toy_collector

(This was originally in the C6Z06 discussion area, but I'm pasting over here where I may get a better response.)

My car was built up a few years ago. The car makes great power, 608 rwhp, but driveability is horrible. In neutral give it a little gas to 3000rpm or so. Let off and the motor will drop to nearly 0rpm then jump to 2000rpm then back to nearly dying then back up, etc. It will do this until it eventually dies. Very light throttle application will help settle it down. The problem seems to have gotten worse.

So I'm looking for a local tuner familiar with big cams, big intakes, ported heads, big throttle bodies, etc. A complete retune is not necessary. Housecall would be great.

If anyone is capable of this or knows someone who is, please PM. Thx!

Maligator

Did you try Straightline?

toy_collector

Straightline did the build and initial tune. They did a great job and I'm happy with the build. But they're an hour and a half away. I'm hoping to find a local shop or someone who will make a house call.

schpenxel

What cam? Has it always done this or is this new? This is usually simple to fix if it's a tune issue.

Maligator

then its the probably the same cam I have; when it comes down to it, isnt a 1.5 hour trip worth it when it comes to your z06? Is your z06 red with black rims? Wondering if its Keiths z...............

Maligator

and the surging sounds like a vacuum leak, something could have taken a **** from when they did the build til now. Especially with the fast and nw tb.............................

JEPopp

Try Libertyville Chevrolet. Kevin is their Master Tech in the High Performance Shop and is superb. When you call, ask for Andy in service and he'll help get you set up.

Good luck and keep us posted.

toy_collector

My car isnt red with black rims. But I do have the lumberjack cam set up. At the time my car was tuned by straightline, even they were surprised at the 600+ rwhp the car put out. On the way back home the car shut off twice. It fired right back up so I kept going figuring the ecu was learning. Never happened again. As for the build I thought Straightline did a great job in building what I asked for. But now the car is no longer my track beast. So it needs better street manners.

Fast forward a year and the car started low rpm surging as noted in my post. I had a couple maintenance items to do so I took the car to Libertyville Chevrolet Performance Center. They sent it out for dyno tuning. Car ran ok briefly but still had low rpm issues. I talked to Kevin at Libertyville Chevrolet and got the name of who they sent the car to for dyno tuning. Drove the car there and the tuner just plugged his HP tuner in and made some tweaks. Car ran ok for a while then the low rpm issue returned in full force. Car really isnt driveable. My 2k clutch wouldnt handle even a short drive at this point given the hard throttle required to get rolling.

Yep, there's probably a vacuum leak or a gobbed sensor somewhere. I'm going to try the COW. Chuck already has my ecu and hopefully over the next couple weeks it'll get sorted.

There is another shop in the area that has done tune work on the car prior to the build. Very poor experience. Based on a download of the tune it doesnt appear their tuner was very experienced. As they may be a forum sponser, I'll refrain from further comment.

I'll post a follow up. Fingers crossed!

0Chuck CoW

Looking at it now..... I'll get back you you with my opinion.

Chuck CoW

norris_83

do u have hptuners by any chance? I've been fighting my idle for the past 3 days and low bucking and surging to finally get it where I want it. The problem though is its my car and not a customers, so I wasn't working on it as hard as I shouldve been.

schpenxel

Basics on your setup?

0Chuck CoW

Yes, I have both....

Send me a file and I'll have a look.... EFI LIVE is easier for me to see what's going on, but Let's have a look.

Chuck CoW

toy_collector

Update:

I tried Chuck @ COW but after waiting months for hardware and dealing with poor communication I scrapped that idea.

I ended up driving the car an hour and a half to Straightline. At steady throttle the car surged/bucked/puked and basically made for a miserable experience. Handed it over to Nick. He put it on their dyno and reviewed the current tune. There were a number of changes from their original tune so he changed it back to have a known starting point. As noted previously, the car makes great power (700+rwhp) and throttle response is instantaneous. But driveability has gotten terrible. So Nick fired it up and ran it like one would in typical Chicago area traffic. Eg focus on low rpm operation. He pulled data, made adjustments, pulled more data, adjusted, etc. After a couple hours I could tell the car was running smoother at low rpm. Now instead needing to be at 2300+ rpm, I could run at 1800 rpm. For a car with a big cam, intake, heads, etc I think this is a big deal. Nick thinks we could improve things more and gave me some to-do's:

1. As the car has sat a LOT for the past few years, run a few tanks through with Lucas fuel injector cleaner.
2. Put it on the lift and check the cats for internal breakdown.
3. After the injector treatment, install new front O2 sensors.
4. Bring the car back down anytime for tune adjustment.

My to-do's are in process but the car is much better to drive. It's been very hot hear lately and the issue of the MAF with integrated IAT being on top of the radiator is very apparent. This probably isn't helping driveability so I'll be checking into relocating.

Anyhow, thanks to Straightline and Nick for making the C6Z06 tolerable again. As I said, Nick spent 2 hours on this. They did the build back in 2012 but I didn't expect any freebies at this point. So when I asked Nick what I owed him and he replied "nothing", I was pretty surprised.

I'm a very satisfied customer of Straightline Performance and highly recommend them. They did a great job on the initial build and provided timely support even 4 years later. Thanks Nick! http://www.1320hp.com/