I'm starting this thread to show the progress and how I'm doing the conversion of using the factory fuel rail system, factory plenum and mating the SLP runners to the First Injection intake manifold. Here is a picture of the intake manifold showing the modifications.

You can see where the new custom EGR is going to go between runners 4 and 5. By the thermostat housing you can see where I added a piece of metal so that the fuel rails have a place to bolt to in the front.

I had to cut down the fuel rail standoffs about 1/2" to get the proper angle of the fuel injectors into the runners and clear the SLP runners. The machinist made up the little adaptor plates to move the bolt holes out a little. I was going to weld up the area and redrill and tap the holes but he wanted to make the adaptors. We had to cut the one fuel rail post by cylinders 6 and 8 to make clearance for the factory fuel regulator.

 

Looking good! and like a lot of work. Why the numbers on the intake?

 

So I can keep track of what parts go where. If you look closely you can see the adaptor plates are also marked with which ports they go to. They are all the same except they will be slightly customized to best line up with their individual ports. After the runners are welded to them it won't matter as much.
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Here is a head on view of the adaptor plates. They are one inch thick and we left on as much meat as we could so that when the welding process begins hopefully the warping will be at a minimum. The port on the right of the pair is at 14 degrees to better line up with the SLP runners.

However in two spots there will still be a gap of .300". The welder will earn his money in those areas. The runners are at the welder for some work and I will pick them up this afternoon and post more pictures.

 

Here is a picture of the factory fuel rail mounted on the intake manifold. You will notice that I had to make custom fuel cross over tubes. They need to be shorter to allow the fuel rails to fit the First Intake manifold. Also had to do some minor clearance of the factory fuel rails as shown on the side view in order to clear the adaptors.

 

Here is a picture of the factory plenum that I opened up for the AS&M monoblade throttle body that I will be using. Can't have enough air. Hahaha. I have to finish the detail work but the majority of the work is done.

 

Head on view of adaptor plate that won't post in the above reply for some reason.

 

Way to go Allen!!

 

Ah makes more sense now! the hole in the top and the "plug" are you adding egr somehow?

 

Yes that is correct on the EGR. Putting it where it belongs so to speak for the smog techs and of course having it functional.

Here are pictures of the First Intake manifold, modified SLP runners and the factory plenum all bolted together. As you can see from the side view there will be quite abit of welding to cover the .300" gap of where the SLP runners meet the adaptor plate. There is a spot like this on each side.

And to go with the whole lot of welding will be a whole lot of grinding by yours truly.

 

That gap shouldn't be a problem for a good welder. Ive got a TPI plenum that I opened up in the front like that in about '87...........didn't have a clue at the time what I was doing. I also opened up some SLP runners and welded them back together with a plate. I didn't realize the intake restriction until the post about it lately. I may play with a stock intake I've got 8 or 10 laying around.LOL...........would like to have a SDPC base for vortecs to modify when I get a chance.

 

I just got back from the welder as I had him weld up the old lower center bolt hole area on the SLP runners as you can see. Anyways I mocked it up for him as you see in the pictures and he said it would be no problem for the welding that I wanted. Actually there are no hurdles left just the work to get it done and finish it off.

Well maybe one small hurdle and I won't know that until I get it all in the car and bolted up. That would be the strut tower brace. It is going to be close with all the measuring I have done. I might have to modify it where it crosses over the plenum to gain maybe a 1/4" but that will be no biggie.

 

Now see this is some nice work ....... Great job guy

 

Don't take the following comment to be a put down WHATSOEVER, but why are you not just using the FIRST plenum and runners? You are going to an AS&M monoblade, just like the FIRST comes with. It seems like you are putting in ALOT of effort to get this to work and I'm not sure what you are looking to gain.

Again, I am not trying to knock you at all, just want to understand. I know that you have already mod'd the plenum and runners, but I wasn't sure if that was it.

 

subscribing. Awesome FAB work. Can't wait to see how it works out for ya.

 

First of all thanks everyone for the encouragement.

Hi Jeffrey. Actually that is a good question which I have thought about myself over the past year. We have a group of local guys that are always looking for ways to increase horsepower in our Third Gens and still be "smog legal" here in SoCal.

As the horsepower has gone up in our motors it has become increasingly clear the horsepower choke point is the TPI intake manifold and specifically the Edelbrock design. We are way past the factory TPI manifold. The runner entry into the heads is not that good and the cross sectional area leaves alot to be desired for the higher horsepower motors and the bigger CID motors.

