A friend of mine, Jerrywho (you know him as the guy who made up the siamesed SLP runners) has done it again in the TPI fabrication department. Using three differently-ported Edelbrock intakes, he used special modeling rubber to create a visual look at what a TPI intake is like on the inside. I know its really difficult to see in pictures, but I'm posting these along with their measurements to give you an idea of where the restriction is in the TPI intake. Its right where the injector bungs are; it really narrows down in that area just before the air enters the head. I took pictures of all four sides of the rubber. On the left is an extrude-honed Edelbrock intake, the middle is my ported Edelbrock intake, and on the right is Jerry's intake. He welded up the roof by the injector bungs, then CNC'd the port to raise the roof level by .070" of an inch over the extrude-honed intake. You can see the difference in the second and fourth picture. Now I know why I only gained 5 hp at the wheels after porting my L98 heads to the max, and adding 1.65 roller rockers. I just couldnt get any more air thru the narrow part of the intake manifold. The extrude honed intake measures 1.160" x 1.700" at the narrowest point by the injector bung for an area of 1.972 sq/in. My intake measures 1.140" x 1.650" at the narrowest point by the injector bung for an area of 1.881 sq/in. Jerry's modified intake measures 1.230" x 1.930" at the narrowest point by the injector bung for an area of 2.374 sq/in. Pics here: http://new.photos.yahoo.com/sharkke@...60762390274768

Thanks for the post Kevin. This is one of the efforts going on here in Southern California to improve the flow of the TPI intake system.

The 2nd and 4th pictures show the side view of what Jerry has done. Not only has he greatly improved the cross sectional area of the runner he has dramatically improved the intake angle into the head.

With the modified factory plenum, moded SLP intake runners and what Jerry is doing to the Edebrock intake manifold I believe this system will surpass the Accel Superram. I firmly believe we will be seeing 500hp motors with TPI this year.

As some of you know there is another effort using the First intake manifold with the SLP runners and GM factory plenum. For most I believe what Jerry is doing will be the easiest route to take.

Stay tuned as more information will be comming.

Thanks. One of the coolest posts I've seen in a long time. Would there be any benefit to building up the floor ever so slightly at the exit port of Jerry's manifold to further improve the exit angle? Or will that just decrease the cross sectional area at the tighest point and negate any potential gains.

Mark, you "might" be able to do that somewhat starting out with a stock Edelbrock casting without welding up the floor. I believe the Edelbrock manifold Jerry is using is one that he has modified in the past and the ports may have been enlarged from stock for another project. As I stated above more information will be comming.

It makes since to me. Do you have any pictures of the welded intake?

Good post...Ive always known the base to be the restriction on my setup. Even fully ported it still doesnt flow anywhere near what my ported SuperRam does. I love TPI so i want to keep it or i would have swapped it out for a stealthram when they came out.

Ive been thinking about pulling the base and doing something more with it. This post is just lighting the fire for me.

kevin...do you have any flow numbers? Or before and after power numbers yet?

Sorry, I completely forgot to get pics of the intake too! I'll ask him to get a pic of his work and post it.

Jerry is currently working up a jig to mount an intake to a head flow bench. Hopefully we'll have flow specs in a week or two.

Interesting post.. I find it especially interesting because my whole TPI intake (baseplate and all) is lying on my bench right now

I'm not quite sure what the blue things are... Are these molds of the criss cross passages inside the intake manifold? Or do they have something to do with the runners?

One thought about the narrowing near the injectors.. Could this not have been on purpose? A narrowing would increase the air velocity which (might) help with atomization etc.. (Just guessing of course).

The blue things are molds taken of the inside of the runners. That way you can see the exact shape and measure exactly the size of the runner.

The Edelbrock TPI manifold had to cover both the 305 and 350 motors. Like the factory unit there is a compromise. The injectors are positioned to squirt into the head intake runner. You do not want the intake manifold runners to have a smaller cross sectional area than what is in the heads.

Yep, if all goes well Jerry should have the results from flowing 7 different manifolds in a few weeks. The eight manifold test should be ready by this summer if not earlier. That should pretty well cover the range of TPI intake manifolds and modifications to them.

Most of the TPI stuff was about velocity. But when you really start making good power. Those velocity points now become known as restrictions.

I would like to see pics of the outside of the base that jerry is working on as well. To get a better idea how this was done. Looks promising from the base runner plugs you guys posted.

