DSG problems on a rolling road

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miketweed

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Took my REVO'd 2.0FSI T DSG to Prosport in Manchester yesterday to get it on their rolling road.

Got it strapped down and running but as soon as he went for the power run, i.e. full throttle from just below 2000rpm in fifth (in manual mode obviously) the revs would build but then at 4500rpm it would change down a gear on its own!!!!

This happened in sixth and fourth too but only on full throttle. Notes:

1. Gear selector was in +/- of course
2. ESP turned off
3. This happened with the stock ECU code, we didn't try it with the REVO as the guy wasn't happy with the car doing unexpected shifts on his rollers as it made the car lurch quite a bit.

The dash was like a christmas tree because of all the ABS warning lights caused by the rear wheels being stationary. Also the headlight allignment failure alarm was up because of the car being strapped down a long way at the front.

They've got no idea why it changes down and it certainly doesn't do it on the road.

Any ideas?
 
Very odd, when we did the runs at Stealth, we had to strap the car down front and back as the DSG wouldn't change with the handbrake on.

But the runs were fine using manual mode, changing up to 4th then doing the power runs from 1000rpm to 4500, then dropping it back to neutral for the power down and load assessment.

John (cosmicblue) had his runs at Stealth as well with no problems.
 
well havent had that one before, My car has been on the rollers many times now and was in manual mode with 5th gear selected.

Never changed down once,

Are they loading the rollers do you know ? or are they running the rollers with no load ?

Ive got a video of mine somewhere.. ill find it mate.
 
Jeez, thought the S3 was about to go for a second there. Starting twitching around.
 
Mine changed gear fine with the handbrake on, but we had the brake off for the runs so it was strapped front and rear.

MikeP - if you put it in neutral for the run down then how does the dyno get the full transmission losses? In a manual car you'd leave it in gear for the run down wouldn't you (always have when I've seen them)

S-Line - The retarders were off, i.e. no loading. The operator wondered weather that might have an affect on the DSG, but he wanted to speak to bosch in the week.
 
yep as mike P says, Clive Drops it into Neutral for run down.

On my first run, there was loading on the rollers ( the video )

Clive Now has New software and more sensors on the rollers so No loading is required, ( this was my last run) it picks up the valves changing at 4000 rpm, and is far more accurate /ubbthreads/images/graemlins/smile.gif

sounds like Prosport are running the same, somethings very strange about your knocking down a gear in Manual Mode though ?
 
We tried several runs and it always changed down at 4500rpm exactly, only with full throttle applied from low down.

If you progressively applied the gas it would hold the gear right through as you'd expect.

But they definitely left it in gear for the run down on the two previous manual cars before mine. I've had loads of bikes dyno'd and they always did the same. How does the dyno get the full picture on engine & primary shaft friction losses with the transmission in neutral?

Anyhow, hopefully I'll hear from Pro Sport soon.....
 
[ QUOTE ]
somethings very strange about your knocking down a gear in Manual Mode though ?

[/ QUOTE ]

I think there's something strange about mine knocking up a gear in manual mode as well... /ubbthreads/images/graemlins/wink.gif
 
I wondered if you'd comment on this come Monday morning!

Unfortunately this is in the middle of the rev range, not the top when some would consider it a useful feature.
 
its not a useful feature, i would drive around forever in my "proper" manual cars bouncing off of the rev limiter in second, that was truly useful /ubbthreads/images/graemlins/wink.gif
 
audi upgrades
the DSG also Bounces off the rev limiter in S mode so please dont knock DSG !

Just cant understand why this DSG would Knock down when in Manual ??

Has anyone else seen this ???
 
i wasnt - i was being sarcastic, why on earth would you want to drive round while bouncing off of the rev limiter!
 
[ QUOTE ]
i wasnt - i was being sarcastic, why on earth would you want to drive round while bouncing off of the rev limiter!

[/ QUOTE ]

Lol some people do believe /ubbthreads/images/graemlins/MexWave.gifit or not ) the DSG changes just before it hit the rev limiter - which is great if you forget to change gear /ubbthreads/images/graemlins/smile.gif
 
Made some enquiries.

I spoke with my brother who builds VW Cup cars, uses specially developed Revo codes and uses stealth for the RR. In his experience:

1. RR Retarders should be on (they were off when mine was done)

2. On 2wd modern VAG, should remove ABS fuse to block ESP fully, else problems will be caused by the stationary rear wheels. (didn't do this on mine)

3. He's never heard of putting a car in neutral for the run down either, stealth have never done it with any cars he had there (2wd or 4wd) This will surely give a high crank BHP due to under measuring the full transmission losses for additon to the wheel BHP.

in gear example:
eg: 150 wheel BHP + 50bhp losses = 200 calculated crank BHP

in neutral example:
eg: 150 wheel BHP + 20bhp losses = 170 calculated crank BHP

I'm not doubting the knowledge or expertise of the RR operators, but from a basic principles angle, I'd love to know how it can work any other way?
 
i was just thinking about the dsg knocking down in manual,and it states in the manual,that if using paddles,and they are not used for 30 seconds the box reverts to auto mode,

although this might not be the case when in tiptronic mode (using the gear lever to change) im not sure?
 
page 184 of the owners manual,i guess tat does'nt cover the tiptronic mode though?.
 
excuse my ignorance,but are we saying that the transmission loses on the dsg in gear is 50 bhp,

as i had mine on a rolling road and was only given wheel figures,because they couldnt do the overrun as it was auto,hence no accurate fly wheel figure,i was given a wheel figure of 132bhp,and they told me to expect around 170 for flywheel figs,

if loses of 50bhp are about right then im even happier with 182bhp?.
 
