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Yes, however when you're embarking on the journey and you're considering what base car to start from if you don't have to upgrade the gearbox it's $ off the build cost.
I was reading up a little about torque numbers today, and torque is usually multiplied by the gear ratio, but seeing as most runs are done in 4th gear, which I think for most cars is close to 1:1 it seems strangely high. I really would like to learn more about how dynos operate.
Ok I spoke to Brett who is the guy that usually runs the dyno (he was away unfortunately) and to get the derived torque figure he needs to know what RPM each run was done to. He can then punch this in and get a value for derived torque - which is more meaningful for most people.
So if you want this value send me a PM with the redline cut-out for your run and I'll see what I can do. Otherwise if you know engine RPM to road speed we could do it that way too as the road speed was recorded on the dyno.
Thanks for everyone turning up and running their cars today - perfect weather for it too. Another great day to own a VW.
A few people left scratching their heads trying to work out where they are missing kW, however the dyno has been calibrated by Mainline only last week so today's figures should be right on the money.
Anyway here's the results from today's dyno day in running order:
Year/Model
Performance Modifications/Tune
Power(kW)
Torque (Nm)
2012 Polo GTI
Stock
110.5
408
2013 Polo GTI
ABT Stage 1, CAI, CBE
118.8
470
please note torque figures are uncorrected.
.
Yes lots of head scratching on my part as to where 10+kW went (2013 Polo GTI on chart above) although the AFR figures on the charts point clearly to the problem. Soon after the AFR dropped below 12 to 11.5 on my chart the max. power levelled out and stayed there not dropping off until the red line (I was watching the tacho in the car). Denning's chart shows the AFR stayed marginally higher at a low around max power of 12 air:fuel.
The dyno operator and my mechanical engineering background (I'm no engine tuner but remember from my practs. I did on engine tests at uni a million year ago) tells me 11.5 AFR is way too rich. Yes I realise VW/ABT are very much about protecting this 'fragile' engine.
The dyno charts are with ABT in Germany now and hoping for a positive outcome.
Incidentally I ran the fuel tank down for dyno day and filled up, at a busy high turnover outlet, with 98PULP just before the test.
2015 Polo GTI with DA pack : Milltek Turbo back exhaust |DD spacer|JB1|VWR Turbo Intake elbow and intake hose|BMC panel filter|KW Street Comfort coilovers| Whiteline adjust. endlinks |Harding DSG Perf. tune|Wagner Intercooler|Dotz Mugello 17 x 8 32ET
I think most tuners tune to around 12:1 AFR or lower for tunes to be safe. My graphs show my stage 1 starting off ridiculously lean for some reason (24:1? the tailpipe sniffer probably wasn't aligned properly) but evened out to 12:1 for the higher rpms...
Looking at the stock standard car's results, they appear to be around the mark in relation to SAE specified factory engine output, so don't really think the dyno is 'out' and appears to have been calibrated.
Are people annoyed on lower figures based on a previous dyno day or something? Many factors coming into play that could have affected the results on two different days, including the 'ramp rate' programmed by the dyno operator which will alter the power reading.
As to 11.5:1 AFR, I don't see any concern regarding that given the increased boost levels (from the ABT tune), (assumed) factory intercooler and high load situation. Assuming you're making the comparison against the stock polo AFR result (approx. 0.5 difference), which would be running slightly less boost and running a bit cooler intake air as a result. Its just the ECU compensating for the increased heat as a result of higher boost and trying to protect the engine... a larger intercooler would aid bringing down the intake temp and adjust the AFR a bit leaner.
My last car (ralliart colt) which had a remap and increased boost (19 psi) was running something like 11.4:1 at full noise and full load, but was on a standard side mount intercooler. A similar car (tune wise) but with an aftermarket front mount IC core was safely achieving 12.1:1 at full load.
I have some of the derived torque values for those that wanted them.
APR Stage 2 Ed35 - 212.9kW/408Nm
APR Stage 3 Jetta (K04) - 212.2kW/407Nm
DNA Stage 1 Scirocco R - 190.6kW/341Nm
Also if you would like a pdf of your new torque curve with RPM and derived torque please PM me your email and I'll send it through.
The power figures for the dyno are quite accurate as the dyno was calibrated by Mainline techs only the week before the dyno day.
I think that last dyno day some of the figures may have been a bit more "generous" for whatever reason. The main benefit of the dyno days is that you can compare results across a range of (similar) cars all run on the same dyno on the same day. This is about as good a comparative data that you can get from dyno testing. Comparing results from different days is possible but given the dyno was recalibrated between runs it may be difficult to compare these 2 sets of results.
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