hello i been told i cannot get more than 450-500hp on pump gas is that true? i have a petit racing street ported engine t78,hks front intercooler,850 pri,1600 sec,fuel rails upgraded, controlled via AEM ems.
i am on a steedy 400 at the wheels about 460 to flywheel on 17-18 psi on my stock t-78 ,they told me if i raise the boost the engine will go to hell because it will not hold the detonation and i am running 95 octane pump gas,that is the octane level in my country,let me know what you think.

 

400 whp at 17-18 PSI? Get that **** tuned, should be around 450+ at those levels. I have heard of 500 whp T-78's, not sure about on pump though/ Here is one.
http://www.rx7store.net/shopcar.htm
As you can see you are running only 1-2 PSI less and are making about 100 hp less

 

I wouldnt go over 15psi with pump gas just to play it safe. All it takes is for it to detonate once and your motor is done.. so 15psi is usually around 400-500 hp depending on what your setup is...

Dont take any chances, if you want more then 450-500 you have to run race gas...

 

AFAIK, most cars with the Greddy T78 kit DO NOT make similar numbers to the Rx7store's car. Now, that said, I agree that 400 whp @ 17-18 psi is low for the Greddy T78. I would think 440-450 whp would be "acceptable." I don't run any more than 15 psi on 93 octane. There are some who run more boost on pump gas, especially those who run some type of water/alcohol injection; however, you're playing with fire and you're asking to get burned. The margin for error narrows considerably.

 

Water Injection will let you run 25PSI on pump gas

 

I posted a dyno sheet in some other post in this forum, fc doing 619 rwhp on pump gas..
I run 20 psi on premium pump on a pretty regular basis and have done for awhile..Max

 

as long as you dont tune for it.

rx7store.net's 506hp rx7 was @ pump gas on 19 psi


but water injection will help out alot.

& i would expect a bigger horsepower than that @ 15-17psi. BTW get a wideband also

 

Also, the t78 was upgraded with a different compressor wheel. Not sure how much effect it had though. Contact Jason.