heyall my camaro has a 1986 305 TPI engine in it, and the RPMs stop increasing after 4500 RPMs. the gauge can go to like 74 or something, but the car just redlines at 45. i have the stock air intake. could that be the problem? if so, would it be beter to like drill some slits into that pastic y-shaped piece that gives air to the MAF sensor and plenum, or should i invest in an open-element intake? how much are those? what are some good ones?

ke:rockon:

 

It's not the air cleaner, it's the TPI design itself. Only option is aftermarket runners and base, Superram or Miniram.
The Miniram isn't for stock 305's though, it's best suited for a mild 350 and up. Only drawback is the price, $1200-1500.

I have an alternative, the LT1 intake. It's less then half the price of the Miniram but still needs a mild 350 or better for peak performance.
http://www.LT1intake.com

 

are you saying you can't rev past 4500 no matter what? if so then you have a problem. you should be able to rev to 5500 or 6000, now i'm not saying you will make power up there but you should be able to get there. i would do a good tune up on it, plugs, wires, cap, rotor, fuel filter, oil change etc then see what happens.
Andrew

 

Don't drill holes in your intake ducting. Even if the added air helped, it wouldn't help much. It would be turbulant, unfiltered air. Bad move.

 

No, I am saying it won't pull past 4500rpm with a stock TPI.

 

i was asking the original poster, but thats ok. yeah it falls on its face after 4500 rpm

Andrew

 

you say it falls on its face at 4500rpm's, is that with the stock cam, or any cam? thx, tom

 

the torque drops off really fast after it peaks. the hp ends up leveling out for a little then dropping fast. what that means SOTP wise is you get no more pull after 4500 rpms. with an aftermarket cam you can help this as well as the different runners and headers.
what it is is the intake is tuned to make peak torque low and what that ends up doing is making high hp hard because it can't breath at a high rpm.
you can still make hp on up to redline but it won't be substantial and you may be able to benifit from shifting before redline
Andrew