ASE doc

I won't talk down AS&M's Large Tube Runners. They allow me to make some pretty serious power. However, if your XXLarge runners had been available when I built the beast in '99, I wouldn't have used AS&M. I'm quite sure that we will be pleased with the results of your build. The fact that you have done this project(a day dream of my own), gives me renewed confidence that another visionary shared my same vision. This has me thinking of my next daydream/imagineering feat. I need to put together some fab capablities, and capital, and get to work. Imagine your XXlarge runners but shortened, something like the Superram, but with dual cylindrical plenums. It would push the top end capabilities even higher and could be fine tuned to support 650HP and still make drivable mid range torque. Maybe..............

Dyno Don

iTrader: (7)

You "SIR" are a genious ....that is truely amazing.

1989GTATransAm

iTrader: (3)

Thanks Don.

AS&M makes a fine product. I am glad to see they still support the TPI.

Thirdgen89GTA

iTrader: (5)

Sounds like the current evolution of cars and their weight.

Orr89RocZ

iTrader: (20)

Looks good so far. The results of the current motor are spectacular, i cant imagine what gains this intake will give, but I'm starting to think you are near the limit of the heads

1989GTATransAm

iTrader: (3)

"but I'm starting to think you are near the limit of the heads "

Good point. I am hoping I can squeeze some more out of them and this project works out.

therain2008

dude you need to fabricate others! you'll make alot of money! awesome job, I sure want some.
to say I'm all happy to have finished match porting my plenum to my 58mm TB and did a great job, man you are worlds ahead of me!! lol

ASE doc

I just watched the video of your dyno run with the SLPs and First base. Very impressive. If you did offer these for sale, I would be first in line to buy them. I paid $420 for the large tubes I have now. I can't imagine what I would be willing to pay for the XXLarge.

1989GTATransAm

iTrader: (3)

The XX large runners are only part of the package. You need a plenum and intake manifold to bolt them to and also opened up. The current First/SLP package is going to my friend Pat. We have done some trading as it is/was his Accel intake that I am highly modifying.

We will of course open up the First intake manifold and SLP runners to the proper size before he bolts them on to a motor. I see no reason why my SLP runners cannot be opened up to 2" ID where they meet the intake manifold. That will support some serious horsepower.

Steve Mack

iTrader: (5)

Allen you say you are running a 368 ci.I know what a 383 is.What makes your motor a 368.

1989GTATransAm

iTrader: (3)

4.060" bore with a 3.562" stroke.

ASE doc

What rod lenth do you run in your 368?

1989GTATransAm

iTrader: (3)

The rods are 6.125". The deck is 9.025". The pistons stick out of the hole .002". Running a .038" head gasket with a .036" quench. Using Mahle flat top pistons with 1.5, 1.5, 3.0mm rings.

ASE doc

Long connecting rods. Excellent.

1989GTATransAm

iTrader: (3)

Just a little update. While the intake manifold is getting fully ported I have been working on the plenum and runners. What I wanted to show was the nice radius entrance into the runners from the plenum but the pictures refuse to cooperate. Here is a picture anyways.

GTA Sammy

iTrader: (1)

You never said anything about cutting the plenum floor off!!!!... did you?
You guys are so crazy, I love it!!!

Are you hogging out the inside of that plenum as far as possible or are you gonna drop the floor for more volume?
Unbelievable!!!

1989GTATransAm

iTrader: (3)

Yes, I am dropping the floor of the plenum and hogging it out somewhat. It needs more volume in a big way. I will also blow out the back side of the plenum as there is room because the newer models have a smaller distributor. This will also help on the entrance to runner #8. About the best I can do is 45% of engine volume considering the parameters I have to work in.

dspencer24

iTrader: (3)

Wow ur to much!!! Your work on the entry way looks great.

ASE doc

Make sure before you do final assembly on this project, to check for small children or full grown cats who may have become lodged in one of those runner tubes.

therain2008

sick work man! wow!

Quick99

Looks GREAT !!!

dhirocz

iTrader: (2)

What radius are those runners? I have considered this, and am interested in seeing the powerband. I was going to start by using an extrude honed FIRST on a SBC 427 but I haven't even gotten my vortec 383 TPI/T56 '88 GTA up and running yet. Maybe tomorrow...