The factory plenum design is quite good and can be opened up for all the air we need. No problem there. For the runners, the SLP's are not that great out of the box but they can be heavily massaged to flow all the air we need.

For what it's worth the Super Ram uses the same Edelbrock style intake manifold though the earlier variations are much better. So it suffers from the same problems.

The question then is how to solve the problem. One is the First Injection intake system. This a TPI system on steroids and technically not smog legal here in California. However the First intake manifold itself is first rate and solves all the design problems and can easily be made to flow a ton of air and including the big inch motors. Problem is it is not readily compatible with anything else other than the First system.

From what I know today it could be made to pass the visual smog inspection and would be a good candidate to use. One could siamese the runners and plenum for increased flow and tune the runner length. I believe BadSS is going this route and I'm anxious to see the results. The throttle body is a round monoblade and is unlike what we are using on our cars. However it looks to be very posible to adapt one of our throttle bodies to it.

Another route that some of the club members are doing is heavily massaging the Edelbrock TPI manifold. There is a thread on this elsewhere in Third Gen. What they are doing is welding up the top exterior of the runners so that a proper head angle from the intake manifold can be created. Then the runners themselves can be opened up so that they are no longer the choke point of the intake tract. This is probably the easiest route to go but will still require a lot of welding and hogging out of the runners.

Another posibility would be the BBK TPI intake system but right now we know very little about it. If designed correctly it could very well be the route to go.

If I had to do it all over again would I go the route I'm taking? I really don't know. Maybe after the dyno results I can give you a better answer. If I get 30 plus horsepower than maybe yes. If I wind up with just a 20HP boost or less I would say no as I could probably have got that with a heavily massaged Edelbrock.

To finaly answer your question why I did not use the whole First Intake system. When I first started this I did not think it would readily pass the smog visual. I have sinced looked at the whole thing and now I think it could at least with most techs.

I had a set of heavily modified SLP runners that if you look closely are far from stock. They have had the plenum extended into the runners. Both sides of the runner pairs are siamesed. So they are quite capable of supporting the First intake manifold with all the air it needs. Plus I can massage the runner length to pick up the 3rd harmonic wave in the rpm range I will be running. So I already had the runners and plenum that would work. It was just a matter of how to do it. Once a solution was found the challenge was there and I was off and running.

 

I think Ken at FIRST may be working on an exemption. I also agree that the entire FIRST system would probably visually pass most stations,, especially if you cut and welded a stock t/b mounting flange to the FIRST's plenum,,, along with grinding "FIRST" off the top of the plenum. You know,,,, it would be too dang easy if they would just check the emissions and let it ride if it passes,, regardless of what's under the hood.

As others have said,,, that's impressive work getting the SLP runners mated up to that FIRST!!!

 

FWIW, I sent the following email (summarized) to Ken @ FIRST:
When will the Vortec version be ready?
On your homepage "creating changes that will improve this product and create an improved version for the 21st century." What changes are you making and when will they be done? A nice update would be to use fittings on the fuel rail, they look a little scary! Also, offering a "ported" option would be great for larger motors, especially if you considered working on a BBC version.
Also, do you whether the stock "dual snorkel" units found on the MAP (90-92) Camaro's fit on the end of the monoblade TB?
Is the EGR in the stock location and use stock parts? "

He responded as follows:
WE HAVE CHANGED THE ELECTRONICS USED ON THE ORIGINAL FIRST, TO A WIDE VARIETY OF MORE UP TO DATE ELECTRONICS SYSTEMS. WE ARE ALSO GOING TO OFFER A COMPLETE CNC PORT MATCHED SYSTEM, AND WE ALREADY DO OFFER SOME MILD PORTING OPTIONS.

ACTUALLY THE ORIGINAL FUEL RAILS ARE QUITE SAFE, AND WE HAVE NEVER HAD A PROBLEM WITH THEM YET. WE HAVE CHANGED THAT DESIGN TO A EXTRUDED 6061 RAIL THAT ACCEPTS 3/8 PIPE WHICH ALLOWS THE USE OF AN FITTINGS AND SUCH. ALSO, THE NEW RAILS ONLY HAVE ONE CROSS OVER HOSE INSTEAD OF TWO. BOTH ENDS OF THE RAILS ARE TAPPED SO THERE IS NOW THE OPTION OF FRONT ENTRANCE AND EXIT OR REARWARD ENTRANCE AND EXIT.

WE HAVE THE FIRST VORTEC BASE SOLD ALREADY, BUT WE ARE WAITING TO GET FEEDBACK FROM THE GENTLEMAN THAT HAS IT AFTER HE INSTALLS IT BEFORE WE RUN PRODUCTION.

