1989GTATransAm

iTrader: (3)

Yes it was done and the Votec TPI flowed around 235cfm on average. A little worse than the average Edelbrock TPI.

Mark A 91Formula

iTrader: (3)

Wish I was closer to you guys, Would love to see what this thing will flow when done...
Bought Mike Davis' old intake. Siamesed way out, notice the missing ridge on the top of the intake port. Even with a set of SLP runners there was quite a gap missing at the top, lol lost the pics but compare to a stock photo and you'd see what I mean, huge hole. I was told there would be a gap but damn it was a space big enough to fit my pinkey finger. Had a welder friend add ALOT of material to the top on the runner port. Gotta port match the runners to the intake now and further siamese out the runners.

1989GTATransAm

iTrader: (3)

Looks like maybe an inch or so of runner left in that intake manifold.

Mark A 91Formula

iTrader: (3)

Just measured it, 3" of runner left in the intake.

briggsbuilder

Dam reading this whole thread, makes me want to sell my lt1 and get another camaro, this time no carb..... just good old tpi

Mark A 91Formula

iTrader: (3)

Finally getting around to making custom gaskets and start port matching the intake and runners. You can see just how much these puppies have been ported out.

Also have a question for the guru's On the floor of the ports there are 2 holes, they are in every port, well, every pair anyhow, are these something uncovered in porting and need to be filled, or are they supposed to be there?

1989GTATransAm

iTrader: (3)

Yes they are supposed to be there.

Kevin91Z

iTrader: (1)

Those little holes are for the fuel from the cold start injector. They're necessary for an 85-88 engine and do nothing in an 89-92 engine.

IrocZTPI

what size of throttle body are you using

Daniel U

Most of us are using 52mm or larger. I personally have the 58mm from Summit. I think AZ. S&M has one with a monoblade that flows even more. At some point there are other areas of the air pattern that become more restrictive than the TB though.

Shinobi'sZ

Did this thread die out with respect to trying the HSR intake? I am shooting for a setup that will pull to 6K rpms. What TPI manfiold (intake) is working the best for this?

1989GTATransAm

iTrader: (3)

The thread is concerned about "smog legal" intakes for California. The HSR is not smog legal in California.

Kevin91Z

iTrader: (1)

We didnt have a Stealth Ram available to us back in March/April when we did this testing. Also, that would require removing the intake manifold and breaking the seals and I didnt want to do that.

There's another sticky thread that compares the Stealth Ram to other intakes on an engine dyno. Read that one.

PonyKiller87

Ok I just read through all 5 pages of this and the 2 pages of the Visual thread and several other treads that were linked in. Can one of you guys that was doing all the testing and stuff do a cliff notes post lol. I just want to make sure I got it all because I'm getting ready to start a major build.

Sounds like you need modified base (injectors moved and ported), larger runners, more plenum volume, bigger TB, bigger MAF. Is that it?

My plans are a SBC 400, possibly stroked to a 434, with Edlebrock e-tec(vortec) heads. Running a roller cam conversion, huge cam(forgot the specs already have it at home) modified vortec tpi base, custom larger tube runners, modified plenum to add volume, mono blade TB. As for the maf I am planning on doing the OBDII conversion and running this with the LS1 style computer and going MAF less. I want to see 500-600 hp at the crank. The idea is to keep it looking like a bolt on TPI motor that the average person wouldn't think anything of. What do you think?

1989GTATransAm

iTrader: (3)

You might need to raise the injectors on the TPI Vortec manifold. We are getting over 300cfm through the runners without raising the injector on the regular Edelbrock TPI manifold. The Vortec TPI intake does not flow as well out of the box and may need the additional work for what you are doing. I have not seen anyone get more than 290cfm through the E-Tec heads. Those were worked over pretty good with a larger intake valve. So you will need some serious work on those heads.

More plenum volume would not hurt anything. We will be running a test on 1/10/09 with fully siamesed SLP runners and we will see how that goes. That motor does not have increased plenum volume. Larger runners for sure. Shorter effective runners for sure with a 400+ cubic inch motor.

I think a 58mm throttle body will suffice most on this forum but in your case a monoblade may be in order. The OBD2 would be the way to go on the MAF. Make sure you have a good cold air intake to feed that bad boy.

I think it is entirely possible to get 500 to 600hp at the crankshaft with that setup. You will just need to open things up to get some serious airflow through the motor. By the way I'm looking to get over 500hp at the crankshaft with my next motor and only with 370ci and TPI.

You would have sleeper for sure.

PonyKiller87

Any idea why the vortec manifold doesnt flow as well? I would think its pretty much the same just with the very end of the runner at the head side being adjusted. Thinking maybe its the angle or something that the injectors arent aimed right for the vortec heads?

Was the 290 cfm with the e-tec 170 or 200 cc heads?

