New log, 2nd gear pull, 1* timing?

[95 gsx]

I just did a few logs on the talon. Im running a B16g at 18psi, evo injectors, SAFC, pocketlogger for logging...

2nd gear pull:

RPM Timing Thrtl O2
1908 17 44 .90
2112 16 59 .92
2364 16 82 .94
2632 19 100 .94
2932 19 100 .94
3256 17 100 .94
3564 14 100 .96
3924 10 100 .96
4444 1 100 .98
4836 10 100 1.00
5144 7 100 1.00
5612 8 100 1.00


3rd gear pull

RPM Timing Thrtl o2
3112 22 76 .94
3232 18 98 .94
3412 14 100 .94
3580 11 100 .96
3724 8 100 .96
3912 8 100 .96
4148 2 100 .98
4276 9 100 .98
4516 8 100 .98
4792 7 100 .98
4872 8 100 .98
4920 9 100 .98
5168 9 100 .98
5228 10 100 .98
5540 11 100 .98
5580 11 100 .98
5852 12 100 .98
6144 14 100 .98
6252 14 100 .98
6376 15 100 .98


It spikes to 20 psi and drops to 18. Is this my problem in the midrange when the timing plummets? I know Im doing something wrong here, the curve isnt smooth and the timing levels out in a couple of spots. Im going to drop the boost down to 16 until I get this figured out but it still spikes at 20 at that level. Any ideas?

 

[spyderturbo007]

Can you post up all of your SAFC settings, such as TPS trigger points, correction factors for Hi Throttle map, etc.

 

[95 gsx]

Sensor: karman
type: 4 cyl, throttle up
Th point: 30% 80%
Correction +/- 3%

Lo
1000 -14
1600 -19
2200 -10
2800 -13
3400 -13
4000 -13
4600 -13
5200 -13
5800 -13
6400 -13
7000 -13
7600 -13


Hi
1000 -14
1600 -9
2200 -10
2800 -13
3400 -12
4000 -13
4600 -11
5200 -7
5800 -4
6400 -2
7000 -2
7600 -2

Fuel trims set to 0 on low map

 

[spyderturbo007]

Your Hi throttle table is really rich. Mathematical correction is -18% to compensate for the 550's and that still leaves you at the factory target AFR of 9.5:1.

When is your turbo reaching full spool? By the look of your log, it isn't spooling until about 4k or so. Have you checked for boost leaks? What plugs and gap are you running? Exhaust leak at manifold?

 

[95 gsx]

18psi around 3500-4000 depending on what gear Im in. NGK bpr7es, 0.26 gap. I dont have any exhaust leaks before the turbo. As for boost leaks....yikes it's been a couple off weeks. Ill check and let you know what I come up with. The last time I did a leak test I had to replace the throttle body shaft seals, afterwards it held just fine. I know when I initially tuned the car the logs were nothing like posted above. They were normal so to speak (dip down to 10-11 when building boost then a steady increase to ~17*). Do you think a boost leak may be an issue in my case?

 

[spyderturbo007]

Well, if you have a boost leak, you are going to be running rich, combined with your rich SAFC settings, it's very possible you are experiencing rich knock.

That spool seems late to me, but maybe the Big 16g spools later than the EVO III 16g. I normally reach full spool by 3200 or so. Can anyone with a Big 16g chime in here and confirm their spool time.

 

[95 gsx]

I just did a search on tuners, keyword: b16g spool time and most people that replied said they were getting full boost by 3000-3200 rpm. I think it varies depending on setup, SMIC vs. FMIC etc. I must have a leak somewhere. I may try to re-tune after getting any leaks fixed then shoot for .94 o2's. How do the low throttle settings look? I used the vfaq SAFC tuning method BTW.

 

[spyderturbo007]

It's hard to say on the Lo throttle map, since every car is different. Whatever settings bring your FT's in line are fine. I think mine are in the neighborhood of -12% or so with 650's, but like I said, all cars are different.

 

[95 gsx]

Depressing update: Engine jumped time, bent 4 exhaust valves, snapped off 4 exhaust valves, destroyed a head and all pistons. Anyway, the 560s werent enough so Im stepping up to 650s and get this:

The 6 bolt block that was in my car had non-turbo pistons! Just think, 18 psi, 9:1 compression and 560s?! Yikes. The weird thing is, despite chunks of the valve stems embedded in the top of the piston, they looked absolutely fine. No pitting or broken ring lands, absolutely nothing. I guess they're good for around 300 horsepower, .