Jump to content
SAU Community

Recommended Posts

Ok, well, last night I threw in the sniffer and pushed my boost from 16psi to 18psi.

Car responded ok once the AFRs were set to 12:1, but I seem to be getting no where rom 6000rpm to 7000rpm (redline.

here are my maps.

http://members.iinet.net.au/~pacey/18psi1.htm

http://members.iinet.net.au/~pacey/18psi2.htm

Wonder why the car isn't really responding to anything above 6k?

Could it be the Ground out RB25 housing on the GT30, or could it be a blocked cat from running stupidly rich maos from the retarded tuner that tuned my car?

I'm thinking of dumping the cat and seeing what happens..

Anyone got any ideas?

Going to dyno the car on this setup, then set it back to 16psi and my other tune. If the power is less than a 5 - 10 rwkw diference I'm gonig to leave it at 16psi...

I had to pull out massive timing on the load row "11571" (thats as far down as the Powerfc goes)

Edited by The Mafia
Link to comment
https://www.sau.com.au/forums/topic/119828-last-nights-powerfc-tune/
Share on other sites

my 25 is also the same, power drops off past 6 and never goes higher.

i think its normal and fairly good for the stock cams. i think youll find with bigger cams it wont. bass junky went from stock cams to tomie poncams (i think) and that cured his power drop off problem

I'm thinking of dumping the cat and seeing what happens..

Snip...

I had to pull out massive timing on the load row "11571" (thats as far down as the Powerfc goes)

Having to pull out heaps of timing indicates that you have a backpressure problem.. Check blocked cat, Turbine A/R and all the usuals.

that sounds weird to me though... my car seems to pick up quite a bit from 6000 to 7000rpm... i also have a GT30R... doesnt really die much anywhere, just down low around 2000rpm, thats prob just coz of air fuel ratios down low.... but if others are having the same probs then i guess its a normal thing, jono how much of a difference is there in power loss up top? is it noticable or does it just stop making power after 6000rpm?

i agree with MattSR check out ur cat..

Edited by mass_iv
Having to pull out heaps of timing indicates that you have a backpressure problem.. Check blocked cat, Turbine A/R and all the usuals.

Well, I'm going to do all of that, but the turbine is a Standard Skyline Turbo Turbine ground out to fit the GT30. Do you think that could be too small?

that sounds weird to me though... my car seems to pick up quite a bit from 6000 to 7000rpm... i also have a GT30R... doesnt really die much anywhere, just down low around 2000rpm, thats prob just coz of air fuel ratios down low.... but if others are having the same probs then i guess its a normal thing, jono how much of a difference is there in power loss up top? is it noticable or does it just stop making power after 6000rpm?

i agree with MattSR check out ur cat..

I'd adjust those AFR's down low, you'll be suprised how much of a difference it will make.

As for the power, it doesn't die, it just stops making power after 6000rpm.

I'm going to drop that cat at some stage this week and see what the hell is going on. Might be blocked.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • -10 is plenty for running to an oil cooler. When you look at oil feeds, like power steering feeds, they're much smaller, and then just a larger hose size to move volume in less pressure. No need for -12. Even on the race cars, like Duncans, and endurance cars, most of them are all running -10 and everything works perfectly fine, temps are under control, and there's no restrictions.
    • Update: O2 sensor in my downpipe turned out to be faulty when I plugged in to the Haltech software. Was getting a "open circuit" warning. Tons of carbon buildup on it, probably from when I was running rich for a while before getting it corrected. Replaced with new unit and test drove again. The shuffle still happens, albeit far less now. I am not able to replicate it as reliably and it no longer happens at the same RPM levels as before. The only time I was able to hear it was in 5th going uphill and another time in 5th where there was no noticeable incline but applying more throttle first sped it up and then cleared it. Then once in 4th when I slightly lifted the throttle going over a bump but cleared right after. My understanding is that with the O2 sensor out, the ECU relies entirely on the MAP tune and isn't able to make its small adjustments based on the sensors reading. All in all, a big improvement, though not the silver bullet. Will try validating the actuators are set up correctly, and potentially setting up shop time to tune the boost controller on closed loop rather than the open loop it is set to now. Think if it's set up on closed loop to take the O2 reading, that should deal with these last bits. Will try to update again as I go. 
    • More so GReddy oil relocation kits, sandwich plates, etc. all use 10AN fittings. And same, I've only used 10AN and my car sees track work (circuit, doing laps, not 10 sec squirt business).
    • street use or race track, what hose size and why? what factors change with the hose size options ?   see most comon is an10. when you see most oem external coolers are closer to an12? does high volume oil pump like nitto need an12 or 10 be just fine
×
×
  • Create New...