Drivetrain bad idea? ltwgt crank pulley AND ltwgt flywheel??
6th Gear
Joined: Jan 2005
Posts: 1,719
Likes: 1
From: New Brunswick, NJ
Idea:
Maybe if the usual suspects would AGREE to not **** and moan and instead allow the person to write a simple, succinct opinion, we could then 'enter it into protected evidence.' Assuming everyone behaves like their mothers would have them, I agree with Andy that that would be an INVALUABLE asset. The truth is, I think we've all had enough of this bickering. I personally am putting one on my car. But, many people are gonna need some more OFFICIAL information. For the good of those people, please let's 1) just get someone in the know on here, 2) not question their qualifications [like always happens!!
], and get a final word. VENDORS: this would help your sales, I'm sure you recognize. Everyone wins 
!
Maybe if the usual suspects would AGREE to not **** and moan and instead allow the person to write a simple, succinct opinion, we could then 'enter it into protected evidence.' Assuming everyone behaves like their mothers would have them, I agree with Andy that that would be an INVALUABLE asset. The truth is, I think we've all had enough of this bickering. I personally am putting one on my car. But, many people are gonna need some more OFFICIAL information. For the good of those people, please let's 1) just get someone in the know on here, 2) not question their qualifications [like always happens!!
], and get a final word. VENDORS: this would help your sales, I'm sure you recognize. Everyone wins !
No OEM will deliberately recommend the use of non-OEM approved and warrantied products. The Tritec group admitting off-the-record that their test regime included certain testing is already asking more than we can realistically expect. The Tritec team is now disbanded, and doing other things. There's no reason for them to help the MINI aftermarket, and them risking doing so only creates trouble for themselves if they have a non-disclosure agreement with their employer. Not everyone wins 
3rd Gear
Joined: Dec 2004
Posts: 161
Likes: 0
Horses are great, but the proof is in the miles driven. Have switched from a -19% SC to a -15% & +4% crank, ~10,000 summer miles ago (CT to LA, LA to CT, etc.). Butt dyno says . Lower end hasn't let go yet 
. Aren't those the same design engineers that put that behemouth of a crank on our car in the first place
.
. Lower end hasn't let go yet . Aren't those the same design engineers that put that behemouth of a crank on our car in the first place .
Originally Posted by andy@ross-tech.com
, maybe it would be a good idea to get one of those people to come on here to explain the benefits/drawbacks of crank pulley damping as it specifically applies to the engine we have. That way, info could come straight from the horse's mouth, as it were.
****yikes!!
:impatient.
Originally Posted by Ryephile
No OEM will deliberately recommend the use of non-OEM approved and warrantied products. The Tritec group admitting off-the-record that their test regime included certain testing is already asking more than we can realistically expect. The Tritec team is now disbanded, and doing other things. There's no reason for them to help the MINI aftermarket, and them risking doing so only creates trouble for themselves if they have a non-disclosure agreement with their employer. Not everyone wins
6th Gear
Joined: Oct 2002
Posts: 3,652
Likes: 6
From: Lansdale, PA
Originally Posted by Ryephile
No OEM will deliberately recommend the use of non-OEM approved and warrantied products.
3rd Gear
Joined: Feb 2005
Posts: 202
Likes: 0
This underdrives the supercharger to minimize wear.
Quote from ebay auction below:
[font=Arial]"The way Underdrive Pulleys works : Reduces power loss through the drive train and you gain more power at the wheels. Most noticeable power gain after a bored Throttle body, it works and well to, no noticeable electrical power loss, idle is a bit smoother and much revs easier ."[/font]
Quote from ebay auction below:
[font=Arial]"The way Underdrive Pulleys works : Reduces power loss through the drive train and you gain more power at the wheels. Most noticeable power gain after a bored Throttle body, it works and well to, no noticeable electrical power loss, idle is a bit smoother and much revs easier ."[/font]
Originally Posted by Dr Obnxs
I emailed on of the vendors...
Originally Posted by ted leist
This underdrives the supercharger to minimize wear.
Quote from ebay auction below:
[font=Arial]"The way Underdrive Pulleys works : Reduces power loss through the drive train and you gain more power at the wheels. Most noticeable power gain after a bored Throttle body, it works and well to, no noticeable electrical power loss, idle is a bit smoother and much revs easier ."[/font]
Quote from ebay auction below:
[font=Arial]"The way Underdrive Pulleys works : Reduces power loss through the drive train and you gain more power at the wheels. Most noticeable power gain after a bored Throttle body, it works and well to, no noticeable electrical power loss, idle is a bit smoother and much revs easier ."[/font]
Matt
Former Vendor
Joined: Jul 2003
Posts: 1,594
Likes: 2
From: los angeles
Wan't to second that one Randy...
We had one of those two piece pulleys
fit an finish was deplorable.
