i have a gsr with itr pistons and was wandering how much psi it could handle safely. any boosted itr's out there with stock internals? how much power do they hold up to?

 

i heard from someone say 25 psi

 

You could seal the WG hole on a 14b and get the max 27psi they provide...but like the DSM guys who did this, you'd make no power. On a t6-frame s4xx borg warner, you may only make a few psi before you break pistons.

Long story short it's power not PSI. Just like all the other threads that ask "how much boost", the answer relates to your goals, where it will be driven, and how often.

300hp with a safe tune on 12-14psi with a 60trim T3, or 8-10psi with a 50trim t3/t04e.

 

30 psi?

 

10 psi

 

pick a power goal, find a tuner, and let the tuner and dyno tell you what PSI the motor can handle. In my opinion it is a bad idea to look at a project and think im gonna hit that motor with 20 PSI, if the motor is done at 15 PSI why keep going?? Idea is to make the most power possible with as little pressure as possible...

 

thats not necessarily true,

more timing and less boost is worse than less timing more boost.

your either gonna make the motor or the turbo do the work, make the turbo do most of it.

 

Safely it is said to go no more than 50% over stock hp, anything above that and ur pushing the limits and it's up 2 u after that. U can only push stock parts so far b4 they will fail and even a great tuner can only get u so far beyond the safety limit. Any experianced tuner will tell u that, if u want to push it further it's ur engine and money.

 

thanks for the input. I should have clarified it will be a t3/t4 ebay unfortunately until more funds come in. I also know 300hp is about what im looking for. I was just curious what wastegate spring to start with. I was thinking 8lbs and boost controller

 

Most of the above comments are true. Never go by psi. For instance, if you have 2 exact B-series motors...one has an 16g, and the other has a GT35 on it, both at 8 PSI, the GT35 will make considerable more power. PSI is a unit of measure...that is it. The correct question should be, how much power can a xxx hold. As an example, I'm using a completely stock GSR motor, ARP head-studs, and a Victor X intake manifold, and making 400whp on 93 gas at 16 psi. Motor is still going strong.

 

Id say 10psi to be safe, the people throwing out crazy numbers, you guys are nuts.

 

your looking at around 11.6:1 compression ratio. that combination with boost isnt the best and requires the proper turbo parts and tuner to be reliable. with a high compression its very easy to grenade a motor. Its not abotu psi its all dependant on what setup you run but if your just doing a run of the mill setup then i wouldnt go over 10 psi with a good tune which should produce some nice numbers

 

I would love to hear your theory on how/why an engine can handle xxx amt. of boost. PSI is only a unit of measure.

 

lol

 

I know...right? It's frustrating when you post a thread...and the very next thread is some dude giving mis-informed information, that completely is opposite of what I just said.

 

Stop listening to Greddy...That is a ignorant comment.

There is PSI and CFM, PSI is PRESSURE. CFM is VOLUME of air. Little turbo, little volume. Big turbo, big volume. Big volume, big power. Little turbo + lots of psi = lots of hot air = high iat's = lots of knock.

Just to put it in simple terms.

Your setup is pretty high on the c/r, which gives you a much smaller window for possibilities of knock, stock piston ringlands and sleeves do not like knock. I would hire a competent tuner and keep turning up the boost until you run out of octane and the tuner doesn't feel comfortable making any more power. Kinda what I did, but we didn't run out of octane, we ran out of wastegate spring. Mine is a 10.5:1 ls/vtec

 

Yep, ur right and then there is VE (Volumetric Efficiency) and cylinder pressure, u have to get it all right and working for u and most ppl don't want to spend the money/don't have the money to do that. What blows up engines is to much cylinder pressure and at the wrong time. I can run 40psi at the wrong time and just waste the pressure or I can run 8psi at the exact right time and make 3x what I made on 40psi. Stock parts can't handle the cylinder pressure at the best time needed to make the power then BOOM, engine's done. Let's not forget about MEP either in our disscusion. In the end the #1 engine killer is detonation

 

You both are 100% correct, and I commend you both for giving accurate info. People like to make PSI goals instead of HP goals, and this is astounding to me.

To the OP's question. There isn't a magical number on what HP a engine can handle. People have run 300whp for a week and have blown a motor. Some like me at 400whp for 8 months and are still going strong. I still believe that the tune accounts for a major part of the question "when/how will my motor fail". My advice to you is to pick a HP goal, and then a turbo to get you their, that will be efficient to get you there. Then, make whatever PSI to get you to that HP goal.