Well if you are dissapointed with your dyno results, take heart in the fact that you will not a find another dyno that reads lower than a Dyno Dynamics. It's not called the
heartbreaker dyno for nothing, of course being the lowest does not make it the most accurate despite this trite association.
As a tuner, what I need from a dyno is paramount consistency back to back and between modifications. It should also give accurate real world results i.e. it must reflect the road environment, afterall that is where the car lives not the dyno. Beyond that I am not too concerned, you can decide for yourself whether you think the "results" of any dyno are correct, but if the car performs in real conditions then that’s all it can do. I don’t just tune Coupes, in fact many other cars factory or aftermarket ECUs. I also don’t operate the dyno, but I have seen many, many cars come through, with some owners elated and others disappointed. A Norris Evo makes 200bhp less than it should, a factory tuned Farbio GTS 400 only makes 380bhp (they had the head tuner from MBE tuning just after I mapped Technic’s Coupe to 360bhp). The list could go on, but it matters not because I tune to the absolute safe limit, so if they are quicker than an RS4, the same as a 360 or a bit slower than a 430… well it’s a moot point.
This leads me to air fuel ratio measurements. Unfortunately this is where dynos can be very poor for modern cars i.e. significant variance, because it is very hard to replicate the load provided by the road. Too little and the engine spins too freely resulting in lower/later boost and a slightly leaner mixture. Too much and the engine is heavily loaded resulting in higher temperatures and associated issues, and of course a richer air fuel ratio. Then of course you have slight variances between lambda sensors, calibrated or not, they can and do vary by a few points. I’ll say more on this later.
So to the cars…
I haven’t finished mapping Barbz’s car especially at the top end due to some issues, but his estimated map is pretty darn close, something only experience can bring with this engine. It actually runs slighty richer on the road as set by me, again no surprise and confirmed by Barbz’s own wideband. The 2.4 is running 720cc injectors, no problem to pass the MOT emissions even with a dodgy cat, and it gets the same fuel economy as his Audi 1.8t. Barbz told me he didn’t think his car was more than 350bhp, nice surprise eh, I called the torque pretty much spot on too
Technics car, well just to confirm the last time I tuned and dynoed the car it gave 361bhp & 344lbs/ft, with significant gains in the mid-range. I have no issues with a Dyno Dynamics giving lower figures, this is to be expected, and is fairly well correlated with every other dyno I have used. Once again the fueling on the road is slightly richer than recorded (as set by me for this particular car). The turbo certainly is capable of 360bhp, especially with the rest of the setup. It’s a cracking car, and in my top two that I have ever tuned… I love it.
Nazo's car, wow this one really tried to beat me up over the Christmas period! I hope you have understood what I explained on the phone without being too technical. There were so many issues to overcome before this car had a chance to come alive, but the results even for a Dyno Dynamics are good. I estimated 330-350bhp for my dyno, so 326bhp & 318lbs/ft is pretty darn great for 1.4bar on a DD. The boost is a little shy of what it gives on the road, again no surprise, but perhaps a little left on the table. I should note there are significant reasons for the lower boost and restricted rpm limiter, as already explained to Nazo. If only tuning was as simple as “I am forged”, turn up the boost and give the “fueling” to match… it’s not. I don’t blame Charlie from Surrey RR for saying what he did, it’s his job to try to enlighten the customer with rudimentary information. Nazo’s car has very high compression, a static compression test gave between 220-240psi for all five cylinders. Compare this to 150psi for a factory Coupe, and 170-180psi for some tuned Coupes. It was not possible to run more boost, the ignition is heavily retarded even at 1.4bar, and severe detonation exists above 6000rpm with elevated EGTs. I’m sure if you asked Charlie again with this extra information he might choose to pass on his comments.
As for the fueling being “dangerously lean”, well it is clear to see from the AFR curve that it has been mapped, but even if it was 12.5 on the road (which it is not), dangerously lean it is also not! Nazo has a very unique exhaust system, quad 2” tail pipes. There is simply no way of getting an accurate reading from here, hell the lambda probe will only go in an inch! So before I could even map Nazo’s car I had to weld a lambda boss in the downpipe, quite simply any measurment from the tailpipe will be contaminated. I mapped Nazo’s car slightly leaner than most at 12 -11.8, but I have and do map cars leaner still. There is no definitive air fuel ratio target, the engine likes what it needs in conjunction with every other parameter, nothing more. If I told you that there are factory turbo cars running 14.5 all the way through... well there are, and even more running in the 13s. On the flip side you will have some cars running in the 10s from factory, cue some rice machines.
So to sum up, well dynos help me tune cars so that they are better than they were before, that's it. Beyond that, listen to your tuner and rest safe in the knowledge that your car is performing to a most superior level!
Now then, any questions
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