ahad

eyy this friend o mine got his fd rewired n got a knightsports ecu...hes runnin intake n downpiping free flow...so when we took the car out for a spin the boost gauge kept showing 20psi!!!same night we checked again n it was giving a 10-8-9 boost pattern...10-15mins later we're back at 18-20psi.... is that possible? HOW could that have happened? and how is his engine still running?

Mahjik

iTrader: (1)

It sounds more like his boost gauge is having a problem rather than the car actually boosting that much.

1souped7

Could you feel a difference in thrust at the different levels of boost you were reading? If so then it wasn't the boost gauge.

ahad

i dunno man the kick was DEFINITELY there im gonna use my boost gauge on his car in the mornin to see whether its the gauge although the guy who did the wiring says the boost gauge is fine...pretty odd...

00SPEC

iTrader: (9)

was that KICK a lot stronger than the 10psi kick? id imagine 20psi would feel a lot more noticeable than 10

dhays

iTrader: (1)

+1

darkphantom

iTrader: (2)

he really wants to blow that motor! and the way you said it sounds like hes on stock twins! go with the greddy profec b, a favorite for every 7 owner and reliable!

alexdimen

iTrader: (13)

So, you think you're overboosting and you're just going to keep trying to overboost?

Whether it's unlikely to boost that high or not, It'd be wise to check out the control system before getting on the throttle again...

ahad

yeah hes not gonna boost the car till he gets a boost controller...i personally use the avc-r so thats why i suggested to em...lets see...but 20psi man bloody hell crazy *** knocking with it....

dgeesaman

iTrader: (7)

20psi is about as high as stock turbos can boost under any circumstances

Have him double check all the vacuum lines going to/from his boost control solenoid. If those lines leak you can boost a boatload.

Dave

samad

iTrader: (1)

dammit man ......this damn rotary just wont get fixed!

anyway ..where exactly is the boost control solenoid?

oh yeah..im the friend with the 20psi problem.

pwwatkins

I remember when I went from 10 to 14 psi on the stockers, and it was VERY easy to tell the difference in power.

dgeesaman

iTrader: (7)

Oh, ahad's car has the AVC-R, not your car, samad. If you have stock boost solenoids and a free flow exhaust that explains much of your problems. First, test to see if your boost gauge is accurate.

Second, inspect your stock boost control system.
From (http://www.autosportracetech.com/RX-...shooting.htm):
- If boost pressure is way above 10 psi, (i.e. spiking at >14 psi) then the tube between the Primary Turbo Compressor and the Turbo Pre-Control Actuator has popped off. Do NOT simply plug the popped off hose back on as it will pop off again. always use a new small hose clamp or a nylon zip-tie / ty-wrap for these hoses.

You can find the vacuum hoses here:
http://www.davidgeesaman.com/rx7/93v...lor.edited.jpg

Third, if you find and fix the problem you still can have major problems running a free-flow exhaust and remapped ECU. Knightsports ECU uses the stock boost control solenoids and these aren't fast enough to control boost spikes. I recommend you install a boost controller (AVC-R is fine) and double-check your boost gauge. By double-checking I mean remove it from your car and test it on another car or using a vacuum pump and tee fittings. Do not boost your car over 10psi again or you'll blow your motor. It sounds like you've been extremely lucky so far, but don't push it.

Dave

ahad

oh yeah the power was definitely there man... it was bloody slow at 8-10 psi and it seemed to bog down after 6k rpm...when it hit 20psi the car'd jus go crazy...

samad

iTrader: (1)

just a thought...if i were to use a boost controller...profec B probably, wud i be bypassing the stock boost control solenoid?

dgeesaman

iTrader: (7)

Yes

samad

iTrader: (1)

cool thanks.... i saw this thread bout how to install one on a sequential turbo the other day..cant seem to find it now!