My mechanic could not even fit it on the customers car as the bore was
of by thousands.....
peter
Team M7
We had one of those two piece pulleys
fit an finish was deplorable.My mechanic could not even fit it on the customers car as the bore was
of by thousands.....
peter
Team M7
4th Gear
Joined: Dec 2002
Posts: 551
Likes: 1
From: Santa Ana, CA
Also, I find it interesting that the "Team" of engineers found it OK to lighten the factory unit and minimize the damper capability in the later cars. Like I stated, it is my opinion that this is a safe modification. That is based on testing I did with several MINIs, not any other brand of vehicle. Take a look at the Cooper -it doesn't even use a vibration damper at all. The S has a longer belt as well, giving better dampening than the Cooper.
We are the only MINI aftermarket manufacturer/supplier/installer that carries the warranty in writing that allows track use, and I certainly don't want to be replacing a gaggle of motors. Just to reiterate, we DO warranty this item.
Hope that helps!
Randy
We are the only MINI aftermarket manufacturer/supplier/installer that carries the warranty in writing that allows track use, and I certainly don't want to be replacing a gaggle of motors. Just to reiterate, we DO warranty this item.
Hope that helps!
Randy
The basic engine for the Mini One and
the Mini Cooper is fitted with a conventional
torsional vibration damper at the front
end of the crankshaft. Calculations and
measurements showed that the addition of
the supercharger with its relatively high
moment of inertia was resulting in excessive
torsional vibration at about 1600 rpm.
This solution was unacceptable both
acoustically and in terms of component
strength.
The torsional vibration damper used on
the Mini Cooper S engine therefore has the
belt pulley additionally isolated elastically
from the secondary mass, with belt drive
vibration damping. Vibration amplitudes
are significantly reduced by the isolated
belt pulley. However, the decisive factor is
that the most marked resonance is shifted
into a zone below idle speed and is therefore
outside the engine’s operating range,
the Mini Cooper is fitted with a conventional
torsional vibration damper at the front
end of the crankshaft. Calculations and
measurements showed that the addition of
the supercharger with its relatively high
moment of inertia was resulting in excessive
torsional vibration at about 1600 rpm.
This solution was unacceptable both
acoustically and in terms of component
strength.
The torsional vibration damper used on
the Mini Cooper S engine therefore has the
belt pulley additionally isolated elastically
from the secondary mass, with belt drive
vibration damping. Vibration amplitudes
are significantly reduced by the isolated
belt pulley. However, the decisive factor is
that the most marked resonance is shifted
into a zone below idle speed and is therefore
outside the engine’s operating range,
***interesting**
?!where to find this article!?
Originally Posted by SteveS
I am thankful Randy has done his real world testing and is satisfied that the product won't hurt the engine. My only stumbling block comes from the article, widely available elsewhere, which analyzed the design of the tritec engine. There is a passage from "The Mini Cooper S Powertrain, German issue of MTZ 7-8/2002 beginning on page 558. where it is stated, at page 2 of the article:
This passage unnerves me a little. It would seem that the vibration is slightly over idle, and higher revs are not problematic. The additional load /drag posed by spinning the supercharger faster (15% + __%) might have an effect on the natural resonance of the accessory drive which seems to be the problem with the S engine. Maybe the resonance is not detrimental to the crank/oil pump/cam, but rather with the accessory drive and supercharger. Nothing I have read is very helpful addressing these questions. A summary of the analysis/findings of the Tritec engineers would be nice.
This passage unnerves me a little. It would seem that the vibration is slightly over idle, and higher revs are not problematic. The additional load /drag posed by spinning the supercharger faster (15% + __%) might have an effect on the natural resonance of the accessory drive which seems to be the problem with the S engine. Maybe the resonance is not detrimental to the crank/oil pump/cam, but rather with the accessory drive and supercharger. Nothing I have read is very helpful addressing these questions. A summary of the analysis/findings of the Tritec engineers would be nice.
4th Gear
Joined: Dec 2002
Posts: 551
Likes: 1
From: Santa Ana, CA
https://www.northamericanmotoring.co...per+powertrain
Revealed by search function. May be in other posts and available at other sites.
Steve
New: I really like the concept and will probably do the crank pulley anyway. I just wish there were some more info provided by those in contact with the Tritec Engineers to explain away this concern. I also am confused by the above quote from the source which says the Mini Cooper (non S) has the traditional vibration damper. I think the facts are that there is no such thing on the Mini Cooper, just a solid pulley. This takes something away from the analysis provided in the article.
Revealed by search function. May be in other posts and available at other sites.
Steve
New: I really like the concept and will probably do the crank pulley anyway. I just wish there were some more info provided by those in contact with the Tritec Engineers to explain away this concern. I also am confused by the above quote from the source which says the Mini Cooper (non S) has the traditional vibration damper. I think the facts are that there is no such thing on the Mini Cooper, just a solid pulley. This takes something away from the analysis provided in the article.
