Silverstone Dyno Day Taster

[bernmc]

I got to follow Marcus to Silverstone this morning so the boys could set up the dyno for our cars. Kinda hoping that Jane's car wouldn't get on the rollers so mine could go ;), but after seeing the hardware scattered about the yard, I realised that there was no chance of that - plenty of ground huggers in that shop!

Easy to find - Folloow the signs to Silverstone, enter the circuit by the main entrance, at the roundabout, turn right, and I think it was the 2nd lot on the left.

A few taster pics:
Following Marcus (secretly taking a speed reading to forward to Warwickshire Constabulary)
Couple of pics of the place itself with Marcus & my car sitting around

[bernmc]

Jane's car on the rollers, and the 'public viewing screen' - that's BHP calculated at the flywheel btw :(

[bernmc]

And some of the cars they were working on... 400BHP 350Z anyone?

[richy rich]

wtf less than 200bhp at the fw

[Wodjno]

Nreb ! SO does that mean there not sure how to deal with our Auto's :thinking:

[bernmc]

We'll be coming back with a sheaf of graphs each - power at the wheels and flywheel, torque, AFR, boost... yummy.

Because we were a bit surprised at the power figure from Jane's car, we had a bit of a play with the G-tech BHP measurement on the way back. We set the weight a bit high (guessing at 1700kg=3740 pounds). Marcus was getting around 170BHP indicated (Dyno said 150 atw), whereas I was getting 180-190, bearing in mind I've got a pre-facelift, running 0.5 bar, whereas Jane's is a post facelift.

Might be interesting for anyone else coming to the meet to try a BHP run with their g-techs too. IF you use the same weight figure, we'll be able to compare...

[bernmc]

Nreb ! SO does that mean there not sure how to deal with our Auto's :thinking:

We need to see the other cars figures to know for sure - if everything comes out with similar figures (for similar spec), then their software is at fault. They've had to use a 'generic' setup to calculate transmission losses, rather than specifics that they'd have for popular cars like evo's and scoobies.

Not sure how 150 at the wheels compares to other dyno figures in the club...?

[SGHOM]

summats not right ?? :inquisiti :inquisiti
I recorded 333bhp at well lane RR ? :2thumbsup

[Wodjno]

We'll be coming back with a sheaf of graphs each - power at the wheels and flywheel, torque, AFR, boost... yummy.

Because we were a bit surprised at the power figure from Jane's car, we had a bit of a play with the G-tech BHP measurement on the way back. We set the weight a bit high (guessing at 1700kg=3740 pounds). Marcus was getting around 170BHP indicated (Dyno said 150 atw), whereas I was getting 180-190, bearing in mind I've got a pre-facelift, running 0.5 bar, whereas Jane's is a post facelift.

Might be interesting for anyone else coming to the meet to try a BHP run with their g-techs too. IF you use the same weight figure, we'll be able to compare...

I did a GTech reading around a year ago.. I got 199.7bhp with weight of 1750kg :thinking:

[bernmc]

summats not right ?? :inquisiti :inquisiti
I recorded 333bhp at well lane RR ? :2thumbsup

You got a g-tech, Grey Man? Could you do a BHP run with the same weight figure as we used and see what you come out with...?

Considering how close our g-tech figures are, it would suggest that their dyno is under-reading, or Mitsi are lying about power outputs... :D

[richy rich]

what was the atw bhp

[SGHOM]

well lane... Leeds. :iloveyou:

http://www.clubvr4.com/forum/showthread.php?t=9097

[BraindG]

summats not right ?? :inquisiti :inquisiti
I recorded 333bhp at well lane RR ? :2thumbsup
That wasnt atw's though...

[Rally205]

I am not surprised at those figures on reflection. Mitsubishi quote 280bhp but that is in Japan with high octane fuel, optimised engine mapping and boost etc. Also the guys at WRC are using a generic setting in their software for the transmision losses.

We will get some useful data when we have the shootout and can compare several cars. If everyone else reads about the same then I will put it down to not having the boost controller switched on and running low boost.

It did make me laugh when I saw the AFR. So rich that it went off the scale!

[soapy1978]

/help so what does this mean we will not get a true bhp reading/help

[Kieran]

It did make me laugh when I saw the AFR. So rich that it went off the scale!

So - what we're saying is that most VR-4s would benefit from being Emanaged/mapped to adjust the AFR for 97/98 RON petrol?

Interesting that your saloon was ultra-rich, as it's one of the 'official' 200, isn't it? And the blurb in the UK VR-4 brochure says that they've been tweaked for UK fuel.....:inquisiti

[RED]

Okay she's not the fastest:happy: but can I be the prettiest/Wyhy /lol /lol

[RED]

So - what we're saying is that most VR-4s would benefit from being Emanaged/mapped to adjust the AFR for 97/98 RON petrol?

Interesting that your saloon was ultra-rich, as it's one of the 'official' 200, isn't it? And the blurb in the UK VR-4 brochure says that they've been tweaked for UK fuel.....:inquisiti

As far as I'm aware I thought that the standard ECU's weren't mappable. I can't see them making 200 diferent ECU's:thinking: So I can't see how Ralliart would have altered the fuel requirement. You wouldn't alter the AFR to get the car to run on a lower octane fuel it would simply be a case of altering the ignition timing but I don't see how even that is possible on our cars without changing the ECU and in the process ending up with a car that produces less power than the stated figure.

[Wodjno]

AFR does not reflect if the car has been mapped for a specific fuel ! AFR reflects how Mitsu have set the ECU up for safety and cooling of the engine. Longevity in a word.. The Standard ECU will advance and retard the ignition to reflect the different fuel octanes.. Again this is for safety... The lower the octane the more the ECU will retard the ignition.. The Higher the octane the more it will advance it..

It is correct that VR4's would benefit in being mapped in some form or another, but not for a specific octane rating.. But to efficiently tune the Fuel to Air ratio to produce optimum performance and also increase the fuel efficiency at WOT..:happy:

[Kieran]

Ah! In a few sentences, you've neatly filled in one of the gaps in my understanding of the relationship between power, ignition and AFR...... Thankyou!:2thumbsup

[caishanvr4]

So my RR figure of 197.2hp tallys in with yours rally205. Who's gonna be the first vr4 to get over 200.0hp on the wrc rollers then /Hmmm

[Spirit]

Just found a print out from a RR I had done at AP back in August 2005.

Figures on this were:

Engine Power: 311.0hp
Wheel Power: 216.4hp
Power Losses: 94.5hp

The car then ran a 318.0hp but the print out didn't work - so with the same power losses = 223.hp at the wheels. Ambient temperature was also high at 24c, so would hope it would perform slightly better at lower temps.

[bradc]

At the NZ dyno day, cars running at 8psi or thereabouts had around 140-150kw at the wheels, and cars with 11psi were getting 170kw or so. I think there is definately something not right with 150hp at the wheels, I have never seen a VR-4 record a figure that low, out of ~25 VR-4 dyno's I've seen.

Try resetting the ECU and running it on 98+ octane beyween now and the actual dyno day and see what happens.

Also can you guys tell them not to give the graphs with some bull**** bhp at the engine figure, they don't know what it is, they can't calculate it for sure, and it is just damned confusing. ATW figures are much much better :)

[bernmc]

They give you both graphs - atw and flywheel. I don't think it was an ECU/fuel thing as the g-tech figures for my leggie and marcus' vr4 were pretty close running similar boost levels.

If anyone coming to the dyno day has done some 1/4mile runs, and knows their trap speeds, bring them along - they'll give a rough idea of the power output to compare.