Boost on a Novi 2000?

[doohboy89]

I have an 89 lx with tfs heads, tfs intake , B-31 anderson cam and 42lb. injectors. I was wondering how much boost it is suppose to make. I know the specs say 8-10psi. But I am making between 5-6psi tops. I has the stock pulley sizes. Other than that it has been working great and pulls really hard with that psi level.

[FoMoCo1]

check the fittings on the boost guage you make have a small leak somewhere.....

[silvergts1998]

Your heads are flowing probobly prety well...and that is most likely why you are seeing loss in PSI plus you maybe experiencing belt slippage issues also. If your heads were open up, have headers, larger exhuast pipes..not cats whatever...it will cause boost loss.

[frdfandc]

When a supercharger company advertises boost numbers, its when they install a supercharger kit on a stock motor. Since you have TFS heads, your boost numbers will be lower since they are flowing better.

Boost is just a restriction indication.

[silvergts1998]

When a supercharger company advertises boost numbers, its when they install a supercharger kit on a stock motor. Since you have TFS heads, your boost numbers will be lower since they are flowing better.

Boost is just a restriction indication.

Also remember that what the stock heads sees in boost and you put on heads that flow better, you may not see too much more gain in HP depending on the set up. So if your stock engine see's 10 psi of boost and then you bolt on heads that flow, you might see 7lbs or so, but now if you go with a smaller pulley and your engine see's 10 psi with the heads, then you will most likely make more power...plus if you lowered your compression with the heads, it will make the boost safer and allow more air and fuel.

[slow91]

psi is measure of backpressure, so when you open her up with high flow heads..etc you will see reduced psi but blower is still flowing same cfm. you still get increased hp from the better flowing heads with lower psi.

[silvergts1998]

I agree with slow 91. My response is confusing. If you open the heads up and don't change the compression ratio...then yes...slow 91 is right.

If you lower the compression and port the heads...it will take more cfm to fill the heads and when it see's the same amount of PSI that a stock head does, this will result in alot more HP. maybe what I am writing is still confusing...

[slow91]

I follow. changing to hi-perf heads and dropping compression will not give you as much of a gain given the same blower setup, but does give you the capability of going pretty wild with the boost.

[Promach1]

I'd say your belt is deffinatley slipping! I was seeing 10-11psi running stg.3 ported TW's, e cam & holley systemmax2 intake. When I first got it running I was only seeing 6-7psi untill my buddy pointed out chunks missing out of my belt ribs, I put a new belt on nice and tight.....10-11psi...We have liftoff!!!
Good Luck!