A good friend of mine has a 1995 Z28 a4 bone stock on a NOS wet efi kit, tr6 and as soon as you gas it on spray it detonates bad all motor its fine but even on a 50 shot it detonates. What could the problem be? I cant figure it out . Unless some LT1's came from the factory with A LOT of timing.

 

What do you have the gap set on the plugs. Had similar problem on friends car and set the gaps at .35 and all was good. Could be fuel or timing also.

 

gap is set at .39 im thinking we should try race gas

 

check the fuel delivery through the wet kit,
or better yet, add the fuel through the injectors.

 

Sounds like the fuel is not getting in

 

try the race gas first. if that works look at getting a timing retard. the opti may be getting ready to take a dump also, or its vacuum system is clogged. maybe try a seafoam treatment to clean the combustion chambers also.

 

Sounds like jetting may be wrong. Did you put the correct jets in and also in the right location?

 

I would recommend checking the jetting, checking the timing, inspecting the opti, and checking the fuel side of the nitrous system to make sure fuel is getting through the nozzle. Also, lower the gap on the plugs to .035".

What do the plugs look like? Also, if you can, see what the knock sensors are doing when you use the nitrous. Sometimes people think they are hearing detonation when it's really something else in the engine.

 

Im waiting for him to get some more money so we can buy the race gas.

 

Im waiting for him to get some more money so we can buy the race gas. I got the car jetted at .52 nitrous .36 fuel

 

That jetting seems to be bit rich, what is your fuel pressure.

 

Definitely check the fuel pressure. If the car still has the stock fuel pump (especially with a lot of miles on it) it is probably time to upgrade to a 255lph pump and put in a new fuel filter.

Dave

 

If 50hp is causing it to detonate then you have to not be getting the proper fuel if any. The stock fuel system should support up to 100-125 with no problem. Take the fuel line off the nozzle and put it in a bucket. With the nitrous bottle off activate the system and see if fuel is there. If you truly detonate it bad enough to hear it while it's under load you'll hurt something on the stock motor. As Jeremy said you might want to log it and make sure it is knock.