I'm to the point I'm ready to try and solve some of the issues with this C3.
It's a 2001 with the awd, 4l60hd-6.0lq4 with a whipple sc. Engine and tranny were both recently gone through, but the tranny still slips on 2-3 shift and the engine is still setting codes for a lean condition (occasionaly) and a continuous issue with low idle (sets code for throttle position jive).

Vehicle has had the tps and the trottle body replaced under warranty, and the issue on the idle would go away for a few weeks, and then return.

I'm planning on the asm 42lb injectors, and bypassing the whipple craptronics, but I'm not sure wether to do the Nelson tune, or get ls1 edit (or the equevalent) to solve some of the drivability issues, along with improving the setup??

Those who have some input and/or experience with this feel free to comment. Thx!

 

dyno tuning is infinately more effective and just plain better than a mail order tune. if a mail order is all you can get at the time it's suffecient, but a custom dyno tune is always the BEST way to go.

 

Hard to find all wheel dyno'd for the C3
going to have to street tuning the thing
For the money buy Hptuners and get there Scan tool aswell
I've seen both Ls1edit and HP tuners get HPtuners
and Find someone local to help you out
Get some bigger injectors and ditch the whipple craptronics

 

i think that a four wheel dyno is going to be difficult to find. a mail order tune can work great. nelson has tuned many with whipples and radix as well as sts. i think he can get it darn close if not dead on. i true tune would be to get with him in the truck.but he can tune very well mail order also.

 

Actually, for the dyno all we've done before is just take out the front driveline.
I'm going to talk with Allen tomorrow, I think he's probably done enough of these now to have a pretty good basis for a tune-I hope!

 

Get LS1 edit/HP Tuners and do mail order tunes if your not sure of your tuning ability. That way problems are quickly and easily fixed intead of waiting on PCM's and such. GMCSKI should be able to help you out with getting it tuned through email, your setup is pretty basic and shouldn't be too hard to get 99.9% perfect through mail order tune. The only major advantage to the dyno is the ease of access to a wideband since most dyno places have them, but I'd say get HP Tuners and a portable wideband and have at it. Have Jim Ski (GMCSKI) help you out if he will.

 

allen for sure will be able to get it right. ive seen him tune many a superchargers.

 

I would go to your guy with the dyno. About a year ago we put a 408ci in a Tahoe with a Whipple. Very nice power, but a little hard to tune. We also installed the Dynatech LT's, Flexalite electric fans, and a 2000 stall from Hughes. I will tell you our tranny was doing the same thing. It wasn't long until I lost 2nd, then 3rd gear. We ordered a street strip tranny from Hughes to fix that problem...

 

I have a mail order tune from Nelson and I dont have AWD but I have used scan tools and shared my info with him and I can tell you that although there may be a very small amount that could be changed it is as close to perfect as I ever thought it could have ever been done even with a dyno. I dont have the SC and that makes it a little tricker but I am almost positive that Allen can perfect a tune for you!

 

whipple electronics are terrrible, I have a customer with a silverado SS 03 with the same problem you are describing. What we found after spending countless hours on the phone with jeff from whipple is that they intercept the signal from the mass air flow sensor & change it before it gets to the pcm. He is currently (right now) taking all the whipple electronics off as well as the auxillary injectors & bying a new fuel pump & injectors. He is also spraying this with a 75 wet shot. Ed Wright is doing the tune on the vehicle & it should be done by friday. Whipple knows they have an issue with fuel delivery, its is terrible they do not do anything about it.

Jeff at whipple said they are working on having software that actually changes the pcm parameters but it will not be out for maybe a year.

This ss (lq9 6.0) was setting coeds for misfires & lean conditions, LTFT was a positive 25%, hydrocarbons were none existant. Hopefully this should resolve the issue.....