04-07-2024, 06:35 PM | #1 |
Drives: 2010 camaro RS,2017 camaro 1Le Join Date: Mar 2016
Location: Charlotte, NC
Posts: 195
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Autocross advice needed
I’ve been autocrossing my car here and there for the past 4 years. This is my first exposure to autocross in any car. I have had the car full bolt on and tuned for the entirety of this. The car has always been extremely tail happy and I have just chalked it up to being a RWD car on the stock supercar 3’s which take time to get heat in them. Yesterday I attended an autox school where I was able to get about 10 runs in the morning and 10 in the afternoon which got the tires sticky. An instructor rode with me who is use to running RWD V8 cars, his advice to me was that my throttle inputs were way to aggressive. He asked to drive to show me how it should be I agreed. It only took the first turn for him to ask what the hell kind of throttle mapping I had because the tiniest input upset the car. There isn’t any kind of progressive power when applying throttle. Hearing this made sense I’ve learned to drive the car but always fighting the car. He explained a lot of tuners tune for drag racing and the throttle tip in is overdone. Does anyone have any advice on a tuner that would be able to tune this correctly. Or should I try to get a tire setup that can handle the aggressive throttle.
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2017 camaro 1le
ROTO fab, Ported MSD, Ported 95mm tb, 2in TSP catless longtubes, flowmaster x-pipe, flowmaster American thunder npp, flex fuel, |
04-07-2024, 07:43 PM | #2 |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
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It'll make a big difference to use Track mode and within track, enable the PTM (Performance Traction Management) modes, or hold the traction off button for 8+ seconds to disable both traction and stability control. This will also change the behavior of the rear diff, as well as linear throttle mapping.
You can also independently choose what steering weighting you want, track is a bit heavy imo... I also keep the exhaust in track mode all the time. You can't change throttle mapping independently of mode though. If you're going to autox I'd get dedicated wheels/tires. 18x12 square is possible, but if you want to stick to street class, go oem 1LE sizes but in 19" diameter. Bridgestone RE71RS tires, 295/35/18 or 305/30/19 (all 4). Also get an alignment with max camber and zero toe front, 1/16-1/8 toe-in rear. Good Luck!
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04-07-2024, 11:05 PM | #3 |
Drives: 2SS 1LE Join Date: Oct 2011
Location: AK
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Track mode track mode track mode, for the throttle.
I also like the heavier steering in track mode, that helps to minimize you getting the steering angle too far, which will send you spinning, but the throttle is a much bigger part of it. Sport mode is pretty horrible for track stuff. It's great for getting into 4th from 1st, but otherwise, it is significantly regressive. If if the pedal goes 3", it gives you more than half the available throttle in the first 1". It also means when you are at 4500rpm and you "punch it" from there...you don't really go, that part takes fun out of higher RPM driving IMO. At higher RPMs you have a lot less throttle response in sport mode. I will often do the first lap or maybe two in PTM Race, and then after that it's everything off. Even PTM Race robs significant time/power.
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04-07-2024, 11:35 PM | #4 |
Drives: 2018 SS 1LE Hyperblue Join Date: Jul 2017
Location: Lacey, WA
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With regards to the throttle mapping, I think Randy Pobst commented that he used a pedal commander or something to make the throttle response curve more linear. A lot of the throttle response "solutions" simply hasten the opening of the throttle to make the car feel more powerful, when in actuality they are making it less modulatable/controllable. I'd talk to your tuner.
Also, PTM, as above. |
04-08-2024, 08:02 AM | #5 |
Drives: 2010 camaro RS,2017 camaro 1Le Join Date: Mar 2016
Location: Charlotte, NC
Posts: 195
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I have used probably every PTM with the exception of track mode and holding the button to turn everything off. We actually found that sport mode and competitive mode was the least violent but still small inputs upset the car. I do have the GM track alignment. I will most likely go with 18 x 12 as I am already in CAM due to the other mods. I have no issues with my tuner however he is use to drag racing. Was looking for a a tuner that had experience with track / autox cars.
