ok, I have a 90 GTU, with a Bonez race pipe on it, under partial throttle, I can feel the 5th and 6th ports kick in at 5500 rpm, but for some reason, under full throttle, I don't feel that same kick, and it almost seems like it isn't accellerating as fast, could that be from running too rich? I always thought the ports should open regardless of the mixture though. Any suggestions on how to tune the car to run better under full throttle? S-Afc maybe?

5500 rpm is awful high man.....they should open up at 3400-3800 rpm....you aren't creating enough back pressure to open them up with the air pump....just wire them open

umm, from everything I have heard, the aux ports are supposed to open at 5500 rpm, the secondary injectors activate at 3800 rpm, maybe that is what you are thinking of? and wiring them open just makes me lose low end power, which there is far to little of to begin with.

edit: and since I have a series five, my 6th ports are not opened by backpressure. they operate of the vdi, which works, at least at 1/2 to 3/4 throttle, it just doesn't kick like it should when I am at full throttle, maybe I just can't feel it, but it is almost like I lose some power by pushing the pedal all the way down

they will open regardless of the mixture. To see if they are functioning fully use an air compressor and blow air into the vacuum hose. To see if they work under load put a some grease on them and go for a drive then come back and see if its smeared. I forget exactly when they open but i thought it was somewhere near 4000rpms.

well i know they work, at least at partial throttle, I will be accellerating, then, at exactly 5500 rpm, my car kicks a bit, and I am suddenly accellerating faster, but, i don't feel that added acceleration at full throttle.

maybe u don't have enough backpressure until 5500rpms. Thats too high its supposed to be way lower. Somethings wrong, go fiddle with it.

hmm, even when I had the stock exhuast, it did the same thing, except it worked at full throttle, and I am not going to mess with it now, it is dark, and raining, and I have no garage. when is your car gonna be running?

soon as i get some more C@sh, need k2rd rail, and some adapter for stock primary rail, then im pretty much set, still need to wire it though, so soon.

on a 90 there are 2 different things. the 5th and 6th ports and the vdi. the 5th and 6th ports are the rotary valves in the intake and they open at 3600-4000rpm and they are actuated with the air pump and a solenoid. the vdi is also activated by the air pump and a solenoid, it turns on at 5500rpm. the vdi you can blow into it opens at about 1psi.



mike

So his ports should be opening between 3600-4000 and not at 5500 like they are now then?