Ok just had my car tuned on a rolling road dyno.

375rwhp @ 18psi (simplified seq)

My problem is peak power is achieved at around 6500rpm then boost drops off, sometimes loosing 1-2psi and others up to 4.5psi.So obviously power drops as well.

Any ideas why or what i can do to hold boost steady?Will an EBC controlling the wastegate instead of the stock solenoid fix this?

Car has following:
Mild port
PFC
FMIC
3" DP.... My car is RHD so collector may not be as open as what US spec can run
3"MP
3"CB
Efini Y pipe
Tial 50mm BOV
850cc primarys
Walbro pump
Sard reg -8an fuel line and fittings
Removed airpump.powersteer,a/c

Air temp was consistent 33deg Celsius
Injector Duty around 93%
Fuel pressure was good on every run

 

Did you try a stiffer spring in the waste gate. Looks as if the differential pressure may be opening the valve.

 

Im not 100% sure but i think its an actuator issue.

 

Remove the sequential system and you'll be able to maintain the power. If you want to keep the sequential setup, you'll probably need to use a regulator on the pressure tank to see if it will help:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/high-boost-sequential-pattern-743365/

 

hey thanks for the link i will definitely look into that.

I haven't tried different wastgate spring, can they be changed in the stock wastegate actuator?

 

 

Thats right you have the stock setup. Nope you cannot. The only thing you can do is to preload the gate deeper into the stock spring. Your best bet is to reduce the pressure as the others say at this juncture.

 

Also, you can switch to 3 port boost control solenoids (same kind used in aftermarket EBC's) inexpensively by buying this one: http://www.frightprops.com/FrightPro...ID=A-0013-0082 .

and the stock connector (solenoid side) is here http://www.bmotorsports.com/shop/pro...oducts_id/1674

so if you have two 3 port solenoids you will be able to have individual control for precontrol and wastegate using the PFC. If you buy an aftermarket EBC you will lose individual control over wastegate and precontrol.

 

Right Im off to the local Norgren.

Thanks everyone for the help, absolute legends!!!