On an 87-88 TII engine configured to generate 400-425 crank HP, can 9.4:1 rotors be used to generate that BHP reliably on just 91 octane and no auxiliary injection?

 

talk to Aaron Cake

 

It'll do it reliably for awhile.

If you want reliability for a long while, inject H20

 

I ran the high-compression NA rotors in the last S4 TII motor, it made 380 some-odd whp @12psi on e85. Did not really need to use e-85, but I do anyway.
AI will help on the higher compression motor, however there is no substitute for simple accurate tuning of the engine and proper maintenance. How long the engine will last is usually directly related to how lazy or stubborn the end user is. Stick with a crappy EMS that you are constantly having to fiddle with, fail or just dont bother to pay attention to the upkeep, or simply ignore the boost control etc. and it wont be long until something dramatic occurs.

 

Thx. Very impressive whp#s @ 12psi!

 

My last setup was 9.4 rotors on 87 octane /stock turbo and rtek2.1 lack of fuel in 4th gear in the winter=rebuild i really just fuel added in up to about 11 psi, should mapped the hole thing higher.. going to fd twins with i guess 9.4 rotors again, can't get a good deal on some 9.7's.... wheel sea.... i'm using a tweaked version of one of arghx's maps( less timing over 3 psi). need to get something to measure knock better then the stock sensor.

 

this is why I love NA, im a cheapass. I may not make as much power but I flog my engine prettty hard generally all the time

 

I'm putting parts together for a high comp turbo motor now...I have one 9.7 rotor that I know is good. I'm wondering if I should look for another 9.7 or sell it and get some 9.4's ?