Indie. Rolling Road Results

[Ren]

Well, following yesterdays figures I was somewhat miserable as mine only managed 202 @ wheels or 232 @ fly (15%), but it was in the late 20s early 30's heat.

As some of you know I had already planned on a Power run at Powerstation, Tewkesbury for today. I have the results in hardcopy, video and pdf (had to make sure. lol). Please see attached and perhaps one of you more 'technical' guys out there can give me there opinion.

Note. I was told that they can provide club RR days @ £30 each, providing there is a minimum of 15 cars. I have to say that sounds good. The facilities are real clininical and clean. You could probably eat your dinner on the floor of the workshop (although not recommended of course). It's really easy access from the M5 J9, in fact it's under 2 minutes.

[Dan F]

Hi.
I think Powerstation are the place previously mentioned by Don as a good indie dyno that we could use with state of the art equipment.
At a cursory glance it looks like a fairly good result given the ambient conditions.
Cheers,
Dan.

[bobcat]

Hi Ren,

with the 202whp you got on the swautos maha lps 3000 (same as the powerstation one), you cannot correct for the transmission loss alone as this does not take into account the drag from the rollers and loading. The dyno will workout the drag and calculate crank figures from it.

you made more whp on the swautos maha than the powerstation one but they may have been loading the dyno or you had more drag in the rollers.

however if you look at your graph, the whp plotted is pretty much spot on with what you got on the sw's ones analog dials.

yesterday figures were given as whp with no loading and all that was controlled was the lowering and raising of cars which was visible to all. However the figures should be used as a comparison only, becuase as mentioned they do not take into account drag which will vary between cars and thus why for 100% accurate figures from dyno you need to measure drag.

Yesterday was setup as an opportunity to allow us to run as many cars in the few hours we had, thus why the dials where left on whp and the cars where dropped on and ran.

But, we will be running another dyno day probably october\november (when its a bit cooler) and this will be with the digital equipment all hooked in which will give accurate crank figures, as well as a/f and boost readings etc.

for more info on the digital hardware\software see here:

http://www.tat-rd.com/dyno_htm_e/dyno_start.htm

maha:

http://www.tat-rd.com/dyno_htm_e/mahadyno.htm

[Ren]

Also noticed that the traction control was off @ Powerstation. Was this off yesterday Bobcat?

Dave

[bobcat]

Originally Posted by Ren

Also noticed that the traction control was off @ Powerstation. Was this off yesterday Bobcat?

Dave

Yep, you will get you abs\tracs lights on as the car thinks its driving down the road, but isnt getting a reading from the rear abs sensors.

[Ren]

The only reason I ask is because I didn't get that message yesterday, but when I got in to drive home today from PS the ABS and traction lights were on.

[Dan F]

Hi Bobcat.
I was showing a friend of mine who is very up to speed on Dynamometers, (used to work for FKI) some of the pics posted up, and he had a couple of questions:

Are you sure it is a MAHA LPS 3000? He pointed out that the pictures show an old RAM 12 dyno controller......... Why is that?

Also, if it is an LPS 3000, why are you not using the very capable control system and software that typically comes with them?

Interesting questions I think you will agree.

Cheers,
Dan.

Originally Posted by bobcat

Hi Ren,

with the 202whp you got on the swautos maha lps 3000 (same as the powerstation one), you cannot correct for the transmission loss alone as this does not take into account the drag from the rollers and loading. The dyno will workout the drag and calculate crank figures from it.

you made more whp on the swautos maha than the powerstation one but they may have been loading the dyno or you had more drag in the rollers.

however if you look at your graph, the whp plotted is pretty much spot on with what you got on the sw's ones analog dials.

yesterday figures were given as whp with no loading and all that was controlled was the lowering and raising of cars which was visible to all. However the figures should be used as a comparison only, becuase as mentioned they do not take into account drag which will vary between cars and thus why for 100% accurate figures from dyno you need to measure drag.

Yesterday was setup as an opportunity to allow us to run as many cars in the few hours we had, thus why the dials where left on whp and the cars where dropped on and ran.

Bobcat,

From the pictures, this dyno appears not to the same as RICA's or Powerstation' s MAHA LPS 3000 and looks to me to be the much older SUN Road-a-Matic 12 model that is based on a Maha dyno which is now obsolete.

The Maha LPS 3000 CAN calculate engine power from measured (not calculated) transmission losses, and can account for the rollers and the loading.

The MAHA LPS 3000 does not use analogue dials. It uses a fully digital electronic control system, matched to a MAHA supplied data aquisition system, which is all controlled by PC.

The dials on a RAM 12 dyno can ONLY display wheel power and will automatically display negative power during coast down. It is not possible to switch the dials on a RAM 12 dyno to give engine power. It's also physically impossible to measure transmission loss in real time during the full throttle dyno run itself because this can only be done during the coast down phase.

Having owned and operated several SUN/MAHA/Dynojet dynos over the last 20 years, I can use my vast experience to dispel any inaccuracies in this field.

Regards,
Hamish.

[pyaap]

Originally Posted by Ren

Well, following yesterdays figures I was somewhat miserable as mine only managed 202 @ wheels or 232 @ fly (15%), but it was in the late 20s early 30's heat.

Hi Ren,

Well done on getting these tests done at two independent venues. It is interesting indeed that the figures from both venues are very close to each other; 202whp@ SW Autos, and just over 200@wheels (according to the your graph) at Powerstation. Your car's definitely performing really well given there was a near 10 deg C difference in ambient temps between the two days so congrats on getting a cracking example of a car!!!

If you're ever in the Bristol area, pop over for a drink or something as I'd love to meet you and see your car too.

[pyaap]

Originally Posted by hamish

Having owned and operated several SUN/MAHA/Dynojet dynos over the last 20 years, I can use my vast experience to dispel any inaccuracies in this field.
Regards,
Hamish.

Hi Hamish,

With reference to post no 36 in the following link:
http://www.vpcuk.org/forums/showthre...t=11996&page=4

can you please confirm that your previous dyno was indeed the same one that SW Autos have just acquired? Do you have any pictures of your previous setup?