Thread: Tuners help needed

someone please help me make sense of this data. I feel like my tune could be better, it is a JWT tune. When I set the timing at 19* it pulls 25-30whp harder easy and still no signs of detonation. Mods in sig. 15psi.

All logs were a 3rd gear pull. Air flow crossover for the VVL was at 5600rpm so that's where i need to switch the cam. max speed in 3rd at rev cut is 97.5 mph.


Duty cycle at 7400rpm for injectors. 70.46.
Max air flow: 4.52V
Max speed: 97.5 (with oversized tires so this should be around 100 or so)
TPS voltage 4.02V WOT
MAX timing: 22*btdc most runs hit 21* only. (dizzy is set at 19)
MAX water temp: 199.4 on last run.
AFR: solid 10.7:1 at rev cut, between 12.5-11.5. Higher rpm=richer mix.

I wish someone knew how much hp worth of air 4.52V on the Z32 maf was.

The motor is 8.5:1 and i am at 4500ft elevation on 91 pump. I feel like the car is at 350ish whp, but on 16psi I should be around 380 or so. Can I benefit from more timing? There are no Nissan tuners around here, let alone one that has ever touched a VE. I am trying to justify the cost of a Calum ECU but I just wanna know if I can benefit 30whp or so.

The timing map is rediculous. As soon as 4k hits it pulls timing to 15-16* and raises slowly almost on an rpm basis. 5k 17*, 6k 19* and so on.

u have cams gears i see wat are they set at

cam gears are set at the stock settings for now.

Timing of 15 degrees BTDC at torque peak and 15 psi is about right for 8.5:1 compression and 91 octane (maybe a little conservative). After torque peak, timing should be brought back which explains it raising towards redline.

I don't see a problem. Is this with base timing at 15, or 19 degrees?

this is with base timing at 19*. My datascan shows 21* advance at 7400rpm. The car is slow unless the timing is brought to 19*. On 15* the car feels like 280whp. On 19* the car feels like 350whp-360whp. I am at 4500ft and the 15* base would be embarrassing to dyno on lol. I know the VEs love timing. With the JWT VE map I had to run 19* base as well in order to make 170whp when I was NA.

I feel like the tune should have more timing, especially under the curve. At 3k I am not even in boost yet and timing is pulled to 17* at WOT.

My friend has his celica all-trac set at 21* on 21psi of boost.

Leave it at 19 degrees base then.


This isn't even close to being right. I have 31.75 degrees BTDC at 3,000 rpm and 100 kPa (WOT but no boost). See map:

http://www.sr20-forum.com/showthread.php?t=600

I had this problem on a customer car, this was on a 96lb program.I called jwt and they said to run 25 degrees base timing.this car was on 93 pump gas and made 455whp with a stock gtir manifold and t3/t67ho.

^^^ holy crap. That is a ton of timing. Maybe the stock DET timing would be good. (20* base), but the idle likes to jump around just a little bit when the timing is advanced too far in hot weather. I will be getting a new laptop soon and getting a calum ECU I think.

Why are the VE tables so much farther advanced? I know the VE loves timing, but that is insane! Ben you have been a great help any more ways I can pick your brain???

Never knew that they were. Don't know why they would be...
If you're referring to the timing and fuel maps I linked you to, those are for a stock SR20DE, not a lower compression VET. You could probably use a tad more advance than my map.


What is insane? How far off your timing is from what it should be at 3k rpm? Yah, that is insane. I don't think JWT is that bad, maybe you're measuring method is at fault?


Ask me anything you'd like. It's been so long since I could be of help on this forum I'm stuck over at the e30 BMW forums where they understand the need for engine management. =]