Putting together a 4port 13B with 12A plates and SE rotor housings. Should I just use the SE rotors and call it a day or a set of S4 rotors. Are the compression ratios the same? The s4's are suppose to be lighter right? Just trying to get every little bit of HP!

Thanks, Ed

 

The TII rotors are higher compression.

 

I belive the compression ration is the same but the s4 rotors are deffinately lighter. If you chose to use the S4 rotors, you would need to use a S4 front counterweight and a stock S4 flywheel, or a s4 rear counterweight and a lightened flywheel

 

The TII rotors are lower compression. 8.5 compression for S4 TII rotors and 9.0 Compression for s5 TII rotors.

S4 N/A rotors are 9.4 compression and s5 N/A rotors are 9.7 compression. All s5 rotors are lighter than the s4 ones

 

Blah! Brain fart. Sorry. I meant lower compression, but your post is more helpful because you actually know the numbers....

 

cause he just looked them up. ha has ha

 

I have been using GSL-SE rotors for many years with no problems. But I have friends also who prefer an 86+ as they are lighter.

 

Ive seen a ton of 89-91 motors at the junk yards lately I think I've seen about 5 within a months time. Even lighter rotors!

 

Don't the s5 engines have a higher redline, 8k, due to the lighter rotors?
They also have the highest n/a hp .

But, I thought I saw someone post that there is a slight difference between the shape of the s3 and s5 rotors, and that the s5 shouldn't be used in s3 houseings, anyone know more on this?

 

Yup except, Im staying away from them for now. I have the carbon 3mm apex seals already.

 

The Mazda dealer here can get Renesis Rotors (10.0:1 compression, apex seals, oil seals, all seals included) for 459 each.

 

Dude! If I had a thousand dollars..... american..

Jon

 

last I heard it was still up in the air if the renesis rotors and seals will last in a peripheral exhaust ported engine

 

I have been useing 87T2 in my RX7 for years with no problems and in my REPU I have 93 turbo rotors in it.

What do you plan on doing to this motor ????

Dan

 

the nice thing is if you put the turbo rotors in it when you start to get bored with it you can always turbo it. And if you get rotors that didn't come in the engine like was said before get the balance weights that match it so you can buzz it or send it out and have it re-balanced.

 

yup, no use spending more money to get them milled out for 3mm when the se rotors are already 3mm

 

Stay with the the SE rotors from 86up there is slight variance in the rotors and housings you don't want to put 86up rotors in 85 and earlier rotorhousings. Search around you can find info on it and I think the Racing Beat performance catalog talks about it also if you happen to have one. Some people still do it and say there is no problem to them each their own.