Dyno Day! Sunday May 3

[dnegative]

which car you gonna bring?

The MX;
See how much life is left in the fucking thing

[-GT-]

I'll be there about lunchtime - hopefully just in time for the bbq. Am getting quite keen actually, have missed dyno day during it's hiatus!

[trdee]

Was a good day all round, thanks for coming everyone

24 cars in total, so we achieved our target. Lots of variety and quite a few non-toyotas, but we won't judge

The day seemed to run fairly smoothly if a little slowly, hopefully we can get our act together later this year and organise a bigger one for toyotafest.

Dyno results below!

[JustenGT8]

Stout 3SGTE?

And Matts car laid down an awesome number

[-GT-]

Argh, rolla could've snapped up <1800 NA and I got belted by an S5 in the >2800. Still good to get out there and see what it can do.

[trdee]

there were no trophies for this day, just bragging rights the toyotafest dyno day will have trophies

[egamirrorim]

That IS200 was crazy!

There will be another Dyno day for ToyotaFest?!

Can someone explain how the AFR is measured?

My AFR is really flat - is this common for a factory car?



Also, how am I supposed to read the tourque? JZS171 only has 379NM from factory so I cant see how my car makes more than that at the wheels?!

[trdee]

Egamirrorim:

1. Yes we are planning on doing another dyno day for the Toyotafest weekend, we are trying to improve Toyotafest every year with more events and whatnot and this year we will try to add a dyno day along with the drag racing and dinner.

2. Stock ecus all behave differently from one type of car to another, depending on how the manufacturer wanted to tune it. A hallmark of turbo toyota ECUs is that they all seem to go straight to 10:1 when you hit boost and sit there the whole way. It robs power but is very safe in regards to detonation etc. Nothing to worry about. The torque curve is flat and consistent too, which is what a VVTi 1J should look like

3. The engine torque figure (and the KW figure) is derived from the motive force at the rollers. This can change depending on gear, dyno ramp rate, air temp correction factor, how the car is strapped down, even tyre pressure! Don't worry about the headline figure too much, basically what I would take from your run there is that everything on your engine is working as it should and the power/torque figures are still in the ballpark for a factory motor, so you have a nice healthy engine!

Dynos are more useful as analysis tools to see how the torque and power curves change over the rev range, and how your AFRs look etc. They shouldn't really be used to compare headline figures back to factory stuff as there are too many variables which can skew the figures

[NME308]

Dynos are more useful as analysis tools ...snip...

Rubbish they are all about and have always been all about the ego points!!!
Analysis is purely something we waste some time on during the process of obtaining more ego points!!

Cheers,
Jason

[woggin]

Yes, i won the under 1800 FI class!!!

[JustenGT8]

Torque is a misnomer...teh Dyno measures tractive effort and expresses it as NM. Of course it is higher than engine torque as you have the mechanical advantage of gearing...that's what gearing is supposed to do I'm not 100% on the calcs used but at a guess the tractive effort will be something similar to your engine torque multiplied by your final gearing (including wheel diameter). It's a pretty useless measure for 99% of us so don't know why they even bother providing the graph?

torque and hp will be equal at 5252rpm...for any engine

[trdee]

he means the torque figure to the left on the results justen (the figures say torque - power - motive force). the torque figure would be a conversion of the power figure using the 5252 formula you just stated

[robk]

That IS200 is one of the best sleepers I've ever seen!

Stout 3SGTE?

:-)
That would be mine, in a black SW20 MR2.
I made a few changes in the tune and put the car back on the dyno again at the end of the day after everyone else was done. It made 337rwkw on that occasion.
That was with 60% ethanol, but it makes 353kw on 85% ethanol.

More info here if you're interested:
http://www.toymods.org.au/forums/thr...rbo?highlight=

[trdee]

what was the go when the power figures were dropping on the dyno in the afternoon? playing with boost settings? almost sounded like it was misfiring on boost for a bit there..

[robk]

what was the go when the power figures were dropping on the dyno in the afternoon? playing with boost settings? almost sounded like it was misfiring on boost for a bit there..

It was due to the way that the car was strapped down, but it took a while for us to realise it! I was looking for problems in the tune but it was just wheel slip all along.
Eventually Mark adjusted the straps and the power jumped up by more than 20kw! When he was adjusting the straps, he noticed that my tyres were very sticky and hot because they had obviously been slipping against the rollers at high boost.