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Discussion Starter · #1 ·
Following the fitment of my new JT 3" system, do i need to adjust the Base boost?

The car seems to drive well since fitting, but what effect will it have if is set incorrectly?

Thanks for your help!
 

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Yes, you probably will need to adjust the base boost as it is determined not just by the spring setting of the actuator, but also the back pressure from the exhaust which helps keep the wastegate shut. Performance exhausts for turbo cras generally reduce the back pressure to help the turbo spin up quicker. Thus your base boost will probably be lower than before you fitted the exhaust.
 

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I've lost aboout 1.5 psi off my old base of 7psi after I fitted a 3" Jt to the carly last month.

Time for a turn or two I think.

A low base boost will mean a more lethargic rise in boost and possibly a lower peak boost at higher revs.

Andrew
 

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Discussion Starter · #4 ·
Thanks all.

Sounds like a good excuse to get a boost gauge. I have read the info on BillJ's site as to how to adjust this.

Has anyone got any reccommendations as to which gauge to go for?

Out of interest on a '94 Aero what should my peak boost be reading?

Thanks again!
 

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I picked up on Mark's comment about base boost when a similar thread was on before - I have a JT 3" front pipe on my GM900T and noted that when a pressure gauge was fitted I checked and noted that my base boost was at stock 0.4/0.5bar so hadn't changed. It did however tell me that the APC was knackered! and I had been running a LPT for some time. All is now restored to get the benefit of the stage 1 upgrade.


Mike
 
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