Timing During Spool Up

[Mike 99GSX]

My mods are listed. The exception is that I have switched back from 660s to 550s. I'm having trouble making the 660s work with my VPC but thats another question down the road. I am humoring my respected tuner and putting the 550s back in to see if I can get enough fuel out of them. Here's my question: Normally when I log, I start from about 2000 RPMs and go through the gear and into a shift. As the turbo starts spooling, the timing drops to about 7 or 8 and then gradually rises to about 18-20. I know this is normal. Here's whats happening. (2nd gear)
RPM Timing O2
2101 26 0.00
2289 22 0.02
2347 26 0.04
2429 27 0.02
2511 28 0.02
2593 27 0.02
2687 27 0.02
2769 27 0.02
2875 26 0.04
2964 26 0.06
3078 26 0.08
3183 24 0.42
3304 23 0.86
3429 21 0.88
3562 21 0.90
3687 20 0.90
3843 18 0.92
3992 17 0.92
4167 15 0.94
4394 14 0.94
4605 13 0.92
4835 12 0.92
5101 13 0.90
5375 13 0.90
5605 15 0.90
5859 17 0.90
6097 18 0.88
6625 20 0.86
6816 21 0.86
6996 22 0.86

I don't know why the timing is so high during the spooling process. It never takes a big dip and climbs it stays in the 20s all through the spool up. What does this mean. This was at 17-18PSI FP set @ 43. The gain on the VPC is at 0. The GCC setting were at:

700 -3
2400 +3
4100 +3
5800 0
7500 0

Any help would be appreciated.

 

[kpt4321]

You didn't provide us with any information about the boost threshold, so I cannot tell what timing correlates to what manifold pressure.

Try to guestimate boost vs. rpm.

However, it doesn't look *that* bad to me.

Put the 660's back in!!

.....Kyle T.

 

[Mike 99GSX]

Originally posted by kpt4321
You didn't provide us with any information about the boost threshold, so I cannot tell what timing correlates to what manifold pressure.

I'm getting full boost about 3900RPMs and start building around 3000. I just don't understand with the old setup why the timing would drop so low when I started to build boost and this is what I thought it should do. Is it OK to have real high timing like I am during the spooling?
Here's the short version with the 660s. Basically, I can't get the car to run right at WOT. I get a bad hestitation going into each gear and the timing isn't great at the top of 3rd gear either (around 15). I was running 20 PSI at the track that weekend. I tried C16 and I still had the hesitation and the pulled timing. I tried going richer and leaner but nothing seemed to help. I've got about 12 timeslips with matching pocketlogger logs to each one where I recorded my VPC/GCC settings. I could send you a few if you're curious. I was running low 13s all weekend and it was very frustrating. Buschur sells a "660 chip" for the VPC but they say it only works in a 1g. I'm tempted to get it just for the hell of it and try it because I know they really focus on 1gs and I wonder if they've really tried it in a 2g. Ultimately, I'm not going to be happy if I can't run some real boost with this turbo. If the VPC really isn't going to work with the larger injectors, then I'm going to have to move to a standalone or something else. I haven't found any 2g/VPC users out there yet using anything bigger than 550s. I'd like to think I can make it work though.

 

[1LE]

IMHO, "that's not good". Why is it happening, I dunno... Are you sure you don't have a boost leak or something odd like that? As I roll onto the throttle, it drops from 35 to 25 or so, then holds until boost hits, where it drops to 12 (used to be 7-8 with broken FPR), slowly climbs to 20 or so at 7100 rpms, holds to 8000 rpms (Doesn't seem to be knock related, I think the ECU holds timing above stock redline).

 

[Mike 99GSX]

Originally posted by 1LE
IMHO, "that's not good". Why is it happening, I dunno... Are you sure you don't have a boost leak or something odd like that? As I roll onto the throttle, it drops from 35 to 25 or so, then holds until boost hits, where it drops to 12 (used to be 7-8 with broken FPR), slowly climbs to 20 or so at 7100 rpms, holds to 8000 rpms (Doesn't seem to be knock related, I think the ECU holds timing above stock redline).

I definately don't have any boost leeks. What you described is exactly what used to happen. The car feels fine and is spooling reletively normal. I just don't know what the high timing numbers mean during spoolup.

 

[deusxmachina]

I don't know why you would be thinking that timing log is a problem at all. Looks a little out of tune perhaps, but pretty normal, especially for second gear that flies by so quick. A log of fourth gear would be nice to see.