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As part of preparation for the Bruntinthorpe Max Speed run AmD kindly offered to check and service my brakes, and then give her a run on their Rolling Road to see how much power this extra boost was giving. Thanks Scott [img]images/graemlins/wink.gif[/img]

here Crank up the volume [img]images/graemlins/laugh.gif[/img]

Unfortunately we couldn't take any readings past 3800rpm as the rollers are only calibrated for 550bhp [img]images/graemlins/frown.gif[/img] [img]images/graemlins/laugh.gif[/img]

The next plan was to fit in a trip to G-Force (1800bhp RR) on the Tuesday but other committments for their race cars meant we had to postpone till next week. This should see the fuelling/timing/load sorted for the high gears (5th & 6th)

Andiroo

Mine's at AmD tomorrow and I'm getting a RR check too. I do hope that your run didn't harm it!!!

reminds me of the story about Porsche's 917 engine testing for Le mans ; ran engine for 24 hours on dyno , had to rebuild at the end of the run, the dyno - not the engine !!

Hi Andiroo !

My knowledge of dyno's is closed to zero, can you explain why the test had to stop at 3,800 rpm because of the 550hp calibration ?
And also which gear were you in ?

Thanks !

Eric

Hi Eric, the test didn't stop @3800rpm, the results just couldn't be recorded after that rpm ie. the bhp and torque plots just flatlined. The power run is always done in one gear below top gear = 5th gear pull from low revs.

Andiroo

So that means you reached 550hp at 3,800rpm ? [img]images/graemlins/shocked.gif[/img]

Thanks for the explanation about 5th gear [img]images/graemlins/thumbs.gif[/img]

Eric

No mate, it means that peak torque was probably reached around this point. As bhp is a function of torque, there must be a torque limit on the rolling road as well as a bhp limit. Plus the AmD rolling road is split to calibrations per axle, and who knows what the Quattro system was throwing at it [img]images/graemlins/wink.gif[/img]

G-Force will be the test [img]images/graemlins/laugh.gif[/img]

Andiroo

Hey Andiroo, are you in Durham (northeast UK?) if you are out & about sometime, I wouldn't mind a look [img]images/graemlins/smile.gif[/img]

though if you are off to G-Force, I guess you are down south.

A

G-Force will be the test [img]images/graemlins/laugh.gif[/img]

Andiroo

You might need to go to NASA after the JATO is fitted. [img]images/graemlins/wink.gif[/img]

Hi Andy !

I heard S3 users can record their Torque and RPM data through the channel 122 of the VAG-COM during running trials (in third gear until red zone).
And then compute the horsepower as a result.
Apparently they found it quite realistic, as done just before a Dyno (same day, same weather conditions).

Have you tried it on the Babe ?

Eric

Sita and I have recorded torque via vagcom (in 4th gear) and then did a rolling road - we found vagcom to be pretty accurate too

Dunc

Depends a lot on what tables have been changed in the ecu.
I'm running a custom program writen by Mitch, and Vag Com says my Glof is putting out 150hp and 160lbft, yet it does low 14 sec 1/4 miles, and had been dynod at >250Hp,>270lbft.

Andiroo is running 1 off softwere as well, so I doubt Vag Com will tell him anything realistic. But had a ride in it last week, and timed 50-100 in third at just over 5 seconds, with 3 people in it. Spent most of my time giggling like a child.

Having researched this issue, I'm fairly sure that after the S4 gets remapped the VAG-COM torque reading is no longer valid.

Having researched this issue, I'm fairly sure that after the S4 gets remapped the VAG-COM torque reading is no longer valid.

That's very interesting, can you share more about your research and why precisely the Vag-Com torque is no longer valid on a remapped car ?

Thanks,

Eric

Sure, the research was checking out lots of car forums such as this and also of course the VAG-COM forum. Based on the experiences of people who posted, I think there were enough to be confident that a remap does invalidate the torque readings.

However as to why - no-one sees to know!