mx5cartalk.com

So, the standard NA8 engine when new produces 98kW @ flywheel. With transmission losses of ~20kW this should put down ~78kW @ rear wheels. From my research of this forum and others this seems to be correct. Yet my results from a dyno run gave this:



It's almost completely stock other than a K&N panel (not pod) filter and a mild steel catback exhaust (installed by previous owner) - hardly anything that would dramatically increase power output. I have asked for, and still awaiting an explanation from the shop.

So unless there's something I'm missing these results seem far too good to be true. Would you agree? Please comment.

Travis

Mania dyno is known to be quite happy. Have a look in the for sale section for the na8 with an adaptronic installed and minor mods making way over inflated power figures.

A dyno result is only any good really for measuring an improvement. Each time you go to a new dyno you should baseline before making an improvement.

Sent from my GT-I9100 using Tapatalk 2

Looks to be 15-20% higher than it should be.

I may be wrong...but the rear wheel torque figure is never actual torque output due to the torque multiplication through the gear / diff ratios?

sailaholic - I guess your comments are a very positive way of looking at things. As a paying customer, I think it is fair that I get reasonable readings and not relative figures which now forces me to use that particular dyno everytime just to see gains.

deviant - Yes, I believe you are correct in terms of torque figures only. Not 100% certain though.

According to that dyno you have more torque at the wheels than a turbo BP has at the flywheel. It's way off that dyno.

Of course it makes more torque at the wheels, he has flywheel torque multiplied by diff ratio at the wheels.

Dann

Yep, hence I am more concerned about the power figure than the torque figure at this stage. I guess a calculation could be made to work at the torque at the flywheel, but again I would've thought this would be included for a paying customer.

Its one checkbox inside the dyno software.

Either forgotten or something.

Dann

Travis, I was trying to be nice / positive. It's actually really annoying if you get numbers on an accurate dyno then someone else goes well I got this much hp with just these mods.

For the non questioning person though, it makes the shop look good as the found heaps of power.

Unfortunately, happy dynos aren't uncommon.

This is true, if you have a megasquirt you can use virtual dyno which will let you know if the shops dyno is accurate or not.

Dann

they are tuning tool as far as i am concerned. the butt dyno is good, if you can't feel it you haven't gained much power regardless of what the numbers say.

WOW all so true, it took a few reads to realise what a happy dyno was but I did hear about there faulty dyno

I've seen the same on bike dynos. Like any piece of measurement equipment, there is a margin of error which usually increases over time between calibrations.
I remember putting my CBR1000RR on a mates dyno only to see it pull bigger numbers than his race bike had done a few weeks earlier. Sure enough we rolled his race bike on and it pulled about 20kW more than it had a couple of weeks previous.

This is my biggest gripe with speed cameras, particularly in Vic where they have such low margins of error. The Lidar systems have a factory tolerance of 7% yet in Vic you can get pinged for 3kph over in a 50 zone. Someone can't do their math.

The point here however, is that Mania's dyno has produced a result that is MUCH happier than is has done in the past. At previous dyno days, the power figures they were getting for stock NA6s was around 68-72kW and for stock NA8s was around 74-76kW. Clearly your run gave a much higher figure than is reasonable to expect from the limited mods you listed. Probably around 80kW is more likely. It could just be a matter of using a wrong setting in the dyno software. Best to ask Mania to explain.