Most Horsepower on the lowest boost

[dsm's can fly]

I know it is a trivial thing to even wonder but, i am curious. So i figured i would ask. I know turbo size has a lot to do with it as well as displacement and such. The questions still is.

1. What is the most horsepower on 4g6x engine at the lowest boost?

I of course ask this out of selfish reasons. I am wondering if i have, or could have some sorta stupid record.

so for the first entry: (my own)

1. GT4088R, 2.4L, 630HP @ 19 PSI

 

[92AWDHX40]

4g6x engine, too many vairables, the only way to know for sure is to dyno it, while experimenting with different boost levels.

 

[ed1380]

Whoever has the most displacement and highest compression ratio.

 

[dsm's can fly]

Whoever has the most displacement and highest compression ratio.

Maybe not sure that is why i asked. I figured there might be some body who put a GT45R on something @ 10 PSI and made 700 hp or something. I guess we will see.

4g6x engine, too many vairables, the only way to know for sure is to dyno it, while experimenting with different boost levels.

That is what i am trying to find out. Most people dyno there car at the lowest boost it will run to build a base map. I am just trying to find out what the highest power at the lowest boost anybody has seen. The variables dont really matter. It could be a methanol motor, or just some back yard build. I just see so many threads with a large horsepower number and 40+ psi so i wondered about the other side.

 

[WES_393]

What compression ratio are you running on the 4g64? That could have a lot to do with it.

 

[ShizzySupra]

What compression ratio are you running on the 4g64? That could have a lot to do with it.

13:1 according to his profile.

The question itself is slightly absurd as it doesn't take into account area under the curve at all.

 

[dsm's can fly]

13:1 according to his profile.

The question itself is slightly absurd as it doesn't take into account area under the curve at all.

I know but i was curious. I just see so many high boost high horsepower stuff it just made me think. and lets be honest anything making high power, what is under the curve really???

 

[945liter]

35.7psi 2liter 62mm turbo 750awhp with alot under the curve

 

[dsm's can fly]

35.7psi 2liter 62mm turbo 750awhp with alot under the curve

Nice so that's 750 / 35.7 = 21 Hp per pound of boost

This is the stuff i was looking to see

 

[ShizzySupra]

Incorrect on many levels.

. and lets be honest anything making high power, what is under the curve really???

 

[spoolin ddub]

Whoever has the most displacement and highest compression ratio.

There are more factors to that puzzle than just compression ratio and displacement. To a certain point those two are the easiest to a reach a hp goal at a lower psi. One of the highest I know of is on a 2.0. At 24psi it made 770 awhp!

 

[jrohner]

Whoever has the most displacement and highest compression ratio.

Smaller displacement means more rpm potential, so not necessarily less hp.

 

[spoolin ddub]

Smaller displacement means more rpm potential, so not necessarily less hp.

You are dead on with that.

dsm's can fly those nice numbers for that amount of boost.

 

[bastarddsm]

I'd say your up there, but I bet somthing like shep or rau's car would still be plenty nasty at 20-25psi.

I feel like your missing power tho. I can't believe how hard yours nose dives at 7000+ considering the turbo/cams/intake. Even with the 2.4 I'd expect you to be making peak power at 8000.

 

[dsm's can fly]

There are more factors to that puzzle than just compression ratio and displacement. To a certain point those two are the easiest to a reach a hp goal at a lower psi. One of the highest I know of is on a 2.0. At 24psi it made 770 awhp!

that would be the highest i have seen. and would be straight nasty

You are dead on with that.

dsm's can fly those nice numbers for that amount of boost.

thanks for the kind words.

I'd say your up there, but I bet somthing like shep or rau's car would still be plenty nasty at 20-25psi.

I feel like your missing power tho. I can't believe how hard yours nose dives at 7000+ considering the turbo/cams/intake. Even with the 2.4 I'd expect you to be making peak power at 8000.

Agreed if there was a 20 ish psi graph of Sheps car it would be insane i am sure.

The power does not fall off that i have seen. the torque does. there is less than a 15 HP difference from 7000 to 8000 RPMS. and that slight dip is because of boost fluctuation, it has about .5 PSI more boost at 7000 than 8000.

 

[bastarddsm]

I should have worded it different. I mean more that it's not on the rise at 7k, and peaking at about 8k.

Nevertheless, those are still very impressive numbers.

 

[LandSpeed-DSM]

The formula for big power on low boost with a small displacement motor is relatively simple. The obvious would be a big cam suited for very high rpm, 10.5-11k. Switch to a fuel like E85, E98 or Methanol and run at least 14:1CR with as much timing as you can get away with past peak torque.

