which manifold for twins

morkable

morkable

Just Over Broke
Joined
Jan 30, 2008
Messages
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I got a silly question, but which manifold is it that you use for twins? Is it a 12v or a 24v one? Is there a particular year that is better than others?

Thanks

Kevin

ps, if anyone has one for sale for a reasonable price let me know
 
24v for a 24v or a CR truck and preferbly a HTT, they give you the most clearance for the top turbo.
 
You can use a stock one, but the aftermarket 3 piece versions will spool quicker and lower egt's. I ran a stock 24 valve for a while and noticed a considerable difference in low end power going to an aftermarket 3 piece.
 
A 98-02 24v one would work but if your doing twins and making good power with it you will most likely crack it after a while and would be better to have a thicker one to support the weight and be able to expand and contrat with the 3 piece unit.
 
A 12 valve manifold has rectangular ports a 24 valve and CR has round ports.. Your stock manifold would work, but are more prone to cracking and shrinking so's that you can't get the bolts back in once it's been removed.. The HTT is one of the best for building twin setups.. With the ATS you have to use at least a 1 inch spacer for the turbo to clear the slip joint on the manifold..
 
any experiences with the new 2nd gen PDI manifold with twins? that looks like a nice piece
 
The PDI manifolds work great they fit nice and they are made of the same material as the turbo housing so they cool and heat at the same rate.
 
PDI manifolds that i have used worked real good and they are cheaper than HTT and ATS.
 
Doughboy said:
With the ATS you have to use at least a 1 inch spacer for the turbo to clear the slip joint on the manifold..
Click to expand...

Not every time. I've got one (2nd Gen) flipped for twins with an S300 based charger on it with no clearance issues at all....and no spacer.
 
Which manifold

dzlfarmboy said:
24v for a 24v or a CR truck and preferbly a HTT, they give you the most clearance for the top turbo.
Click to expand...

Exactly!! Been there.

Get yourself a grinder and port match the exh ports though. I've had stock, ats and htt and ALL needed it.
 
I like the HTT's because they're smaller OD on the outside, easier to clear turbos.

I've never seen a performance difference between a stock 12v manifold and an aftermarket 3pc, but it might be different w/ the 24v manifolds?
 
I posted this on DTR a while ago but, I had a ported 12v stocker, a ported HTT (identical to BD) and a unported ATS. Brought them all to a race shop who then flow benched them all. I was told the HTT flowed about 20% more than the stocker and the ATS flowed 10% more than the HTT. He noted the stocker and HTT were pretty loud on the bench compared to the quieter ATS which he attributed to more turbulence.

After using all three, I can say the ATS spooled and cooled the best.

If doing twins, I can't help you in that department.
 
a stocker

flipped upside down with crossdrilled gate on a top charger works well.. I dont see how a manifold would give better performance though, but with the bigger holes i do see the egt reduction... Had i the cash for a manifold id probly do HTT... but the stocker has worked well enough and not cracked..

why not save some coin and try it that way? IMHO its not a dramatic powergain if any with an aftermarket..

Rick
 
I know this subject has been beat to death... but I have yet to get any worthwhile response - I've been looking for a tubular manifold for twins. I've heard that Jefferson State Diesel should be coming out with one for sale-anyone else?
 
hell, i'm running around with a 12valve manifold on my truck, seems to spool the turbo a lot quicker than a 24valve manifold (I think). I'm going to be port-matching it though when I throw a 72+mm turbo under my cat one
 
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