1989GTATransAm

iTrader: (3)

3" radius. Hopefully I will have my intake manifold back this week from Dr J's. Then some more progress can be made. I have just been doing some odds and ends during the wait.

dhirocz

iTrader: (2)

Looks good! I'd be interested in seeing what the impact of runner velocity will be on torque under the torque peak. It'll be interesting to see how the engine behaves with a runner that large and little restrictions to flow. Id be always erred on the large size slightly when doing intake manifold calculations to cover flow losses due to directional changes in the runners mostly. I'm also curious how throttle response and off idle performance will be.

According to my calcs a sbc 427 stump puller still only needs a 1.75" tube but that doesn't take other flow losses into account. This includes directional changes, port transitions, fuel, etc... This can help us determine what extra real world data we need to really get runner sizing nailed down for tuned ports.

ASE doc

Tube diameter is 2". By radius, I believe GTA means the bend radius. The RPM range at which peak runner velocity is acheived will certainly move northward with the larger runners. With the shift in runner velocity so peak torque will shift as well, or so one would assume. GTA has taken pains to smooth out the flow path to minimize turbulence and maximize total flow. The key here is to push the RPM ceiling and power limit of full runner TPI. We will see how much runner size impacts these limits.

dhirocz

iTrader: (2)

It most certainly will. The question is how far. The data from this intake should provide enough to come up with the 'loss factor' not accounted for in your typical intake runner/ cross section and length formulas used to calculate optimum runner length and CSA for a given engine at a given RPM. Those formulas dont account for some of the losses in even the most efficient tuned port systems.

Problem is the tuned port is a balance of not just runner length and cross section but resistance to flow which speeds up the air in the runner helping to make the tuned effect. Any unneeded resistance hurt power tremendously, but not enough kills the tune. Theres more to it than length and max cfm. It's a trade off. If you look at the AS&M's for example and run their specs in these formulas, you would see that it was intended for a 4000 RPM peak on a 383. The Accels on a 350, etc... but there isn't extra space to make up for the wet flow of the fuel (mostly in the head though), or the other factors in the intake that scrub off some of that potential. Air hates changing direction. I'd be willing to bet that a 4000 RPM 383 would pull a bit better with a runner a little larger than 1.660, maybe 1.7". There's only so many choices in mandrel bent tubing of that size in a given radius too.

Nice thing, an intake like this regardless of it's state of tune will still provide some downright mean midrange torque due to the runner length and cross section, even if the tune is weak. It sounds like GTA did his homework so it should work rather well.

Factory tuned ports run around the 4000 RPM range on a 305 and 3400 on a 350 (off the top of my head) but that doesnt factor in the bumps, transitions, fuel, etc that share that area which can really throw things out of whack. I'm really curious to see how she runs.

GTA, do you have an ETA on getting that thing on the dyno?

You know, you could get that manifold casted rather cheap. Once the tools to mold it are made, sand casting duplicates out of aluminum is really rather cheap. I think the runners would be hardest, since they are mandrel bent extruded aluminum tubing and not thick cast runners like accels. Plenum would be easiest. If you could sort that thing out, it would solve the TPI dilemma for some large ci sbc applications above and beyond that of the FIRST. I've been looking into doing this after I finish my bbc TPI intake (gen VI long stroke 496, 4.37" stroke from a Gen VII) I'm hoping for 700 ft. lbs @ 4000, N/A but am still barely out of the design stages.

*sigh* I wish I had 4 more hours in a day...

I find it rather ironic that there are a few people on this board that have better understanding and knowledge of intake tuning than the engineers did in the early '80's. These remarks come from unnamed persons well endowed in the GM community. This is why the stock intake is based more on formulas and does not figure in real world losses named above.

I'm really eager to see how well she works! Why do you guys have to live in California??? lol

BTW, Dr. J's really seems to pay attention to detail and the quality of his work looks great. We need more people like that around here. Good call on using the Accel base, if anything, because the sealing surfaces are thicker (GM TPI bases used to have a problem with warping if they got too hot).

