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101st Airborne 1/327 Inf
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Discussion Starter · #1 · (Edited)
Just finished talking to Dennis of OGTS about the possibility of tubular headers once again being offered by them. To my surprise he informed me that they are in the process of testing a prototype that will be offered once again this year. With the old header (LT2400 in the catalog) a modification to the intake manifold was required to clear the #2 and #3 pipe. The new design will fit to the block with no interference from the orginal intake manifold. The price should be around $300.
 

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Opel Tinkerer and Rescuer
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Or better yet.. are they doing a Manta one as well?

Charles
 

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I was supposed to be prototyping the GT header for OGTS on my own personal GT, but other things keep getting in the way. It will happen, I just don't know when.

The real issue is developing a header that is easy to produce (affordable), doesn't take 4 hours to install, makes more power (rather than perceived power), and will work with a stock downdraft intake, dual sidedrafts, or EFI. It's a tall order.

No requests for a Manta header from OGTS, sorry Charles.

Bob
 

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Got a request from me ;) How much to prototype one after the GT one is done?
 

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cucumbershampoo said:
are these gonna be mandril bends welded or complete, or normally bent tubing?
The prototype will be made from mandrel bends, cut and welded together. I will try to design it in such a way as to allow the manufacturer to be able to make each primary tube from a single piece of tubing. This means I can't have two perpendicular bends immediately adjacent to each other, or the CNC tubing bender can't perform the bend correctly. The prototype will be used for testing purposes on a dyno, and for the manufacturer to 'dissect', and that's it. I suspect it will eventually end up being thrown in the trash.

Bob
 

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Old Opeler
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RallyBob said:
I suspect it will eventually end up being thrown in the trash. Bob
Careful, Bob - or you will end up supporting a whole colony of "Dumpster Divers" on your front lawn! ;)
 

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Tru-Craft said:
Bob, did you ever finish the prototype?
Another thing on my never-ending list of stuff to do. No, never finished it. Collected all the parts, that's all. The primary issue: I need to fit it to my GT w/automatic transmission. That's at home in my barn, but all my tools are elsewhere, and my barn is unheated.

Basically, I need to be sure it fits any GT chassis, whether it's with a manual or automatic tranny, and I will need to mock it up with a stock downdraft intake, an EFI intake, and various sidedraft intakes. It pretty much has to be a 'catch-all' design, but it will be for warmed-over engines or nearly stock engines.

Bob
 

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1970-GT
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RallyBob said:
Basically, I need to be sure it fits any GT chassis, whether it's with a manual or automatic tranny, and I will need to mock it up with a stock downdraft intake, an EFI intake, and various sidedraft intakes. It pretty much has to be a 'catch-all' design, but it will be for warmed-over engines or nearly stock engines.
Bob
Yep, that sounds almost impossible!
Why not 2 designs?
1) Stock/nearly stock. 2,000rpm to 5,500rpm.
2) Performance engines with a set "minimum" of modifications. 3,000rpm to 6,500rpm.
Nearly stock/warmed over = smaller primary tubes.(1-3/8")?
Higher compression, big valves, big bores, bigger carb or carbs = 1-1/2" tubes?
The little bit I know and have read about exhaust design is it will only produce max power at a narrow RPM range. Tuning the length and back pressure only moves the power band up or down the RPM scale. Also the pipe size behind the header and muffler back pressure is critical!

On 2-cycle "stock" GoKart racing motors, the expansion chamber must be a fixed length, we adjust the header pipe length by an 1/8" to get the power band to match gearing, track layout and weather conditions. But, some classes allow slippy pipes! These pipes allow the inner cone in the expansion chamber to be moved while racing! This allows the peak power band to be moved up or down the RPM range at different parts of a track, amazing power over a very wide RPM range. Illegal in most classes!
Hey, how about an adjustable 4-cycle header design!:banana:
Bob, I don't see how you can make an exhaust system to do everything!
Lyle
 

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this just seems like a lot of work for someone to do, especially to design 2 of them...i mean the time and cost factor for bob to just design and seem all this up to see if someone would be able to mass produce these...
 

