Addressing Power Hop on the IRS - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

*Mr. Wyndham* · 10-31-2008, 11:08 AM

Quote:

Power Hop

Axle Tramp
What is "power hop" or "axle tramp"? There isn't a short answer to this question in technical terms but, in the real-world sense, it's an annoying oscillation of the drive wheels (thumping vibration) that occurs when you're trying to impress your friends with a burnout.

The end result of severe power hop is giving up on ever achieving a decent 0–60 time and never being able to put a pair of black stripes down Woodward Avenue in August.

In technical terms, power hop or axle tramp is the excitation of the driveline (prop shaft, differential, and drive axles) causing the rear suspension to be excited into resonance. The technical answer to how we combat this problem can include many factors but, in the end, we need to balance the frequency of the rear suspension in its "hop/tramp" mode and the torsional stiffness of the driveline components. The problem with doing these two things is that they tend to drive the cost and mass of the driveline components far beyond its requirements. There should be a better way to do this, because the customer won't necessarily see any advantages; in fact, the extra mass will negatively effect fuel economy, throttle response, and performance.

A Nice Little Secret
For those of you who have read about the new ZR-1 Corvette (very limited availability in late summer 2008), you may have noticed some obscure mentions of the wizardry within the driveline system to improve launch feel, the Asymmetric Drive Axles. What are they? Simply put, one axle has a larger diameter than the opposite axle.

The mechanics of how this works are presently a nice, little GM engineering secret, but it's safe to say that the development that took place on the ZR-1 has been adapted to the Camaro project and will be introduced when the car is launched.

So is power hop on Camaro a thing of the past? That's the plan!
— Andrew D. Holmes

Evotion · 10-31-2008, 11:10 AM

Nice info

*The_Blur* · 10-31-2008, 11:11 AM

This is great! As addressed in the secrets thread, GM has some tricks that make certain cars far superior to the competition.

*radz28* · 10-31-2008, 11:58 AM

Hopefully this will get the power to the ground better.

My brother broke his pinion and ring gear doing a burnout when he and I were getting our tires hot in the burnout box. We were both running MT DRs and numbn*ts felt the axle hopping and thought he'd try to power through it and rolled into the throttle more. We went to the line, staged, left and as he was going by my (he was on N20) I heard a bunch of bad noises from his car. First, I thought it was his engine, but he mentioned the rear end was making all sorts of Heck and when he pulled the diff' cover the next day, found several teeth sheered off both gears. Admittedly, they were aftermarket 3.73s (because his car started as a 2.73 car) but they were toast. It was a good thing that rear end didn't lock-up on him as we were going down the track because if it had, he could've taken both our cars out if he lost control...

Good job GM

TheCaptain · 10-31-2008, 04:14 PM

Indeed. The asymetrical driveshafts will be great! The new CTS-V uses this technology as well. This is why GM is a leader!

*radz28* · 10-31-2008, 05:12 PM

Quote:

Originally Posted by TheCaptain

Indeed. The asymetrical driveshafts will be great! The new CTS-V uses this technology as well. This is why GM is a leader!

- In so many ways

1_2Many · 10-31-2008, 05:18 PM

My '91 Firebird Formula had terrible axle hop...especially in reverse. Don't ask.

*CamaroSpike23* · 10-31-2008, 06:39 PM

didnt we already go over this?

nice info, but just repeating known stuff about the IRS.... tho i gues it does give some insight to those who dont know what wheelhop is. or maybe it was something i wrote in a pm to someone....?

*CamaroSpike23* · 10-31-2008, 07:02 PM

Quote:

Originally Posted by CamaroSpike23

didnt we already go over this?

nice info, but just repeating known stuff about the IRS.... tho i gues it does give some insight to those who dont know what wheelhop is. or maybe it was something i wrote in a pm to someone....?

http://www.camaro5.com/forums/showth...f+shaft&page=6

start at post #238

garfin · 10-31-2008, 07:02 PM

Quote:

Originally Posted by CamaroSpike23

didnt we already go over this?

nice info, but just repeating known stuff about the IRS.... tho i gues it does give some insight to those who dont know what wheelhop is. or maybe it was something i wrote in a pm to someone....?

Yeah... Al Oppenheiser confirmed at the Indy event that this is no longer an issue.

Best regardSS,

Elie

*Mr. Wyndham* · 10-31-2008, 07:03 PM

There was an article online somewhere that was posted, but I found this right off of Chevy.com/Camaro...so I figured it was worth posting again -- especially for those unaware.

Dom · 10-31-2008, 07:20 PM

Thanks for posting again. I was unaware and feel much better about the car now.

*CamaroSpike23* · 10-31-2008, 08:19 PM

Quote:

Originally Posted by Dragoneye

There was an article online somewhere that was posted, but I found this right off of Chevy.com/Camaro...so I figured it was worth posting again -- especially for those unaware.

just giving you crap dragon. lol

and promoting myself as well....

Quote:

Originally Posted by Captain Awesome

Holy cow! Spike is the smartest guy on the internet. Thanks!

*TAG UR IT* · 11-01-2008, 12:30 AM

Quote:

Originally Posted by CamaroSpike23

just giving you crap dragon. lol

and promoting myself as well....

