If I had a plenum ported for a stock TB/Runners, would I be wasting time and money? I dunno if I should have my plenum ported or not.

yes.

Save the $$ and get the bigger base to go with.

The base is the restriction... remember that.

Andy what do you mean by a bigger base? What base would I put on my 90?

by itself its waste, need bigger runners and a ported or aftarmarket base.

there are four parts to the TPI intake.

The base.

The runners (2).

The plenum.

The base is just that, the part that bolts to the engine. The ports are just too small to be effective. You have to realize that the TPI was designed for the 305! It was simply bolted to the 350 and the rest is history!

think about that... an intake designed to support a 305 is expected to feed a 350.

Edelbrock and Accel offered an upgraded base. Infact, it was an Edelbrock base that Accel used on their SuperRam intake.

Now, the bigger runners... they are very important with the bigger base. No question.

The stock Plenum isn't so much the problem, but some cleanups won't hurt one bit.

You can port the stock base, but there isn't a lot of meat... pearce it and you might be seeing water.

This is something to think about:

The Corvette C5R and C6.r both use the 7 litre Katech variant of the LS1. Lord knows how much LS1 is left, but they had to start somewhere...

With the restrictors, about 1.37" each (1 for each bank), they were limited to about 620hp.

To get that power, they recammed it and dealt with the stall (think air going too fast) restricted intakes, the engine runs within the RPM range of 2900 to 5400!!!! According to Johnny O, if the engine was uncorked, it would be over 900 HP!.

I can only imagine what the torque must be like.

Quote:

While I can't say you're wrong on this point, this wasn't the case when I held each of them and looked. The 1st time I saw an aftermarket TPI base it was an Edelbrock at Jeg's.
I noticed it had a casting # on the bottom to represent the
generic series of casting it was made from.
The 1st base I bought was a big mouth from TPIS. I recognized the same casting number and looked around on the net for an Edelbrock. The #'s were identical, so for that much I agree with you. After reading some threads claiming fitment difficulties on the edelbrok/TPIS parts, I sold my TPIS and got a Superram base. It's definitely a different casting than the others. So from my experience, they aren't all Edelbrocks. The exception to this being that the Superram bases sold new for the last couple years ARE Edelbrocks due to the production issues at the plant where the s/r was being made.

Bob -

I think you nailed it... there were some strange bedfellows in this biz back in the day.

I suspect somewhere between what you say and what I say is the truth.

The next time I run into Vic, I will ask... if he still remembers! or even cares!

Quote:

There is a lump right behind the throttle body that many port out in the plenum.... other than that, there isn't a lot you can do with it. Having said that, I've never heard of it hurting to port it, thus it probably helps just a bit.... but just don't expect to even feel the difference.

I think the others are right, get rid of the entire system and go aftermarket. I recommend abandoning the Long style runners all together and getting something with shorter runners.

good luck !

TPI runners are 19" long!!!!! The LT1 runners are like 4" long...

Last year I put a Superram on my mostly stock w/headers
Vette. I know the headers did alot, but I'm truly impressed with my SR. The butt-o-meter tells me it's pulling as well or harder, plus it's pulling well into the 5k rpm range before it drops off. No more 5k wall.

Now all you need is roller rockers... the stock stamped steel rockers are absolute junk...