all of it. Without PCV or good air filtering the engine is sensitive and will become trash rather quickly.

Bishopts

I've heard about the 5.3 valve cover redesign because of poor pcv control.
ideally 5.3 with a turbo would be the route I go.
I had a mk3 supra that I swapped a 2jz into years ago, it was completely stock with a boost controller and map clamp that i built and it was 426 to the wheels. It had an amazing feeling of power all the time but I had to part with it when my girls were born to get something with a back seat. So now that they are a little older and im better off financially I can get a project car, (88 gta) so I'm trying to find a direction on it. 1: Build up the 350 to its original standard and don't plan on having a fast car based off of today's standards, 2: bone stock 5.3 with a turbo and possibly take away from the value of an all original gta.

QwkTrip

iTrader: (22)

Never seen a nice LS swap devalue a car.

Kingtal0n

There is nothing wrong with the pcv or valve cover design. The issue is people modifying their engine without understanding how PCV works or what its supposed to do.

For example if you take a stock 5.3L truck engine and simply remove or replace the air filter with a high flow filter. That ruins the WOT pcv system and now the engine will begin blowing oil and leaking oil, ruining the oil quickly, sludge the engine, clog oil orifices and turn it to garbage. Just from a filter upgrade.

I use factory valve covers 2002 tahoe style 5.3L And no issues 40k miles clean as #(@*@# because I measured crankcase pressure using MAP sensor and logged the data and selected an air filter which provides a reasonable 2" Hg Drop at WOT

Same thing happens to 2jz sr20 and RB engines which Is how I learned about it in the first place, all engines require PCV crankcase pressure monitoring if you modified the engine and nobody ever does it, people dont even know it exists

https://www.supraforums.com/threads/.../post-13980010

Bishopts

Very good info. I'm very aware of the importance of pcv systems and ccv systems due to the training class I had to go through for the Cummins engine when I worked for dodge. The injection sequence on the 6.7 is really complex compared to tpi for sure. It will spray fuel 3 to 7 times per cycle. To preload the cylinder and to regen the dpf.

Bishopts

A common failure on those was people wouldn't change the air filter as often as they should and it would start pulling too much air through the ccv filter and then it would clog that and suck the oil seal out of the turbo.

Kingtal0n

Thats awesome. Its a very simple thing, air filter + PCV and yet soooo many individuals miss the importance. They don't know what 10 to 1uM debris in normal air can do to piston ring seal over time. They don't understand what pressure in crankcase does to piston ring function and oil control, how oil snakes up into rings and the light chains dissipate leaving behind muck/gunk carbon glue which prevents rings from spinning and switching sides, causing more blow-by and more oil related issues. And the effects on seals, and the density of the crankcase gas influence on what is coming out of the crankcase. High density crankcase gas contains more oil suspension which is then pushed out via pressure differential and so forth. Its a slew of issues related to PCV.

I believe one major difference between diesel and gasoline engine is for gasoline engines, the air filter drives WOT pcv action, you need the pressure drop of filter supplied to crankcase 0.5" to 2" Hg for example, otherwise no pcv action. Diesel I read do it some other way, perhaps they use an aux pump to drive crankcase evac?

Bishopts

The few diesel brands I've worked with and reading about it, diesels use the slight vacuum from the airtube before the turbo to pull crankcase gasses out of the crankcase. Which is the ccv system. Since they usually don't have high number in their rpm range I guess WOT isn't really that big of a factor that can't be mitigated by simple increase in vacuum before the turbo from higher volume demand.

Kingtal0n

Oh I was thinking of natural aspirated diesel. They can't use a typical throttle valve PCV pressure drop placement like gasoline engines do, or so I read.

Turbo gasoline does it the same way you described. Post filter pressure drop drives WOT pcv. It is critical.
See my cool crankcase evacuation tube??!

