"HOLE SHOT" ATTN: Programmers
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Racer
Joined: Jul 2000
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From: Warren MI
"HOLE SHOT" ATTN: Programmers
The C5's traction control is connected to its engine rev limiter. Thus when pulling a hole shot and the rear tires break loose the engine computer prevents further RPM increse (shuts off acceleration):mad:. One can dis-engage the traction control and avoid the Rev limit scene but then only one wheel provides hole shot traction:cryING:.
NOW HEARS MY PLAN.:reddevil :
If any forum members or vendors (Powerloader) can re-program the PCM to engage the posi-traction portion of the system and not the rev limiter, we could have C5s pulling great hole shots. Imagine both tires smoking and no rev limiter shuting us down
THUS MY CHALLENGE TO THE C5 COMMUNITY
RE-PROGRAM THE THE C5'S PCM TO ENGAGE THE POSITRACTION WITHOUT ENABLING THE REV-LIMITER. We could pull awesome hole shots, like we should.:cheers:
NOW HEARS MY PLAN.:reddevil :
If any forum members or vendors (Powerloader) can re-program the PCM to engage the posi-traction portion of the system and not the rev limiter, we could have C5s pulling great hole shots. Imagine both tires smoking and no rev limiter shuting us down
THUS MY CHALLENGE TO THE C5 COMMUNITY
RE-PROGRAM THE THE C5'S PCM TO ENGAGE THE POSITRACTION WITHOUT ENABLING THE REV-LIMITER. We could pull awesome hole shots, like we should.:cheers:
Team Owner
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From: Overwhelmed as one would be, placed in my position.... DFW, TX
St. Jude Donor '05
Re: "HOLE SHOT" ATTN: Programmers (sjbeck)
Let me see if I understand this correctly- if you turn off traction control, we don't have posi (or a limited slip diferential)? :confused:
Melting Slicks
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From: DFW TX
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Re: "HOLE SHOT" ATTN: Programmers (C5 YA)
Ummm, I don't think so. Turn off traction cotrol and go do a burnout. Look for one or two stripes. I get two. :D
Race Director
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From: Cincinnati Ohio
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Re: "HOLE SHOT" ATTN: Programmers (C5 YA)
This is indeed interesting. I hope Steve Cole or Ed Wright will respond to this. :yesnod:
Instructor
Joined: May 2001
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From: Ridgetop TN
Re: "HOLE SHOT" ATTN: Programmers (sjbeck)
I think the posi-traction is clutch-driven-mechanical and has nothing to do with the electronics.
The traction control monitors the speed of the front wheels versus the speed of the rear wheels to calculate wheel spin.
I also think that the program for the rev limiter is different from the program for the traction control. One has to do with hitting the redline and shutting off half of the cylinders while the other works at any rpm and limits torque to the rear.
The traction control monitors the speed of the front wheels versus the speed of the rear wheels to calculate wheel spin.
I also think that the program for the rev limiter is different from the program for the traction control. One has to do with hitting the redline and shutting off half of the cylinders while the other works at any rpm and limits torque to the rear.
Drifting
Joined: Apr 2001
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From: Austin TX
Re: "HOLE SHOT" ATTN: Programmers (RedLandRocket)
Traction control retards timing to reduce engine power. Rev limiter shuts off the injectors until the engine goes back below the limit rpm, then it turns them on again. Thats why you 'bounce' off the rev limiter.
Limited slip doesnt have anything to do with either of these, its entirely mechanical.
Eric
Limited slip doesnt have anything to do with either of these, its entirely mechanical.
Eric
Le Mans Master
Joined: Aug 1999
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Re: "HOLE SHOT" ATTN: Programmers (66ImpalaLT1)
This is ALL incorrect.
Traction control is accomplished through the use of the brakes and the brakes only.
We ALL have POSI rear ends at ALL times.
The rev limiter is NOT actuated by cutting fuel, it's actuated by cutting spark.
Hopefully that clears some things up.
Traction control is accomplished through the use of the brakes and the brakes only.
