I have a JDM GSR swapped in an EG turboed to 10 psi on brand new stock internals. I've been babying it since I've owned the car (700 mi. ago) keeping the boost below 5 psi. This weekend I will have it dyno tuned to 8 psi.
How well can a JDM B18C handle this kind of boost on stock internals (10 psi vs 8 psi)??

Also, which head gasket would be most suitable if I wanted to lower the compression as much as possible w/out getting forged pistons??

Lastly, which non-forged pistons would be best for lower compression if my plans are to leave it at 8 psi??




Modified by str8mutt at 1:38 PM 5/25/2005

 

So you just rebuilt your gsr internal with oem parts? if you plan on boosting why dont you spend a few hundred buck and get forged internal for the peace of mind, just get some forged piston with 9.5:1 or so compression and an set of eagle rod and your good. I think import parts is selling the combo for 800 shipped

 

What compression is the jdm gsr again? See if you can bring it down to the 9.5:1 to 10.0:1 range if you are that worried... you shouldn't be though.

If you stay with stock compression, you will be fine with 8-10psi. If it were me tuning it, I would remove a tad bit of timing and run a tad bit richer to keep heat off of the pistons.

 

It irritates me that people think 10PSI is too much or there compression is such a HUGE issue. Don't change anything, baby the car until 1000 miles and then when you tune it, make sure your tuner understands your goals and he will try to put your car to those goals as safe as possible. Remember, you can run a lot of boost, it's the tune and power that hurts the engine. Retard the timing correctly, run 12:1 AFR in boost, and don't push over 300whp and your car will last a long time. If you make 300whp at 6 PSI or 14PSI it doesn't necessarily matter as long as the tune is in check . GL with making good power

 

stolenteg ~ that's exactly what i asked the previous owner but i guess he didn't wanna spend all the $$ sleeving the block and going forged if he was probably going to sell it anyways.

precisionh23a ~ the compression is pretty high (10.6:1)! can this newly rebuilt motor with OEM parts withstand 8 - 10 psi??

 

Adseguy ~ thanks for clearing that up! gave me a better understanding as well a little more confidence!! i'll have it dyno tuned this weekend. before the rebuild it dynoed 283 whp @ 8 psi.

 

A buddy of mine had his ITR tuned with 6psi of boost. I believe it had 11.0:1 compression once it was all done... everything turned out fine.

If your tuner knows what he is doing you'll be fine.

 

cool! thanks a lot guys!

any suggestions on the head gasket and would LS pistons be a bad investment if I don't plan to sleeve the block anytime soon??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by str8mutt &raquo;</TD></TR><TR><TD CLASS="quote">cool! thanks a lot guys!

any suggestions on the head gasket and would LS pistons be a bad investment if I don't plan to sleeve the block anytime soon?? </TD></TR></TABLE>

don't change the headgasket or pistons...your compression is just fine. Don't listen to rumors. Look at real life data. Jeff Evans (very good tuner) has the same engine on his car and runs 300whp. He has taken it to road racing, the track, probably hundreds of dyno pulls, and every movie I see his car in he is hammering the throttle . Guess what? His car is doing just fine, it's all in the tune

 

Thanks Adse! I'll just reduce the boost then.

I just got a quote on a reputable tuning shop in my area and they quoted me $185/hr to have it dyno tuned. Said it should only take about an hour...it BETTER! that's all i can afford!!

 

PSI means nothing.. What size turbo are you using..

 

tgreaves ~ t3t4...should i be alright with this??

sorry, having a turbo setup is new to me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by str8mutt &raquo;</TD></TR><TR><TD CLASS="quote">tgreaves ~ t3t4...should i be alright with this??

sorry, having a turbo setup is new to me. </TD></TR></TABLE>

Its best to get it on a dyno and have it tuned to what whp is safe for you setup.. If its a stock motor then like 280-300whp is the most I would go.. if it takes 10psi or 20psi to get there is doesnt matter, as long as your in the efficency range of the turbo you tune to a whp..

 

&lt;--------usdm gsr motor on 11 psi right here daily driven.

a guy i know had his jdm gsr motor on 10 psi tuned, and it made 300 hp to the wheels.

 

AzntaggeR ~ is that 11 psi on stock internals??

 

JDM GSR compression 10.6:1. 10psi is fine, i'm looking to make 300whp on 10psi but my tuner said he can do it at 8-9psi. But I asked the same question he said 10psi is fine. That's tuned though w/ hondata s200b.

 

glad to hear that EM2! this is my daily driver, so if anything happens to it, i'm done! will definitely have it tuned to be sure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by str8mutt &raquo;</TD></TR><TR><TD CLASS="quote">AzntaggeR ~ is that 11 psi on stock internals?? </TD></TR></TABLE>

yup

 

i ran my on ten pounds of boost and melted two of my pistons but i didnt run a intercooler u should be alright if u have an intercooler

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by derrickracer2000 &raquo;</TD></TR><TR><TD CLASS="quote">i ran my on ten pounds of boost and melted two of my pistons but i didnt run a intercooler u should be alright if u have an intercooler</TD></TR></TABLE>

wow that's almost sig worhty...and I don't do that ****

 

9 psi on a jdm itr stock internal 320whp @ 9 psi... BONE STOCK gT30R