Earlier in the thread someone said you guys figured out the secret, what exacly was it?

1989GTATransAm

iTrader: (3)

When Edelbrock changed the runner by the head to match up to the Vortec port the cross sectional area became smaller right behind the injector. However like the standard Edelbrock TPI intake manifold it can be opened up to a good size for some serious airflow.

Dyno Don has one in the works now. Maybe in a month or so some flow numbers can be posted. The Edelbrocks were the 200cc heads.

As guess you could say secrets. Open up the intake manifold runners as decribed, open up and shorten the effective runner length. If you can increase the plenum volume so much the better.

Edelbrock is notorious for overstating their products. I think the basic designs are quite good and excellant performance can be had from them but it takes some extra work.

PonyKiller87

Oh ok, when you posted that for some reason it seemed like there was something else beyond what you guys were putting in the post.

As for the runner length I dont think theres any way I can do that without it being obvious, so Im just going to make the biggest stock looking runners that I can. For the plenum volume, being that Im not running an EGR Im going to cut the bottom of the stock plenum out and extend it down as far as possible to the base, paint it black so it hides under everything... Thats also why Im going to take the stock Tb and make a mono blade.

Daniel U

Finally there's some more on this thread. I want a stock appearance under my hood as well. Has anyone thought of a high rise intake. I know the idea is old in the carb world, but would the extra cfm help the TPI? I have a cowl hood and could fit one under without to much clearance issues. I am not real smart when it comes to this but enjoy reading along. Someday I want at least 400bhp with TPI.

Russ-So Cal

Daniel, the problem with a high rise intake for your car is that it won't pass the visual in Ca. The siamesed runners that the guys are using all have CARB EO numbers making them smog legal. If SLO County doesn't require the enhanced smog testing (dyno), you might get something past a smog inspector if it runs clean enough on the exhaust, but we can't do that in Los Angeles/Orange County area.

Daniel U

If you could get good #'s with the , how hard would it be to get a CARB # and patent them? Or is there not enough people interested in TPI to make $?

Kevin91Z

iTrader: (1)

Last I checked it cost $35,000 to get a CARB EO# exemption, and you had to test it with EVERY model you wanted to sell it on. That means testing on a 305 TPI 5-speed, a 305 TPI automatic, and a 350 TPI automatic, for EACH year of TPI thirdgens. That's 20 tests times $35,000 = $700,000. Do you have that kind of money? I dont. You'd have to sell 100 intakes at $700 each just to break even on the testing cost, not to mention R&D and fabrication.

Ponykiller, there's no way you're going to get 500+ horsepower out of a TPI setup unless you're running shorter runners. And for a 400+ cubic inch, you'll need a Stealth Ram or MiniRam for sure. Long tube runners are NOT going to get it done, as I found out. I was limited to about 320 RWHP using bigger long tube runners. One of our members is using a 406ci with a SuperRam and the intake manifold is ported using our tricks and he made 403 RWHP. That's 475 at the crank or so. I would highly suggest you sell the ETEC heads and the base and get yourself a set of the new AFR's, either 195 cc's or 210 cc's. The ETEC 200's dont flow as well and the Vortec TPI base flows like the stock one out of the box, 235 cfm. An Edelbrock standard base out of the box flowed 250 cfm and 260 cfm after extrude honing.

I think a 58mm will be fine for you. You dont need to spend the money for a monoblade. Spend it on new heads instead.

PonyKiller87

Which runners were you using? Does anyone have flow numbers on the different long tube runners?

Has anyone done all of your tricks to a vortec base? I find it hard to belive that it can't be made to flow over 300 cfm just like the other bases if you putt he same effort into it.

You guys are the first that I have heard that don't like the E-tec's. The engine shop that Im using says that with very little work to them he can make them flow huge numbers.

As for the TB, Im going with the mono more to keep the stock TB in place, more for looks than anything. Wasn't planning on buying one, just going to modify one of the ones that I have sitting around.


I'm really not trying to stir the pot here, I just find it hard to believe that its impossible to make a LTR TPI make the kind of power that Im looking for. If it has the flow and its tuned correctly it has to be possible.

1989GTATransAm

iTrader: (3)

You will have to make the diameter of the long tube runners large enough. We have not done it so I don't know what that number would be. It may turn out to be so big that it would not fit the design of the Edelbrock intake manifold.

Maybe buy a program like EA Pro where you can change the intake manifold dimensions and see what they do.

Actually seeing as you will be doing some fabrication why not start out with a First TPI intake manifold and go from there as it is plenty big enough. From a visual standpoint it looks like a stocker when installed in the car. Mine passes California smog.

tshack

I may of missed this but has any one thought of running one of these trick set up on a older smaller displacement 4" bore small block like a 327 or 302 with a matching retro fit cam. Just to see at what rpm the power falls flat. that would be interesting to see. But yes more costly.

