I've been wanting to upgrade the 2.5" to a full 3" w/ high flow cat to go along with kteller's group buy for the 3" exhausts...but when i asked the muffler shop to fabricate me a downpipe one for my teg, they looked at me like i was crazy, WTF? well whatever, so what I'm wondering is if anyone on here fabricates them, or can point me to a good guy who can?

TIA, much appreciated

 

DRAG has 3" DP upgrade.
call us up.

 

sent pm

 

DONT upgrade to a 3" downpipe w/ a drag manifold, unless u like boost spiking.

 

It won't spike if you increase the diameter of the WG opening.

 

just to let you know, i have a revhard cast manifold...are those very prone to spiking also with a larger dp?

 

nope. they dont spike at all. revhard works great, thats what im running w/ a 3" downpipe. no spike!

 

also pm'ed

 

will anybody borrow me a drag manifold and a revhard manifold so I can make them?

Maybe a greddy also

 

You can also make it yourself. I ordered a 3" donut from http://www.raceengineering.com and cut and tacked it up myself. Here are some pics. It is just an idea though that building them isnt that hard. Sorry, the pics are a little hokie.

 

why is there boost spiking on the drag 3 manifold w/a 3" downpipe.... sorry if newbie question. thanks

 

Yeah I wondered the same thing, I have seen it happen, so if anyone can help let us know...

 

spiking has to do with the wastegate, not the manifold

 

I have a 3" dp with no spike problems ever on my drag III kit and tial wg with no upgraded wg size. Perhaps only on low boost levels.

 

well we have actually gone into some pretty good discussions about this on H-T. Using the search function you can dig up all kinds of good info. its been proven that the drag manifold spikes when back pressure is released off the turbo because of the placement of the wastegate on the 4th runner. look at revhard/inline, sfp, max rev and the wastegate is in the middle. Its not an issue with these manifolds. porting the the manifold for the wastegate might help vent more exhaust gases, i guess u would have to give it a try to see if it worked. everyone on this site who has upgraded to a 3" downpipe w/ a drag manifold has swapped to a revhard style and it solved the problem. only thing is, most people kick themselves in the *** after they do this cause the 3" drag downpipe no longer works w/ the new manifold.





[Modified by DIRep427, 11:19 PM 1/14/2003]

 

Actually, the rev hard and drag both dump off of number 1. The differece is that on the rev hard the four merge into one very early and it's somewhat open inside the manifold. On the drag, each runner is seperate almost all the way until it hits the turbo. This makes it almost impossible for the wastegate to dump anything except the gas in the number one cylinder. I've seen many boost creep problems with drag manifolds set up with tial wastegates and big dp and exhaust systems. As if that isn't enough, the rev hard manifold always seems to make more hp.

 

rev hard , no spiking, I used to spike 1-2 psi on regular basis with the drga manifold, again due to the placement of the WG flange and liek tony said, the way runners are routed before it hit the turbo inlet..

stan

 

I had a drag 3 turbo kit and I had my dp flare to 3" as soon as it got to the bottom of my car by the oil pan and I had 3" thermal exhaust with no cat and I never had spiking...

I used a 40mm hks gate but it was just routed through the 35 mm wg hole in the drag manifold via a 90 degree pipe, so I dont think the size matters...

 

Interesting...Thanks for all the input and help guys...

 

is the drag DP universal say with a Greddy kit ?

 

still want to know what flange a drag turbo has...anyone know?