MTM 730 Disappointing Figures

[Kit13]

Evening All,

I decided to finally put my MTM 730 Avant on the dyno today to check/confirm the numbers. I've owned the car for a year and the previous owner had the upgrade done at QST in 2012, so I thought I'd take it back there. I met with the owner (Kim Collins) this morning who ran it three times on the dyno and gave me the disappointing news that it was 'only' making 650bhp. Kim gave me the dyno print out and was able to show mw the power dropping off after 5500rpm? He'd not seen this before and suggested sending the results over to MTM for advice. He also noted that there weren't any fault codes or obvious issues being flagged on Vagcom and the car had good torque at 817Nm.

I know it's a little silly as the car is still making 650bhp but I was really hoping the figures would be 700bhp plus considering the upgrade was completed relatively recently? Whether or not the car made 730bhp after the initial upgrade, 650bhp seems like a significant drop to me?

Any advice from the forum experts? Should I try another dyno, to double check? Is a drop in power like this to be expected two years after an upgrade? Is there anything else I should be looking at?

Thanks in advance for any help/suggestions.

Kit

[RS6chris!]

Obvious answer....

MRC?


What fuel was it mapped to run on?

Have you checked condition of air filters....these cars really respond to amount of air through filters power wise?

Clogged up/dirty air filters may knock performance?

[Kit13]

Hi Chris,

Thanks for your response. Regarding your fuel question, I'm not sure? I always run the car on Optimax, so fuel 'shouldn't' be a factor?

I've not checked the air filters no. Without wishing to highlight my ignorance is this an easy job to do yourself?

Kit

[HYFR]

Optimax?!

[Kit13]

Sorry, that should be v-power!!

[classba]

Firstly, 730 to 650 is a massive drop in power and considering that it was KIM@ QST who initially mapped the car back in 2012, he sure can dig out the original graph to check the differences. Vag Com do not always flag up all the faults ie possible damaged turbo compressor blade. IMO, he should had at least conducted a vacuum leak test to make sure that you are not loosing boost within the system. A leaking intercooler or hose would kill the power.

Having torque of 817nm is about right for a 650 PS car which ultimately is only a stage-1 state of tune for the 6.

[perthwaRS6]

Evening All,

I decided to finally put my MTM 730 Avant on the dyno today to check/confirm the numbers. I've owned the car for a year and the previous owner had the upgrade done at QST in 2012, so I thought I'd take it back there. I met with the owner (Kim Collins) this morning who ran it three times on the dyno and gave me the disappointing news that it was 'only' making 650bhp. Kim gave me the dyno print out and was able to show mw the power dropping off after 5500rpm? He'd not seen this before and suggested sending the results over to MTM for advice. He also noted that there weren't any fault codes or obvious issues being flagged on VAGCom and the car had good torque at 817Nm.

I know it's a little silly as the car is still making 650bhp but I was really hoping the figures would be 700bhp plus considering the upgrade was completed relatively recently? Whether or not the car made 730bhp after the initial upgrade, 650bhp seems like a significant drop to me?

Any advice from the forum experts? Should I try another dyno, to double check? Is a drop in power like this to be expected two years after an upgrade? Is there anything else I should be looking at?

Thanks in advance for any help/suggestions.

Kit

Hi Kit,
May I ask what was the dyno horsepower at the wheels?
Also what type of dyno was it and what was the shootout mode.
These all make a difference to whp seen on the dyno.
As a poster pointed out, best to compare with the original QST dyno run when upgrade fitted as removes the type of dyno variability factor.
More importantly, the true dyno test is the quarter mile drag strip.
My RS6 runs 11.7sec at the strip on Shell V power/BP ultimate 98 octane and 11.4secs on Sunoco GT 105 octane.
just my two cents worth.
cheers,
john

[Kit13]

Hey John,

I've attached a scanned copy of the dyno results. I'd welcome any thoughts/feedback about the results, particularly the bhp stall around 5500rpm? Would a vacuum leak show up at this point in the range or much earlier?

The dyno horsepower at the wheels was 399.4 bhp.

The dyno was a MAHA LPS 3000 PKW. I'm not sure what the shootout mode was? Kim just confirmed that he gave my car three runs?

I'll see if Kim@QST can dig out the original dyno figures for me to compare.

Kit

QST Dyno 31102014.pdf

(431.1 KiB) Downloaded 149 times

[kirbz73]

Is the transmission loss really 40%? I know on the skyline it's around 25%? 40 seems a lot?

[kirbz73]

Just to add was reading an interesting article about the Nissan gtr and on a dyno depending on speed that recorded between 5 and 17% losses through the drive train and from a specs point of view similar as it's an auto and awd?

[classba]

The numbers doesn't stack up. I would insist QST to provide the original MTM 730 package graph for your car. Did Kim confirmed that the ECU map is of a MTM one?.

I would take the car to MRC just to have a health check which will include dyno runs.

[Kit13]

Thanks guys. I'll have a word with Kim when he returns from holiday in a couple of weeks time about getting a copy of the original dyno graph. Kim didn't specifically confirm that the ECU map was an MTM 730 but I do have a copy of the original invoice for this installation.

Could you elaborate a little more when you say the numbers don't stack up? What in particular? I'm somewhat new to this (!) and am genuinely interested to learn, particularly if I'm going to be talking to the QST and MRC boys.

[RS04YOB]

Take it somewhere else tell them the pior RR results are <beep> and they will tell you its a 750bhp car then you will be happy

[classba]

Thanks guys. I'll have a word with Kim when he returns from holiday in a couple of weeks time about getting a copy of the original dyno graph. Kim didn't specifically confirm that the ECU map was an MTM 730 but I do have a copy of the original invoice for this installation.

Could you elaborate a little more when you say the numbers don't stack up? What in particular? I'm somewhat new to this (!) and am genuinely interested to learn, particularly if I'm going to be talking to the QST and MRC boys.

Kit, the measured wheel power against the corrected engine power has a massive difference much more than I would have thought.

With Kim knowing it's one of his car with the MTM 730 tune then alarm bells should had rang when it only produced 650?????

Book it in with MRC NOT telling them the story and get a health check which includes a dyno run.

[kirbz73]

As above have said based on my previous experience of dyno runs from previous cars and doing a little mapping myself if their dyno is measuring right then the wheel figure will be correct but that points out to possible problems with the car, like he said the boost is dropping off so that to me says there an issue? Possible loose inter cooler pipe or boost leak maybe?

Based on a more realistic drivetrain loss of 25% I would say the flywheel power is more like 500 bhp so there's something going wrong there that needs looking into