We ALL have POSI rear ends at ALL times.
The rev limiter is NOT actuated by cutting fuel, it's actuated by cutting spark.
Hopefully that clears some things up.
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Melting Slicks
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From: DFW TX
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Re: "HOLE SHOT" ATTN: Programmers (EdwardETraylorIII)
Traction control is accomplished through the use of the brakes and the brakes only.
[Modified by Godspeed, 11:21 AM 10/17/2001]
Drifting
Joined: Apr 2001
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From: Austin TX
Re: "HOLE SHOT" ATTN: Programmers (EdwardETraylorIII)
The rev limiter is NOT actuated by cutting fuel, it's actuated by cutting spark.
This would make LS1's go against every previous GM car with a rev limiter.
Eric
Melting Slicks
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From: DFW TX
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Re: "HOLE SHOT" ATTN: Programmers (66ImpalaLT1)
Do you have any evidence to back this up?
This would make LS1's go against every previous GM car with a rev limiter.
This would make LS1's go against every previous GM car with a rev limiter.
Instructor
Joined: May 2001
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From: Ridgetop TN
Re: "HOLE SHOT" ATTN: Programmers (Godspeed)
I don't know whether it is fuel or ignition but it only does it in half of the cylinders. Even or odd.
On a complete fuel shutdown, there is a definite pause before refuel reaches the cylinders. On the C5, you bounce on the redline i.e. no complete shutoff.
On a complete fuel shutdown, there is a definite pause before refuel reaches the cylinders. On the C5, you bounce on the redline i.e. no complete shutoff.
Thread Starter
Racer
Joined: Jul 2000
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From: Warren MI
Re: "HOLE SHOT" ATTN: Programmers (RedLandRocket)
Sorry All, I stand corrected. On my first trip to the dragstrip, my hole shoot was pityful. The rear end spun, wheelbounced and the rusulting hole shoot was poor. I didn't think it was still using both whees for traction, it sure didn't seem like it. I still ran a 13.11,with the stock EMTs. I'm confident with a decent hole shot it could break 12.s. Any suggestions as to getting a strong hole shot?
[Modified by sjbeck, 7:58 AM 10/18/2001]
[Modified by sjbeck, 7:58 AM 10/18/2001]
Le Mans Master
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From: Burlington ON
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Re: "HOLE SHOT" ATTN: Programmers
Our cars have posi at all times except for going around a corner when it is allowed to slip thus its called a "limited slip differential".
You will never get a good launch at the track without disabling traction control all together. I can't fathom launching my car at 2000-3000rpm with traction control on. I have done it by mistake a few times and it felt horrible.
I feel that traction control backs off the throttle to reduce the power going to the wheels which stops them from spinning. Obviously since our car is throttle-by-wire we cannot feel the pedal push back up on us like on previous cable-throttled GM cars. Also, if you have a wide open throttle nitrous activation switch that runs off of the Throttle Position Sensor, you will notice if you leave traction control on, when the nitrous kicks in and the tires spin, and active handling activates, the nitrous will stop spraying because the WOT switch is no longer seeing 100% throttle. This to me tells me what the Traction Control system does to stop tire spin.
[Modified by MattG, 9:01 AM 10/18/2001]
You will never get a good launch at the track without disabling traction control all together. I can't fathom launching my car at 2000-3000rpm with traction control on. I have done it by mistake a few times and it felt horrible.
I feel that traction control backs off the throttle to reduce the power going to the wheels which stops them from spinning. Obviously since our car is throttle-by-wire we cannot feel the pedal push back up on us like on previous cable-throttled GM cars. Also, if you have a wide open throttle nitrous activation switch that runs off of the Throttle Position Sensor, you will notice if you leave traction control on, when the nitrous kicks in and the tires spin, and active handling activates, the nitrous will stop spraying because the WOT switch is no longer seeing 100% throttle. This to me tells me what the Traction Control system does to stop tire spin.
[Modified by MattG, 9:01 AM 10/18/2001]
