Hey I need some advice on ungrading my FD. I'm getting a KDR motor street-ported with reliablity mods and I getting a SST downpipe, high flow cat, and HKS exhaust, intake, and eventually bigger radiator and intercooler. With these mods do I need to also upgrade my ECU or fuel pump? My car is a 1993 touring automatic. If the ECU does need an upgrade does anyone know somewhere that works on upgrading an auto ECU I don't think M2 does it well any advice will sure help thanks guys.

 

I have every thing you do (just different brands) EXCEPT the High flow cat and run just a stock ecu and 10-11psi boost - as long as you limit boost to 10-11psi you will be ok - after that you will need a FUEL PUMP and Raising rate Adjustable Fuel Pressure Regulator to add some fuel (12-13psi boost) and for any more than that you WILL need an ecu - to keep the full function of the auto you will have to use a PIggyback unit (like PFS/EFI Purple box), piggyback the Apexi PFC, or wait for the AEM ecu. Also rember that the Auto is only good for about 350fwhp so if you plan on staying with the auto you will have to upgrade it to run more than 12psi boost

PS with the high flow cat you will probably need to port the wastegate to be able to keep boost under 11psi

 

fwhp? Looks like somebody's been surfing clubsi too much

You only need to port the wastegate with a midpipe. With a highflow cat you won't experience boost creep because of the backpressure.

 

^Flywheel horsepower.

 

350? really?

 

350 at fly wheel is much less at the wheels ^^

 

check out my sig. keep it at 10 psi and no ecu upgrade needed. I've also added a bonez highflow cat and still no problems. "The Key is the 10 Psi rule".. and the auto trans can handle 325-350 HP just have it serviced with a good synthetic oil and you will be fine. with your mods you will be well within the HP rating for the auto trans. as long as you keep it at 10 psi.

Jeff

 

So what exactly is the problem with the auto trans then? Is it oil temp or a parts issue? Just curious as to the weak link of the FD auto trans.


I think there's a general rule of thumb that the difference between auto trans flywheel and wheel HP is about a 10-15% loss.

 

also save your money like I did and put it into a set of 4.33 gears. its the best upgrade for the auto cars. makes it a whole new car. more power to the wheels and quicker shifts

Jeff

 

LOL Jeezus resurrected a 5 year old thread!!!

+1 on the 4.3 gears.