Backfire between 25% and 75%???

[XxrusianxX]

I just started to play with tunning, I have my S-AFC set for 25% for Lo and 75% for Hi throttle. When I am in between those values, i.e. 60% throttle, the car starts to build boost but as soon as I hit like 10psi it starts to misfire constantly untill I let off and goes nowhere. Anybody know the remedy for this or atleast why this is happening. Mods are as follows:1G awd, ported 60 trim, 660, 190lph, S-AFC, full 3-in exhaust, front mount and all the basic stuff, running 13psi.

 

[GVR4592]

What is your fuel pressure at? What is are the SAFC correction settings? Do you have any datalogs?

 

[grnchevyz]

hmm...correct me if I'm wrong but I believe the SAFC is sorta unreliable for injectors bigger than 550's.

And what are your AFC settings?

I'll go to the car and jot down mine for you.

 

[grnchevyz]

I have close to the same setup but use an EVO3 instead, here are my settings on my SAFC

Throttle Points:

LO 30%
HI 80%

NePoints:
1000
2000
3000
4000
4500
5000
5500
7000

Lo Correction
-13% across the board

HI correction
1000 -23%
2000 -23%
3000 -22%
4000 -26%
4500 -27%
5000 -34%
5500 -33%
7000 -33%

Try those out and see what happens...I had a similar problem where I couldn't get passed 5k rpm, tweaked the SAFC and voila!

Oh and I run a ProfecB Spec 2 set for 14psi and 22psi. Those setting work like a charm. I'm sure I'll be able to squeaze out more with DSMLink once I swap ECUs tomorrow but for now they work great.

 

[XxrusianxX]

I have close to the same setup but use an EVO3 instead, here are my settings on my SAFC

Throttle Points:

LO 30%
HI 80%

NePoints:
1000
2000
3000
4000
4500
5000
5500
7000

Lo Correction
-13% across the board

HI correction
1000 -23%
2000 -23%
3000 -22%
4000 -26%
4500 -27%
5000 -34%
5500 -33%
7000 -33%

Try those out and see what happens...I had a similar problem where I couldn't get passed 5k rpm, tweaked the SAFC and voila!

Oh and I run a ProfecB Spec 2 set for 14psi and 22psi. Those setting work like a charm. I'm sure I'll be able to squeaze out more with DSMLink once I swap ECUs tomorrow but for now they work great.

Thanks for the advice, I will try those values out. What is dec. air. Mine is TH 1% Ne1. is 10% and same for Ne2? Right now I don't have a datalogger since I lost the software. For that reason I am kind of scared to lean it out to much to the point of bad knock.

 

[grnchevyz]

My TH is *.**
Ne1 and Ne2 are 10%

 

[GVR4592]

I have close to the same setup but use an EVO3 instead, here are my settings on my SAFC

Throttle Points:

LO 30%
HI 80%

NePoints:
1000
2000
3000
4000
4500
5000
5500
7000

Lo Correction
-13% across the board

HI correction
1000 -23%
2000 -23%
3000 -22%
4000 -26%
4500 -27%
5000 -34%
5500 -33%
7000 -33%

Try those out and see what happens...I had a similar problem where I couldn't get passed 5k rpm, tweaked the SAFC and voila!

Oh and I run a ProfecB Spec 2 set for 14psi and 22psi. Those setting work like a charm. I'm sure I'll be able to squeaze out more with DSMLink once I swap ECUs tomorrow but for now they work great.

Those settings look extremely rich for 650's and stock fuel pressure.