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View Full Version : How much boost can I run?


David Gordon
03-04-2006, 11:05 AM
I have a 89 TTA and the boost gauge only goes to 14# we tried turning it up then the car wouldnt shift gears, I had to let off the gas so it would shift. Still turning it up I dont think it ever went over 14.5# max. I tuned it down 4 turns and now the boost only goes to about 13.5 #. What am I doing wrong.
Has anyone ever tuned their car on a dyno? I have the adjustable fuel pressure and adjustable boost thingy on the turbo. I dont want to run in the 12s just get what I can out of her.

Mtocrs1
03-19-2006, 04:03 AM
Boost really shouldnt effect shift points. A nunmber off things effect the amount of boost a car can make (exhaust,intake) I would start by changing the chip and making sure it has fresh 93 octane fuel. The knock sensor might be retarding the timing and boost.

Keller
03-19-2006, 04:15 AM
I dont want to run in the 12s just get what I can out of her.
:what: So....would 15's be OK then? Something tells me no.

Stock TTA's should be able to break into the high 13's. But the stock fuel pumps were not adequate, just like the GN's and T's. In good shape, they might be OK. Well used, they likely aren't.

Do you have a scan tool to see what's going on? (i.e. See if it's knocking, etc.)

Do you have a fuel pressure gauge to see how high the pressure is being adjusted? And how high it stays under boost?

Are you going by the stock boost gauge in the dash? Or an accurate aftermarket one?