Equal Length Tubular Exhaust Manifolds

[GreenEagle]

Lately I've been researching the pros/cons of running an equal length tubular manifold on a dual purpose street/track car. As many of you know, equal length runners benefit power and turbo spool up. (One site actually claims an 800 RPM drop in spool time ) The downside is, if not constructed properly with thick runner walls and high grade materials such as 321 stainless, they are prone to cracking. I have looked around and found a few people making these for DSM's:

DN Performance http://www.dnperformance.com/eclipse.html
Reasonably priced and looks like a nice unit, although I believe it is only 304 stainless, which is not great for turbo applications because of the high exhaust temps.

Full Race Motorsports http://www.full-race.com/products
Looks nice, VERY thick runner walls, only 304 stainless though, EXPENSIVE!

ETD Racing http://www.etdracing.com/manifold.html
From what I can tell these guys are developing on one for DSM's. If it turns out like the ones they make for other imports, it should be great: 321 stainless, thick runner walls, and very reasonably priced.

I know some of you out there run this type of manifold, and it would be great to hear from you. How many RPMs did it lower your spool? Did you notice any power gains? It sure would be nice to have a 400HP, 50 trim street car that spooled by 3400!! But then again, maybe these manifolds aren't all they're cracked up to be..

 

[CraigB]

I have a manifold from www.turbo-performance.com I just got it from a friend that ran it for about 6 months on the street. I inspected it for any cracks found 0. My friend was told by the owner of turbo performance that if it ever cracked he would replace it free of charge. This manifold is very thick and heavy I do not think it will crack any time soon.

As far as spool up it helped alot but I can not tell you by how many rpms I only drove it about 8 miles after this mod after a hard roll on in 2nd I broke something in the pressure plate or clutch disc.

 

[DSMJim]

I work for ETD and were not going to start developing a manifold for the DSM probably until next year. We have a few other cars on our plate that need it worse than we do. Miata and 240SX are the main focus. We'll probably make a B series one too shortly. That will fill the majority of our time up for this year as far as manifold development goes.

 

[GreenEagle]

Craig, sorry to hear about about the broken car. That Turbo Performance Manifold looks pretty nice, especially for $425. When you say it helped spool a lot, do you mean somewhere around 100-200 RPMs or more like 300-400? (if you had to guess)


Jim.. It's a bummer you guys aren't going to make one for a while. It really looks like you guys know how to build a quality product. I wish more shops were using the 321 stainless, instead of heat unfriendly 304. If you can do it for the proposed $430, it will be an excellent value when it does come out.

 

[DSM mechanix]

does the decreased spool time come for the most part from the manny being equl length or just because its a tubular manifold?

 

[GreenEagle]

The decreased spool time is a result of the equal length runners. They space the exhaust pulses apart evenly, which spools the turbine more efficiently.

 

[CraigB]

If I had to guess I would say about 300-400. I could feel a difference right away.

 

[marshall]

The Full-Race manifold is 321...

 

[gritsak]

Originally posted by marshall
The Full-Race manifold is 321...

no its 304

 

[marshall]

Hmm, when I spoke with Geoff on the phone he said he was using 321, that was a while back though...

 

[GreenEagle]

According to a post he made here: http://www.dsmtuners.com/forums/showthread.php?s=&threadid=3861&highlight=equal+length+header Geoff said:

The tubing is 304 stainless steel and is certified to contain 3000 psi of highly corrosive/caustic gasses at ~2000 degrees.

That was back in June though, so maybe he's changed.

 

[swordfish]

The Full Race manifold is $1199. I would rather have this Manifold from turbotrix. Truthfully, um.... no way I would pay for either of them unless I was in this to make money and trailer my car around from event to event.

jeff

 

[GreenEagle]

Jeff, I'm with you on that. $1200 is entirely too much for a manifold IMO. For $500-$600 I think it would be a worthwhile mod though.

 

[DSM mechanix]

as ive heard, the Full Race manifold is made from 304, but if requested he will make if from 321.

 

[Turbodenz]

my buddy has his own shop and makes turbo exhaust for all cars and equal link runners on all. ill have mine in a few weeks and they cost alot less than $600

 

[DSM mechanix]

Originally posted by Turbodenz
my buddy has his own shop and makes turbo exhaust for all cars and equal link runners on all. ill have mine in a few weeks and they cost alot less than $600

Details???