I AM NOT SURE IF THE DUAL SNORKEL SET UP ON THE CAMARO WILL WORK, WE HAVE NOT TRIED IT YET OR KNOW OF ANYONE WHO HAS. I DO KNOW THERE ARE PLENTY OF ADAPTER BOOTS OUT THERE THAT CAN ADAPT THE 4" T.B TO OTHER SIZES.

THE EGR MOUNTS ON THE PASS REAR OF THE PLENUM, NOT UNDER THE PLENUM LIKE THE ORIGINAL TPI DID. IF YOU HAVE ANY OTHER QUESTIONS PLEASE LET US KNOW.

Would be interesting to see how much the CNC version flows!!!

 

Nice Job so far. Took me till you posted the runners to see that you are welding the 1" plates to the runners themselves. I thought you were using them as adapters.

I do have to say it does seem like very large amount of work, rather than going to route of all FIRST stuff. No biggie, I understand why you are donig that.

A quick comment, suggestion, whatever....From the picture of the runner gap, would it make more sense to fab a small piece of sheet aluminum, in kind of a runner extension, rather than just filling the gap with weld? This way, the extension could start about an inch up the runner, and blend nicely with the port. Obviously, you would grind out the end of the runner so that the new piece becomes the outer wall of that runner. Would be less grinding, and less hassle welding, since it would all be nice tight joints, plus would be a better port match. I hope that was clear enough..... Would kind of look like a curved triangular shape.

 

If Ken is doing the conversion to the Vortec heads then that is the better route for those using the Vortecs. However it would not be hard at all to convert the existing First intake manifold to the Vortec style.

There is plenty of aluminum around the bolt holes and flange area where it bolts to the head. You could use custom aluminum dowel pins to plug the existing holes and weld them in place from the top. Then machine off the top flat like on the Vortec manifold and then drill the holes. There is a ton of room to match the First intake manifold ports to the ports on the Vortec head.

JWSCAB: I had thought about adding a piece of filler aluminum as you describe to close the gap. Thats one of the reasons I took the whole assembly down to him to see and visualize what needed to be done. He had no problem filling in the gap and with a good full inch or more out into the runner. This way it will blend in nicely on the outside when I smooth it out. Should look like it came from the factory that way. Yes it is a lot of work.

You are correct in that I will be welding the SLP runners to the adaptors. I have a lot of prep work to do before I get to that point.

 

Pics of runners welded to adapter plates? I love these kinda threads.

 

Just a progress report. Have not done anything for two weeks as I was on vacation one week and was working on the HT383E motor for my Tahoe.

Anyways back at it. Here are a couple of shots of the adaptor spacers. Shows how I have formed an hour glass shape on the entrance. The SLP runners will be welded to this side so I have to finish this portion before the welding can begin.

 

This is a picture of my SLP runners at the point where they have been cut back 1.25". On the one side there is quite abit of material in there and shows how the standard runner is squeezed at this point.

I had previously removed quite abit of the tunner in that portion. Now I get to remove quite abit more with maybe 1 1/2" of runner that will be remaining. On both most of the hump in the bottom middle will be removed.

 

A few more pictures to show how much material was removed from the runners compared to the above pictures. Since the pictures were taken I have had the parts cleaned and bead blasted. I'm ready to do the welding. Probably will do that next week.

 

im waiting for some impressive numbers once this thing is slapped on top of a sbc

 

I found something interesting yesterday as I was starting to clean up the runners on the intake manifold itself. Jerry had used this First intake manifold for his flow testing. Using number one port he came up with 301cfm which is quite good. He used number one port on all the manifolds he tested.

Well come to find out while I was taking the port measurements the number one runner on this particular manifold has a big restriction right in the middle of it. As it turns out that is probably the worst flowing of the runners. I knew going in that runners 1 and 8 had restrictions but I did not know it was that bad. Oh well just some more grinding to square it away.

Edit: After further measuring the #1 runner has the smallest cross sectional area in the middle. I have to assume it has the worst flow.

 

Is the goal of this project to shorten the runners, straighten the path, add volume (or all of the above)?
Bill

 

Bill, in our search for more horsepower using a "standard" TPI system it has become apparent that the weak link is now the Edelbrock style intake manifold. The factory plenum is fine and suitable for modifications. The SLP runners can be opened up and modified for more power. We are sill waiting on the BBK system.

