Pick Apart My Ign Map - Rb26 Tune

[djvoodoo]

Hi all

I am happy with the state of my tune and power delivery (263kwatw). Knock sits between 15-30 on an average day (say between 20-28 degree temp day)

The highest i've seen knock was at about 42-43, but that was on a 36+ deg day and me giving it some (prob not the best idea i know)

Using map tracer, when on full load (about 1.1 bar), I generally use L14 and L15 on the map.

Exh temp sits around 600-700 degrees when on light load areas higher in the map where timing is around 35-40 deg.

What do you guys think of the timing map?

[Dale FZ1]

Making assumption that full load fuelling is right - you'd want to be in the 11.5 - 12.0:1 AFR on petrol.

L15, L16 rows might be worth revisiting, try -2 adjustment and see how things respond from knock perspective.

I wouldn't have absolute faith in the sensor outputs, you would really do well to run it on a dyno and use chassis ears (aka knock box) to physically listen for any signs of knock.

Have a good look in the L5-L8 rows, in rpm range 2500-4500. You might add 2-3 degrees there and see if it makes the thing any perkier on cruise.

[Badgaz]

put a knock block on....i could hear knock through the headphones that was not registering on the PowerFC assuming this is what you have. what mods?

[djvoodoo]

Hmmm, will take that on board. I have used the temp ign adjust to dial back the entire map by -1 and doesn't affect knock reading whatsoever. have also tried adjusting +1 all round and same deal, knock reading is pretty much the same all round.

Def felt perkier in low rpm though when I went up +1 on the temp ign.

I don't have a datalogit and couldn't be bothered with mapping out the entire inj map, but will put it on the dyno to look at AFR's.

[djvoodoo]

put a knock block on....i could hear knock through the headphones that was not registering on the PowerFC assuming this is what you have. what mods?

Mods are very mild.

200 CPI catco metal cat, Apexi N 1 3.5inch cat back. boost restrictor removed. Power FC

[Badgaz]

I'm tuning my wifes GTR after i scored a Powerfc off a friend. The stock maps use relatively advanced timing. i think its more cruicial getting your fuel dialed in properly before ignition...but 1 or 2 degrees here and there ain't too bad....until you can get fueling map done it looks alright, you've taken timing out in areas of deceleration/light load what were your thoughts on doing this? you can usually put more timing there.

[djvoodoo]

I'm tuning my wifes GTR after i scored a Powerfc off a friend. The stock maps use relatively advanced timing. i think its more cruicial getting your fuel dialed in properly before ignition...but 1 or 2 degrees here and there ain't too bad....until you can get fueling map done it looks alright, you've taken timing out in areas of deceleration/light load what were your thoughts on doing this? you can usually put more timing there.

The majority of higher knock (25-30) happens on light/mid load areas of the map. I'm taking a guess and saying the fuel load for these areas is prob on the leaner side to try maintain fuel economy while cruising.

[Badgaz]

does the knock happen when you start ramping up the load (accelerating?) my car did the same thing at about 3000rpm...

[djvoodoo]

does the knock happen when you start ramping up the load (accelerating?) my car did the same thing at about 3000rpm...

Yes, i'd say between 3500-5000 rpm on light/mid load

[Badgaz]

a shame you're in sydney...could've just come over and gone for a drive with the datalogit. i'd recommend getting one if you want to start learning to tune. i think they are cheap enough these days....i bought an old one of a mate. I pulled a little bit of timing out. if you graph the values you can often see the troughs and peaks that need smoothing out. if you pm me your ign map i'll wack it into datalogit and produce the graph and see how it looks. These motors are usually quite linear....but again fueling has to match.

Edited March 9, 2014 by Badgaz

[Dose Pipe Sutututu]

in my opinion, that's quite a lot of timing in that map on load (but could be due to the CAS being retarded)

what's your EGT reading when you're on full noise?

[Guilt-Toy]

its retarded across the whole map.

what fuel are you using? was the timing set correctly?

[djvoodoo]

Using Pulp98 - Cas was set at 20 deg manually, then tuned. i have not physically checked this though.

EGT on full noise will be in the vicinity of 500-600 degrees. I need a second set of eyes though as I cannot be certain. the most I have seen exh temp was around 760, but that was highway driving at 110k's in 4th/5th.

[Badgaz]

base timing 20 degrees? is that stock for r34?

[djvoodoo]

base timing 20 degrees? is that stock for r34?

Sure is for an RB26

[Badgaz]

sweet spose its lower compression, this is what my rb25det ign map looks like in comparison.

[Don Dada]

Stock rb26 ecu run around 24* at 0.9bar, so youre a little advanced ign wise around peak torque area. You should get a wideband on it and look at the afrs just to make sure.

Ive heard audible knk from a rb26 and the controller only read 30's so be careful with it especially in the off to on boost areas at cruising speed in the higher gears

[STATUS]

timing should not be tapering down with increase in rpm..should do opposite.. more advance with rpm.

you may need to pipe the timing down bit to start then ramp it in.

[Badgaz]

timing should not be tapering down with increase in rpm..should do opposite.. more advance with rpm.

you may need to pipe the timing down bit to start then ramp it in.

I did wonder why this is? is that because the duration between each compression stroke is effectively shorter?

[Dose Pipe Sutututu]

I did wonder why this is? is that because the duration between each compression stroke is effectively shorter?

torque drops off, less cylinder pressure so you effectively can dial in more timing

hence at peak torque you take off timing, as cylinder pressures are highest.. looking at that map, it's terrible.. there's more timing at peak torque than after peak torque.....

feel free to PM me to chat, I don't like talking about this stuff on the public forum as people like to have stabs at me.