3rd Gear
Joined: Aug 2003
Posts: 231
Likes: 0
From: Woodbury, CT
From MiniMadness: "We simply feel that the risk far outweighs the gain and have chosen not to offer this mod through our company."
I do not know why they are so concerned about warranty and product liability issues on this product, since my experience with their throttle body proved that they do not stand behind their products, anyway.
I do not know why they are so concerned about warranty and product liability issues on this product, since my experience with their throttle body proved that they do not stand behind their products, anyway.
thx...
..
Originally Posted by SteveS
https://www.northamericanmotoring.co...per+powertrain
Revealed by search function. May be in other posts and available at other sites.
Steve
New: I really like the concept and will probably do the crank pulley anyway. I just wish there were some more info provided by those in contact with the Tritec Engineers to explain away this concern. I also am confused by the above quote from the source which says the Mini Cooper (non S) has the traditional vibration damper. I think the facts are that there is no such thing on the Mini Cooper, just a solid pulley. This takes something away from the analysis provided in the article.
Revealed by search function. May be in other posts and available at other sites.
Steve
New: I really like the concept and will probably do the crank pulley anyway. I just wish there were some more info provided by those in contact with the Tritec Engineers to explain away this concern. I also am confused by the above quote from the source which says the Mini Cooper (non S) has the traditional vibration damper. I think the facts are that there is no such thing on the Mini Cooper, just a solid pulley. This takes something away from the analysis provided in the article.
Temporarily Banned
Joined: Oct 2002
Posts: 3,382
Likes: 2
From: Denver
Originally Posted by SteveS
I am thankful Randy has done his real world testing and is satisfied that the product won't hurt the engine. My only stumbling block comes from the article, widely available elsewhere, which analyzed the design of the tritec engine. There is a passage from "The Mini Cooper S Powertrain, German issue of MTZ 7-8/2002 beginning on page 558. where it is stated, at page 2 of the article:
This passage unnerves me a little. It would seem that the vibration is slightly over idle, and higher revs are not problematic. The additional load /drag posed by spinning the supercharger faster (15% + __%) might have an effect on the natural resonance of the accessory drive which seems to be the problem with the S engine. Maybe the resonance is not detrimental to the crank/oil pump/cam, but rather with the accessory drive and supercharger. Nothing I have read is very helpful addressing these questions. A summary of the analysis/findings of the Tritec engineers would be nice.
This passage unnerves me a little. It would seem that the vibration is slightly over idle, and higher revs are not problematic. The additional load /drag posed by spinning the supercharger faster (15% + __%) might have an effect on the natural resonance of the accessory drive which seems to be the problem with the S engine. Maybe the resonance is not detrimental to the crank/oil pump/cam, but rather with the accessory drive and supercharger. Nothing I have read is very helpful addressing these questions. A summary of the analysis/findings of the Tritec engineers would be nice.
Actually, since it is a German thesis paper, I would assume (and you know where that leads
) that his information came from the BMW side.The engineer that I spoke with was US based, and according to his info, they informed BMW it was unnecessary to have a damper installed. BMW has issues with vibration on their straight sixes.
Certainly there are harmonics in play - the thing is rotating. However, there is an amplitude to those as well, and they are apparently minimal.
Look at it another way that is quite a bit more practical. These issues are at a specific RPM, and the type of damper we have only dampens at a very specific RPM range. If we change the pulley, and the supercharger now spins at a higher RPM range, it will change where that harmonic is problematic, yet the damper is still damping the original site. No problems with several cars I've done which are now at over 100,000 miles with S/C pulleys, despite that the harmonic damper is now damping the wrong RPM range.
How's that for long term testing
.Hope that helps!
Randy
4th Gear
Joined: Dec 2002
Posts: 551
Likes: 1
From: Santa Ana, CA
Randy, thanks for your follow up and explanation, especially about what the Tritec guy said. I can understand BMW being real conservative here, maybe excessively especially given their bad experience with the E46 M3 engines blowing up catastrophically. (per Roadfly.com)
On reflection, it is news to me that the damper only damps at a specific frequency/harmonic. I would think it would work across a broad range of frequencies. Maybe better at some than others, but damping nonetheless. If the harmonic is relatively small to begin with, the capacity of the damper to work at other frequencies would probably be adequate, unless it is truly tuned for a specific frequency only.
On reflection, it is news to me that the damper only damps at a specific frequency/harmonic. I would think it would work across a broad range of frequencies. Maybe better at some than others, but damping nonetheless. If the harmonic is relatively small to begin with, the capacity of the damper to work at other frequencies would probably be adequate, unless it is truly tuned for a specific frequency only.
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