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hardtopper
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Discussion Starter · #1 ·
My car has been running great but I haven't tried to turn up the boost passed 22-23PSI yet. At those boost levels it holds boost great and I have no issues from 15PSI through 23PSI.

Now I have tried to turn the boost up and it doesn't want to hold. If I try to set it to 27-28PSI it spikes to 30-32.5PSI!!!! If I set the boost to 24-25PSI and start to get on it at like 4200RPMS it boosts fine but if I sart out at like 2500RPM and let it come up it overboosts to like 30PSI!!!! I just can't seem to figure it out.

I am using a HKS EVC5 for a boost controller and HKS 60mm wastegate with a 13-14PSI spring. PT67mm anti-surge turbo with .68hot side.

Does anyone have a clue as to what my problem might be? It holds boost fine down low under 23PSI. Might it be the spring is to soft of a spring to hold above that pressure?
 

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hardtopper
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Discussion Starter · #4 ·

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hardtopper
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Discussion Starter · #5 ·
?
 

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cast manifold, correct? that could be your problem.

Jason
 

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hardtopper
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Discussion Starter · #7 ·
HotSoup said:
cast manifold, correct? that could be your problem.

Jason
that is correct. it is the induction motorsports manifold though which is supposed to have been ported and coupled with the 60mm wastegate to take care of those problems. I know other people on the forums have the same kit and don't seem to have this problem. it doesn't have
any problems with lower boost. not even a hint of it.
 

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HotSoup said:
cast manifold, correct? that could be your problem.

Jason

Thats what i'm thinking as well. Josh does however have a 60mm wastegate installed on there in place of the smaller 38mm or 44mm. Maybe it has the same problem with the RPS tubular manifold where the actual location of the wastegate was the issue. I told Josh to try a hallman boost controller to eliminate the possibility of it being the boost controller.
 

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I love sequentials!
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Put race gas in it and disconnect the wastegate or connect it's source to vacuum

Use your brain when you do this, but if you 1/2 throttle it until 5k or 6k, and then floor it to see if it will hold the boost, you can rule out everything else.
 
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