Effects of compression ratios

[Pablo]

I'll have to agree with Don here on the Nitrous assistance.

I run a 150 wet shot on a completely stock longblock (exc. valvesprings) with a 66mm turbo.

It comes on at WOT 2800 rpm, and shuts off at 16 psi. The difference between a nitrous assisted turbo spool and a non nitrous assisted turbo spool is nothing short of breathtaking. Using this method I hardly use any nitrous either. The nitrous is only on for a fraction of a second.

The tuning and setup is quite simple if you are using an aftermarket ecm or piggy back like I am (the GenII translator) with my GenII the entire nitrous activation, timing retard, and nitrous de-activation is all automatic. If I wanted to, I could even run a dry shot because the activation window allows me to add any amount of fuel I wish. Everything is then ultimately corrected to whatever AFR I desire as monitored by the wideband.

If my CR was even lower than stock I would still have plenty of spool with this setup.

 

[Alky V6]

Except boost and CR on a good tune.:biggrin: I would understand if he said he was going to run over 9.5:1. With his goals i doubt he would ever be able to achieve enough boost to hit the detonation limit which would still be in the high 30's with c16 and proper tuning. I dont think the wastegate would ever be able to deal with the backpressure of a 3 bolt setup without throwing A LOT of pressure behind it to hold it closed. 30 psi on 9.0:1 is very common on any hard running engine these days.

I agree with you completely. I doubt he's going to be running C16 all the time, though.

 

[Alky V6]

If my CR was even lower than stock I would still have plenty of spool with this setup.

Sounds like you got the setup. Good for you.

Pinching the CR to the edge is not even the slightest concern with a nitrous setup.

 

[bison]

I agree with you completely. I doubt he's going to be running C16 all the time, though.

Yep. He wont be running over 20psi all the time either.

 

[Alky V6]

Yep. He wont be running over 20psi all the time either.

For his sake, let's hope not. Otherwise, he may find a good reason to lower the CR with his next engine.

 

[karolko]

well i am planning on having the street boost set to 20-24lbs.

 

[Alky V6]

well i am planning on having the street boost set to 20-24lbs.

There will be no room for a mistake. Run out of alcohol for just a moment and you will regret it.

 

[bison]

There will be no room for a mistake. Run out of alcohol for just a moment and you will regret it.

Yeah. One second and your engine is done

 

[karolko]

trust me i know. that is how i killed the first engine. 250+km/h and all the alcohol splashing to the back, PING and she was done!!!