fd boost problem
 

my stock fd is getting 10 psi on the first turbo and when it transitions to the 2nd turbo i get about 6psi. i know boost pattern should be 10-8-10 and the 10 should hold till redline. any ideas?

https://www.rx7club.com/3rd-generati...tified-841821/

Turbocharger Overview

If it's stock, check the Y-pipe connector. While that may not be the problem, they pretty much always fail

The OEM rubber couplers do fail. But I doubt that's the issue since he's reaching 10 psi until transition.

Check your wastegate solenoid ( hoses and connection ) . Did you work on the Car before ? Or did it just stop working from one day to the other ? If the wastegate solenoid is not working you would get only 6-7 psi on the secondary as it would only work of the wastegate actuator spring . The wastegate solenoid is the right one of the two that are mounted left of the black pressure tank in front of the UIM

prior to this i was only getting 6-7lb primary until i noticed the previous owner changed most rubber hoses. checked the hoses on pre-turbo control and waste gate and they didn't have restrictor pills. installed original hoses with restrictor pills and got 10lb on primary. steve kan told me to change the solenoid rack also. just haven't had time to swap it yet. i thought solenoids are either on or off so if it works it works and if it doesn't it doesn't meaning i wouldn't even get 6-7 on secondary turbo. i could be wrong. will keep u guys updated when i change it tho.

Have a look if your wastegate and precontrol solenoid connectors are swapped arround . Wastegate connector has a white dot on the connector . I had that problem recently and it gives you about 10 psi on primary and 6-7 on the secondary . Took me 2 weeks to find that out lol.
To your question a faulty wastegate solenoid would still create 7 psi on the secondary as the boost is then purely controlled by the wastegate actuator spring

u right markus! the previous owner plugged in the solenoids in wrong. i have a spare fd engine and was gonna swap out the solenoids but noticed the white dot on the connector and the solenoid wasnt plugged in right. swapped the plugs and bam im getting 11-8-11 until i blew a hole in the stock plastic crossover pipe. i have a efini y pipe ready for install but waiting for the gasket to get here. if its not one thing its the other with this car. love it tho

^Just curious, where did you source one of those gaskets? And how much? Mine is fine for now, but just in case....

Glad I could help ;) took me almost exactly 1 year to sort out all my turbo problems , but finally everything works correctly . Luckily the series 7 has the nice all cast y pipe and cast crossover pipe . I got rid of anything plastic when I was still on my stock intercooler , as I blew the pipe to the SMIC . Finally I converted to FMIC and greddy elbow so no more weak points in the piping .

got the gasket from rx7.com. pretty much the only place you can buy it.
i also have that greddy m style front mount. bought it from rx7store.net. got mislead by the pictures and description. in the pictures it shows that the kit comes with t-bolt clamps and description said inlet/oulet 3". i received it yesterday and inlet is 2.75" and came with regular hose clamps. then i called him about it ansd hd changed the description. offered to send me t-bolt clamps. was gonna ship it back but costs $90 so im just gonna keep it. wtf

check your turbos same problem happened to me and 2nd turbo ended up not kicking in and leaking oil form it now on the road to single turbo

This is EXACTLY what happened to me haha. Got the car, all was well, a few weeks/months later i noticed that i was only getting 5-7lbs of boost and only above 5k (meaning i had some serious boost issues).

Started stripping the engine bay, found out two actuators under the turbos were missing clips and popped off the pin, meaning no primary turbo!!! or something weird like that, very confusing. Also noticed oil was leaking out somewhere even though they apparently only had ~5k miles on em. So inevitably, i decided to go single as well. Ditching all that vacuum crap and tossing a ton of junk/weight out of the bay, Cannot wait to get the single all done!