Tuning for spoolup

[Mike 99GSX]

My mods are accurate in my profile. I went to the dyno yesterday and got my topend of my setup tuned successfully at 22 PSI. I have reletively slow spoolup though and have some questions about how to make it faster. Here's what I think I understand, correct me if I'm wrong. If I had a standalone and complete control, the way you improve spoolup is by leaning out the fuel and retarding the timing. I'm seeing full boost at 4800 which I know isn't great for a 50 trim with a .63 A/R. I'm running a VPC/GCC. The VPC gain is at 0. The GCC settings are 700= -4, 2400= 0, 4100= +2, 5800= +6, 7500= +8. When I logged the 3rd gear pulls, I have crazy high timing advance during the spoolup (like 25-30 degrees). Is there anything I can try with the lower 3 GCC settings to make the timing retard which would help the turbo spool faster? I made 395HP at 22 PSI with an AFR of 12.5. I'm pretty happy with those numbers on my stock 2g motor. Now if I can just get the spoolup going a little better, I should be in good shape.

 

[Ronin17]

Originally posted by Mike 99GSX
When I logged the 3rd gear pulls, I have crazy high timing advance during the spoolup (like 25-30 degrees).

Have you found out what should be done for the high timing during spool up? I have the same problem. Should I richen up the lower RPMs to help the timing to stay alittle lower? Thanks!

 

[Mike 99GSX]

Originally posted by Ronin17


Have you found out what should be done for the high timing during spool up? I have the same problem. Should I richen up the lower RPMs to help the timing to stay alittle lower? Thanks!

I think so. I'm going to go out soon today and try some stuff. What turbo are you running? This wasn't a problem until I got the 50 trim. I think what's happening is that the ECU is advancing the timing too much because it thinks there is less airflow than there really is. If that's the case, richening up the low settings should make the timing go down and increase the spoolup. I'll let you know in the next few hours what happens.

 

[Mike 99GSX]

OK I og a bunch of 3rd gear spool up runs and the data isn't very conclusive. These are timing number based on the RPM

#1
GCC Settings 700= -3, 2400=0, 4100=1
2550 3000 3300 3600 3950 RPM
27 24 21 18 14 Timing

#2
GCC Settings 700= 0, 2400= 4, 4100= 2
2550 3000 3300 3600 3950 RPM
26 22 19 15 12 Timing

#3
GCC Settings 700= 2, 2400= 6, 4100= 3
2550 3000 3300 3600 3950 RPM
26 23 20 15 13 Timing

#4
GCC Settings 700= 4, 2400= 9, 4100=5
2550 3000 3300 3600 3950 RPM
25 21 19 16 14 Timing

#5
GCC Settings 700= 6, 2400= 12, 4100=2
2550 3000 3300 3600 3950 RPM
23 21 19 15 12 Timing

#6
GCC Settings 700= 6, 2400=9, 4100=2
2550 3000 3300 3600 3950 RPM
24 22 19 15 13 Timing

#7 (Extremely lean other direction)
GCC Settings 700= -8, 2400= -6, 2400=-3
2550 3000 3300 3600 3950 RPM
28 26 23 20 16 Timing

Thats it. I don't know what to make of it exactly. It seems like there is some point in between #5 and #6 that are best but none of them are that great. I'm thinking at this point of trying Buschur's 660 VPC chip. I still have the 550 chip because they said that the 660 chip only worked on 1gs. But they also told me that the 660 injectors wouldn't work right at all with the 2g/VPC but they were shocked at how good and perfectly flat the A/F was on the top end pull when it was on the dyno a couple days ago. Its probably worth a shot at this point.

 

[Ronin17]

I am running a SBR-GT10. I richened the lower RPM's on my Hi settings, but I haven't logged a run yet. Seat of the pants, it feels like the turbo wants to spool alittle quicker now. I just need to see what my timing is doing now.

I really shouldn't be messing with anything since I have a nasty injector leak that is making me loose alot of power and killing my spool up anyway. I'm waiting on new seals that will hopefully fix the problem.

Thanks for the info btw.

 

[Mike 99GSX]

I honestly couldn't tell any difference in spool up going between all those changes listed above.

 

[Ronin17]

I felt the most difference on the highway. Going ~75 in 5th sitting at ~3300 RPMs the turbo spooled alot faster to 16psi then it usually does.

