How high can you safely go for the street? I have heard anywhere from 11.5:1 to 12.5:1. How much of a power difference does compression actually make? I dont feel like running race gas all the time, or retarding the hell out of my timing. What compression should I shoot for?

 

Depends on how much power you want to make.

 

many of my friends and I run over 12:1 compression with base timing above 16 degrees and computer programs with advanced fuel/timing maps on pump gas with no detonation problems...and it will help with power output as long as the car is tuned properly.

 

I'd say with larger cams(like Spec B) you can get away with more compression. Because on those big cams, you lose a lot of compression through their long duration.

I'd say 11.7:1 is optimum for ITR cams or Spec A's.

 

Mike K ,

What would you recommend for JUN stage II cams ?

 

I have read that for every point of compression you gain 4percent over stock power wise, but this is just a rough estimate. I have heard of 12.5:1 compression but only on race gas...I would also say get a bigger cam like spec b's or Jun stage II or III and raise comp to about 12:1 or 11.5:1

 

I want to run spec C's or the eqivalent. Probably a 2.0 stroker motor, I wanna put about 230-240 to the wheels. This car isnt gonna be half *** built, I wanna pull ewverything I can from it.

 

Im running 11.8 compression with Toda Spec B's. Have no problems so far.

 

I've ran over 12:1 in all but one of my cars and had no problems. Proper tunning, good gas and your good to go. Breaking in my roomates 12.6:1 GSR motor now on 100 octane and should be able to tell you in a few weeks how it runs tuned on 93.

 

cool, keep me updated.

 

huh? where'd you come up with that?

D

 

I think....

The valves are still partially open on the compression "up" stroke, and that will lower compression because the air is flowing out instead of being compressed.

 

hrmm

"All TODA Racing camshafts must be tuned using adjustable campulleys to attain maximum performance."

Will