Building 402 for nitrous, do I want high or low compression?
Will only be spraying at the track (for the most part). Considering doing the SLP 402 motor, low compression is 9:1 and high compression is 11.3:1.

I have heard that nitrous loves low compression, but in the same thread someone posted that nitrous loves high compression

whats the verdict???

 

If I was building a race motor for nitrous I'd definitely go with the higher compression. Are you changing your mind about the 427?

 

Nitrous LOVES high compression! Boost likes it low. Get as high as u can and still run pump gas unless you have a track only ride. So your 11.3 would be great.

 

Actually low or high compression will work well with nitrous...but for a MAX effort nitrous motor, stick to somewhere in the 10.5:1-11.5:1 compression range...its alot easier to get away with no detonation on big units (300+) compared to 13:1 type setups...

 

thanks for the replys guys, i will stick with the high compression
next-yea, i scrapped the 427 in light of the new SLP 402 pkg . . much much much cheaper and just as good of a motor (for the most part)

 

I haven't done any reading on the slp 402. Have you talked to any sponsors over there about options >>>>>>>

 

The more compression you run the more important tuning becomes. There aren't many people in the country that can safely tune a 14:1 nitrous motor.

 

I'm gonna stick to 12.5 to 1 on my new 408, and the direct port kit. I won't be running pump gas, high octane unleaded motion lotion only.

Get the higher compression motor, and be damn sure to either O ring it, or use Cometic gaskets if you plan to spray it.

 

I almost think its a secret people dont realize, to run lower compression and more nitrous...

Ive had a few hondas on my dyno with 8.5:1 compression with 250 shots on them...its unbelieveable...yes they gave up 20-30hp with the low compression, but now they are running 100 unleaded on 250 shots on 4cyls.....

 

I guess it all comes down to how bad you want to make more power.

 

Then why do SSO cars that still use nitrous use lots of compression? If you're going to keep the thing a street-car, stick between 11:1 and 11.5:1. If you're building a race-car, you can start thinking about using 12:1/12.5:1/13:1.

Like I said before, it depends on your tuner.

 

It depends on how much torque/CI (IE: HP/CI, but normalized for RPM), and what kind of fuel.

Nitrous can cope with higher compression than forced induction setups because it doesnt add as much heat to the incoming charge and because there is negative parasitic loss. As such, it is less succeptable to detonation, but it is not immune.

The fact that you're running a 402 is a key piece of information, but in order to give an informed answer, you will need to divulge more about the torque curve. Which, of course means building it to see