Bishopts

Oldsmobile had a 350 diesel back in the 70s and 80s. I wonder if you could fit that into a tpi engine and use gas to make a direct injection tpi engine

newbvetteguy

I’ve only seen like 1-2% on NA engines; I think that thread is talking about BIG HP forced induction, but with a knock limited TPI motor, if the evaporative cooling packs in 1-2% more air AND allows you to avoid retarding timing around that pesky torque peak, I could see ovi providing even a bit more than that.

Right now Pipemax is telling me that I need 95.3-99 octane to avoid knock but I know it doesn’t consider quench, intake air temps, or coolant temps; the previous version of Pipemax recommended 95 octane but I’m hoping my cold air intake, 180 thermostat, Seattle’s cool summers, and open valve injection let me get by with Washington 92 premium although I’ll keep a bottle of Boostane in the car just in case. (And I’ll be calibrating my knock sensor.)


Adam

Bishopts

cool because of the thermal wrap? Or cool because it's a super simple design that works? Lol

Bishopts

I've tossed around the idea of getting a 3800 series 2 or 3 and putting a turbo on it. It worked with the grand national and the turbo t/a on more inferior technology so you would think that it shouldn't be a problem.

Kingtal0n

I'm part of 'that thread'. We are discussing *all* mpfi engines overhead injection to a valve or through a valve

7:00 picks up 50 to 70hp from dialing injector phase in an N/A engine

Its worth dialing in for all setups because of the influence on economy , power and fuel efficiency

Bishopts

very cool video that puts the 305 in a new light. All I ever hear is people talking down about them

Drew

iTrader: (58)

This is the strangest "TPI" thread I've ever seen. Seems the topic has wandered a bit.

Bishopts

I was thinking that too. No one said anything about my suggestion of using the Olds diesel injection setup as a direct injection option for the tpi

newbvetteguy

Thanks! Great example! Looks like 394 rwhp to 408 rwhp from just the injector end angle tuning or 3.5%. About 50% more gain than I’ve seen so far, so a great example. All great gains from just tuning and like the author of that video said that engine wasn’t knock limited; more is possible from a knock limited TPI engine, I think.

3.5% for free and like you said, fuel economy gains from avoiding spraying during or before overlap is nice, too!

Now I just need to figure out how to calculate how big of injectors I need for this fueling strategy (I’ve read sizing at 20% injector duty cycle at your hp level works well) or how to figure out at what RPM I’d start spraying during overlap if I start x degrees before intake close and at what RPM ID start spraying on a closed valve. (Although the fairly rapid decline in VE with a long-runner engine beyond the torque peak might help with that.)

-I want to run the biggest 12 hole injector I can find. So far that’s a 550cc injector but I COULD run it at 4 bar for a bit more…

Adam

newbvetteguy

LOL! It definitely did but my ADHD is totally fine with it and I’m following it.

Open valve injector / injector end angle tuning to me naturally leads to talk about ultra high injection pressure that can inject in fewer angles and more accurately and to DI discussions which appear to be the final evolution of the subject.


Adam

Kingtal0n

More like 15%
He adjusted it immediately to gain 20 or 30hp by inputting a random injector data which moved the end of injection spray
Then he moved it again to finalize the tune a little bit further and it picked up 10hp or 15hp more on top of that
It sounds like two different things but the only thing you can do to an injector is move the end of injection spray, there is literally no other adjustment available to us which would change power.

Fast355

iTrader: (2)

I am calling bullshit!!! Plain and simple, PCV is not ruined by a low restriction air filter. Otherwise every engine I have would be gunked up garbage. Mine do not burn oil either. You can take that stupidity elsewhere and try to keep regurgitating that garbage. I pulled this 350 Vortec because the oil pump pickup tube fell off the pump and starved it of oil damaging the bearings. Still had like new compression and leak down numbers but a slight startup knock. Was losing oil pressure at heavy throttle that I thought was a gauge issue. This 350 was run every mile with a K&N and got WOT from ZERO miles. The little bit of surface rust on the head is because it sat in my humid shop for over a year before I finally tore it down with open valve covers.




