[Ehloo]

Trying to figure out if I need to find a 4 wheel dyno. Does dyno mode put the car in 2 wheel drive

[BMWDriverX]

4wd only!! If you try to dyno in 2wd mode your car can switch into 4wd mode mid dyno, and kaboom.

[limeypride]

Originally Posted by BMWDriverX

4wd only!! If you try to dyno in 2wd mode your car can switch into 4wd mode mid dyno, and kaboom.

Confirmed, I experienced this, too, and it's disconcerting to say the least. In addition, unless you really plan to drive the car in RWD mode, the numbers are meaningless for apples-to-apples comparisons.

[Used2be]

Originally Posted by limeypride

Confirmed, I experienced this, too, and it's disconcerting to say the least.

Interesting. I've never had a car on a dyno, but why would the M5 switch out of 2 wheel drive on a dyno? If it can do it there, is it possible on the street as well? Do the dyno operators explain why this happens?

[BMWDriverX]

Originally Posted by Used2be

Interesting. I've never had a car on a dyno, but why would the M5 switch out of 2 wheel drive on a dyno? If it can do it there, is it possible on the street as well? Do the dyno operators explain why this happens?

The car goes ape sh1t because the front wheels are not spinning while the rear ones are.

[limeypride]

Originally Posted by BMWDriverX

The car goes ape sh1t because the front wheels are not spinning while the rear ones are.

Right, but that doesn't explain why it would do it in *dyno* mode.

[JK-M5]

just watch evolves dyno using dyno mode on youtube only vid ive seen of this getting done

[prodigymb]

when engaging dyno mode the car wants to be in AWD mode. i think dyno mode overrides the selections made. i have seen 4 different youtube videos of people running them on the dyno in RWD mode alone.

I confirm that running the car in dyno mode with RWD selected will end in damaged parts. Maybe without dyno mode selected it will work better... but that one I haven't tried LOL

[limeypride]

Originally Posted by prodigymb

when engaging dyno mode the car wants to be in AWD mode. i think dyno mode overrides the selections made. i have seen 4 different youtube videos of people running them on the dyno in RWD mode alone.

I confirm that running the car in dyno mode with RWD selected will end in damaged parts. Maybe without dyno mode selected it will work better... but that one I haven't tried LOL

Oh no! What happened?

[prodigymb]

Originally Posted by limeypride

Oh no! What happened?

2WD conversion lol

[limeypride]

Originally Posted by prodigymb

2WD conversion lol

Oh shit! But from your description.

Would you mind describing the circumstances? Like was it the car suddenly re-engaging 4WD during the test or...

[prodigymb]

Originally Posted by limeypride

Oh shit! But from your description.

Would you mind describing the circumstances? Like was it the car suddenly re-engaging 4WD during the test or...

it didn't do anything exciting really. the first pull there was a faint smell of brakes/clutch, we thought it may have been the dyno brake. the second pull it was a strong smell of brakes/clutch and a small cloud of smoke from behind the left front tire which is where the transfer case is located. it also only made 550whp Dynojet which is lower than anything I've seen from Dynojet. We pulled it off the Dyno and onto the street, tried to launch it and it did a 50ft long 2WD burnout and came up with all sort of 4WD malfunctions.

Again we put it into Dyno Mode and then into RWD mode, I think it would have worked if we just put it into RWD mode only. Since I have seen others do this, I have also done burnouts in the car at the track to heat up the tires etc.

[onfireX5]

Originally Posted by limeypride

Oh no! What happened?

I think Terry smoked one as well on a 2 wheel dyno before anyone knew there was an issue.

[Fuel-It!]

I've heard of multiple customers smoking the transfer case doing 2WD dyno runs. It can work but not worth the risk. That transfer case is $6k I think.

[limeypride]

Originally Posted by Fuel-It!

I've heard of multiple customers smoking the transfer case doing 2WD dyno runs. It can work but not worth the risk. That transfer case is $6k I think.

So what does dyno mode do? I've only ever been successful on a Mustang dyno with connected front/rear drums. We simply turned off traction control and that was it—hub dynos and rear-wheel dynos upset the car briefly triggering limp mode.

[prodigymb]

Originally Posted by Fuel-It!

I've heard of multiple customers smoking the transfer case doing 2WD dyno runs. It can work but not worth the risk. That transfer case is $6k I think.

4,500$

Originally Posted by limeypride

So what does dyno mode do? I've only ever been successful on a Mustang dyno with connected front/rear drums. We simply turned off traction control and that was it—hub dynos and rear-wheel dynos upset the car briefly triggering limp mode.

no clue what dyno mode does. maybe shut off the ABS and stability controls.

[Fuel-It!]

Originally Posted by limeypride

So what does dyno mode do? I've only ever been successful on a Mustang dyno with connected front/rear drums. We simply turned off traction control and that was it—hub dynos and rear-wheel dynos upset the car briefly triggering limp mode.

I've only driven an F90 don't own one, but it's supposed to lock the car in 2wd mode. It just doesn't work right.

[limeypride]

Originally Posted by Fuel-It!

I've only driven an F90 don't own one, but it's supposed to lock the car in 2wd mode. It just doesn't work right.

Thanks. And agreed; it dropped back to 4WD twice on me on a hub dyno.

[onfireX5]

Hub or drum dyno, the best way/safest way and possibly the most accurate way is to use a Linked Dyno. If the operator doesn't understand what that is, go somewhere else. Some ops thinks that any all wheel dyno is linked, but they are not unless specifically built that way or upgraded.

[limeypride]

Originally Posted by onfireX5

Hub or drum dyno, the best way/safest way and possibly the most accurate way is to use a Linked Dyno. If the operator doesn't understand what that is, go somewhere else. Some ops thinks that any all wheel dyno is linked, but they are not unless specifically built that way or upgraded.

Agreed. Initially, I couldn't find one hence the other attempts. The Mustang was linked and she gave us a pull every time thereafter.

[bm5bullit]

Wheel speed sensors are the first thing that the DME's pick up as matching the algo's or they don't match. It has a lot to do with real world driving and all the variables that the DME's consider with regards to slippage and grip.

[rumeet14]

So I just had a Shop dyno my car and they asked if it was rwd or awd and I said both and they did the dyno in rwd and I saw it smoke up in the rear but it just smelled like the tires. Then went into awd did 2 pulls lost 70hp on the second one and now everytime I give it gas I get a diff lock code and it reduces all the power in the car. Have any advise on this and what the issue would be? I can’t give it any gas without it throwing the car into limp and it just looses all traction if I give it gas and then goes in limp till I restart the car