pyscho7

I have a 88 se and i am going to be tearing the engine down shortly, and i want to do a street port on it while the car is down. i am wondering, how much horsepower should i expect if i do a street port on my rx7?

I have heard of using a ITO or PP port but am not to sure of the differences and gains. so maybe if i tell what i am looking for ya'll can help.

i dont care about idle, as long as it doesnt stall out, i'd like to have an increase in power top end, no more then 9k.

can anyone give me some tips or advice about this, i am still new to rotaries, and have not done porting on my previous vechicles

MisterMatt

it all depends on your intake and exhaust setup. I have a streetported 13b with a holley 4 barrel, header, and free-flowing exhaust, and it's putting out around 225 hp at the crank... but with stock induction and exhaust, you're talking to the wrong guy...p.s. my redline is 10k rpms, and my idle is about 1.25k rpm

fcdrifter13

There was a site that had all the + and - to all the porting methods. PP is not recommend for anykind of street driving i do remember that at least.

pyscho7

thank you, that is what i am looking for, i think im probably going to look for a while to see what porting best fits my setup. i plan to get rid of 2 of the 3 cats and my buddy says he can hook me up with working on the intake system, so hopefully all goes well

C. Ludwig

iTrader: (27)

On a six-port there isn't much to be gained from porting. There isn't enough meat on the primary port to go much bigger at all and the timing of the secondary is already screwed toward very late opening. Do some reading here... http://www.mazdatrix.com/faq/port6p.htm

The basic consensus is that if you have the engine apart anyway go ahead and port it. But it's not worth tearing a good engine down just to port it. FWIW we make 175rwhp on stock ports and stock injection in our ITS racecar. That's a pretty common number. So that's somewhere in the neighborhood of 205+ crank hp.

C. Ludwig

iTrader: (27)

Wow...4am posting owns me. I meant to say that the secondary port is [i]skewed toward late closing[i/]. And actually it's not really skewed. It was has a very late closing line compared to any 4 port engine.

diabolical1

iTrader: (3)

since you'll have the motor apart anyway, porting is definitiely a worthwhile endeavor. it's worth a 10 to 15% increase in power when done right and you retain full streetability. just keep in mind that you will have to augment your setup with a full exhaust system and decent intake (meaning, less restrictions).