Competition Dyno: Does it have the ability to detect slippage?

[JasonCzerak]

Do any of these dyno's out there have the ability to detect clutch slippage?

 

[csutton7]

not to my knowledge---chris

 

[JasonCzerak]

Well, Maybe you can detect it manually after the fact.



For example: 2500 rpm, in 6th = 90mph. Well, if the rollers are spinning at 90mph at 2700rpm, then you know hte clutch is slipping.....



I suppose I'd have to get a print out of the roller speed and RPM that dyno is detecting. Do one pull with little load to the redline to get a base line, and obviously do a fully loaded pull again and see if the RPM vs. roller MPH matches teh unloaded pull.



This sound logical to anyone?

 

[SpicyJam]

Jason, there is no dyno that we play on around here that you would even have to worry about it. If you think about it, the weight of your truck under WOT on the road is way more load than you will ever put on it on a dyno around here. The rollers we spin at High Tech only weigh 4000lbs, besides that, the graph will show slipage and at what RPM it occurs if it ever slips at all. There will be sharp drops in the graph... ... ... . I can talk to you more about if you are coming out this weekend at BWW... ... ..... later Jim.

 

[JasonCzerak]

Jason, there is no dyno that we play on around here that you would even have to worry about it. If you think about it, the weight of your truck under WOT on the road is way more load than you will ever put on it on a dyno around here. The rollers we spin at High Tech only weigh 4000lbs, besides that, the graph will show slipage and at what RPM it occurs if it ever slips at all. There will be sharp drops in the graph... ... ... . I can talk to you more about if you are coming out this weekend at BWW... ... ..... later Jim.

You have a good point about the drop in the graph.



BWW, I need to double check the times. I have some hauling to do this weekend. lemme pop my head back over to the BWW thread.

 

[csutton7]

well yes you can see it after the fact, but no way to tell during the run until it's to late--chris

 

[Bob4x4]

well yes you can see it after the fact, but no way to tell during the run until it's to late--chris

I have had to double strap trucks on a load dyno to try and keep the tire slip down and still had the tires hotter than blazes and yes it was detectable during the runs.



Bob

 

[Evan A. Beck]

Yep, its detectable on our dyno, and you can see it on the graph. Dynojet 248HW, 7000 lb drums.

 

[BPonci]

Yes you can detect tire slippage. When we dynoed my truck we hooked up the optical eye on the tire and compared tire speed to roller speed. I had a 7% slippage at 663hp and 1632trq. We even let all the air out of my air bags and some out of the tire. Sucked everything down and aired up the tires and put 90psi in the bags.

 

[csutton7]

clutch slippage was the question---besides the rpms going ballistically haywire or looking at the graph after the run how does one know the clutch is slipping strictly from the dyno???? we aren't talking tire slippage--if clutch is slipping aren't the rpms the only way to know and in the time frame of the dyno run you usually don't have time to tell to do anything about it---now if you can load the dyno and are doing specific testing then you could probably figure it out, but it going to take someone donating a lot of time and effort to get it accomplished or a ton of cash----or am i way off base here..... plus I am reading his original question as when doing a dyno run for power vs testing purposes... ..... chris

 

[SpicyJam]

clutch slippage was the question---besides the rpms going ballistically haywire or looking at the graph after the run how does one know the clutch is slipping strictly from the dyno???? we aren't talking tire slippage--if clutch is slipping aren't the rpms the only way to know and in the time frame of the dyno run you usually don't have time to tell to do anything about it---now if you can load the dyno and are doing specific testing then you could probably figure it out, but it going to take someone donating a lot of time and effort to get it accomplished or a ton of cash----or am i way off base here..... plus I am reading his original question as when doing a dyno run for power vs testing purposes... ..... chris

You will still see the clutch slip on the dyno... ..... it will show on the graph. When you do a run you are not going to know what is going to happen until you look at the graph. Then you can decide if you want to chose to run again if you are having issues... ... ... ... . if your truck slips the clutch on the street you know what it does, rpm's rev up and truck doesn't move very well, same will be on a dyno if you have that bad of a clutch. Plus dyno rpm and mph will not match your mph on the speedo... ... ... so you can't base off of that.

 

[JasonCzerak]

You will still see the clutch slip on the dyno... ..... it will show on the graph. When you do a run you are not going to know what is going to happen until you look at the graph. Then you can decide if you want to chose to run again if you are having issues... ... ... ... . if your truck slips the clutch on the street you know what it does, rpm's rev up and truck doesn't move very well, same will be on a dyno if you have that bad of a clutch. Plus dyno rpm and mph will not match your mph on the speedo... ... ... so you can't base off of that.

When I orignally asked the question, I was leaning more toward the smaller end of the slippage scale, the kind of slippage that you won't notice ont he road.

 

[BPonci]

What i was refering to is how it can be done to detect slippage. You could set the optical eye to detect driveline speed vs crank speed. If your final drive is 1 to 1 then you could detect it. That is how some of the manufactures detect slippage. Edge uses this method in there juice w/ att boxes in some modles.

 

[DavidTD]

You can graph speed vs rpm and this will tell you if the runs are the same. If you think you are slipping the transmission (or the tires) this will show it. And liek everyone has said, you can see it in the graph if it's a big enough slip.