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2017 camaro 1le
ROTO fab, Ported MSD, Ported 95mm tb, 2in TSP catless longtubes, flowmaster x-pipe, flowmaster American thunder npp, flex fuel, |
04-08-2024, 10:17 AM | #6 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
Posts: 1,878
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04-08-2024, 11:08 AM | #7 | |
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04-08-2024, 10:27 PM | #8 | |
Drives: 2SS 1LE Join Date: Oct 2011
Location: AK
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Everything happens for a reason, except when it doesn't, but even then, you can, in hindsight, fabricate a reason that satisfies your belief system.
2018 2SS 1LE 2023 Colorado ZR2 2022 Stinger GT-line AWD |
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04-09-2024, 06:46 AM | #9 |
Drives: '94 Z28+ '15 Z/28 Join Date: Jun 2009
Location: Cheektowaga, NY
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Could be that your rear toe adjustment is out of whack. My cars makes 588rwhp, and it tracks really good out of corners. Obviously I can blow the tires off at will if I mash the gas, but it will handle aggressive inputs on most turns. I'm running -1.5 degrees of camber, and they are toed in -.125 as well.
Also, what tires are you running?
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04-09-2024, 10:27 AM | #10 | |
Drives: 2004 BMW 330CI, 2022 1SS 1LE Join Date: Dec 2021
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04-09-2024, 07:09 PM | #11 | |
Drives: 2023 CT5 Blackwing Join Date: Sep 2016
Location: Orlando
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No, Randy did not use a add-on. He commented he would like to see a more linear throttle while on track. GM changed the Track mode to give just that. Pedal commanders with this car are the fastest way to a check engine light and limp mode on a track day.
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04-09-2024, 07:42 PM | #12 | |
Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018
Location: Front Range, CO
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DSC is great for those who find the concept appealing, you can have shocks that react to what the car is doing preemptively based on brake and steering inputs, and more. As an engineer I can get carried away with this sort of stuff, and I don't have the time to spend on dialing it in. It requires some time and effort to test n tune the DSC along with a nuanced understanding of suspension to get the most out of it. DSC also offers active coilovers that work with the controller. OTOH, it's not like GM is incompetent at programming their own magride shocks, oem is good but the main difference is DSC uses more info than OEM to decide on shock behavior. If you get the ediff tune on stock tires and sus setup it's still better and more fun to drive, but you can literally feel the rear end locking and unlocking, there's a bit too much exit oversteer and if you're not smooth the rear diff will actually unsettle the car. With 200tw tires and a stiffer front roll bar you're good to go though, rear diff feels totally normal except it puts power down better on exit and is more predictable. It may also unlock on corner entry faster, but there's some debate on that, feels like it does to me. Diff tune is FS-legal now too.
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Last edited by DaveC113; 04-10-2024 at 08:58 AM. |
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04-10-2024, 07:41 AM | #13 |
Drives: Chevrolet SS 1LE Join Date: Oct 2019
Location: St. Charles, MO
Posts: 1,446
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I think we need to go back to basics here with the OP. Baker, what mods have you done to the suspension of the car? Stock SS 1LEs are not "extremely tail happy." They have a proclivity to kick the tail a bit on throttle when exiting a corner due to the stock eLSD tuning. The GM autocross eLSD calibration solves that, but even without it these cars are highly competitive in Street (stock, essentially) class. The kinds of things that upset the forward-traction balance are aftermarket rear suspension links with poly bushings, cars that are lowered such that the outside rear suspension hits the bump stops while cornering, rear toe out, or a way-too-stiff rear swaybar.
If your car literally has an out-of-kilter throttle response (compared to a stock LT1 Camaro), then you need to look at your bolt-ons and/or tune. For instance, an aftermarket throttle body could cause this, especially if there's some kind of "hole" in the A:F curve coming off throttle. If tuning software (e.g. HP Tuners) allows the throttle map to be changed (it probably does) and you've had someone tune the car, then all bets are off. You need to compare your mapping to a stock throttle map to see how it's different: most tuner's idea of improved mapping is probably to give most of the throttle in the first 1/4 of pedal movement (as others have alluded). That's stupid. The stock mapping in Track mode is fairly linear, and in fact I wish we could use that mapping in Touring mode. My suggestion is to find someone who is a good autocross driver in a stock 1LE and ask them to drive the car and give you their impressions, and also to figure out how your current throttle mapping compares to stock in Track mode.
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2020 SS 1LE |
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