Power FC RB25 tuning Q's

[250sxGTST]

I recently installed a Power FC on my series II RB25 and had a couple Q's. What knock level did the oe ecu start pulling timing at? What knock level is acceptable? I have less than 20% and usually a steady 10-15% at 17psi and 21-23 degrees. What EGT is unsafe or acceptable (i prefer to sacrifice hp for reliability) i have 850-900C (about 1600F) I thought this was high at first but im running 10.8 11.1 afr's on a wideband and i get 750C part throttle. The last car i tuned with an EGT had 1300F max and would melt the cast pistons at anything higher. I am an experienced tuner(not an expert though) but im not sure of the limits of this engine and dont want to find out the hard way, so i appreciate any and all input on this subject. What timing is normal for the rb above 4500rpm at 15-20 psi? The mods on this car are GT2530 turbo Stock injectors (Iknow too small 550's to go in soon) FMIC 3" exhaust NGK #8 heatrange plugs Adjustable FPR MSD fuel pump voltage booster Z32 MAF Walboro 255 in tank pump divorced chamber dump tube Sunoco 94 pump gas K&N cone filter . Oh and the EGT is plumbed into the inlet of the turbine housing whe HKS has the 1/8 NPT plug.

[Imissmyturbo]

Well the PFC doesn't pull timing. Just so you know.I see around 20-25 after some 3rd + 4th gear pulls. I personally get worried if it goes over 35 but I have seen as high as 90!I think anything over 60 will set off the check engine light (Flashes) I am running 15 psi on an SC61 turbo. Making around 330 whp. I am not sure about EGT's so I can't help you out there.

[FAST-DATSUN]

get a REAL a/f gauge (wide band) and use that to tune, Innoivate, AEM, or any real one.. cheap insurance to keep motor alive... EGT placement affects reading use manufactor placement recomndations and then temp is only a guide......

[250sxGTST]

Thanx, but ive been using a REAL A/F gauge and it is a wideband. PLX R500, i dont know how good they arebut ive heard good things about them and am happy with it so far. My post wasnt to get exact #'s i just wanted to pick the brains of everyone that knows more than i do and make sure im on the right path.

[250sxGTST]

I was aware the pfc doesnt pull timing that's why i was curious what was safe and what the oe ecu considered unsafe. And thank you, i must still be on the conservative side at less than 20% which was my main concern. Did anything catostrophic happen at 90% ?

[eh?]

Those are arbitrary numbers apexi used to display knock. They're not percentage numbers. To add to that those numbers you are seeing may not even be knock at all, it could be just mechanical noise from the engine.

From what I've read, anything below 20 is good. When I had a pfc I'd see spikes of 50 and above. I believe one time I saw 80+. Nothing happended.

[250sxGTST]

thank you, this is the info im looking for. i figured i was way too rich, the egt just scared me a bit. anybody have any info on timing advance under boost? i dont want to start pulling fuel til i get the timing advanced where it should be.