I have an extra TPI setup for my car laying here in my garage, as we type....I was wondering if porting the base, and plenum would be a better gain in HP than getting the TPIS Big Mouth intake....TPIS said it would, but of course...they want my $$$, and thoughts?


Zach

 

ANyone?

 

if you don't care to sell it just give it a try and see how it feels to ya.
i don't know anything about aftermarket bases because i haven't tried them
andrew

 

I like the edelbrock TPI manifold that I have. It made a noticeable amount of increase and could probably increase even more if you port it out. The edelbrock one will definetely out flow the stock TPI base. As far as the TPIS manifold, I'm not familar with it. You can siamease the plenum with a set of SLP runners and it'll be good to go. Once in a while SLP will run the siamease runners for 199.95, but I haven't see them at that price lately. The edelbrock base is about $355 from summit racing. The part number for 90-92 is #3860. I think the other one is 3861.

 

When u say the edelbrock base with flow more than the stock base, of course it will if the stock base is not ported, but if the base is siamesed, will it flow more than an aftermarket base, regaurdless of brand....Will porting my STOCK base produce more than an aftermarket base UNported.


Zack

 

Yes a stock manifold ported will outflow a edelbrock, unported. I've heard that the accel superram base is a ported version of the edlebrock manifold. so if you compare a ported stock base with the accel base, the accel would flow better, but who would pay $660 for a tpi manifold? I would highly recommend you porting the stock manifold base if you don't have the money for the edelbrock base. If you do get the edelbrock base, and you port it, it'll make the car real happy

 

The tpis bm is just an edelbrock base ported. Save yourself some money, dont use tpis.

 

I'm assuming you don't have TPIS's Insider Hints. In the book they claim the best they could do with a ported stock base is 14 hp on a motor with ported heads, cam, and runners (4 hp on a stock motor). Apparently the floor of the intake runners is too low, and there isn't enough material there to correct the entry angle and enlarge them to improve flow.
You really are better off with an aftermarket base. They all (TPIS, Edelbrock, Accel) will give you roughly the same performance so let the dollar decide.

 

Funny that TPIS would mention the low intake floor... the Big Mouth base doesnt fix that problem.

 

Well i guess I'm a bit confused now...some people say go with TPIS, some people say dont....I guess I'll just port my base (free, aside from tools used), and see how that works, if it does'nt give me adiquit gains...I'll try somthing else....but I can't loose when i've got an extra TPI setup here...

Zach

 

If you are going to get a base, I would go with the Accel or maybe the Edelcrock. The TPIS base is just a ported Edelcrock base, plus $100 for porting it. I guess you have to decide if you wanna spend that much on having them port it for you. Also keep in mind there are more issues in the TPI setup than just the low floor or the base. In general, the design is severly lacking in what I will call 'finishing touches'. I'd really like to get my hands on an older base thats no longer made, someone here picked one up, made by a company or something called First. At least it was obvious from the pics that they addressed the low floor. Havent seen one for sale though.

Start with porting your base. Its not all that hard with decent tools, and you should get some pretty good results from it.