Coat those cylinders and valves to keep as much heat in the exhaust as you can, coat the exhaust to get all of that energy to work on the turbine wheel, then dump the exhaust as quickly as possible to create a large pressure drop across the turbine.

Hog out the ports/bowls in the head, opt for bigger valves.

Large primaries on the manifold, big turbine and housing. Largest diameter as is feasible on the exhaust and short as possible too. That goes for the compressor side as well. A GT4508 in a 1.32A/R turbine would probably be about the biggest you could load up, and it would move a ton of air very efficiently on a 2.0 thats winding to 11k. A good part of the rev-range would basically feel like an NA motor though, and you would possibly be left of the surge line at a few points.

Its going to be all about making your VE mods complimentary.

Take a look at pumping losses and spots that restrict volume flow.

A large plenum short stack intake manifold with a large throttle body. Large charge cooler and piping.

If you have the capability to move a larger volume, and then throw boost at it, you will not need as great a pressure ratio to meet the same numbers.

This is basically what I am working towards with my LSR project.

I am contemplating on moving to an HX60 just for the bigger turbine and compressor. I'll wait and see how this setup performs on the 71mm/99mm HX52 compressor wheel though. I just feel like the relatively tight exhaust side (for emissions purposes on the D12 Volvo trucks) is going to be working against me.

 

[re-rx7]

Rotaries make great numbers on low boost. That has alot to do with the VE f the engine.

 

[LandSpeed-DSM]

Well that also depends on how you are measuring the displacement on your rotary/wankel.

 

[re-rx7]

Well that also depends on how you are measuring the displacement on your rotary/wankel.

This is true as well. No arguing there ability move air or exhaust though.

 

[1990AWD]

Just look to the Extreme Tuners Evo in Greece, that car was making like 890 ps at 14psi of boost. They also had ones making over 1000hp at 30psi, 1200+ at 35psi etc.

 

[LandSpeed-DSM]

What they are doing is not revolutionary.. they just have the money to throw at these projects and can tailor every bit of the project to do what they need. Billet blocks.. CuBe Valve seats, MMC Rods, Ti crank, custom center sections, Ti comp wheels, huge custom billet cams.

Note I am not saying its like putting legos together, Spyros and crew certainly have a wealth of knowledge and experience but that isnt exactly mind blowing.

The principles remain the same.

Look how high they wind those motors and how big the compressor/turbine combos are.

Considering the mid 80s turbo F1 Era saw 1.5L motors chucking out 1500whp @ 85psi boost winding to 11k on an 85% Toluene/15% n-Heptane fuel blend on crude bosch ECMs..

From that perspective, I am not exactly taken off my feet by a 1400whp 2.0L winding to nearly 12k @ 40+ psi on a monstrous turbo.

It's all been done before, precedent has been set and much of it translates from platform to platform because these are all spark ignition piston motors when it comes down to it.

 

[1990AWD]

What they are doing is not revolutionary..

I never said it was.

 

[keltalon]

13:1 according to his profile.

The question itself is slightly absurd as it doesn't take into account area under the curve at all.

I agree 100%.

 

[keltalon]

The formula for big power on low boost with a small displacement motor is relatively simple. The obvious would be a big cam suited for very high rpm, 10.5-11k. Switch to a fuel like E85, E98 or Methanol and run at least 14:1CR with as much timing as you can get away with past peak torque.

Coat those cylinders and valves to keep as much heat in the exhaust as you can, coat the exhaust to get all of that energy to work on the turbine wheel, then dump the exhaust as quickly as possible to create a large pressure drop across the turbine.

Hog out the ports/bowls in the head, opt for bigger valves.

Large primaries on the manifold, big turbine and housing. Largest diameter as is feasible on the exhaust and short as possible too. That goes for the compressor side as well. A GT4508 in a 1.32A/R turbine would probably be about the biggest you could load up, and it would move a ton of air very efficiently on a 2.0 thats winding to 11k. A good part of the rev-range would basically feel like an NA motor though, and you would possibly be left of the surge line at a few points.

Its going to be all about making your VE mods complimentary.

Take a look at pumping losses and spots that restrict volume flow.

A large plenum short stack intake manifold with a large throttle body. Large charge cooler and piping.

If you have the capability to move a larger volume, and then throw boost at it, you will not need as great a pressure ratio to meet the same numbers.

This is basically what I am working towards with my LSR project.

I am contemplating on moving to an HX60 just for the bigger turbine and compressor. I'll wait and see how this setup performs on the 71mm/99mm HX52 compressor wheel though. I just feel like the relatively tight exhaust side (for emissions purposes on the D12 Volvo trucks) is going to be working against me.

How long will the engine last?