Then the question is what to do about it. Two options have surfaced. One and probably the best route for most is to weld up and modifiy the Edelbrock TPI intake manifold. This is being done as we speak and the results should be available in a couple of months. There is another thread on this.

Another option is the First Injection TPI system. In my opinion it could be made to look like a standard TPI system for smog purpose and pass the visual inspection as well as the test portion. None of First systems parts will readily interchange with any other TPI parts and there are some drawbacks to the First system that can be corrected.

IMHO the First Injection TPI intake manifold is the best design available and meets the criteria that we are looking for. I wanted to use my SLP runners and factory plenum as they have been highly modified and meet the performance criteria I'm looking for. I did not want to throw them away and start from scratch.

So then how do I mate my SLP runners and factory plenum to the First Injection TPI intake manifold. That is what this thread is all about.

The goal is to have enough plenum volume, right length of runner to get the 3rd harmonic wave around 5800rpm in my case, proper runner cross sectional area, proper taper of the intake runner and I chose a 2 1/2% taper.

It is quite possible that the BBK TPI system might do all this with a whole lot less work. We are still waiting for its appearance.

 

Thanks for the detailed response. The workmanship and research certainly deserve appreciation. Thanks for passing-on the results of your labors.
Bill

 

Just an update. I have been measuring the cross sectional area on the runners of my First intake TPI manifold inch by inch. I have sinced found out that the port on runner #1 with some exaggeration is shaped like an hour glass.

So I'm going to take some extra time and get this squared away. You basically want the intake manifold runners to be funnel shaped with the small end at the head entrance.

I have ordered some new carbide burrs and extensions so that I can more easily get into the area for enlargement. With the doglegs in the 8+ inch runners it makes it a little tougher. I will then go back and clean up all the runners to get a more even funnel shape. Some of them are not bad as cast such as runner #2.

 

OK, I got the adaptors welded onto the SLP runners today. Here are some pictures untouched from the welding shop. IMHO I thought the welder did a pretty good job. Now I just have some grinding to do. Make that a lot of grinding but the way he welded it will make my job easier.

So yes you can make the SLP runners fit the First Injection intake manifold and retain the use of the GM factory plenum. That is the nice thing about the SLP runners is how much they can be modified.

 

Here are a couple of more pictures. You can compare these latest pictures with the pictures further up in the thread such as post number nine. Those big gaps have nicely been filled in. This baby is going to flow some air.

 

Well, i must say, whatever the results are, you sure put a lot of time and thought into this, and you should be commended for it.

 

Thanks Ken. I just came in from the garage scoping things out. I think I will use my mill to hog out the big stuff. Then on to the carbide bits and then the sanding drums etc. Should not be to bad with the mill taking out say 80% of it.

Actually the hardest part has been increasing the cross sectional area of runner #1 in the intake manifold. The narrow point is right in the middle of the runner with dog legs from either end. In reality it would flow good enough for most applications at 301cfm. I'm about half way on opening it up to what I want.

By the way I have to get ahead of Vincent and his Accel Superram.

 

I am waaaay lazier than you...
I would just go for an off the shelf SR and a mild 415

 

Not to discount your work on this WHATSOEVER, but too bad you weren't able to dyno your engine w/ a stock FIRST before all of these mods. I'd be willing to bet your mods will allow the extended RPM range you are looking for and an additional 15hp maybe, but it would be nice to be able to quantify.

Good luck, and keep up the great (and time consuming ) work If you don't beat Vincent I think we'll all chip in and through a NOS Sneeky Pete system on there

 

Actually the First intake manifold has not been changed all that much as far as the internal part of the runners go. I just opened up the portion at the head to 2.21 square inches which did not take much and then squared away the openings at the runners to 2.68 square inches which is about what they are as cast.

The real work was runners one and eight. Eight was not to bad as it narrows to clear the distributor but plenty of meat to open it up. As stated above runner number one will take some effort but I'm making good progress.

As to the dyno my old intake combination put down 350rwhp and 370rwtrq. That is through an A4 and a 3600 Yank torque converter. That will be the benchmark. The major change is removing the Edelbrock intake manifold and replacing it with the First intake manifold and of course mating up the SLP runers to the First intake.

Hey Ken, this gives me a challange and hopefully some gratifying results. With luck I will exceed the Superram as it has virtually the same intake manifold as my old setup.

 

Two more pictures. I have cleaned up one set of runners on the inside and they have blended in quite nicely. Since the pictures were taken I have done 3 runners on the other set with one to go. I decided not to use my mill. The carbide bit in the picture was getting the job done.

