theedge

Yes, multipeice!!!!! Bad bad bad idea doing the downpipe and cat pipe combined! That would increase the labor for several other things, like engine drops, clutch jobs, etc. That and the bolts for the downpipe to turbo are impossible to get at with the turbo installed. IIRC one of them isnt even accessible with the turbo mounted. Nevermind getting any solid torqing on them.

I also really like the idea of multiple bungs. One in the stock spot for the stock narrowband, and one or two after the turbo. Ive got one just below the downpipe mating flange on the cat pipe, and one in the traditional spot under the door on that curve. I like the higher spot more, its way less vulnerable. And the EGT bungs are a good option too, id pay for those.

marksportcts

Does anyone remember Alex Broadfoot's 4-into-1 headers? Sound just like what Mark is building.....







These aren't cheap either...

Eyal 951

yea, and nobody buys em cause their not worth the price.

Zero10

The setup posted one or two up looks pretty good to me, just not the price

I am interested, but I'm not sure I want to replace my entire exhaust...
So, what I would like to see available, is a header/crossover, with a stock-ish wastegate tie-in. So, I can either change flanges or whatever I need to do if I wish to upgrade to a Tial later, but retain my stock downpipe. I'll just buy another stock one from somebody who has upgraded theirs, and weld an O2 bung on for a WBO2 at a local exhaust shop. (It's single-walled, right?)
I would also like to retain my stock cat-back. I don't want to make huge power, but I do want my exhaust leaks gone, and the potential to upgrade the rest of my exhaust down the line.

Am I on the same page as everybody else here?

MarkRobinson

Yes, I guess it would look similar to that, though I'll notch the flange so that the runners can come out a little farther before turning down, decreasing a little pressure there. V-band will be very close to what's shown above: it needs to be well before the turn-under so that it doesn't cause turbulence with the exhaust pressured to one-side while crossing the V-band. Anyone know the stock primary & cross-under diameters?

What about the 2.5" choke at the DP? If I make my own 3" dp, you'll need my 3" cat-pipe to go with it since it'll be v-band, otherwise, I'll have to put a 2.5" bolt-flange in there for other company's products or worst yet, stock parts. Comments??

Mark.

streckfu's

Can you make a 3" DP bolt up to the stock turbo? I think that keeping as much as possible 3" is the best route.

code5coupe

What is the reasoning for both SS and coated?? Seems that you could drop the price by going with one or the other, not both...?

Larry

pole position

IMO the best way to cover the market would be to offer the manifold,crossover,WG tie in,3" downpipe,3" cat bypass ,V-band and finalize it with a true 4 " catback a la Fabspeed. Offer some options like wideband/EGT bungs, ceramic coating etc and if everything is priced right it will translate into a on stop exhaust shop for many 951 enthusiasts.

MarkRobinson

Yes, my plan pretty much.

Supra guys usually don't go 4" post-turbo until they're well over 800hp...why so much 4" hype here? Have there been some recent dyno testing to show it's advantage? 4" SS tubing is very pricy...

Matt H

Mark, the answer is that they were told it is better. I agree, rare to see 4" on anything make less than about 700HP, on the Supras I used to work on I cant recall ever doing it and most of them were putting out at least 2 times the HP that 99.95% of people make with the 951.
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theedge

Canadian Turbo Cup cars had 4" and were faster than the normal Cup cars. So its said anyway.

Zero10

Haha, so really there's no proof that 4" provides measurable gains in our setups.

3" sounds just peachy to me
Please keep up on the development of this, and please let us know what it will cost, and when it will be available.

I like the single-piece header flange, much easier to line up. Although I am a little bit concerned about it warping. Is there any way to address that?

951Boost

Hi Mark, as I have said before, I’m interested in a complete system from header to muffler.

1) True 3” system from downpipe to muffler = YES
2) 2.5" choke down on cat test pipe to accommodate stock downpipe = NO
3) 1 piece downpipe/cat test pipe, as others have stated; BIG NO-NO
4) 4” anything = Absolutely NO interest at all for many (personal) reasons.
5) Wideband/EGT bungs = YES, even if they are optional.

Did you give up on the idea of a flexible joint somewhere (post #10)? I don’t want to start a flame fest here since none of the other manufacturers offer one and I’m sure that is to be taken as “not needed” but a few months’ back I spoke with Martin Schneider (MSDS inc.) to see if they made a header system for 951’s and he said that he didn’t believe that the market was large enough for them to take the time to develop a system with a flex joint somewhere and they would not sell a system for these cars without one because sooner or later they WOULD crack. Plus the factory did switch to the bellows type headers due to cracking.

I am not saying that the cracking will happen; I’m new to these cars and still learning about their quirks, just offering this up as a FRIENDLY point for discussion.

Thanks for going forward with this project.

nize

alex broadfoot's 4-to-1 headers do not look like they are equal-length. i think equal-length would be important for aftermarket headers. anyone else?

reno808

Equal length is the way be.