Lost HP
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Instructor
Joined: Aug 2003
Posts: 249
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From: Round Rock TX
Lost HP
Not too long ago, I got an A&A Supercharger and blower cam installed on my C6. At that time it dynoed 669 RWHP. With that much power, my stock clutch wouldn't hold the power. I got a McLeod RXT clutch and aluminum flywheel installed and after the breakin period I also got an Alky meth kit installed. I just knew for sure that with the Meth I would push the car over 700 RWHP. Instead, after the tune, it dynoed 648 RWHP.
Anyone know why I would have lost power? One theory was that with the new clutch and aluminum flywheel the engine had to work less hard to generate the power and that it "tricked" the dyno into reporting less power.
Any other theories or real world experience?
Also, the McCleod RXT makes all kinds of noises! I'm not at all happy with the noise that it makes. It makes a "rolling can or marbles" noise at idle with the clutch pedel out. It also makes a laboring noise in each gear when it's pushing the car to get to speed. Is this just the characteristics of this clutch or do I have a clutch problem? I've heard people with this clutch say it's quiet and other say it's characteristic of a twin disk clutch.
Anyone know why I would have lost power? One theory was that with the new clutch and aluminum flywheel the engine had to work less hard to generate the power and that it "tricked" the dyno into reporting less power.
Any other theories or real world experience?
Also, the McCleod RXT makes all kinds of noises! I'm not at all happy with the noise that it makes. It makes a "rolling can or marbles" noise at idle with the clutch pedel out. It also makes a laboring noise in each gear when it's pushing the car to get to speed. Is this just the characteristics of this clutch or do I have a clutch problem? I've heard people with this clutch say it's quiet and other say it's characteristic of a twin disk clutch.
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Joined: Sep 2009
Posts: 2,144
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From: Central Florida
Different dynos, different days, never gonna be the same. Did you ever run it down the track before the meth and clutch?
Does it feel faster now?
Was it initially tuned and then retuned by the same person?
As for the clutch noise, sounds like a possible install issue. If it were a Ferd I'd say throwout bearing...
Does it feel faster now?
Was it initially tuned and then retuned by the same person?
As for the clutch noise, sounds like a possible install issue. If it were a Ferd I'd say throwout bearing...
Thread Starter
Instructor
Joined: Aug 2003
Posts: 249
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From: Round Rock TX
Same dyno, same tuner, different day. It was a lot hotter on the most recent dyno, but 20 HP down, when I was expecting to add 40?
I did run it down the track before the clutch and meth. I haven't tracked the car since the clutch/meth install. On the road, it feels pretty peppy...but it could be because the motor revs quicker with the lighter flywheel.
Thanks for the observations on the clutch. Do you have experience with the RXT? Are the noises that I've described "not" normal? I would prefer not to live with the noises, if they aren't normal.
I did run it down the track before the clutch and meth. I haven't tracked the car since the clutch/meth install. On the road, it feels pretty peppy...but it could be because the motor revs quicker with the lighter flywheel.
Thanks for the observations on the clutch. Do you have experience with the RXT? Are the noises that I've described "not" normal? I would prefer not to live with the noises, if they aren't normal.
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Joined: Jan 2008
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curious:
what were the correction factors for each run?
what was the ambient and intake temps for each run?
was timing being pulled due to intake temps?
were the AFRs the same for each run?
any logs of the runs?
I would believe a slipping clutch would impact dyno numbers.
what were the correction factors for each run?
what was the ambient and intake temps for each run?
was timing being pulled due to intake temps?
were the AFRs the same for each run?
any logs of the runs?
I would believe a slipping clutch would impact dyno numbers.
Thread Starter
Instructor
Joined: Aug 2003
Posts: 249
Likes: 1
From: Round Rock TX
I don't know any of this information. I don't believe that the clutch was slipping during either dyno series, however.