[ QUOTE ]
excuse my ignorance,but are we saying that the transmission loses on the dsg in gear is 50 bhp,

as i had mine on a rolling road and was only given wheel figures,because they couldnt do the overrun as it was auto,hence no accurate fly wheel figure,i was given a wheel figure of 132bhp,and they told me to expect around 170 for flywheel figs,

if loses of 50bhp are about right then im even happier with 182bhp?.

[/ QUOTE ]

Given that we are use Stealth Racing and Vince as the benchmark for getting it right my TDi DSG recorded 164bhp stock, the Stage1 Revo map made 187bhp/293ft/lb on his then freshly calibrated rollers.
 
Tinka -

I was only estimating the losses for the purposes of the example which was to do with in gear or out of gear for the run down.

Also, whoever did your rolling road was wrong to say they couldn't do the overrun. That applies to regular torque convertor automatics where there is no lock-up on the clutch. He appears to not know how the DSG works. It should be treated exactly like a manual for the power runs.

It's not suprising, I had to discuss the DSG at length with Prosport as they had no idea how it worked having not done one before, They initially said '"oh you can't get proper readings from autos".

Mike P - I think I am the only 2.0TFSI with DSG that has been on the rollers, all the others are oil burners or a 3.2 DSG. Apparently the 2.0T can, under some circumstances, force the DSG to change down as part of its anti-knock software (to jump the revs past the worst knock point which is coincidentaly around 4500rpm), although it shouldn't do it in +/-. I suspect the plethora of ABS & Traction faults on the RR are causing problems.

Also, apparently REVO's RR development tests on a Golf 5 GTI DSG were done with the ABS fuse removed as a matter of course.
 
I can also tell you from a TDI point of view, if your air intake pipe falls off after the MAF, this also causes the car to change up early.

So there may be some sort of protection in there for various reasons....
 
miket,it was power engineering in uxbridge who tested it,

ill have to find someone in or around kent who knows what they are doing i think,and try again?.
 
Just tried mine in Maunual in 5th

It Knocks down to 3rd if you floor it to the knock down switch. Which is hard to the floor of the throttle pedal.

Never done that before and is a right pain specially if you are doing 80 in 5th, knocks down to 3rd ! and Yellow mr Red Line what am i doing revving so high.
 
So are we saying there is an issue here??

As I've just finished a speeding ban, I can't find anywhere to drive at 4500rpm in fifth gear to test it!!

MikeP - any ideas?
 
Mike, speak to Kev at Revo, I've not come across this before as you're the first guy I know with a DSG TFSi. It doesn't sound right. Have you checked for any faults?

What I want to check is if my car downshifts in manual mode when I hit the kickdown switch. I'll try it on my way to Cambridge this afternoon. I don't think it should, let's see what Audi have implemented.
 
No I have no errors on the vehicle.

Eeef - Whats the point of that?

Also AKAIK there is no kickdown switch, they used those on conventional cable throttle auto's to tell when the pedal was right down. The audi has an electric throttle anyway so it knows where the pedal is. Haven't seen a kick down switch anyway.

Bowfer will love this one.
 
I'll have a look later, probably never noticed it before.

Whats it supposed to sense??? If the ECU already knows the exact throttle position (which it does) what does the kickdown switch tell it?

Maybe its to detect REALLY aggressive throttle pedal pressure?
 
The kickdown switch is not electronically connected to anything. Afaik it's only purpose is to provide feedback to the driver, so that you can feel the point after which the kickdown will happen.
 
On the 2005MY 3.2 DSG I had on loan for a few months, there was definitely a kickdown option if you pushed the pedal beyond the normal stop. It dropped it by a gear or two depending on what revs / gear combo you were in at the time like a more conventional auto. Personally, I hated it, as you could easily do it accidentally and look like a bit of a prat, especially as you have the option of paddles and a stick if you really want to drop a cog or two.
 
I've had my 3.2 DGS for 1.5 years now, and if you have half decent control of your foot, then it's yet another option at your disposal... if you want the instant kick-down of more than 1 gear, it's there under your foot when ever you need it... if you do it by accident, then you simply have a heavy foot or 3 inch soles on your shoes.
 
I must say I've never been that heavy with the throttle. I only ever gently push it down the the first stop. Why mash it into the floor? It won't make you go any faster.

Maybe the RR operator at Pro Sport has big feet?
 
[ QUOTE ]
Why mash it into the floor? It won't make you go any faster.

[/ QUOTE ]

Actually, I guess with the click-down at the end of the pedal travel, mashing does make you go faster /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/wink.gif
 
Well i tried it today, and yep as i said it kicks down in Manual mode if you floor it hard enough,
But what has also surprised me is the Kick down in AUTO.

In 6th doing about 80 and then really push your throttle pedal to the Floor and past the Click feeling, and it Instantly changes down to 3rd.

Its very responsive as well, i was very surprised at how quick it changed from 6th to 3rd, not the usual (lets have a meeting to see what to do) it just does it very quickly /ubbthreads/images/graemlins/smile.gif Well pleased, in fact Ive been doing it most of the afternoon now /ubbthreads/images/graemlins/smile.gif
 
Yup on the road to Cambridge this afternoon, tried it in manual mode an it changes down when the kickdown button is hit. But it's a long way down, much further than I'd normally need to go very fast.

Mike that prolly explains your RR problems, Vince & Clive must have smaller feet than the guy at Pro Sport.
 
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