5.9L 12V Performance Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps Related to Performance and Longevity

New Valair 500hp Clutch Slipping

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Old 12-02-2007, 12:26 AM
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Default New Valair 500hp Clutch Slipping

I was doing a little stop light drag racing not even full throttle and at about 2500 rpm in 3rd and 4th my clutch would slip a little nothing to bad but I am almost sure it was clutch. What else could cause that feeling? Maybe a lack of fuel. Maybe supply pump can not handle the flow. What sort of HP am I running with my setup. Could I have over run my clutch all ready? I was told that this clutch:

13" x 1.25" Performance Replacement
Organic / Feramic Facings
Rated @ 500HP / 1000 ft lbs Torque
3400# Pressure Plate

was under rated. I broke it in for about 350 miles at least.
Any ideas?

Thanks
 
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Old 12-02-2007, 01:30 AM
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what is your setup fill out your signature and let us know what you got done to your truck, also welcome to the site
 
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Old 12-02-2007, 01:51 AM
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I have heard that this clutch with the feramic facing will take longer to break in so I am going to just take it easy a little while longer.
 
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Old 12-02-2007, 02:46 AM
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A ceramic clutch never really laps in and faces off. Thats why ceramic is so good at sharpening knives and anything with an edge. Sounds to me like your pump is falling off. This is a typical tale tail sign of a common rail not getting enough fuel at WOT but yours being a '97 sounds like your having pump issues.
 
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Old 12-02-2007, 12:36 PM
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Originally Posted by estrada5.9
I was doing a little stop light drag racing not even full throttle and at about 2500 rpm in 3rd and 4th my clutch would slip a little nothing to bad but I am almost sure it was clutch. What else could cause that feeling? Maybe a lack of fuel. Maybe supply pump can not handle the flow. What sort of HP am I running with my setup. Could I have over run my clutch all ready? I was told that this clutch:

13" x 1.25" Performance Replacement
Organic / Feramic Facings
Rated @ 500HP / 1000 ft lbs Torque
3400# Pressure Plate

was under rated. I broke it in for about 350 miles at least.
Any ideas?

Thanks

if your clutch is slipping you should see a rise in rpms's with no raise in speed........
 
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Old 12-02-2007, 03:52 PM
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Default Lack of fuel

I was thinking it was a lack of fuel because there is a smooth decline of acceleration. I know what a slipping clutch feels like that is why I have a new one. Would it be possible that my supply pump can not keep up with demand of fuel? If so what should I do to fix it? Would an inline electric pump work to help feed the supply pump or should I just replace my current supply pump?

1997, 2500, 4x4, ext. cab, long bed, 5spd, 185000, valair 500HP clutch,4 GSK,DDP 3's,Timing 18*,Dragon Fly P-pump, Super B, ATS exhaust manifold.
 

Last edited by estrada5.9; 12-02-2007 at 03:53 PM. Reason: sig not showing up
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Old 12-02-2007, 06:29 PM
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Put a fuel pressure guage on it before changing the lift pump. How much does that Dragon Fly pump flow?

A FASS that would flow enough would be $600-700.
 
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Old 12-04-2007, 06:32 PM
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The Dragon Fly flows 500cc I believe. Where can I get some info on hooking up a pressure gauge to determine if it is the supply pump?

---AutoMerged DoublePost---

Talked with the aussie guy from Valair he told me that my clutch was in the final stages of being broke in and it was time to play a little to help it seat. Well I heard play and out I went, I drove moderate to hard for about 20 min. stop lights and a few straight stretches. Kind of got sideways on accident. I am going to take out again later and keep working it. I think that this is going to solve the problem. Can't break somthing in driving it like a old lady.

---AutoMerged DoublePost---

I have been told slipping was just part of the process to get the clutch seated. So on the way back from the gym in got on it again in 3rd WOT(never went wide open til now) and it held strong up to about 2800 then slipped a little. It is for sure getting better.

---AutoMerged DoublePost---

Got on it hard today WOT in 2nd and 3rd it was intense. I can't believe that this thing keeps holding better and better!
 

Last edited by estrada5.9; 12-04-2007 at 06:32 PM. Reason: Automerged Doublepost
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Old 01-24-2008, 07:49 PM
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I slipped the clutch on my old 24v one hard time after I broke it in (drove easy for several hundred miles, then moderate to hard for another couple hundred), and she held good from there on out; Good enough to bust the 3rd gear cluster matter of fact. It was a big south bend single disk - rated for similar #'s that yours is rated for.
 
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Old 01-24-2008, 10:16 PM
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The more miles you get on your clutch the more you will notice that it holds better. Im glad you're happy with the clutch you have. The longer you run it the more fun you will end up having with it.
 


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