Twin turbo boost limited by exhaust?

Coyote'13

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I’m running a hellion 6266 setup with an ams 1000 boost controller and the car seems to be limiting boost around 18psi. It has 3” hpipe with gt500 mufflers. Does this sound like an exhaust restriction preventing me from making more boost? The car makes over 1000hp at 17 psi.


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clinton2003

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not to be a dick, but WHY are you running a full exhaust at that boost level..... Easy way to find out is strap the H pipe to your trans brace and take off over axle pipes and mufflers. see what happens. if you can take off the H pipe and leave cat deletes on (need a bit of pipe after O2 sensor for correct readings) that would be better. see if you get more boost. I wouldnt think with the ams you would need a bigger wastegate spring....

my car, stock hellion setup, with 64's makes as much boost as i want it to. I have a cheap boost controller (Daytona TC-1) and 4 port solenoids with dual 4 port solenoids. i have 0 issues controlling my boost. After the hellion down pipe, where it would connect to the cats, i have some custom pieces made, comes down flat, to a 9" long (overall 12" long) by 3" ID resonator then a turndown. exhaust ends about mid door, and connects to the trans bolts of the transmission cross brace. Solid and quiets it down some without restriction.
 

98 svt

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not to be a dick, but WHY are you running a full exhaust at that boost level..... Easy way to find out is strap the H pipe to your trans brace and take off over axle pipes and mufflers. see what happens. if you can take off the H pipe and leave cat deletes on (need a bit of pipe after O2 sensor for correct readings) that would be better. see if you get more boost. I wouldnt think with the ams you would need a bigger wastegate spring....

my car, stock hellion setup, with 64's makes as much boost as i want it to. I have a cheap boost controller (Daytona TC-1) and 4 port solenoids with dual 4 port solenoids. i have 0 issues controlling my boost. After the hellion down pipe, where it would connect to the cats, i have some custom pieces made, comes down flat, to a 9" long (overall 12" long) by 3" ID resonator then a turndown. exhaust ends about mid door, and connects to the trans bolts of the transmission cross brace. Solid and quiets it down some without restriction.


Any pics from under the car?
 

Coyote'13

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not to be a dick, but WHY are you running a full exhaust at that boost level..... Easy way to find out is strap the H pipe to your trans brace and take off over axle pipes and mufflers. see what happens. if you can take off the H pipe and leave cat deletes on (need a bit of pipe after O2 sensor for correct readings) that would be better. see if you get more boost. I wouldnt think with the ams you would need a bigger wastegate spring....

my car, stock hellion setup, with 64's makes as much boost as i want it to. I have a cheap boost controller (Daytona TC-1) and 4 port solenoids with dual 4 port solenoids. i have 0 issues controlling my boost. After the hellion down pipe, where it would connect to the cats, i have some custom pieces made, comes down flat, to a 9" long (overall 12" long) by 3" ID resonator then a turndown. exhaust ends about mid door, and connects to the trans bolts of the transmission cross brace. Solid and quiets it down some without restriction.

It’s the hellion down pipe to 3” o/r h-pipe. I don’t want the car loud all the time with a single chamber resonator. Already planned to disconnect the hpipe, the point of the post was to see if anyone else has experienced boost limitations on a chambered muffler. I’ll be running qtp cutouts for kill mode if that’s the problem.

Why would you want to dump exhaust mid car? You got any pics of it?


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KEVINS

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I don't know if my combo gives you any help since I'm not making quite as much power as you but my TT 2V makes 900+ at 32psi through 4R70 and a full length exhaust including three mufflers.

I have dual 3" DP's that feed into dual 2.5" at the firewall then into a X-muffler that I made located at the end of the transmission, back into a pair of Dynamax Ultraflow mufflers then back to the bumper.

ks
 

clinton2003

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Why would you want to dump exhaust mid car? You got any pics of it?
I dont have pics on my phone, but i did it as a compromise to just straight dumping it after hellion downpipe. I knew i'd be going with more boost than should go through the full exhaust. I had a straight through exhaust (no res, and open MBRP mufflers) but was almost stock sounding. was too quiet.
Originally had planned on doing this until i can purchase cutouts, but havent had the chance. The longer dumps give it a good sound. Bit on the loud side for the average person, but sounds great and have nothing but compliments on the sound of the car. Even an older lady in a minivan commented on it. HA!
 

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