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Adam, I was hoping Bob had a 4-1 header that he made for someone's hot GT. Then he could just copy it!
Anyone out there with a Bob designed GT header we can have to copy?
Lyle
 

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spdkilz02 said:
this just seems like a lot of work for someone to do, especially to design 2 of them...i mean the time and cost factor for bob to just design and seem all this up to see if someone would be able to mass produce these...
The real cost is not in the design, but the tooling. I can make a prototype header in about one work day.

If you make two different header designs (still talking about GT's, haven't gotten into Kadetts or Mantas yet!), you will need to build two separate jigs to fit/weld the headers, and design the tube bending sequence (CNC) for each header type. Unless OGTS is willing to soak up the costs of two jigs and sets of programming, this is unlikely to happen.
 

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RallyBob said:
The real cost is not in the design, but the tooling. I can make a prototype header in about one work day.
Unless OGTS is willing to soak up the costs of two jigs and sets of programming, this is unlikely to happen.
Bob, I talked to Gil before Christmas, and he wanted a prototype header that would fit all GT's! He said he would have them produced if he had a prototype to copy!
Give him a call.
If you do take this job, there seems to be enough interest in a performance header to easily pay for your developement and fab time!
My Pace-setter #1 tube is 1/16" away from the intake manifold, we need to change this on the new header, for more air gap!
My 2 cents.
Lyle
 

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Tru-Craft said:
Bob, I talked to Gil before Christmas, and he wanted a prototype header that would fit all GT's! He said he would have them produced if he had a prototype to copy!
I spoke with Gil last week for quite some time. I will be speaking to him again soon in order to order some more parts. As far as the header goes, we spoke about me prototyping one for a GT quite some time ago, it all boiled down to my 'free' time (yea right!). I need to do it, but as I said it's not logistically easy for me to ensure it fits all applications. I could built it on my Dad's GT, but that's a 4-speed w/downdraft in there right now, it would be a bummer if it didn't fit a Getrag or an automatic, or EFI. I wouldn't know until I tried it out.

And I really wanted to fit it to an existing car and dyno it, Travis said he'd bring his car down so we could dyno before/after the header was installed (he has a modified 1.9, about 120-125 hp @ the wheels with a Sprint). No use in building a header if it doesn't make the numbers, right?
 

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RallyBob said:
I need to do it, but as I said it's not logistically easy for me to ensure it fits all applications. I could built it on my Dad's GT, but that's a 4-speed w/downdraft in there right now, it would be a bummer if it didn't fit a Getrag or an automatic, or EFI. I wouldn't know until I tried it out.
And I wanted to fit it to an existing car and dyno it, Travis said he'd bring his car down so we could dyno before/after the header was installed (he has a modified 1.9, about 120-125 hp @ the wheels with a Sprint). No use in building a header if it doesn't make the numbers, right?
Bob, if you build it to fit a GT, and Travis will donate his GT for a dyno run, and it puts out some good numbers.....your done!
Let Gil try it on some cars he has and local customers he knows.
If it needs a little heating and bending that's easy!
Don't waste your time doing it all!
Move on to the next project!:D
My opinion.
Lyle
 

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It's a New Year! What projects are we going to hire Bob to work on?
I say get him to build a prototype 4-1 header for a performance GT and Dyno it against an "un-available" sprint manifold.
Then get Gil or someone to get them mass produced by a header shop!
What do you think Bob?
Or just build one for me, if there is no interest!
Lyle
 

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Hi Lyle,

I agree it would be great to have quickly, but I also see where rushing it will cause some issues. I think one of the big keys to it is making sure it fits with the 5 speed. It seems that many guys going to the work of getting more HP are also doing that conversion.

Realistically, how many automatics are out there with hopped up non-stock engines? My guess is that the number is fairly low. (single digit, even?)

Maybe we should run a poll on this website asking who would be interested in a think wall header and what configurations they want. I will see if I can figure out how to do it! It might be interesting, if nothing else.
 
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