bigdave8301

I've got an '89 Formula 350 WS6 that I've had for a couple of months now, and although I love the ol' girl, she isn't the quickest thing around. Most of this lies upon the fact that it being a TPI car, it dies after 4500 RPMs. Don't get me wrong though, on the way there it's a hell of a ride due to the sheer torque, and she comes out of the hole like a scalded dog. However, the car's dynoed for what, around 330 ft./lbs. of torque and around 230 hp? To make a long story short, I need to improve the top-end, but what exactly can I do without going up to my genitalia in debt? I was thinking about lower gears, but it's a 9-bolt Borg and Warner with 3.27s and due to the hassle I'm leavin' 'em alone. Right now the transmission just got rebuilt with kevlar clutches and the Corvette servo, and it's got a B&M shift-kit, K&N air filter, and a racing chip. The engines still as healthy as a horse *knock on wood.* Can ya please help me?

grumpyvette

it all has to do with letting the engine breath , youll need to figure what your budget can handle but a good cam with around 215-220 degs intake and 220- 225 degs exhaust duration on a 112-114 LSA, headers and a good free flowing intake system like the steath ram will make a huge improvement, the heads can be ported or replaced with much better than factory heads.
the cheap route would be to port the factory intake,(base,plenum,&runners) and the heads and add a good cam, both CROWER and CRANE have excellent cams for that application, just the cam and porting alone should get you 700-800rpm and 50-60hp if done correctly. btw if you can find some SLP siamese runners and remove the divider in the upper 2" and port the plenum to match so theres no divider from the plenum entrance in the runners for that first 2" in the runners it helps
look here, do not remove the divider in the base as it does not help it only hurts performance, believe me Ive tryied it both wayshere,this site gives you good pictures of porting the runners
https://www.thirdgen.org/newdesign/t...meseport.shtml

but dont get carried away ONLY PORT THE PLENUM AND THE FIRST 2" of the siamesed runners, leave the divider in the rest of the manifold and runners, just inlarge and smooth the lower runners and ports in the base do not remove the divider in the base as it does not help it only hurts performance, believe me Ive tryied it both ways, what your trying to do with the porting is increase the air flow potential, what your doing by useing divided runners that are siamesed and ported is to shorten the intake port length, together with the increased flow the shorter runners raise the rpm range and the ported plenum and first two inches of the runners adds to the plenum volume (makeing basically a SUPER RAM style port length and volume to some extent) this combined with a cam like mentioned above greatly adds to the beathing potential of the engine over the stock TPI system, now theres no way these mods will come close to equaling what a HOLLEY STEATH RAM can flow BUT IT WILL HELP a BASICALLY STOCK TPI
"matching roller cams that work"
crane #119821 hot street
crane #119831 very hot street , requires headers/2500 stall
both require head/spring clearance/checking mods

matching FLAT TAPPET HYDROLIC CAMS
crane #114132 hot street
crane #114142 hot street, headers required/2500 stall a good idea

tpi_roc

Get some lift on that cam mentioned above and im onboard, thats exactly what you need, any of the LTR-TPI setups just aren't going to do what a short large runner will. So either the HSR, LT1, super or miniram will do you great, because we all like money I recommend the HSR and LT1.

bigdave8301

Thanks for the pointing me in the right direction. I'll have to look for some siamese runners on ebay. So I should go with an LT1 intake setup for great performance? When I get the engine overhauled I'm slapping some headers on it but not until, because I'd hate to pull the engine just for that. I'm getting a stall put in it now, a 2500 RPM. Could you please post a link to whichever one of those cams is best? And I'd like to avoid computer work if I can.