 

So what is that going to total, like 8 inches of runner (lower manifold plus thickness of lower runner flange)?

I'm thinking of going single plane, custom elbow, with TPI style twin blade TB.

 

Truly phenomenal work!

As a seasoned TIG welder/fabricator I can appreciate the
work and research done to make this happen. If the numbers
are through the roof.. Id put a patent on that so you could
possibly collect from your innovative thinking in the future.

Id love to throw that setup on a mild small block.

I remember when I first joined TGO was because of the
pictures of Allen's TIG projects on his runners, Now to
see this come full-circle must be gratifying.

Determination, a wonderful thing no?

 

awesome job man... still waiting those dyno results! :P

 

I understand completely, I was just saying I wonder how much your combo would have made with a complete FIRST system as compared to your FIRST lower manifold, SLP runners, stock plenum, and ASM monoblade. In other words, if you made 350 rwhp with the old setup, and 375 w/ your FIRST/SLP setup, would the complete FIRST setup made 350, 360, 370rwhp???

Keep up the great work. More than I could ever THINK of designing or completing, but I'm sure it will be worth it.

 

Gotcha Jeffery. No way to really know how much more horsepower the First Injection TPI intake system would have made. I can say the intake manifold is a vast improvement over what is out there. Maybe the BBK system will be close.

Thanks for the complements. Regarding the runner length. The Dart 200cc head is 5.625". The short side of the First intake manifold is around 8.125". Measured in the middle I would guess 8.375" to 8.5". That is a full two plus inches longer than the Edelbrock style TPI intake. My adaptor is one inch thick.

However in making the hour glass shape of the adaptor to meet the incomming air the shortest portion is .600". So my total runner length is in the neighborhood of 14.6 inches. That should be just about right to pick up the third harmonic wave around the 5800 rpm mark. So yes it is still a "tuned" intake system.

However the big unknown is what effect the siamesed runners will have on the tuning if any. Hopefully they will just act like a plenum as that is really what they are at this point. Just an extension of the plenum.

 

What would your "rough" estimate be for flow #'s for a SDPC Vortec TPI manifold with extrude honed newer style SLP runners (extrude honed to 1 3/4")??

Think it could flow close to 270-280 CFM?

 

I would estimate that a stock Vortec TPI manifold would flow around 250cfm. I don't think you can Extrude Hone the SLP runners to 1 3/4" without some prior work on them and that may include some welding. You would need to talk to Extrude Hone. So I would think the total flow would be less 250 cfm.

 

I have pretty much finished the modification to the SLP runners. Just some very minor clean up work. Here are some pictures of the finished runners. In the pictures I was mainly concentrating on the blending of the adaptor plates to the SLP runners. It won't be to much longer with the project. All the major stuff is done.

 

A couple of more pictures. Whats interesting is that just casually looking at them they look like regular SLP runners. You may not notice they are made to fit a First Injection intake manifold.

 

AMAZING JOB!

awesome craftsmanship my friend, congradulations.

cant wait to see the dyno results

 

All I can say is dayam!

As you said, to 95% of on-lookers those look just like stock SLP runners except when you can see the face where they mount to the lower manifold, which is all but hidden when installed. Good job!

 

Thanks guys. I think you are correct. Most people will not notice the difference when mounted in the car. Even the First Injection intake manifold looks pretty much like a stocker when in the car.

The holes are huge compared to the stock runners and manifold. They are big even compared to the Edelbrock. The dyno and track numbers will be interesting. The chasis dyno numbers can run anywhere from a 0 gain to maybe 50rwhp gain at tops. I'm hoping for somewhere around a 30rwhp gain. That would put me at 380rwhp.

I'm basing the upper gains compared to other dyno graphs. My car currently makes 300rwhp at 4500rpm and 350rwhp at 5000rpm. I have seen other dyno graphs with power points at those rpm's making close to 400rwhp. However with the high stall A4 that I'm running it is unlikely I will be that high. Now if I was running an M6 than maybe that would be a posibility.

 

Well I lucked out big time. I just placed the intake manifold on the motor with gaskets. I wanted to see how much the intake manifold ports would be off with the heads.

Everything matches up just fine. I thought for sure I would have to have the intake manifold shaved as the heads had been milled around .030", the block deck was taken down another .015" and I'm using the GM .028" head gasket.

The intake manifold bolt holes are well centered and I can screw in the bolts with my fingers. So with this development the project will speed up. I should be done by the end of the month only because my machinest is taking a two week vacation. So maybe in early November I can have some dyno results.