jangy

I would like to know what each of the competitors uses as their Pulley design, so can those that have aftermarket ones chime in?

I have the RennTech one and it has the OEM dampner in it. Do the others have a dampner as well, or are they a single piece? It would seem that you need the dampner to protect the crank from vibrations, no?

ROCKETW19

yes it has the stock damper(sp?) and yes you need it for vibrations. if we didnt need it i could have a all bilet aluminum one made any size for about 120 bucks. i know your havin second thoughts on your tunner choice bro but IMO i belive you made the right one.

jangy

Actually, I am only having second thoughts due to customer service. I know I made the right choice. I'm wondering if the other aftermarket ones are also dampened.
RennTech, the brand is the ****. Even if I walk away from them, I will not be going with another current brand. It will simply be hold off on mods or focus on handling mods that I can design myself.
RennTech quality and design is not the concern here.

NagsHD

renntech and kleeman use the stock dampner/damper then press a larger outer ring onto the stock one. evo does not, they use all metal 2 piece design. dont know about asp though.

MNG

ASP also uses the OEM pulley with a welded ring

jparch

you must be out of your mind to run a pulley without a damper. I would like to see the bearings after 40K out of an engine running a solid pulley......

Vadim @ FD

To the best of my knowledge all tuners use a stock factory damper. The outer ring is machined off and new bigger ring is either screwed or welded on.

Evosport is the only one that makes it's own damper. The damper uses friction damping and has a much wider frequency of damping compared to stock.

In addition, evosport over drive pulleys system comes with redesigned tensioners to keep the belt in proper alignment when kompressor clutch kicks in and out.

jangy

Actually, I saw VIC55's EVO setup and I do agree that the tensioner pulley with the lip is a nice addition. I am not sure if it is "needed", but it shows a good design thought process. Also, VIC55's pulley was running smooooth as silk. I gotta give props for that. In all honesty, I wish I hadn't burned that bridge when I was on it.

Vadim, can you explain the friction dampening system a bit? i don't understand.

NagsHD

why would evo make there own? if everyone else who has a long track record in mb tuning (except asp, i dont know about them) uses the factory damper wouldnt there be a reason? and if the evo has a much wider frequency of dampening doesnt that mean it could fall outside the frequency stampings on the factory pulley itself? and why the need for redisgned tensioner? no one else needs that?

Vadim @ FD

This design came about, because I had found out that under WOT street driving, the belt had a tendency to oscilate and eventually destroy itself over very short period of time.

This problem became more obvious in US, due to more stop-n-go kind of driving vs Europe where a lot of high-performance driving is done at WOT.

Because kompressor clutch cycles during low load to high load driving it sends out 2D harmonics that cause the belt to stretch and do a very bizzare dance (I actually have it on video).

The solution to keep the belt in check, is what you saw on Vic's 55 and what is now has been sold by evosport for the last couple of years.


As far as friction damper.

- In the past I have had a lot of problems with rewelded dampers from ASP going back to early 1990s. The dampers they modified would either be off balance of fail very shortly. This goes back to early SHO/LT1/5.0HO days. I do not want to get into details, it was over 10 years ago and at this time, not fair to ASP - they did change ownership.

When I saw that the only way to increase boost on 55s was bigger crank damper, I went to a number of friends who had a lot of experience in the field and used their knowlodge and abilities to make a whole new assembly that utilizes a sliding weight to counter harmonics.

The gentlemen who designed 55 damper is well known for his work in Harley-Davidson circles. If you have ever ridden a Harley you will know what I mean.