Boost Control
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Teching In
Joined: Dec 2024
Posts: 20
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Boost Control I'm runnign a 427 dart block in an 89 foxbody. 98mm promod turbo. The old setup was a forged internal 6.0 with a FIS 88 mm turbo. We were having boost control issues. The waste gates were not in what my tuner said was the ideal location. So we moved the waste gates. The piping running from the header outlet is 2.5" before they merge to the turbo. My tuner said we may want to look at moving that up to 3.0" as the 2.5" may be adding velocity on the air to the turbo. I'm running holley dominator. Before we moved the waste gates, we commanded 7 psi on the dome control. The boost ramped to 38/39 PSI almost as soon as the boost hit. After we moved the waste gates, we commanded 7 psi and the boost ramped up to arounnd 14/16 psi. Better. The car is new to me. Holley is new to me. We took it to the track yesterday to get in a couple of test hits. We managed 2 runs in the hour that we had. The first hit, the tires blew off at the line. 2nd hit, same, tires blew off, but then hooked and ran it out to about the 1000 ft. Track wasn't that great. I didn't see them put any adhesive down. Saturday fun drags. We commanded 7psi on the dome on the 2nd hit and when looking at the data log, we had around 24 psi for a bit, then it ramped down to 14/16 psi.
If anyone would like to look at the data log, I'd be happy to share. Not sure how to do that other than just e-mail it to a member, but definitely willing to do so.
The motor made 1200 hp at the wheels on 14 psi. The guy who had the motor previously ran it at around 38/39 PSI boost consistently.
Any input that I could get would be much appreciated.
If anyone would like to look at the data log, I'd be happy to share. Not sure how to do that other than just e-mail it to a member, but definitely willing to do so.
The motor made 1200 hp at the wheels on 14 psi. The guy who had the motor previously ran it at around 38/39 PSI boost consistently.
Any input that I could get would be much appreciated.
TECH Fanatic
Joined: Jan 2009
Posts: 1,063
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From: Bostwick, GA.
" The waste gates were not in what my tuner said was the ideal location. So we moved the waste gates. The piping running from the header outlet is 2.5" before they merge to the turbo. My tuner said we may want to look at moving that up to 3.0" as the 2.5" may be adding velocity on the air to the turbo".
So, where were they, and where did you relocate them to?
Not sure what your "tuner" is thinking.
Post your tune and a data log of the issue. It has to be in a zip file.
So, where were they, and where did you relocate them to?
Not sure what your "tuner" is thinking.
Post your tune and a data log of the issue. It has to be in a zip file.
Thread Starter
Teching In
Joined: Dec 2024
Posts: 20
Likes: 3
My car is still at the shop. I have more work being done. DS speed sensor + front wheel speed sensor for traction control, plumbing in pneumatic cylinder to activate the chute, and potentially looking at replacing the converter. RPM's stayed near redline through the pull. I was told the converter is a PTC and was sized for around 1200hp. What we laid down on Sat should have been in that neighborhood.
I don't have pictures of the turbo piping to show where they are now. Best way I can describe it is that the waste gates (dual's) were very close to the inlet of the turbo. After the bends in the tubing to route to the turbo. My turbo is located on driver side and located in the front bumper. The waste gates were moved to right around where the first bend starts in the turbo inlet piping. I don't have the tune file, but do have the data log. I have a video as well and I'll get a link to that.
Thank you.
I don't have pictures of the turbo piping to show where they are now. Best way I can describe it is that the waste gates (dual's) were very close to the inlet of the turbo. After the bends in the tubing to route to the turbo. My turbo is located on driver side and located in the front bumper. The waste gates were moved to right around where the first bend starts in the turbo inlet piping. I don't have the tune file, but do have the data log. I have a video as well and I'll get a link to that.
Thank you.
