99BackNBlackZ28

iTrader: (5)

Got the car tuned yesterday. Needless to say Im very satified with the way things turned out. Just had a couple of questions to see if I could combat a bucking/surging issue around 1500rpms as well as a cruise affect the car has (wanting to drive ahead) after coming to a complete stop. The tuner said the cruise affect is pretty common for a cam/stalled car, just seeing if there is any other input out there.

Car info
2002 WS6
3200 stall
230/232 114LSA cam
underdrive pullies
longtubes


Thanks in advance!

Another_User

From what I have seen it is impossible to completely eliminate all surging at low RPM cruise. I have eliminated nearly all of it on my car. There are a LOT of things that affect it. It is affected by fueling, spark, and IAC. As for the cruise control effect, it is pretty common. If they didn't tune your car properly. I have absolutely no cruise control effect on my car.

99BackNBlackZ28

iTrader: (5)

Would you explain how you worked on eliminating your cruise affect? Or is it some big ?

2001CamaroGuy

iTrader: (6)

second that.....even though I am a M6 (clutch = no pull ever) I no longer get any "cruise control" unless I flip the cruise control switch

luv2spd

iTrader: (1)

Cruise control effect is from too much idle air.

pkincy

iTrader: (1)

The biggest problem I see with the "professional tuners" is that most of them won't tune your car anywhere but at wot. And that seems to have happened to you.

About 95% of the time it takes to tune a car properly is for idle and part throttle operation. Until that is done you can not begin to tune for wot, since wot is simply a richening of the initial tune.

You may have your wot AFR spot on now, but by the time a real tuner finishes your car, it must be retuned for wot, since all the basic air, fuel and ignition parameters have been changed.

I would recommend hiring a tuner with more than dyno experience.

A car is not drivable with surge and the cruise effect.

Perry

NicD

iTrader: (7)

Your throttle cracker table is very agressive from the factory, which I told you when you picked up the car. You are driving on just a base tune right now and that stuff will be adjusted when you bring the car back on wednesday for the rest of the tune. Your idle air table is sitting near 10.2 which is just about right on for what your car uses. With larger cams it is impossible to eliminate ALL the buck and surge at lower RPMs, period.

NicD

iTrader: (7)

No, that hasn't happened to him. I am in the process of tuning his car and he is driving on a base tune to just get it running and driving until he brings it back to me on wed for the rest of the tune. The car hasn't seen a dyno yet at all nor have I actually driven it myself to feel what it is doing. Rest assured this stuff will be taken care of when it is done. It idles cleanly at 900 and I told him I could even drop it a bit more if he wanted more of a lope.

99BackNBlackZ28

iTrader: (5)

Its just more that I noticed after actually driving the car at more RPM ranges & stuff on the 35 mile trip home, thats all Nic. Not knocking your tuning skills for the car runs extremely well for what was done to it and the 2 issues IMO are minor. Again I was just looking for input from other folks.

Black02SS

iTrader: (36)

I have found the Base RunningAirflow table will take care of your cruise control problem. I have a spreadsheet in the sticky that will make a new table for you based on the cars requirements, but your VE table has to be dialed in first for it to be accurate.

99BackNBlackZ28

iTrader: (5)

Thank you for the info.

pkincy

iTrader: (1)

I am relieved your tuner isn't one of the "fire and forget" types. He is right, you need to sneek up on a good tune. Get the idle right first, than light part throttle followed by cruise than when all that is spot on you can go after the dyno run.

When I did my LTs/H/C a couple of years ago I tuned darned near steady for 4 months. And finally got it spot on in my Tune # 39 and # 39RaceGas (more timing). Than I drove it for 18 months without thinking about the tune.

Now I am relearning all the old tuning tricks for my 402. I am on Tune 402T22 (the 22nd iteration) and still haven't gotten to the PE or WOT tuning yet. But that is close as the car is running really really good as a driver now. No cruise control, some bucking but only lugging the car in 1st or 2nd at 1500 rpm or less. Smooth idle and off idle acceleration.

So next week (running Sears Point in the race car this weekend) I will get on the PE tuning.

Good luck on yours. It will all be worth it in the end.

Perry