Then again, with the horrible injector leak I have right now, my car is anything but consistent. I'll go log a run sometime soon and see if there was really anything different. Most likely not, probably just my imagination.

 

[Mike 99GSX]

Another thing worth checking into is: on another thread someone posted that if you're injector duty cycles are too low, then the ECU will advance too much timing. Since I have no way of seeing my cycles, I don't know what they're at, but I could try lowering my fuel pressure and see if it brings the timing down. I'll probably give it a try too and see what happens.

 

[irn__man]

Originally posted by Mike 99GSX
I made 395HP at 22 PSI with an AFR of 12.5. I'm pretty happy with those numbers on my stock 2g motor. Now if I can just get the spoolup going a little better, I should be in good shape.

Was this on Race Gas or Pump Gas? Also my Green spools up by 3700 rpm, I am running it on a Auto. So far I am very happy, but i am debating on doing the Auto->Manual conversion on the tranny.

iron

 

[DSM mechanix]

Originally posted by irn__man


Also my Green spools up by 3700 rpm, I am running it on a Auto. So far I am very happy, but i am debating on doing the Auto->Manual conversion on the tranny.

iron

Id say go for it, it will only increase the value of your car .

 

[Mike 99GSX]

Originally posted by irn__man


Was this on Race Gas or Pump Gas? Also my Green spools up by 3700 rpm, I am running it on a Auto. So far I am very happy, but i am debating on doing the Auto->Manual conversion on the tranny.

iron

C16- I'm running on a stock 2G motor so I was convinced to stop at 22 PSI. I'm doing a 6 bolt swap this winter but I think 395 is enough to get my 11.xx ET. I'm convinced the spoolup is dircetly related to the timing problem. I have between 170-180 compression, no boost leeks, no exhaust leeks so I don't know what else it could be.

 

[Turboniam]

Once your motor is built and ready to go in, you should turn up the boost and see what the 7 bolt can do

 

[Mike 99GSX]

Originally posted by Turboniam
Once your motor is built and ready to go in, you should turn up the boost and see what the 7 bolt can do

Exactly. I'm picking up my core motor tomorrow. Believe me, when the last day of the season comes around at the track, I plan on going down in flames

 

[FastRthenU]

You pretty much get the point. If you have a stand alone, or something similar. Then you want to richen up during spool up time, and retard the timming. By doing so you ignite the mixture later. Which cause the exhaust gas to be hotter while it is in the manifold, and turbo. Also with the extra fuel, you will have more unburnt fuel in your exhaust. Because the mixture is more dense because of it, it will also help spool

 

[Mike 99GSX]

Originally posted by FastRthenU
You pretty much get the point. If you have a stand alone, or something similar. Then you want to richen up during spool up time, and retard the timming. By doing so you ignite the mixture later. Which cause the exhaust gas to be hotter while it is in the manifold, and turbo. Also with the extra fuel, you will have more unburnt fuel in your exhaust. Because the mixture is more dense because of it, it will also help spool

Yeah I got that but it doesn't seem to affect anything with my VPC/GCC. Believe me, I've cranked up the lower RPM settings and it did not retard the timing. Someone posted that the high timing is not the problem, it is the result of a problem, which I think is probably right at this point. I just don't know what that problem is at this point.

 

[FastRthenU]

What size injectors are you running??? What is base timing set to. The only way you can really set the car up like that is. IF you have some sort of timing control. if not, then just richen it up like you have have been in the lower RPM's. It wont give you the complete effects you were looking for but it should help a bit.

 

[Mike 99GSX]

Originally posted by FastRthenU
What size injectors are you running??? What is base timing set to. The only way you can really set the car up like that is. IF you have some sort of timing control. if not, then just richen it up like you have have been in the lower RPM's. It wont give you the complete effects you were looking for but it should help a bit.

I have 660s. I have a 2g so I can't adjust my base timing. I have checked all my timing marks though and everything is perfect so thats all I can do. Believe me, I have richened up the settings on the GCC almost as far as they can go for extreme testing and it didn't help. I'm just at the mercy of the stock ECU's fuel maps. We now have a new theory. I think the spring in my wastegate isn't stiff enough and is opening prematurely. I ran a line from my compressor housing directly to the wastegate and I only got 13 PSI of boost. Its supposed to be a 1 bar spring so it should be closer to 15. Buschur feels pretty strongly that this is my problem and a tech at Tial suggested the same thing. The secondary spring is on its way. I've got my fingers crossed.