i hear TPI is good for mid 12's when fully built.

But with fully siamesed/ported SLP runners and aftermarket base of somesort and matched plenum, larger TB, and proper suspension, is 11's possible?

Cuz several superram cars i know are in the 11's on 383's and close with 350's. Can TPI be ported out to flow to 5500rpms on a 350-355? i am interested in keeping TPI but may go superram or new BBK intake depending on what it looks like. LOL

 

I could run the same times shifting at 5300 or 5700 on a relatively mild 355 with a fully ported stock base and plenum with SLP runners with the dividers removed to about the ½ way point. I could not hook the car, but it ran 13.0s at 110mph with 1.9 sec 60s in 88 degrees (86 IROC with 3.23 gears). That set up could have run EASY 12.4s with traction in 60 degree weather. The heads only flowed about 235cfm at cam lift so I could see that intake system running 11s on a 355 with heads in the 260 range with a better “TPI” cam and a little more converter.

How fast the car goes depends more on the combination, than JUST the intake system. An engine with the potential to run 11.0s with a MiniRam or 11.20s with a SuperRam will still run solidly in the 11s with a modified LTR TPI. The heavier the car, the smaller the cam, the smaller the converter, the less the gear ratio,,, the closer the ETs will be for the long tube runner system.

 

I think people sleep on the STOCK TPI more than they should.

I am currently on a mission to try and get into the 12.7 range w/ a completely stock tuned port setup.

I went 13.39 @ 102 w/ stock TPI and stock exhaust manifolds, stock converter, and a 125K mile tranny. Next comes the Hooker LTs and a 3500 stall Vigilante converter... We will see what it does...

 

Why in the world would you put a 3500 stall on a stock TPI setup? Your effective RPM band would be 3500-4500 and you'd be launching over your peak torque point?

 

Ah nm didn't see the cam in that sig

 

Why? What are you going to prove to who? Everyone knows if you throw enough money at it you probably can do it. Now run 12.7's on $500 worth of mods, that's something impressive.

 

I remember this came up once before. It was either on this board or at CamaroZ28.com. Anywho, at a corvette forum, a guy was running a 383, solidly built (sorry don't remember any specs) and had a miniram on top. Something came up and he had to switch to a stock TPI system, and he ran like 11.8 or something. I will try and find that post if possible, but trust me it's real....in a y-body. I haven't seen or heard of any F-bodies doing it yet.

 

thanks. I am trying to decide on wether i should just fork out the cash for superram when it comes time for the motor or just built TPI up. I want to be close to 11's with a 355. i know superram/219 cam and tunning will get low low 12's where i will be happy with for most part. i could do the TPI system with SLP runners probly for cheaper than superram. superram used is like 700-850.

ebay has slp runners all the time and i missed out on several deals for 200 or less. bases are like less than 400 so its a TPI setup for 600-700 bucks, a bit cheaper than used superram but easier to install and deal with. LOL

 

Whats the cam have to do with it?

You know, I was stuck on the retard wagon for a while too. even though all the books (including lingenfelters) said TPI IS DONE AT 4500, I didn't believe it. I thought everyone was crazy.

Anyway, after 3 years the TPI setup (all aftermarket, siamsed, ported, hell I tried everything) went on ebay and I built a singleplane holley manifold into EFI. Started reading about intake manifold design, bought more books, talked to guys who have been doing this for 30 years..

With that ONE CHANGE, I went from high 12s at 110 on slicks, to 12.40 @ 119 every pass on street tires.

What's even funnier, I detonated 2 cyls and broke the tops of the piston off. (the singleplane manifold suddenly meant the injectors were too small!) I continued making passes in the mid 12 second range at 114-119mph. After the season was over, tore it apart and was SHOCKED how well it ran.

I'm at the point now, when I see people talk about how "wonderful" TPI is, and how they're gonna built a "torque monster" i'm like. "for what, plowing?".


-- Joe

 

Very true. Even my 305 loses power after about 4500RPM. I can rev it to 5500 without trouble in 1st gear, but after 4500 it doesn't pull as hard. I could only imagine in a 350 where it just completely dies at 4500.

LT1 heads/intake is getting closer and closer to reality!

 

I'd go with the HSR before an LT1.

-- Joe