aleks77

hey guys just curious if the amount of psi you run makes a difference on how long the stock sleeves will hold or is it only the amount of power you actually make?

Lets say you want to make 420whp, is it better to get a quicker spooling smaller turbo that is rated at 450whp max and run high psi to achieve your goal, or is it better to get a turbo rated for 550whp and run lower psi to achieve the same power goal, but ofcorse more lag.

IAD_ek

Whether or not stock sleeves will hold up is all about power. But the most important thing if you want to run that much power is having a great tune. Jeff Evans has repeatedly tuned cars make 500whp on stock sleeves but the question is, how long will they last?

So to answer your question.......power

tokesGTR

I would venture a guess and say the larger turbo would be safer.

Smaller turbo = faster boost
Faster boost = more torque
more torque = more cylinder pressure

Also,

Smaller turbo = more boost
more boost = more heat
more heat = greater chance of detonation

I have a feeling you were trying to go in the direction of "xx psi will crack sleeves!" but the actual boost doesn't really mean much, it's the likelyness to detonate and amount of cylinder pressure you produce that will be the main factors.

boosted k20

power band wont be as great with a bigger turbo. what power r u looking to make?

marcj

learn more about the mechanics involved and you will be able to make a setup good for stock sleeves.

many factors are involved, including intake temps, EGT, oil pressure, pre-detonation, etc.

i'm experimenting with water injection soon.. the DSM guys have really benefited from it, and it's cheap security.

Schister66

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tokesGTR &raquo;</TD></TR><TR><TD CLASS="quote">Smaller turbo = more boost
more boost = more heat
more heat = greater chance of detonation</TD></TR></TABLE>

This is more what i was thinking. If you run a turbo to a higher pressure ratio, its going to create more heat. Unless you can disperse that heat (via a good IC), youre going to have a better chance of detonation. Fuel grade and timing are going to play a role in this as well...

aleks77

Im lookin to make 420whp on 94 octane pump gas here in canada. My last turbo was running 18 psi and making around 380whp.

Schister66

Well at that point, there are several turbos to choose from. What is your budget and what are your goals?? Are you only making 420whp on pump gas with no desires to run race for more?? This will just give a better indication of which turbo will suit your needs the best...

I forgot about this thread.... https://honda-tech.com/zerothread/2413368

Looks like you're pretty close to getting your answer already,.

HiProfile

Torque is a function of cylinder pressure, exhaust backpressure, and oxygen involved. Given the same IAT's, 500whp with a large turbo at 10psi vs 500whp with a small turbo at 25psi, you will have almost the same amount of air pushed into the cylinders. Teh difference would be exhaust backpressure.

That said, a lrager turbo can stuff more air into the cylinder mainly due to lower IAT's and less backpressure to fight with. If you choose a goal that won't push the smaller turbo to hell & back, get the smaller turbo. A good example is that VW posted here making 500whp on a GT30 @25psi. Most people on H-T with GT35's aren't making 500whp.

And FWIW, the smaller turbo can be more dangerous since it makes peak torque earlier, and generally much higher than with a larger turbo at the same max HP level. The Bullseye website show a good example with an S200-series vs a GT35 - same max HP, but far more torue down low (as it 'falls off' quicker from a higher peak).

To answer the 420whp question - a 57trim could do that just as safe as a GT37, but spool much quicker.

ralph11sec

lets try to use specifics,

say youre choice is

b18 + t3t04e 57trim @ 25psi = 430whp.

b18 + gt35/sc61 @ 18psi = 430whp.


i believe the t3t04e higher boost will kill the motor sooner than the gt35 route. its just too much psi. tokes gtr is right. power is not the only thing we should consider. octane/cyl pressure/ heat. etc.

aleks77

wow thanks for all the info guys

The max i wanna push the turbo is 20psi, hopefully a 57 trim will make 420whp at that? The engine is F22A6 2.2L SOHC.

ralph11sec

not familiar with the efficiency of f22.

since you got a bigger displacement, why dont you get an sc61 or at least 60-1.
borg t3t4 is also nice.

tony413

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ralph11sec &raquo;</TD></TR><TR><TD CLASS="quote">lets try to use specifics,

. its just too much psi. c.</TD></TR></TABLE>

really and here i thought it was CFM's that were important.

to OP: whats your PEAK hp goal? when you decide that go look at some compressor maps and then turbine maps (if you can find them) and pick your turbo based on that info. in any case those a holset HX35 is the way to go. you have the option of picking about 9 different turbine housings and the compressor is a cousin of the SC61. so that turbo is a win win either way you go.