Sequential system... 15psi on primary, 10 on secondary.
Hey guys, so after finally being able to pass emissions I finally had a chance to drive the car a bit. I'm a bit concerned as my primary hits a steady 15psi and then at switch over boost levels stay at 10psi. The car is about 98% stock with the exception of a downpipe and a drop in filter.
I am not having any issues whatsoever with the extra boost, it actually runs and drives great and pulls like a freight train. I redid all my vacuum lines w/ silicone, had the injectors serviced by RC, and replaced some couplers. I live by the mile high city, so altitude is a considering factor. |
My first thought would be a partially clogged cat. Is it the original cat? You could try removing it, and shaking out whatever debris that may be in there. It isnt that hard to do.
|
Isn't it dangerous to pull 15 psi on stock car?
I didn't think stock ecu can handle boost above 12 psi. |
When you replaced your vac hoses, did you test your solenoids and actuators? I was getting healthy boost and eventually got around to testing the control system. 4 or so solenoids and my turbo actuator were all toast (solenoids would open cold, but not hot)
|
Originally Posted by adam c
(Post 12000744)
My first thought would be a partially clogged cat. Is it the original cat? You could try removing it, and shaking out whatever debris that may be in there. It isnt that hard to do.
Originally Posted by 94VRotary
(Post 12000758)
Isn't it dangerous to pull 15 psi on stock car?
I didn't think stock ecu can handle boost above 12 psi.
Originally Posted by TomU
(Post 12000764)
When you replaced your vac hoses, did you test your solenoids and actuators? I was getting healthy boost and eventually got around to testing the control system. 4 or so solenoids and my turbo actuator were all toast (solenoids would open cold, but not hot)
|
When I lived in Colorado Springs with a mostly stock car my boost was more like 12-13 on primary and 10 secondary. I installed some bleeder valves in the charge control activators and was able to fine tune it back to something very close to 10-8-10. I'm amaze this page is still up after so many years: https://robrobinette.com/boost_controller.htm
|
port the wastegate and get a PFC
|
Not here to be negative. If you get a true 15 psi from the twins, which is what it sounds like you are trying to achieve, on the factory ECU. You are begging to blow her up. The old list of mod restrictions for the factory setup is FD 101. Dial it in to 12 psi max or install a PFC and have it tuned. Don't be a victim
|
Originally Posted by TomU
(Post 12000786)
port the wastegate and get a PFC
|
Originally Posted by Tom93R1
(Post 12000802)
15psi on primary turbo and 10 on secondary boost is not wastegate porting issue and PFC will only fix it if you know how to tune the boost control pattern.
... or map more fuel |
Overboost on the primary turbo with a stock setup could be caused by the turbo precontrol circuit. In stock config the wastegate doesn't start opening until after the secondary transition, the precontrol is used to throttle the primary turbo while sending what would be "waste" exhaust to the secondary to prespool it.
Make sure the vac lines are routed properly as well as restrictors installed correctly... |
Originally Posted by furious_rotation
(Post 12000788)
Not here to be negative. If you get a true 15 psi from the twins, which is what it sounds like you are trying to achieve, on the factory ECU. You are begging to blow her up. The old list of mod restrictions for the factory setup is FD 101. Dial it in to 12 psi max or install a PFC and have it tuned. Don't be a victim
I was reading this thread: https://www.rx7club.com/3rd-generati...n-myth-934461/ There's different variables in which the "system" can account for additional pressure according to his data. Perhaps is the altitude at which I'm at. |
IMO the goal is to avoid fuel cut. When your hitting fuel cut your in unsafe territory.
Where fuel cut occours is dependent on a variety of things including load/boost at a given RPM, and gear (i think?), no doubt air intake temp and several other factors. Theres a graph somewhere showing fuel cut vs rpm/load..and its in no way linear. For example the fuel cut psi thresh hold will be higher at lower RPM and in lower gears. (so basically, for example only, you could potentially run 15psi, UNDER 4k rpm, in gears 3rd and lower and still be under the stock ECU's safe max and never see fuel cut). im making those numbers up just for example. IMO the 10-8-10 thing is slightly misleading as the stock ECU does allow more boost under certain load situations & rpms.(not much more) Whats important is at what RPM the 10-8-10 occours. e.g. if it spikes to 12psi straight away on the first turbo, drops to 10psi or a bit below before transition then the rest goes as planned then that would be OK. |
All times are GMT -5. The time now is 10:46 PM. |
© 2024 MH Sub I, LLC dba Internet Brands