PorKen

Sprung, dampened, automatic timing belt tensioner/damper.



Now to make a proper bracket using the rest of the old tensioner bolt holes, that can be rotated to pretension the belt.


(First run, post #27!)

(Finished version, post #97!)

cfc928gt

Feeling a little bored are we?!? You're on the right track! Are you making a bracket that the tensioner bolts onto? Will the airpump still work or will it be eliminated?

PorKen

I've been meaning to do this for a while. If it works, it should provide more even tensioning, better dampening, and all the parts are much sturdier. The pivot points are larger and are all steel. The pulley is slightly larger in diameter and wider too. The pulley bearing is much more robust. All this means the belt should last much longer.

I'm making the bracket that the tensioner/damper, lever arm, and pulley, bolt to. I only use the airpump once every two years, so I will have a separate removeable bracket for it.

DANdeMAN

WOW man, super work you are doing..
Put me on your list when the product as been tested and ready to ship!...

heinrich

Ken, please send me one for my S4.

heinrich

btw I think it's a porkenSioner

PorKen

Heinrich,

Don't you think I should put some miles on it before you install it on your interference engine? But if you are volunteering to be a test subject...

Oops, fixed the 'T'. I'm a bit knackered from all the honey-do's I've done in the last week so that I could 'waste' time on Porsche, again.

heinrich

Dude nope, I want it.

BC

Awesome.

jpitman2

Isnt that pushing the belt onto the idler more than before? Whats the usage of the eccentric in the wheel visible behind the balancer/main pulley? Larger diameter pulley is better in general, but how low/close to crank pulley can it get? Assume its not tensioning in the above pic, as you havent pulled the installation pin yet?
jp, also interested.....

SharkSkin

Looks like it will require cover mods as well, though if you modify that pivoting piece in the center of your pic you might be able to run the tensioner body in almost the stock location. Also, if it turns out that this unit provides too much or too little tension, modifying the moment-arm ratios of that piece might correct it.

pmotts

Ken,

I know someone who has a GT motor on a stand if you need to check some measurements or do some test fittings. Nice job, very nice

The FIGT's cams were in fact retarded (still are) 3 1/2 degree's

Airflite40

Any idea on a price yet? ballpark?

PorKen

The pic angle is bad, there is an equal gap (~2mm) top and bottom. The T/D pushes on the lever, which in turn, pushes on an offset stud on the back of the pulley, which rotates the pulley around the bolt, in a similar arc to the stock pulley. Still a lot of room. Not tensioning, but I stuck a screwdriver under the lever, and was able to make factory tension with little force. (The T/D spring is quite strong, BTW.)

I haven't tried it yet, but I'm guestimating the lever goes through the cover opening almost in the same spot as the old tensioner. I'm a little worried about the A/C bracket, but I think the proper bracket will position the T/D such that it will clear. I can't modify the lever, as it is a stock Audi part, but I could swap out the T/D with another model, but hopefully that won't be necessary. I'm not sure which would be better with a better, more adaptive T/D like this? More tension or less tension than stock?

Borys,

Assuming it works, and depending on how the bracket is made (CNC aluminum or laser cut steel + spacers), I would guess around $300 for the first install for all the parts. After that, it's just the pulley that needs replacing (~$70?). The T/D is only replaced if it leaks, not sure about the lever. All the T/D parts are readily available from any Audi parts supplier.

heinrich

send it when it's ready