whats the max amount of boost i can SAFELY run on a stock s4 engine with the s5 rotors?

 

What all is done to it? With you could run 16 or 17 safely, or you might blow up at 11. Also, don't s4 and s5 rotors heave the same compression in turbos?

 

primary concern is fuel system.

conservatively, the stock fuel system is good for around 8, at which point the fuel pump becomes the weak link.

upgrade the fuel pump and then your good for 12, at which point the stock turbo is pushing hot air ...you can upgrade the intercooler or compressor to keep intake temps low

visit http://www.rx7.com/cgi-local/2ndgencalc.cgi to see your injector needs based on the power you want to make

also, timing is a concern after 8.6 psi ...anything after that and the stock computer doesn't retard timing ...and being that you also have higher compression rotors that is even more of a problem

some have pushed beyond the boost pressure i suggested ...but i am being conservative as mentioned ...too many things can pop a motor, better to be on the safe side. you can get a popoff valve as well

 

so should i stick with s4 rotors then, and upgrade my fuel system and and intercooler and get an aftermarket ecu? if so what am i lookin at running on stock rotors?
btw, what im doing is buyin an s4 tII missing the motor and tranny. im puttin in a new tranny and im gonnna buy a motor, rebuild it and port it (depending on how much it costs to get it ported cuz i cant do that myself). then, once its running my goal is to get it to14sec in the quarter, and still be driftable.

just in case anyone cared.

 

Makes scense. Porting, street porting, is around $350.00.

I would say for 14 sec,
Street Port
Exhaust, 3" w/highflow cat.
Downpipe
Remove smog pump, get block off plates.

Fuel upgrade would not hurt...........


You may get 14's with that? No sure though......

 

stock is 14's with that you can do 13's and is good idea if you change yours injectors low indep. to 720cc

 

a stock TII runs 14"s?
and i can definitely afford 350 for a street port.
ive got a few more questions about boost and compression ratios so im makin a new topic

thanks guys

 

9 or 10 psi.

 

Get the motor and get the car running first...
Then we'll talk about what you can or cannot do with it.


-Ted

 

I agreed ^