I have attached my latest TPI mods. Attached are the highly modified SLP runners and factory plenum. This will add about 30% to the plenum volume and help with the airflow with less obstructions in the way. Going to the Dyno Saturday to see what improvements I get if any. Allen

I would like to say that I was inspired by JerryWho, "Dyno Don" Lorentzen and Kevin Lorentzen who led the way with similiar sets of modifed runners. Those runners have been posted on 3rd Gen.

 

Modified SLP runner. The pair of runners on the left are fully siamesed. The pair on the right still has a portion of the divider left inplace. To much work to get it all out and not sure if it is even necessary to remove all of the divide with the runners being siamesed at the top and bottom.

 

Another view of SLP runner.

 

Yikes! Those are highly modified. They are double-siamesed at the plenum.

Did you modify runner gaskets for it or make your own?

What mods do you have to your engine to justify this mod? I would love to see the before and after dyno sheets for your engine. I hope you see some improvement.

 

Hi

Luckily the Mr. Gasket set works just fine with a little modification of course. The baseline is 283RWHP with my 700R4 transmission.

The basic engine mods are as follows. TrickFlow 23 degree heads. ZZ9 cam and 1.6RR. Custom cold air intake which I will post pictures of when I get my car back together shortly. SLP Tri-Y headers with dual cats and custom exhaust mandrel bent all the way to the muffler by Dyno Don. Running 10.5:1 compression.

What I did not show is the Edelbrock Extrude honed TPI intake manifold. The runner side ports are 1.70 inches as are the matched SLP runners at that point. Allen

 

Wont the air become very turbulant as it can no longer channel into the entry ports of the base? The dividers in the lower part of the runners are no longer there. Good luck . I hope there are some improvements.

 

That part of the runner is standard from SLP. The one on the left is untouched from the factory except opening it up to 1.70" diameter to match the Edelbrock TPI manifold. The one on the right is also virtually untouched from the factory except making the divide(siamese) deeper. Again opened up to 1.70"

These are the early style SLP runners. They are different from the kind you buy today. The turbulance will be minimal as that is the thin part of the divide between the ports on the intake manifold.

IMHO there was more turbulance from the air making a sharp 90 degree turn from the plenum to the individual runners. This is now gone and made into an extension of the plenum. Allen

 

Kind of a small T-ram in a way except the runners go out of the T extensions... COOL!

 

I want some pics of the extrude honed base(believe its a edelbrock by what has been posted).

I seriously hogged out my runners and basically cut out 3 inches from the top of them(slp's also) and debated doing something similiar to what you have done. Was looking for some more plenum volume and airflow. Now since I'm running the 383 w/ tpi, I'm reexamining it again too. Guess I'm not the only one who has problems putting down the die grinder when I get going.

I still dont like the fact that they are siamesed again at the bottom of the runners and then go back to individual runners at the base. Doesnt seem like that would promote even airflow.

Would love to see some flow numbers on those runners vs. stock and with it connected to the base.

later
Jeremy

 

I had the Edelbrock base Extrude Honed last year. It was still on the car for this mod and I probably could not get any pictures that would help you. I got the car running tonight so I'm all set for the dyno tuning this Saturday. I will be post the results good, bad or otherwise.

By the way I seemed to have lost very little torque if any. If I'm going along say at 40MPH and floor it the trans will down shift into second and light off the tires. It has always lit off the tires just about all the way through 1st gear whether from a dead stop or a 15MPH roll. Allen

 

Don't forget Allen it ran lean with the o2's in the 770's. Reprogram the chip before you go.

 

Hi Vincent

Thanks for the info. The place has a wide ban O2 sensor so we can moniter things. He can shut it down if the reading is too lean. I still have the 100 octane in the tank that was left over from the Fontana runs. Allen

 

which set of gaskets was it you used ? are they bigger then the slps/ manifolds existing opening ? i.e a good stencil, part# would be great, I'm doing somthing similar to this, not as extreme though

 

ok i belive i got it, are these the ones here ?

http://go.mrgasket.com/ProductDetail...&minselection=

 

Yes those are the ones. I have the early style SLP runners. Some parts of the runners did not line up well at all with the Extrude Honed 1.70" Edelbrock TPI intake manifold. I had to have those portions welded up to add more material. You can spot the thin areas in a heartbeat by lining up the TPI gaskets. The current style SLP runners are different in many aspects from the early style runners and may have more meat in those areas.

If I had hogged them out without welding either the seating surface would have been razor thin or I would have ground through the side of the runner. The car is up and running and everything seems fine. Can't wait for Saturday and the dyno tune.

One thing about it is that the plenum, runners and intake manifold should not be a restriction for the heads. They should be able to give the heads all the air they want. In other tests the intake manifold bench flowed in the 270-275CFM range. Mine should be similiar. The Trickflow heads flow around 254CFM @.500" lift.

One other theory is that increasing the plenum volume increases horsepower. I have increased mine at least 30% in volume with this mod. I have gone from around 150 cubic inches to around 200 cubic inches. Allen

 

man, nice, depending on yer out come i may just have to do what your did, hows it feel though, not that its running, any differance ?

 

I have not really put the car through its paces yet. I just mainly wanted to check things out and make sure I put the car back together correctly and did not have any air leaks. So far so good. The engine before the latest mods was putting down 354 HP at the motor. Not sure I would notice that much on the street if I picked up say 15 HP. Allen

 

hehe alright cool, cause i have the new style slp's and i'm going to be port n' polishin them and the plenum and the stock intake. so i'm thinkin about just going ahead with this

 

I'm bringing this back to the top to coincide with the posted dyno results for those who might be interested. Allen

 

Very Cool stuff Allen.. Im sure it is going to work well.. All were looking for his more power to the ground..

 

Hi Brandon


Can't wait to see your car at the track. You should easily be in the low 12's. If you can get all that power to the ground who knows. Allen

 

so did this mod ever work?

 

Yes. With no other mods I picked up 21RWHP and 23RWTQ. At the motor that would convert to about 26HP and 29TQ. Here is the link to the thread I posted. https://www.thirdgen.org/forums/tpi/...highlight=dyno

I'm about to drop a new long block in and keeping the same TPI setup for now. Should see another big power increase. See signature for details.

My next mod is replacing the Extrude Honed Edelbrock TPI manifold with the First intake. There is quite a difference between the two favoring the First.

 

Wheres the pic of the exrtude honed base?

 

No pictures of the Edelbrock base. Maybe in two weeks with the new long block?

 

You're still not going to beat me in the quarter.

 

Hey Vincent, first we meet at the dyno and then at the track. I have a series of mods lined up this comming year that should do the trick. See signature.