This is a VQ35HR that has run the last 100K of its 220K with K&Ns. One of the two factory paper filters came apart and got sucked into the MAF while driving for 4 hours straight in a rain storm, limp moding the car and causing me to have to cross 3 lanes of 75 mph traffic with zero throttle. Swapped to K&Ns to avoid that stupidity from ever happening again. At ~220K this engine also has perfect, even compression, low leak down and still put down 318 whp. So please go on blowing smoke up peoples rear about low restriction filters. I change the oil about every 7,500 miles in it. The VCT filters were spotless when I had to change one of the solenoids after it died electronically with an open circuit.



What about my old Q-Jet fed 305 that lived ~300K and still had 190 psi in every cylinder. That old 305 had a seperate breather element in the air cleaner and zero vacuum on the PCV vent at WOT. It was virtually sludge free (only sludge was around the exhaust heat efe crossover in the intake) and ran almost its whole life on Penzoil 10w30 conventional with changes between 3K and 5K.

Fast355

iTrader: (2)

Something was either really wrong with that setup or the tune he started with. I have seen minor fuel trim differences around idle and low throttle on engines with a decent cam, but next to nothing once the throttle is open and the rpm is above about 2,500.

I will go so far as to say, I saw very little power or economy difference between a correctly tuned EFI and well tuned carb on the same engine both with the same manifold. If EOIT made that much difference it would show up even more pronounced with a carb vs EFI especially given that the cam had a fair bit of overlap.

Kingtal0n

1. If you don't measure the crankcase pressure how do you know the PCV wasn't still working with a K&N air filter? Just because you swap filters doesnt mean PCV stops working. It stops working when crankcase pressure rises over 0.5" Hg at WOT. Which you have no clue whether it was or not because you don't measure it

The big point is that there is nothing wrong with OEM pcv from any of these engines, LS, RB, 2J, SR, 4G, etc... I've tuned hundreds of engines and set them all up the same way using OEM pcv system. WHich by the way is OEM = original system works great to maintain low crankcase pressure at WOT For all of the engines in the world, surprise. Yet thousands of owners have 'problems' with the OEM pcv system once they start modding the air filter tract and crankcase evacuation setups away from OEM without actually measuring their crankcase pressure. Thousands of people claim the OEM Pcv isn't working properly and the engine is smoking or leaking because of poor design. Every car forum has these, supra, silvia, skyline, LS1, corvette, etc... there is always a small selection of individuals with no clue how PCV is supposed to work or any idea how to measure crankcase pressure or that they even can measure it, and they complain about oil from the pcv in lieu of their lack of knowledge.

2. You can only change two things about the injector from the tune file. When it fires and for how long, thats it. So if it picks up 1hp and he didn't change the a/f ratio then it was due to injector timing. "something wrong in the tune" The only thing that changed was "when" the injector fired. There is no other adjustment. The comment on HPtuners from Ghuggins he tuned a thousand engines on that forum and gets +100hp from injector timing on a 600rwhp setup, its about 15% of area under the curve available depending when the injector is fired.

Kingtal0n

These are published papers, not my work, very clear about crankcase pressure causing oil leaking



Since the pressure is controlled by the air filter there is only one thing responsible for crankcase pressure at WOT: The Air Filter.
Sorry but if you can't see it maybe you should goto school for 15 years get a PhD MD MS BS then tune a couple hundred engines of every possible make and type 500-2000hp and maybe you will see it also... but then again a degree is just a piece of paper and experience is only worth what your senses tell you

QwkTrip

iTrader: (22)

The Holley EFI comes default with injector end angle (IEA) at piston BDC (0° as referenced in their software). My old LS 427 stroker was dyno tuned with that setting. Fiddling with IEA made the engine more responsive from idle to ~3000 rpm, very noticeable by the butt-o-meter, and the clutch felt a whoooole lot better with the extra off-idle torque. The change was pretty phenomenal. The same butt-o-meter couldn't sense any improvement at WOT above ~3500 rpm. I think rule of thumb is the average butt-o-meter can usually sense a change greater than 10 RWHP. There are some broken butt-o-meters out there, mine is pretty in tune with my car.

