Dynamometer Results & Comparisons Dyno Records | Dyno Discussion | Dyno Wars

Unusual problem

Thread Tools
 
Search this Thread
 
Old 11-21-2006, 12:54 AM
  #1  
TECH Veteran
Thread Starter
iTrader: (1)
 
gametech's Avatar
 
Join Date: Sep 2004
Location: Stockbridge GA
Posts: 4,067
Likes: 0
Received 432 Likes on 307 Posts

Default Unusual problem

We dynoed my friend's vette with M/T DR's tonight, and couldn't keep the wheels from spinning on the Mustang rollers. The HP and Torque #'s were anything from 80-100HP lower than they were a few months ago. We noticed a lot of tire rubber splattering everywhere. We then swapped the rear wheels back to his Nitto street tires. This cured the wheelspin problems, and the dyno #'s were back to where they should be. I am just curious why the tires that hook better on asphalt won't hold on the dyno, and the tires that won't hook on the street stick to the rollers fine. This makes no ******* sense whatsoever to me. BTW, the best 60' on the nittos is 1.9 and the best on the M/T's is 1.6, so I know which tires hook better on the road.
Old 11-21-2006, 03:55 AM
  #2  
TECH Regular
iTrader: (3)
 
Hi Volume's Avatar
 
Join Date: Nov 2005
Location: NoCal
Posts: 430
Likes: 0
Received 0 Likes on 0 Posts

Default

dyno rollers are knurled and steel, not asphalt. Some slick/DR companies have warnings NOT to use them on the dyno...

If all else fails, spray VHT on the rollers....
Old 11-21-2006, 07:55 AM
  #3  
11 Second Club
iTrader: (6)
 
98SS2836's Avatar
 
Join Date: Sep 2005
Location: Dracut, MA
Posts: 493
Likes: 0
Received 0 Likes on 0 Posts

Default

Yea we have this problem with those tires too. You just have to move to the front of the rollors then they won't spin.
Old 11-22-2006, 12:06 AM
  #4  
TECH Veteran
Thread Starter
iTrader: (1)
 
gametech's Avatar
 
Join Date: Sep 2004
Location: Stockbridge GA
Posts: 4,067
Likes: 0
Received 432 Likes on 307 Posts

Default

I was just curious.
Old 11-22-2006, 05:34 AM
  #5  
11 Second Club
iTrader: (6)
 
98SS2836's Avatar
 
Join Date: Sep 2005
Location: Dracut, MA
Posts: 493
Likes: 0
Received 0 Likes on 0 Posts

Default

Is it an automatic
Old 11-22-2006, 08:23 AM
  #6  
TECH Enthusiast
 
dynocar's Avatar
 
Join Date: Sep 2004
Location: Omaha, NE
Posts: 564
Likes: 0
Received 0 Likes on 0 Posts
Default

I'm assuming that this dyno had dual rollers for each tire as apposed to one huge 50" drum like our Mustang dyno. Smaller dual roller dynos create much more tire heat because each roller applies all of the force at small areas of the tire as apposed to distributing the force over a more wide tire patch. Any tire, such as your soft tire compound MTs, will lose traction when overheated, which they obviously were if you were throwing chunks of rubber around the place. So putting your hard rubber Nittos on kept your tire temps within an acceptable range, creating more traction.
Old 11-22-2006, 08:56 AM
  #7  
12 Second Club
iTrader: (33)
 
Hennytime's Avatar
 
Join Date: Jan 2005
Location: winter springs, fl
Posts: 2,584
Likes: 0
Received 0 Likes on 0 Posts

Default

not to hijack, but are nitto dr's ok to use on a dyno?
Old 11-22-2006, 06:53 PM
  #8  
TECH Veteran
Thread Starter
iTrader: (1)
 
gametech's Avatar
 
Join Date: Sep 2004
Location: Stockbridge GA
Posts: 4,067
Likes: 0
Received 432 Likes on 307 Posts

Default

This was on an MD250 with dual smaller rollers.




All times are GMT -5. The time now is 09:18 PM.