Hello Forum Members. I have a question that I hope you can help with ...

​​​​​​2000 Corvette with M6 transmission.

First round of mods included Vararam CAI, XSPower LT headers with high flow cats and x-pipe, Corsa eXtreme axle back, LS6 intake and a street tune using HPTuners. On deceleration (closed throttle) the motor made a wonderful (I loved it anyway) popping, snapping and crackle. Made the car really fun to drive. Most entertaining ...

Second round of mods added a cam 228/232 .613 .601 111+3, 243 casting heads (not ported), Cometic 0.040" head gasket, 36 lbs injectors, new timing chain, oil pump, harmonic balancer and a retune on the street (same tuner). Car pulls strong, has a few drivability issues yet to be resolved (hot start won't stay running without throttle and hunts for idle for 30 secs, some surging up to 1700 rpm, cold start hanging idle) but the sad part is all the snap, crackle and pop is gone!

Question 1: Can I expect the tuner to be able to mostly resolve the drivability issues listed?

Question 2: Is there a way to restore the snap, crackle and pop? I really miss this part of the driving experience.

Thanks for your help!

 

Answers in bold above.

 

a good tuner should be able to take care of the hot start, hunting idle, etc, but the surging may never go away... nature of the beast I suppose, the car probably wants to go and not be lugged around... mine will surge and buck a little in parking lots and whatnot, keep the rpms higher in 1st gear and that will solve it but you will have people looking at you... as far as the popping goes that will probably come back once the car is tuned and they lean it out on decel, pretty much what the poster above said

 

Thank you for your response. I will keep working through these issues with my tuner. One challenge has been to get an accurate data set for the injectors. They are Ford Racing 30 lb Red Top (FRPP M-9593-BB302, Bosch PN 0280155759) rated at 36 lb at 58 psi. I purchased these before understanding how difficult it is to get good injector data. If anyone can help with injector data it would be greatly appreciated. Thanks again.

 

contact fuel injector connection and see if they can help with the data

 

I've got a cam VERY similar to that one and also lost my snap crackle pop. I, like you, am one of the few that miss it a lot, and while my tuner was able to get it driving like stock (I experienced similar issues to you, all have been completely resolved), he doesn't have the time to chase around the snap crackle.

As others have said, make sure DFCO is off, and retard timing on decel should do it. I bought HP Tuners to play around with it myself. Also to change the fan settings and basic stuff. Hopefully I can bring it back.

 

I found that mine would snap, crackle, pop on decel with DFCO off and the decel area (top two rows, roughly) of the VE table set very lean. The wideband was reading 17-18:1. I stumbled across it by accident...I'm not sure if this is a good idea, but I reckon it can't really hurt anything to try.

 

Thanks! We had another go at the tune today and essentially resolved the drivability issues. Hooray!

DFCO turned off, but did not intentionally adjust VE to be very lean (fuel trims were spot on and I was loath to tell the tuner to intentionally make the tune "wrong"). Getting a good pop on upshifts (with DFCO off trims can't adjust quick enough).

Overall very happy at this point, and depending on how much I continue to miss the Rice Krispies boys, might ask the tuner to make just one more change...

Enjoy, we live in a wonderful time. "Cheap" performance cars that I could only dream off when younger.

 

You can retard the timing to 0 degrees of advance in the low load areas on decel, to get the crackle effect.

 

I need to try this. My biggest concern is hurting drivability since it works so well now. I guess there's only one way to find out...

DFCO off seems to have no impact on mine.

 

I think the goal/effect of retarding timing or reducing fuel during decel is the same. Either by starting combustion late (retard) or slowing down combustion (lean) you're creating a situation where there's unburned or still-burning fuel still present when the exhaust valve opens. Snap, crackle, pop.