PonyKiller87

I though about the FIRST setup but it wouldn't fool anyone. Anyone that has seen a TPI would know that its not stock.

Any ideas on how big the runners would need to be to make it work? bigger than 1.8" ???

1989GTATransAm

iTrader: (3)

Ponykiller; I was talking about buying the intake manifold only. Not the runners or plenum. You could make your own runners and use the factory plenum.

tshack; We have a member that will be building a 265 that will be using TPI. That is going to be an interesting build.

Kevin91Z

iTrader: (1)

I'm using SLP runners that have been fully siamesed. Look for posts about "siamesed SLP runners" for pics and info. There is a magazine article I had posted on this website from GMHTP July 2000 that lists flow specs on a couple brands.

The large tube runners I used were AS&M/TPIS.

Dyno Don, my father, bought a set of ETEC 200 heads. They flowed about the same as stock iron Vortec heads out of the box, 240cfm at .500". He had them professionally ported and then he did some more work on them himself and they're up to 275cfm at .500" now. AFR 195's are almost 300 cfm right out of the box. That's why I said what I did.

http://www.compcams.com/Community/Ar...?ID=1737510521

And this article shows you why the short-runner intakes make more power than long-runner intakes.

tshack

oohh ya I'd like to watch that one. A high RPM er i hope. Just seem like a screamer like the old 302 's with a tpi would be cool okay maybe I am a little but it would be fun to see. like normal lots of fun projects in so cal. I miss it at times, until I remember 5 hour drives home for 35 miles.

PonyKiller87

Ok I did some searching around and I see your point on the etec heads, seems alot of people are getting the same results as you. So I started looking at summit, only real requirements I had were, Aluminum, decent cost and large cc runners to get something that will flow. Found 235cc RHS heads, all the specs look pretty good, and the price is right about the same as the etec, but I can't find a whole lot about them. Any thoughts? Heres a link
http://store.summitracing.com/partde...5&autoview=sku

Ok, next thing, the runners. I read that whole article and It seems to support the idea that if you keep making the runners bigger diamater and keep the lenth then you will keep getting a little more torque and the HP will continue to go up. So I would be really curious to see what some custom made 2" runners would do on your tweeked edlebrock base with a big TB.

1989GTATransAm

iTrader: (3)

"So I would be really curious to see what some custom made 2" runners would do on your tweeked edlebrock base with a big TB."

That is where you are going to run into a problem. About as big as you can open up the Edelbrock at the runners is around 1.80" at the very most. At that dimension the width of the .0625" wall runners will exceed the pinch point of the intake manifold by a good bit. With two runners side by side you are talking .125".

With two inch runners the inside diameter will be 1.875". The intake manifold should be larger than that. This is why I suggested the First TPI intake manifold and go from there.

PonyKiller87

Heres my though on that. If the runner has a larger diamater like I said and then at the manifold it necks down to what ever you can get it to, they should flow about the same because the smaller manifold runner is fairly straight when compared to the U shape of the runner tubes. If I had the time and correct computer program I would model the whole thing and let it tell me what size the runners should be, but I don't. So I'm guessing bigger.

As far as the First intake, it just so hapens First Fuel Injection is located In Bristol, WI which is about half an hour south of me, so Im definatly going to be getting in touch with them.

1989GTATransAm

iTrader: (3)

If you made the runner plate that bolts to intake manifold say 3/4 or 1" thick then you could taper the runners at that point to match the intake manifold. You would have to mock it up as I'm not sure how the bolt holes would line up. Again it would be a lot easier to do with the First.

Kevin91Z

iTrader: (1)

235cc small block chevy heads? What are you building, a 454ci small block with a 30 psi blower?? Stick to 200cc or smaller for a 350 on the street.

jwscab

intake runner cc, not chamber.

Kevin91Z

iTrader: (1)

I'm familiar with the difference between intake runner cc and combustion chamber cc. 235cc intake runners are HUGE for a street car.

jwscab

2.08" valves too....they are big heads.....

PonyKiller87

Read what I said the build was. its a stroked 400 so 434, as of now it will be N/A but a little spray or a pair of turbos my be a few years down the road.

This is a street strip car. It gets driven only in the summer on the weekends for fun, raced at the track and taken to work maybe once a month just to show it off.

I want to build this this thing as big and bad as as I possibly can and maybe even have the highest HP LTR TPI setup out there but that would just be a bonus.

jwscab

with that many cubes, you are going to be limited with any factory or modified runners and base.....your choices really start narrowing up, the FIRST is probably the best bet to stay TPI......