1989GTATransAm

iTrader: (3)

Here are the calculations. Glad to see some people are up to speed on the subject. These are based on a 2.76" CSA right up to the head. I am hoping to be close and when I get the intake back from Dr J I will know for sure. I know that where the intake meets the head will be somewhat less as I am not touching the heads, but the majority of the runner tract should be close. So the actually fps will be somewhat higher at the head/manifold junction.

At 6500rpm the air speed is 301.89fps.
At 6000rpm the air speed is 278.67fps.
At 4700rpm the air speed is 218.29fps.

Some more calculations with a total runner length of 21" and a 233 degree camshaft.

For 2nd harmonic, RPM range is from 5,594 to 6789 RPMs with peak @ 6191 RPMs and pulse strength of 10%.

For 3rd harmonic, RPM range is from 4,308 RPMs to 4,804 with peak @ 4,503 RPMs and pulse strength of 7%.

For 4th harmonic, RPM range is from 3,277 RPMs to 3,665 RPMs with peak @ 3,471 RPMs and pulse strength of 4%.

The AFR 195 head has high air speed and helps in cylinder filling in the lower RPMs. Also with the "shift extension" of my Yank SS4000 torque converter it is quite possible after launch that the motor will not see less than 5600 RPM going down the track. That means the motor would be riding the 2nd harmonic wave all the way down the track.

I have the new DynoSim5 engine simulation program and it models "large, long tube runner" intakes such as on the Porsche 928 intake. This one fits in that category like a glove. According to DynoSim5 I will loose a little torque down low but gain big in horsepower on the upper end. This intake system has the possibilities to really, really be good. I have my fingers crossed and don't want to jinx anything.

I have highly polished the entrance into the runners from the plenum and have polished the inside of the runners themselves for the least amount of air resistance. I have talked to the people that will be doing the heat barrier ceramic coating on the inside of the runners in order to maintain as smooth a surface as possible. I am hoping they look like the outside of a nicely polished header with the ceramic coating. Dry air so no need for a rough surface.

I am hoping to have this all done and and ready to install by sometime in July. Then it will be up to Dyno Don's schedule as to when he can fit the car in for the intake swap out. Then we have to schedule a dyno day. My fingers are crossed.

As a side note I am building a new 4" cold air intake system in anticipation. I have another thread on that. Can't have any air restrictions. Hahaha

Orr89RocZ

iTrader: (20)

I think you got a good formula here. You have the 195 heads with the 2.08" valve correct? You have large valve, lots of air flow, and an aggressive lobe for quick valve motion and high lift. Recipe for big power in the 4000-6500 rpm range as noted by engine greats Darin Morgan and others who compete in EMC.

With those runners being that large and that long, you will also likely have the volume of one cylinder per each runner. Another noteable characteristic of some top end intake designs.

You already know what the motor will do with a single plane carb setup. You already know what it will do with a lesser flowing TPI setup, and its been impressive so far. These results should be very interesting

1989GTATransAm

iTrader: (3)

Orr, you are correct on all counts.

godreject

iTrader: (1)

Simply impressive. As always Allen, i'm willing to lend a hand to both you and Don when you guys are ready to swap things out. Just let me know.

Luis

1989GTATransAm

iTrader: (3)

Thanks Luis. That might speed things up. For those that do no know Luis is a member of our SoCal TPI club.

dhirocz

iTrader: (2)

If you were closer I'd be happy to lend a hand too. I love making it look stock.

I already did my 4" CAI on my '88. I'm running MAF right now until I get my 0411 up and going later in the year. It's tight but it fits. Let me know if you have any questions on it.

Orr89RocZ

iTrader: (20)

you do a 4" MAF or kept stock 3"?

1989GTATransAm

iTrader: (3)

"I love making it look stock"

Some of the comments I am getting is that it kind of looks stock with out one side by side to compare it with. So someone just casually walking by and I had the hood open would probably just think "just another TPI".

Long Beach Z-28

iTrader: (1)

"Just another TPI"

I'm planning on making a bunch of $$$$ from the guy who walks by your car in the pits and says that!!

