1uz On NOS?????

[BlownV8]

A quick question for those in the know.

Building up and engine for my car, and would like to know if this seems realistic.

1uzfe with 8 throttle body manifold. Probably the one from tmiller in NZ as seen on this forum. EMS of Austronic or similar ecu, stock bottom end, 91 thou copper gaskets as adverised on this forum, modified cams to suit, and maybe a little port work on the head plus 150 shot of nos. Planning to use direct port wet system.

Any comments, or will i need to go forged pistons and a full bottom end rebuild. Only after about 500 - 550 HP at the flywheel.

Also, turbos and blowers will not fit under my bonnet.

ADAM.

 

[Miles B]

Why do you want to lower the compression ratio?

 

[BlownV8]

My understanding of NOS is that like other forms of forced induction eg turbo, blower, you need to lower comp ratio to avoid detonation. I would be replacing the gaskets any way so they were up to scratch for the nitrous, and was thinking that a lower comp ratio with gas would be the way to go.

Is this not needed?????

 

[Miles B]

Any car I've ever seen running a small shot like that has stuck with the stock compression ratio. The reason you drop it with forced induction and not n2o, is that n2o cools the intake air, and apparently sucks more heat when it splits into nitrogen and oxygen. That's enough to avoid detonation with a small shot. FI, on the other hand, does nothing but heat the intake. Of course you should look for more opinions than just mine, but I have seen many a big block with 200+ wet shots on 9.5:1.

And since the rest of your work is NA, why shaft it all by dropping the CR?

I wouldn't even bother taking the heads off. The gaskets should be fine. If you blow your motor, another one from a wrecker is cheaper than pulling the first one apart. The motors are strong enough to do 800hp in boats with blowers and thick head gaskets. I've even heard of boats running methanol, stock everything, blown, 600+hp.

 

[BlownV8]

Thanx for the info Miles B
Sounds Fair enough.
Has anyone else had experience with nitrous on these motors

 

[jcm3]

re

Im running a 100 shot nitrous system w/ msd window switch set at 3000 and 6000 rpm. Ive changed the plugs to one range colder and gapped them down to .040". Also changed the fuel pump to walbro 255lph high pressure. Car was running great but is having a hard time upshifting at 5500 rpm when im spraying. When off the nitrous the car runs great.