Update,

Ready to get on a flow bench. I will call BPE and flow tech to see if we can get a couple of hours of bench time this week.

Jerry

That's cool. I'm watching this thread with great intrest. If you get a chance I would like to see a picture of the welded manifold.

Yikes that was quick. I will try and retrieve my manifold for the test. I put in a call to see if my machinest is in. Good looking adaptor.

Hey Jerry.. thanks for sharing this with the rest of us. I admire your fabrication skills, a welder of my own, is something i plan to add to my shop.

My question is why didnt Accel, edlbrock, lingenfelter. who ever it was that revamped this thing, from the stock TPI base, didnt do something similar? You think they could have gotten it to flow more like 275/300 cfm.

When those companies designed the intake back in the 80's, they didnt have the knowledge that we have now. Look at all the replacement street intakes that Edelbrock has. They're only slightly better than stock. They put all the good R&D into the race intakes.

To add to Kevins reply. TPI's also came on 305 motors. IMHO the Edelbrock TPI intake was a compromise so as to work on the 305 motors. I say screw the 305s and get it on with a proper intake for 350 and larger motors.

Amen.

The heads on my car flow over 300 cfm and now I am on a quest for an intake that will support them.

Jerry

Who made the intake on the right? (the one not stacked)

The intake is made by First injections. It's not a bolt on replacement.

Jerry

Ok I've seen the first stuff. Just didn't recognize the manifold without the rest of their stuff with it.

WHOA!!! That bellmouth you made for the test is outstanding. If fact the test stand that adapts to the flow bench is a nice piece of work. Exellent job Jerry.

Looks like its time. Time to mill out an entire intake from a block of aluminum, anyway.

Or you can just order one. But us third geners like to DIY most of the time.

Jerry

Whats that, a Wilson or Hogan? Think I can cover that cost with a handful of 20's? Probably more like 100's...

Whens the test date?

Nice...work,.. looks like your all set. Amazing what can be done with just a chunk of aluminum.

Is there a certain number your looking for as far as flow goes from this intake? What heads are you running that flow over 300?

I know you want the intake to flow more then the heads if possible. So as not to be a restriction. I think a stock Accel/Edelbrock base is right around 250 cfm. Extrude honed 275 maybe?

I would be happy if i could get around 300 cfm out of my base. Dont know if that will happen. My SuperRam runners are ported out about as far as the castings will go. Stock they are around 280/290. so runners must be over 300cfm now. If i could get that out of the base as well. when bolted together it would drop im sure. Your RPMS and victor jrs are flowing in the 280 range. Would be nice to get that out of a complete TPI setup.

Hehehe. We are working on it.

Jerry, Don has access to a Vortec TPI manifold. I don't know if you could bolt it to your set up or not even with the bolts at an angle. Maybe a clamp? Also don't know if you could get it in time.

I also have heads flowing over 300 cfm at cam lift and hope to have some data with my hogged out FIRST flowed on the heads - since the local shop has no provision to flow the intake alone. I have an untouched FIRST base and will test a stock TPI base and fully ported GM TPI when I finally get some time to flow everything. I'll include the on head flow numbers,, along with the flow including the runners and plenum while I'm at it. I saved flow numbers posted a couple years ago when someone else flowed a stock TPI, SuperRam, and MiniRam on a set of heads flowing in the 250 cfm range and it was very interesting.

It will be here tomorrow.

What intake gaskets are you guys using with the edelbrock manifold ?I have 200 cc ports with heat cross over and cant find any with large enough ports and heat cross over for egr .Thanks

I'm using the Felpro 1205 intake gasket with my Dart Pro One 200cc heads. My heads only flow 280cfm at .600" lift.

BadSS are you still going to have the First Injection runners siamesed part way?

Allen,

280 cfm at .600 lift is nothing to sneeze at especially with a 1205 opening!!

Still planning to have them welded. There is one guy in the area that is semi-confident that he won't warp them,,, but Ken at FIRST injections said if they did warp he could cut and reweld them in the jig for me. So,,, as soon as he can get to them,,, it's a done deal.

Wish I lived around you guys,,, I'd love to throw this ported FIRST in the mix,,, but I'm sure Jerry has his hands full,, although I'd pay for my part of the bench time!!!

