safc dec air VPC

[cjridert1]

I keep reading that the dec-air is not suited for our setup. When I first got it, I installed the safc with 450's with the previous owners dec-air settings (no idea what they were). Car ran fine, no problems. I put 550's in and now when I shift gears it gets very rich (WB o2), not to the point of misfiring, but rich regardless. I read that people (not dsms) set their ne1/2 points based on airflow, not karmen. Is there any other reasons for it to get rich when shifting?

relevant setup: VPC, 550s, SAFC 1, UEGO

 

[Stainbox12]

Set your car to karman, then set the safc to 0. Are you venting your bov? if you do recirculate it, and it will stop being rich between shifts. Dec-air is not used in our cars, so i won't work if you vent.

 

[cjridert1]

The car is set for karmen. My safc #'s are around -27 or so. BOV is vented, but I didnt have this same problem with 450 injectors (everything else being equal). Its a ssbov and the intake pipe isnt interested in recirc. I played with the dec air today, not one bit of a difference (go figure). Thanks!

 

[robbo185]

what chip do you have in the vpc? If its a not a chip for 550cc there is your problem. Rule of thumb, taking more than 20% usually isnt good when using the afc. Also get that bov recirculated. Thats more than 50% of the problem right there.

 

[LTUDSM]

what chip do you have in the vpc? If its a not a chip for 550cc there is your problem. Rule of thumb, taking more than 20% usually isnt good when using the afc. Also get that bov recirculated. Thats more than 50% of the problem right there.

 

[cjridert1]

yea, vpc is chipped for 450's. I assumed it didnt matter with the SAFC changing the #'s. I cant find 550 chips anywhere, but there are some 650 chips - toss one of these in? Thanks for the replies guys!

 

[robbo185]

yea, vpc is chipped for 450's. I assumed it didnt matter with the SAFC changing the #'s. I cant find 550 chips anywhere, but there are some 650 chips - toss one of these in? Thanks for the replies guys!

of course with that option you have the chance of running a tad lead. However Im sure you would be able to tune it out with the safc. Btw do you have an aftermarket fuelpressure regulator or a bigger fuel pump?

 

[cjridert1]

of course with that option you have the chance of running a tad lead. However Im sure you would be able to tune it out with the safc. Btw do you have an aftermarket fuelpressure regulator or a bigger fuel pump?

Aftermarket pump, but FP is ~37 with stock regulator so thats good enough for me. Seems like lean between shifts is better than rich (like fuel cut when decel?). Should I just get a 660 chip or keep hoping to find a 550? The safc wont let me modify afr when shifting (unless I am not using it correctly?) Thanks!

 

[robbo185]

what size pump do you have?? Did you check to make sure your fuel pressure is 37psi?? with the bigger fuel pump you may be overloading the fpr cause a rich condition in general. Also you cannot odify afr when shifting. Im not sure how the vpc works but if the sensor for it is before the bov thats what is causing your rich condition between shifting

 

[Stainbox12]

what size pump do you have?? Did you check to make sure your fuel pressure is 37psi?? with the bigger fuel pump you may be overloading the fpr cause a rich condition in general. Also you cannot odify afr when shifting. Im not sure how the vpc works but if the sensor for it is before the bov thats what is causing your rich condition between shifting

Vpc, changes the maf reading when using its own sensor. Its basically an alernative to MAFT but much better, not easly accesible though. You should be able to vent properly with a vpc if you have it hooked up correctly, with the sensor and all.

 

[cjridert1]

I checked the FP about 3 months ago with a legit meter. Only thing I have changed was safc and 550's. The car didnt run rich between shifts with 450's + safc, so I think you guys are right that it is the VPC chip. I am still looking around for a 550 chip (or thinking about putting 660s in and calling it a day).

 

[cjridert1]

If I end up getting a 660 chip - this means the car wont see as much airflow and timing will be higher (right?). How much of a problem will this be?? I dont have any tuning tool to modify timing besides the CAS. My car has mad knock @ the moment, so it runs like crap anyhow - but it seems I will eventually get this all figured out.