I am going to do a Race Gas tune, but seems backpressure is whats holding me back, not lack of fuel. I remember (should have taken pics) but the QTP 3 inch cutout is actually just a little over a 2" plate that opens up and while on the DYNO there was a lot of exhuast coming out of the back of the Invidia, so clearly the cutout didnt really do its job & the Invidia doesnt flow all that well

I was thinking rather than swap to a single if their is a Way I can just remove the Cut-out section when I want to run the Race gas and just have the exhaust dump out the bottom of the Downpipe and leave the exhuast their for basically looks

Is this the ridiculous thing you guys have heard or have some of you guys done this?

 

If your dual WGs can vent enough of the exhaust flow (since theres pretty much no back pressure at all with no exhaust) then I dont see why you cant.

 

No reason why you can't. Lots of drag race guys run open downpipes.

This is what i will be running at the drag strip...or if i just want to piss people off haha.



I will have another down pipe built that will connect to a inline pro exhaust for the streets.

You could have a peice build with vband on each side. One side on the down pipe, the other side on the exhaust. Remove it when you want the open down pipe, hook it back up to go through the exhaust.

 

Exhaust back pressure post turbo, or pre turbo?

EL top mount mani right? What turbo a/r again?

 

Post Turbo, I have the PFAB Top Mount Divided manifold with a GT35r 1.06 Divdided.........

J-GO That is exactly what I want to do, be able to remove a piece so I can just go with a down pipe, probably so F----- Loud. The Cut-out only allows a really small amount out, Kind of dissapointing

 

put the cutout on an optimal (air) flow path, and get a true 3 inch cutout

excuse my crude drawing, but is what i am talking about. It can be done, as i have it.

 

i ran open downpipe for almost a year, no problems. just suit on the underside of your car and exhaust fumes in the car when you come to a stop. just leave the HVAC on recirc, if its on the "air from outside" mode, you get a strong exhaust smell in the car.

so no real problems, its just kind of annoying.

 

^ with the Open dumop did you still have mufflers on the car or what did you do with the rest of the exhuast

Yea I don't know I like he ease of the electrical cutout, but the opening is small and the part where it splits, the cut on the inside was a real hackjob................

 

pretty sure Rob! ran his like that for a while.

 

Hey Joey,

I love my Electronic cutout as well just because its quick and convenient. Have you consider just running a bigger cutout to meet your needs?

I got my cutout through DMH performance, they seem to be a favorite amongst the V8 crowd. The cutout size goes from 2" all the way to 4" I belief.

But you're right even my 3" cutout, at full boost, I can see some exhaust gas coming out of my dual exhaust. But since I'm not boosting as much as you, my tuner said it doesn't make as much of a difference.