Just wondering you guys experiences with the 3 piece exhaust manifolds. Are they really worth what the want for em? Did you see any real gains?

 

I don't have one, but I think good porting on the stock one will do close to as good a job.

 

I think not so much for performance, but for a cracking
problem with stock manifold.

 

i havent heard of any gains at all!!
but dont quote me!!

 

I havent heard of any gains yet either. For 500.00 i want something I can feel a difference. Ill buy a stock one and port match it to the head.

 

My EGT's dropped a 50-100 degrees or so cruising. Specs say they flow 35-40 CFM better than stock. Plus the shrinking problem, I don't have to worry about it anymore.

 

Its on my wish list because the $$ is worth not having to take the rusty old H1C off the rusty old manifold. When I get the time to tear into the truck I need to make the best use of my time, and being able to have the new turbo and manifold bolted together on the bench before I touch the stock stuff is worth something. (Not $500 but...)

 

Pete, do you have the ATS or the BD?

 

I did a little test about three years ago with all of these.................darned if I can find it in the 12v high performance forum though.

Anyhow; had the test done on a flow bench at a race shop.

Ported stocker flowed the least, and this one had not shrunk.

BD and HTT, which was ported also, are identical manifolds and flowed 20% more than the stocker.

ATS was unported and flowed 8% more than thr BD/HTT manifolds. That is what's on my truck.

I then had the ATS ported which helped with spoolup.

A note about testing; the tester said the stocker, and BD/HTT were loud on the flow bench which he attributed to turbulence while the ATS was much quieter.

He also stated the BD/HTT and ATS numbers were pretty even for every cylinder where as the stocker flowed more at the outer ports than the inner IIRC.

You won't see much of a difference at all unless you have some mismatched ports or making 400+ hp I would guess.

It does seem to lower egt's.

I also recommend you are sure the egt probe is in the manifold as far as it will go for a more accurate and quicker reading.

I have noticed just leaving the probe out a turn or two can have a 100-200 degree difference.

 

Personally I wouldn't worry about it til you were over 400 hp and lookin for every little bit you can find. I ported my stocker and I'm sure it helped a little (swapped turbo at same time so not sure how much difference) I'm gonna wait til mine cracks or shrinks or I'm over 400hp til I get one. I'd say $400-$500 would buy you a pretty dang good turbo which would help a lot more. But I have heard good things about ATS manifolds, and also PDI.

 

I heard recently that some of the ATS manifolds were cracking. Maybe whoever is casting them just had a bad batch of metal at one point?

 

it's my guess with how hot some guys run their trucks and just the heating and cooling cycles, it's inevitable no matter which manifold you're running that some will crack.

 

check out these best one out by FAR

http://www.steedspeed.com/the_ultima...iesel_manifold



price went up $50 from 2 weeks go

 

my first thought when I looked at that was that it was pretty narrow on each side of the collector where it connects to the t3/4 flange. And now my second thought is that it's a 1 pc. Part of the advantage of a 2 or 3 pc manifold is to prevent cracking because the individual pieces allow for better expansion and contraction through the heating/cooling cycles.

It's at times like this that I wish I had the money to do tests on this sort of thing to get real world numbers and find out what is really the best.

 

i thought the same thing but it does have a lifetime warranty and satisfaction guarantee. I wish they had dyno sheets