After your first pass, I guarantee you will never hear it again.

BadSS

He'll probably have the same "problem" I had when I was running the FIRST. Even though my IROC wasn't all that,,, only running high 12.5s (in near 90 temps),,, people insisted I had nitrous hidden on the car somewhere. My favorite quote from one was,,, "There ain't no way in hell that piece of sheet TPI could out run me without naws. I don't care if I can't find it or not,, it's on there somewhere." That's exactly the type reaction I was looking for. What's even cooler about Allen's new set up,, is it REALLY looks stock!!!!

dhirocz

iTrader: (2)

Using the stock 3" for now so its a bottleneck. I'll be moving up to an 85mm z06 unit when I can find time to finish and install my 0411 harness. This will only require swapping bellows, though I've toyed with the idea of welding plates onto the aluminum tubing to make it more trick, then powdercoating it black.

ASE doc

You could go SD and be rid of the MAF altogether.

dhirocz

iTrader: (2)

Maybe with the 0411, but not the 165. I need something to drive and not running MAF and having to swap ecm's is just one more hurdle I have no time for at the moment.

1989GTATransAm

iTrader: (3)

I went by Dr J's this morning to look at the progress he is making on my intake manifold. He is pretty far along and has the CSA up to 2.6 inch square. Just need another .1+ to finish it off. It is looking real good and I am kind of jazzed after looking at it. He said it is taking more work than he thought it would. I know, and that is why I farmed it out to him. Hahaha. To his credit he is doing a very nice job. I will post pictures when I get it back.

Orr89RocZ

iTrader: (20)

Thats the narrowest CSA at the head port right? What gasket size is that?

Arent 195 comp heads only 2.05-2.10 inch square at the throat?

1989GTATransAm

iTrader: (3)

Correct. The AFR 195 Comp version requires a Felpro 1206 intake gasket. Yes the port narrows at the pushrod pinch to around 2.05 to 2.1 CSA. That is the problem according to some people. The air is to fast in that area. I suspect that is also the reason Tony spent a lot of time on the head in order to try and tame the high air speed in the pushrod pinch area.

Edit: I just remembered that Tony also but in a vane in the port. Again most likely to help with the high air speed. He warns to leave it in and I bet that is why.

ASE doc

Im excited to see the finished base. It sounds very impressive.

1989GTATransAm

iTrader: (3)

"Im excited to see the finished base. It sounds very impressive"

I will have to use the stock base I have lying around for a comparison when I take the pictures. One thing about it the Accel ports are pretty straight to begin with and Dr J straightend them out even more. I will not have any trouble looking in and lining the ports up to the head when it is time to bolt it on.

ASE doc

I am pleased with the flow path on my intake with the ported ACCEL base. I can just imagine what yours will look like. So exciting!

TTOP350

iTrader: (8)

This is something Ive always wanted to do/ see done!
Very impressive!

Quick99

Out of curiosity how much do,s something like this cost? Do you plan on selling them when your done? Thanks just wondering.

1989GTATransAm

iTrader: (3)

I have at least $1400 wrapped up in the project now. More to go. I started it in January and will most likely be finished in June. So over six months that works out to maybe $300 a month. That is the only way I could afford to do it. That incudes the base, runners and plenum. I have no plans on selling any of it.

ASE doc

That's pricey but compared to the price of aftermarket TPI upgrades, it's not outragious. Of course, when you combine the value of your time, the cost goes up considerably. For what you'll have when it's done, it's quite worth it though isn't it. And it's only due to your vision and skill that you're able to have it at all.

Orr89RocZ

iTrader: (20)

If it makes the power it should make, then all that effort is worth it. HP gets expensive once you get over a certain amount with standard shelf products.

1400+ into a system like that is worth it considering it meets smog legal requirements and will outflow most any sbc 23 deg intake ported to ported. To do the same in any other intake you could easily have 500+ in porting alone, so even tho its more money to do a TPI system because of all the components, you will get the same end results while keeping CA legal. For others that dont have to me Cali requirements, you have cheaper alternatives to make the power... but chasing every last hp will cost you, especially chasing well over 400whp in a sub 383" motor with 195 heads