Yep...we did go over it. But like Dragon said, it's worth mentioning again. Now...if I have to tell you one...more...time....

Don't make me do it.......again......

turbocrazy · 11-01-2008, 09:11 AM

So what does this mean for a brakestand? Just out of curiosity.

*CamaroSpike23* · 11-01-2008, 02:07 PM

Quote:

Originally Posted by TAG UR IT

Yep...we did go over it. But like Dragon said, it's worth mentioning again. Now...if I have to tell you one...more...time....

Don't make me do it.......again......

tell me what?

Quote:

Originally Posted by turbocrazy

So what does this mean for a brakestand? Just out of curiosity.

it means hit the brakes and smash the gas!

detroitboy · 11-01-2008, 07:15 PM

My 07 CTS has no problem with wheelhop from brake torqueing it.....it just leaves a beautiful trail of rubber behind. I can't imagine how much better it would be with the bigger V6

10-31-2008, 11:11 AM	#3
The_Blur Moderator, USN Drives: 2000 Firebird Formula NHRA SE Join Date: Nov 2007 Location: Officer Candidate School Posts: 12,712	This is great! As addressed in the secrets thread, GM has some tricks that make certain cars far superior to the competition. __________________ Get a good deal on your purchase. Read this. 117:123 RESPECT ALL CARS. LOVE YOUR OWN. newborn gifts

10-31-2008, 11:58 AM	#4
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crapramento, Crapifornia Posts: 12,949 View My Garage	Hopefully this will get the power to the ground better. My brother broke his pinion and ring gear doing a burnout when he and I were getting our tires hot in the burnout box. We were both running MT DRs and numbn*ts felt the axle hopping and thought he'd try to power through it and rolled into the throttle more. We went to the line, staged, left and as he was going by my (he was on N20) I heard a bunch of bad noises from his car. First, I thought it was his engine, but he mentioned the rear end was making all sorts of Heck and when he pulled the diff' cover the next day, found several teeth sheered off both gears. Admittedly, they were aftermarket 3.73s (because his car started as a 2.73 car) but they were toast. It was a good thing that rear end didn't lock-up on him as we were going down the track because if it had, he could've taken both our cars out if he lost control... Good job GM __________________ "...What IS true: We anticipated that this would happen - we are never finished - and yes, Ford DOES deserve to win now and then. To think that GM can come out with a car to make ford throw in the towel is simply foolhardy..." - fbodfather

10-31-2008, 04:14 PM	#5
TheCaptain N7 Spectre Drives: 13 SRX Premium 3.6L AWD Join Date: Jul 2008 Location: Moosomin, Saskatchewan, Canada Posts: 2,570 View My Garage	Indeed. The asymetrical driveshafts will be great! The new CTS-V uses this technology as well. This is why GM is a leader! __________________

10-31-2008, 07:03 PM	#11
Mr. Wyndham I used to be Dragoneye... Drives: 2012 Camaro ZL1 Join Date: Jan 2007 Location: Buffalo, NY Posts: 25,227 View My Garage	There was an article online somewhere that was posted, but I found this right off of Chevy.com/Camaro...so I figured it was worth posting again -- especially for those unaware. __________________ *"Keep the faith."* - - *Read Before You Post.*

10-31-2008, 07:20 PM	#12
Dom Drives: 2000 Z28 Join Date: Oct 2008 Location: Rockford Posts: 119	Thanks for posting again. I was unaware and feel much better about the car now. __________________ 2000 Z28 - current daily 1996 Camaro 3.8 - previous daily

10-31-2008, 11:10 AM	#2
Evotion Warehouse 13 Survivor!!!! Drives: '10 CGM 2SS/RS - 69' Camaro Join Date: Sep 2008 Location: Tucson, AZ Posts: 740 View My Garage	Nice info __________________

10-31-2008, 05:18 PM	#7
1_2Many Drives: 2008 Suzuki SX4 Join Date: Oct 2008 Location: SoCal Posts: 786 View My Garage	My '91 Firebird Formula had terrible axle hop...especially in reverse. Don't ask.

11-01-2008, 09:11 AM	#15
turbocrazy Drives: Cadillac CTS & 2010 BLK SS/RS Join Date: Oct 2008 Location: NY Posts: 72	So what does this mean for a brakestand? Just out of curiosity.

11-01-2008, 07:15 PM	#17
detroitboy Pinholic Drives: 11 Silverado, 08 Shelby GT500 Conv. Join Date: Nov 2008 Location: Macomb, Mi Posts: 698	My 07 CTS has no problem with wheelhop from brake torqueing it.....it just leaves a beautiful trail of rubber behind. I can't imagine how much better it would be with the bigger V6 __________________ Almost had a 2SS/RS, IOM, orange accent interior, 6 speed manual, sunroof & polished wheels ordered 01/19/07 3000 - 2/27/09 3400 - 3/27/09 3800 - 4/17/09 (built and lost in the vortex) ship date ??????? (I gave up and got a GT500) 5/11/09 - order cancelled 5/27/09 - vehicle arrived at dealership for whoever bought it after me

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