MTM 1+ Butt Dyno.....

[teknik]

following the instructions here..

http://forums.audiworld.com/vag/msgs/457.phtml

I got this weight is probably wrong, I guesstimated



I am assuming this is wheel HP

190 ish fly... assuming 25% drive train for quattro but the tq is way down from claims, but so is the samples...

Second gear pull... might try a 3rd gear tomorrow, possibly a 4th over the weekend... need lots of deserted road....

[teutonic_blur]

Good info. I've been meaning to try this but I still haven't found a suitable place.

BTW, regarding your low torque reading, the guy that originally posted this also got lower readings that a real dyno and he attributed it to the fact that he had done the butt dyno in 2nd gear. Maybe if you do another one in 3rd the torque will be higher.

I'll post my results when it butt-dyno my revo.

[teknik]

another run in 3rd gear...

I had to use another decel function so the numbers are probably off, but the tq definetly came up in a higher gear...

[teknik]

kind of Ironic I made almost exactly what they claim

http://www.hoppenmotorsport.com/a402205.htm

I am planning a 4th gear pull so i can get a proper decel function sometime this weekend, but is going to be hard to coast that far from that speed...


what do our cars weigh?

[teutonic_blur]

Originally posted by teknik
what do our cars weigh?

A manual quattro weighs ~ 3400 lbs.

My manual fwd weighs ~3250

[teknik]

damn then my numbers are definetly way off....

[A4NCAR]

Your weight is still off. Here are weights for A4;

Curb weight (lbs.):
Tiptronic quattro: 3550
Manual quattro: 3406
Multitronic FrontTrak: 3362
Manual FrontTrak: 3252


I don't know what to make of these "butt" dynos now. You should use a real dyno just to see how the results compare. Also, don't you have an aftermarket exhaust system? Then your numbers should be guaged more on the MTM Stage 2: 215HP/245 lb/ft torque. I got close to the torque number once or twice, but for the most part, mine was a good -35HP / -30 lb/ft torque off from those claims.

Are you checking the "timing" still, to see if it's retarding/pinging?


Here's a question brought up by Mike at Ikon;

"I'm also curious as to how block 120 plays into his results as they are skewed once the ECU is modified."

[teknik]

dont use block 120....
stock exhuast...

if you read the article you would see that all I am doing is measuring time and speed...
given the mass of the object you can then calculate the power required to move it...

same as a dynojet does...

I really need to do a 4th gear run... but finding enough room to do it is a problem....


and the car still pings....