Kevin (KG)

BadSS I would love to see your intake in the mix. As you saw in the picture Jerry has my as cast First Intake for the test. Maybe you can ship yours out here and I can get with Jerry and get it flowed using his fixture.

This would most likely be a stand alone test as the others would be completed but I would be willing to pay for the shipping back to you and pay for the test. Then we could include the results with the rest of the data as they would be flowed on the same bench.

Then the only test missing would be a fully ported Vortec TPI manifold. However it may turn out to be the same as the Edelbrock TPI. Especially if the unmodified versions flowed about the same.

No, Just to see what will flow what and by how much.

Dart Pro 1 215cc with full port and 2.08 intake valve upgrade.

Will find out soon, I have a stock tpis base and one that just came back from Extrude Hone.

Jerry

a. post bump b. I measured my stock port 062 (1998 Tahoe) casting vortecs: 2.175 x 1.185......makes you wonder. That is really raised runner. That's 2.578 LOL no wonder Vortec heads work..........

Yes 2.175 x 1.185 = 2.578 The thing is, no way do you have a set of Vortec heads that are 2.5 square inches all the way Thru the intake port. Did you measured at the gasket, Remember the air is not traveling 90 degrees to the gasket serface. What you have to measure is roof to floor 90 degrees to the path of the air flow. One other thing is deducting for the radius in the corners this will be -.125 for a small and up to -.250 for larger radius corners.

Jerry

I just got back to work from West tec and it was a great learning experience on Tpi base air flow. The cool thing was seeing a Tpi base flow 300+ cfm. when I get home from work I will e-mail the flow numbers to each of base owners and see if each base owner Will let me post the numbers.

Jerry

One side note we started with flowing the fixture to mount the base and with a 3/8s radius on it we got 430 cfm so you know the adapter will not be a limiting factor on our base testing program.

Jerry

You got the bases flowed today?? Definitely post up the numbers, I am curious to see how badly mine flowed compared to the others.

Awesome...cant wait to hear all the details!

Jerry if you dont mind would you share photos of your base? IM wondering how you went about opening the area around the injector holes.

The base I have for testing is just that and will never see a car again. So posting pictures of it might steer some people in a bad direction from past test fittings. I have more intakes to weld up and will post pictures then.

My ported base was 290 cfm @ 28" and I think that good for a first prototype port. I think 300 to 310 can be a reality

Jerry

290cfm for an Edelbrock intake is unheard of. That is very good. With a little more grinding in the right spots I know you can get above the 300cfm range.

Jerry emailed me the results of my First intake manifold but he is going to double check it next week to be absolutely sure. So I will wait until then to post the results. Things tend to get out of hand on the internet.

CFM at the expense of velocity? Sometimes bigger isn't always better, not saying that this is the case here though. I'd like to see some before and after dyno results if possible.

This is definitely not the case here. With port volume up less than 10% and CFM up over 15%, this will actually net an increase in port velocity. I will be doing some port velocity testing next trip to the flow bench.

The new motor in my car is almost ready to go to the dyno. This will give us a baseline with a mild ported Edelbrock base. After I get dyno numbers with it, I will install an Edelbrock base that has been fully ported to the best of my ability.

Jerry

I can GUARANTEE you that Jerry's motor will eat up that port volume with no problem. I'm also a very interested spectator regarding Jerry's dyno results.

Jerry,

Are you going to use an engine dyno or are you going to dyno the engine after it is installed to get the RWHP?


....All this talk has me browsing through the autotrader looking for a good project car......

Hehehehe. That is good to hear James. I would love to see you back in the fray. With the new AFR Eliminator heads, new design cams and other new products on the market I think someone will go by me. I know if I had to do it over again I would change a couple of things.

Looking at what you have achived as far as power output I think your choices have been proven right so far. The new AFR heads look good and come with a warranty that you won't have if you buy a new set of TFS heads and then send them to the head porter only to discover issues with the heads. I'm not to keen on custom one-off mods but that is necessary when trying to extract every last HP. My thoughts are either the dyno was wrong or it will take vincent and all the other 350-383 CID TPI-based 3rd gens in our area a couple years to catch up to you. I have no doubt you can run sub 12-second times if you can hook the tires. Vincent won't race you if he knows you will win, and you will, so he won't be racing you anytime soon.

The motor is in and the car is driveable. Today I will be finish welding the catback and working on the air filter system. The dyno day is soon.

Jerry