Redheaded stepchild, High Performance TPI project, Tpis base, stock TPI runners vs. ASM runners.

We take a step back and use a stock 48mm throttle body, 100% stock plenum, and go from 100% stock runners vs. Arizona Speed and Marine runners.

[@robmartin5382]

You undervalue yourself. You have some good insight Charlie.

[@servediocylinderheads]

Thanks

[@kylemilligan752]

It's cool folks want to keep hot-rodding the TPI engines. Ford svo/motorsport offered all kinda cool 5.0 parts, while GM abandoned the tpi guys. TPI guys had to buy relatively expensive aftermarket parts with minimal hp/tq gains. Way back when, tpi mods should have been headers/exhaust, 3000rpm converter, and then a performer rpm, and 650 holley. Would have made alot more fast 3rd gens than chasing the high $ aftermarket tpi bs

[@jonathoncouchey7151]

The magnum v10 has thr long tpi type runners with an upper and lower plenum. I wonder how much you could get out of one of them.
From factory they had to detune thr magnum v10 so it eouod blow up thr 48re transmission from all the torque. 488 cui

[@skylinefever]

What is the idle air control like in the TPI? Perhaps different years took different IAC valves. That is what the triangle came from.

[@Madmax.3]

The stock plenum is not to small for the ASM runners you will see when port matching them yes they are smaller but not by much, the stock plenum openings are 39-41mm the ASM runners are 41-42mm, the gaskets are much larger and not aligned to the actual runner openings

[@servediocylinderheads]

Theoretical plenum size for cubic inch is what we were writing about. It is a bit on the small size, if I remember from my engineering books. Thanks

[@Madmax.3]

@@servediocylinderheads yes these plenums are very small I think you'll find that opening the throttle body to one large mono opening and removing the divider where the runners are regardless if the runner aren't siamesed similar to your ported plenum will be the way to go. On extreme builds more of the insides get hogged out right down to the bolts bosses

[@derrelcarter9401]

I have a question, do the stock plenums have sufficent volume for higher HP motors with the shorter/larger siamised runners to raise the peak HP rpm limit?

[@servediocylinderheads]

A good question. According to some engineering books I read decades ago it is on the small side for good rpm. Thanks

[@jsomething2]

I believe I read some where years ago the bottom bumps had something to do with egr flow. I think the egr holes are right behind it?

[@jsomething2]

the triangle, I forget. doesn't that feed air to the ported vac nipple on the bottom by going up into the passage ways under the tpi plate? iac might be the triangle too.

[@hotrodray6802]

🔔😎
Whats the best way to get the crap out of the plenum/runners?
Hot tank?
Im thinking Explorer upper plenum.

[@servediocylinderheads]

It is a good question. Ultra sonic tank?

[@itseithergonnaworkoritaint7852]

🤔🤨🤷😁😎👍

[@juhanahuovinen]

Hi,
Im just thinking if the runner closest to the throttle body flows better with the tb exit angle?
-juhana

[@servediocylinderheads]

New info since I flowed this. It is in the Thirdge.org thread. Thanks

[@davidshields302]

@@servediocylinderheadsThe link doesn’t seem to work.

[@servediocylinderheads]

Not sure what you are asking. I think it flows less because it is very close to throttle body and needs to turn in a shorter distance which limits flow.

[@juhanahuovinen]

@@servediocylinderheadsI mean what is the function of the hole shape / why it has that cut? It looks like it has a "seat angle" that maybe directs flow to the less flowing cylinder.
-juhana

[@CrazyTony65]

I'm betting reversion.

[@jonathoncouchey7151]

First

[@clarkmcmahan1595]

Rough opening for throttle body waz done for alignment if it was done for reversion there would not be any steps at the opening that already create turbulence at the opening ..poor craftsmanship on those behalf