well after playing with lt1 and ls1 I had a tuned port fall in my lap. I figured you guys would know the answer to this. I have a 65 nova ss with a 383 vortec heads and gm hot cam. I was just curious how much horsepower difference the tuned port would make over the edelbrock 750 and weiand stealth manifold. I'm thinking I would lose some power but not sure how much. I really like the looks of the tuned port over any othe efi out there. I downloaded a picture of the intake I bought

thanks in advance

Shawn

 

You would have a boat-load of tire-shredding torque from idle to about 3500 rpms, and then it would start choking and run out of breath around 4500 rpms. If you dont do any racing, it would be a blast to drive on the street.

However, a 383 engine needs to breathe, so a Holley Stealth Ram would be a better choice than a stock TPI unit.

Otherwise, if you want to keep the look of the stock runners, you'll want to cut them open and siamese the runners to shorten the runner length. That's the secret to getting TPI engines to breath and make horsepower.

 

Plus the Cam. is designed for 7000rpm. So your combining a high rpm cam. with a low rpm manifold.

 

would switching to a different manifold and bigger runners help it breathe? I will race this a little but it's mostly a driver/show car and the chromed out intake looks trick

Shawn

 

Bigger runners dont do nearly as much as shorter runners. That's the key. Shorter runners equals higher rpms and more horsepower.

I dynoed my current engine with a set of TPIS large tubes, it made 318 RWHP at 4800 RPMs. Then I switched to a set of fully siamesed SLP runners, and it made 355 RWHP at 5300 rpms, and carried that 350+ RWHP to 5800 before falling off.

 

what's your current set up?