Long Beach Z-28

iTrader: (1)

PonyKiller87,

Which 400 block are you planning to use for your 434ci project? What bore / stroke combination are in your plans? You have got me very interested in your project. Please share any other details of your build. TIA

Russ-So Cal

Pony Killer, the problem you run into is that you are dealing with 2 different dynamics in a tpi system. You can increase runner diameter to increase flow until the physical size of the components max out, but the other issue is that tpi uses wave energy to give the engine a "boost" at certain rpms. Unfortunately, what wave energy gives at one rpm it takes away at another. The rpm that receives the boost is entirely based on the length of the tuned runners and base passages. If you siamese the base you end up with the same problem that the Lt1 had. The tuned length is shortened to the point that you lose all of your bottom end, but you may have an additional problem that the long runners even if opened up may cause an air flow restriction due to frictional losses. If you build a "stock style" tpi with bigger runners and bigger passages without shortening the tuned length of the runners, you will get massive low end torque, but it will still be all done between 4000-5000 rpm. Typically a balanced intake system will put out about the same torque numbers as horsepower in a 6000 rpm engine. You look at some of the high performance European engines like Ferrari or Porsche, and they turn a lot more rpms and put out typically 100 more horse power than lb/feet of torque. The tpi puts out probably 100 more lb/feet of torque than it does horsepower. Your planned build will do the same, except instead of putting out 350 horsepower and 450 lb/ft of torque, you may get 450 horsepower and 550 or 600 lb/ft of torque. The problem is that our rear suspension systems can't handle the torque of the stock 350 tpi without lighting up the tires on any sort of launch. The only way to get the kind of numbers you want at the rpms you want them at is to siamese the runners to get the tuned length correct. I went on the Car Craft Anti-tour a few years ago and I heard what I think is the most apt description of a tpi. A guy told me that the tpi was the best truck intake system he had ever seen in a sports car!

Kevin91Z

iTrader: (1)

Forgive me, I read so many combinations and threads on these boards that I failed to scroll back up and read about what you were doing.

govenorcamaro

iTrader: (2)

hey friends any updates yet

1989GTATransAm

iTrader: (3)

There is a thread on the Super Vortec TPI intake. It is a takeoff on this thread.

Kevin91Z

iTrader: (1)

There are no more updates. We accomplished what we set out to do with the three intakes.

Unless you have a Holley Stealth Ram you want to send and help us install?

We did go back to the dyno in January to test my cut-out. It was worth 7 hp and 7 tq at the peak values.

JASONN20

Hello I read alot about cam changes, improving air flow, and fuel but I have not read any thing about what your ECM is doing with the timing at 5000 above rpm's. I do not believe you are maxed out you should be able to get the 400 hp or better. I would be very curious what would happen if you swapped out your distributer with a vacuum advance. You will need you understand your injecter and map sensor read off the ignition module so it will have to wired correctly in order to see if there is an improvement. I think this may be the limiting factor. I have a 91 z28 1le b2l I have moded since i was 17. I have never had it dyno tested but it runs damn good on low end. I have scat 9000 crank, 4.030 block, speed pro pistons, 5140 rods, holley heads, edelbrock base, slp runners, stock injectors, stock fuel rail, stock throdle body, 2500 stall, 11.1 cr. it will shred the tires in 1st and 2nd but 3rd is geared more for fuel economy as well as 4th gear. I am kinda disappointed that 350hp is all that was achieved. i would really like to see what would happen with a vacuum advance distributer though. nice post

unibuga

ok i have a question i have a pretty much stock formula 350 it has a mild exhaust and it was rebuilt with a differant style piston i think... i was looking at the TPIS miniram and the Holley stealth ram which one would be better for my quRTER MILE TIME

Dyno Don

iTrader: (7)

Here is an update on my setup.

The heads and manifold have received the most attention.

The heads (E-tec 200's) now flow 270 peak flow @ .600 intake
218 @ .600 exhaust. (without the pipe)

The modded Vortec base is now @ 280-290 (did not flow them together).
The injectors raised .300 getting them out of the airstream.
https://www.thirdgen.org/forums/tpi/...pi-intake.html

New square port headers to match the large E-tec exhaust port.

The heads milled to 60cc's raising the compression to 10.6 (was 9.7 on some but I won't go into that here)

We are scheduled to go to the dyno on 8/8/'09

Stay tuned.......results to follow.

firstroc

I dont know if any1 said this yet but is this the stock heads with work done or just stock heads or different heads. I was told by my engine builder that the TPI cars were blessed and doomed by the TPI set up and the factory heads. He told me the factory heads no matter what is done to them will not make power over 5500 rpm, as the stock TPI set up it will not flow enuff with out major surgery, with the amount of work needed to be done to them it would be cheeper and easier to replace the system. This is not first hand experience but it all kinda makes sence to me because I noticed that totally stock my car does not make power over 4000 rpm(but thats where a 150 shot of spray comes in lol). I hope this helps some1.

1989GTATransAm

iTrader: (3)

Aftermarket heads, runners and intake manifold. Factory plenum.