My IEA tables are based on air transport calculations to get the fuel in the cylinder before the intake valve closes. I've since learned how to use the Holley software to automatically sweep IEA for testing but haven't been on dyno to to experiment. Idle is treated different though, I'm intentionally spraying on back of valve to help atomization and that's how I increased idle torque & vacuum and off-idle response.

Kingtal0n

I don't think every engine can gain rwhp peak number using only EOIT. Only gain area under the curve where the injector firing can take advantage of port velocity/swirl or whatever the influence of air flowing into the cylinder at peak piston velocity is for any particular engine. There are spreadsheets going around on HPtuners forums for dialing in the EOIT to PPV or peak piston velocity for this. To see a consistent gain across the board usually means having the EOIT change gradually as RPM is rising to take advantage of some port variables.

In any case, the gains seen in that video from the dyno can only come from 3 places, a/f, timing, and EOIT. And he is clear about which runs are adjusted A/F and timing, everything else was EOIT. Maybe the particular port in the head/intake was particularly poor with respect to injector spray pattern, or direction, or something like that, which allowed the EOIT to have a greater influence on peak or total output. I am also highly skeptical of such gains, actually I am skeptical of everything because I am a scientist, a researcher, and my main focus is cancer. I study cell behavior, I grow cancer and remark upon it's most devious secrets and attempting to develop treatments for particular cancer pathways which are far more convoluted than anything as basic as a combustion engine. What I am getting at is, the simplicity of an engine's tuning efforts: A/F, timing, and EOIT, break it down into it's individual components and realize there is very little other 'tuning' involved than those basic adjustments available. I Mean, some spark dwell or something maybe could influence burn rate, but so can plug gap, perhaps plug heat range, the small details which are constants in such an environment (dyno testing) so we can rule them out despite their influence, they are constant.

QwkTrip

iTrader: (22)

Yeah, you just reminded me there was some trickery to putting the fuel in at optimal times when mixture can occur and not just before valve closing. It's been several years and I don't remember all the details.

Kingtal0n

I think most setups are adjusted empirically on a dynometer, because guessing and theorizing only goes so far compared to the real world situation for each engine inside.

The energy required or imparted to moving air, getting air to move into a cylinder, is kinetic energy which is based on velocity and has a direction , unlike pressure which is a scalar and no direction associated. Kinetic energy is converted to pressure at some point for the fluid as it enters a cylinder and loses or changes velocity, and how the kinetic energy is used or where it is converted plays a role in cylinder fill and resulting scavenging pressure drop associated with flow through open orifice.
Likewise injectors impart kinetic energy to fuel, with a velocity, and a direction.
The two fluids, air is a fluid, fuel is a fluid, interact. Their energy can combine, and increase airflow mass to a cylinder. Or it can impede the airflow to the cylinder if spray at the wrong time. If fuel becomes a gas state before it enters a cylinder it will reduce air density and that will require more energy to get the same mass into a cylinder.
There is this whole theory aspect to what might work. But in the end even after tuning a thousand engines you are still adjusting via experimentation because every engine is different, so theory isn't super helpful. Its just a way to recognize that the energy of moving air and moving fuel, can have powerful influence on air density, and air velocity, air mass to the cylinder, heat exchange, etc...

Orr89RocZ

iTrader: (20)

that was not just injector timing changes. If you watch the video he explains the changes. That was a base tune to get 360. There was alot of change in injector data(which im curious why changing from deka 60 to fic 650cc made 30 hp, i wanna see the log file), air fuel and timing to get from 360 to 420…. Injector phasing alone isnt gonna be more than a few percent but it is worth chasing if you have oversized injectors

Bishopts

On the tpi intake system how long would you think it takes at WOT for air to go from the filter to the valve?