DMPE Screw Absorber

Anyone running one and have any feedback about it? Worth the $900?

http://www.dmpeinc.com/supercharger...-drive-absorber/psi-screw-drive-absorber.html

 

absorber

i have one
never broken a quill shaft
2 years and ive never looked at it
they say to change the rubber pieces every year
i still break belts at 3-4 runs
2 step is hard on things
and yes i would buy another one

 

some guys change belts every run so I guess it's better than that..lol.
Lots of ADRL guys use it and I don't know of anybody WOT on the two step that goes more than 4 -5 runs.
I've heard of a car that was launching belts everywhere because the rubber thingys in the absorber were worn out.

 

Yeah that's about where I'm at in my mind, namely is it gonna save belts?....

Having said that, would a dual belt idler system (tight & slack side) help at high overdrives & 2-step and save belts?

Quill shaft failure is all about fatigue life and I can picture that in my mind. However, what keeps failing the belts, especially if a person is running the PS belts, is what has me confused.

 

belts /absorber

mike i get 3 runs on the 8mm ps belt wo on 2 step 115 od
4th run almost always breaks
qualify and new one for eliminations
maybe the dual idler is worth trying

 

belts

WE are getting 7-8 runs and change them, havent tried to go longer yet max over drive But we do run belt tight as a banjo string with a rcd gear drive inner bearing support.Federlin told me he gets 30+ that way.

 

I run a two step on a screw blower at 128% over. I have a dual idler (not RCD) and with it we get 10 runs on a 8mm belt; at that point I take them off and reuse them as spares for qualifying. We don't run a bearing support, just a standard BAE gear drive.

Brandon Booher
NHRA TAD #323
Torque MGMT. - Owner

 

Do you mean a two step with wide open throttle or air throttle ?...
Thats a huge difference.
99% of outlaw screw cars leave with the blades wide open.

 

I can't keep a belt on for more than 3 passes as well on screw blown promod and we use a throttle controller on that car.

On the TAD that I work on we leave with blades wideopen and I have yet to lose a belt and change them after 6 passes.

Go figure.

 

Ive run the absorber for a year now. I must say, it does seem to help out. The only thing that ill caution is to make sure to have a spare set of the rubber inserts on hand at all times. We let ours go a little too long and it started to shorten our belt life tremendously. Check the absorber every time you put rods in it. Seems like a good way to keep track of it for us.

We get 6-8 runs on a belt, then pull it off and use it for qualifying or testing after that. We leave WOT on the 2-step. Automatic Pro Mod car. Also, we run a dual idler setup.

As far as the quill shaft, weve run a screw for 3 years and never broke 1. We cycled in a new one this year becasue it started to show wear on the splines, but it never broke. This is the Lenco-style as well.

 

We're not wide open but we're not on an air throttle (illegal) - I have 40#'s of boost going through it at stage. I don't use the WOT because I'd red-light nearly every time. My foot pedal slides on the heel end, then I flip my foot to the toe to leave the starting line.

Brandon Booher
NHRA TAD #323

 

What do the belts tend to loook when they let go? Any evidence that they've walked and got cut, or just simply shredded, or?..... It would be really cool if someone had some high speed video of a belt failing, just to see why/how.

 

The belts we have lost break clean in between the ribs. Hell I've had a new belt break as well on first hit so I don't think you are going to see any wear before they break.

Buying belts is a pretty good trade off for blackening the rear main like we used to with a clutch.

 

Just some info for the guys who do not leave at full throttle on a two step, have never run one and are commenting. My experience with two steps is that they are extremely hard on belts compared to just reving it up and launching the car like legal clutch driven TAD's and TA/FC's do. No comparison.

 

So is the belt simply being shock overloaded while it is on the 2-step, or is it actually jumping around and possibly jumping teeth and being tortured/stretched to death while the belt & pulley turn out of unison with each other for a brief period? Would be interesting to learn "why" the belts are actually failing. Of course that's only gonna decrease the revenue of the current belt vendors ....

 

on the two step the belt is loading/unloading violently. The more tension the better it stays engaged in the teeth.
An outlaw promod tested with gates and they wanted the belt 8.5 inches wide and twice the tension we run to work properly.
Some engines are harder on belts..maybe slight detonation.
I've run over 20 laps at 110% with 11mm and air throttle and never changed the belt.
I'm switching to 129% OD which could be harder on the belts.
3-4 runs is not an option for my program so i'm trying to make the air throttle work.
We run a 1705 belt combo with huge pullies. There are numerous engineering issues with the setup but knock on wood its working.

 

Based on your data recorder...how long are you on the two-step for before launching?

I to have a screw blower on my T/D that will only make 40 psi max and my program will not allow for belts to be replaced every 6 runs.

Good topic......

Scott Hall
Sales Engineer
Moroso Performance
115A TAD

 

Anywhere from .70-1.20 seconds, depending on the time it takes the tree to drop.