Technical RR results of standard vs BMC panel vs BMC CDA

[robjnr]

Around 1000 miles

 

[RTech]

Definitely something iffy with the dyno readings....

If the drivetrain is 90% efficient that means that if you have 100bhp 90bhp are going to get to the wheels, if you have 110% then that means 99bhp will be getting to the wheels.

Very strange indeed.

Differing temps, tyre temps, gear box fluid temps, bearing temps, dyno running gear temps......ect

Warmer drive train = higher wheel power less drive train losses
Cooler drive train = lower wheel power and higher drive train losses.

For the test to be carried out correct above all temps need to be the same on all runs, inc tyre temps and gear box temps.

So on this test only the calculated flywheel power should be taken in to account.

 

[paulbfd]

Around 1000 miles

Cheers Rob, think I'll get myself a panel filter then as I'm going to service mine in the next week or two.

 

[D4nny8oy]

So on this test only the calculated flywheel power should be taken in to account.

Don't you mean what was actually measured, ie the @ the wheels power?

Near 40% drivetrain losses are huge for a FWD. A 4WD Mitsubishi Evo only looses approx 25% with all it's running gear.

 

[robjnr]

Don't you mean what was actually measured, ie the @ the wheels power?

Near 40% drivetrain losses are huge for a FWD. A 4WD Mitsubishi Evo only looses approx 25% with all it's running gear.

I've been on many RR's and the drivetrain losses are all different

 

[306maxi]

I've been on many RR's and the drivetrain losses are all different

Which to me says that they're not accurate.

 

[D4nny8oy]

I've been on many RR's and the drivetrain losses are all different

I'm not saying they aren't, different dyno's measuring in different ways/gearbox temps/tyres and different power outputs can affect the readings, plus different calculations and correction standards will mean one dyno's reading of the losses will differ from the next.

But as a rule, FWD loose the least, 4WD loose the most and RWD is somewhere in-between. My RST looses 17% through it's (knackered) 1980's FWD transmission. Are we really led to believe a modern Panda's box has more drag than an EVO 4WD system with 3 diffs and a heavy prop shaft?

 

[GrandeGuy]

Fantastic stuff!
Im a panel filter guy myself, and it just shows Panel on standard car=win

 

[306maxi]

Are we really led to believe a modern Panda's box has more drag than an EVO 4WD system with 3 diffs and a heavy prop shaft?

AND two extra driveshafts.....

I'm with you D4nny8oy, this all seems a little strange to me.....

 

[D4nny8oy]

AND two extra driveshafts.....

I'm with you D4nny8oy, this all seems a little strange to me.....

Indeed. I think either the dyno was run in the wrong mode/out of calibration or there's an issue with the car.

Found these hub dyno graphs while searching for other Panda 100HP graphs-

First, GP 1.4 (granted not exactly the same as the Panda, but more use as a rough guide)- http://www.rri.se/popup/performancegraphs.php?ChartsID=681

Second, Panda 1.2- http://www.rri.se/popup/performancegraphs.php?ChartsID=73

Notice how the 1.2 Panda tested has @the wheels figures almost identical to the standard 100HP that's been tested here (54 bhp vs 56.6 bhp)!

 

[robjnr]

I've been on many maha dynos and they all have large drive train losses, my dad in his RS6 lost 150bhp through the train lol which obviously right. I don't trust wheel power figures on maha dynos, I'd say that the flywheel figure is pretty accurate. All I do know is the gains are what they are

 

[pdtrewern]

I much prefer the idea of just throwing away a filter and putting in a brand new one every year.

:yeahthat:

So true. Same old story, tuning is a mugs game. buy a quicker car in the first place. Manufacturers spend hours and millions on testing the engine on the standard filter. I would not want to amend anything the ecu was setup for. (However, thank you for the information, it was interesting!!)

 

[hmallett]

What i find interesting is that:
a) the BMC panel filter gives less torque than standard below 3000 rpm
b) if the test was done each time until the rev limit was reached, then the BMC filters lose 400rpm at the top end. The standard filter test revs to 6600 rpm, the BMCs to only 6200 rpm.

 

[D4nny8oy]

I've been on many maha dynos and they all have large drive train losses, my dad in his RS6 lost 150bhp through the train lol which obviously right. I don't trust wheel power figures on maha dynos, I'd say that the flywheel figure is pretty accurate. All I do know is the gains are what they are

How can you believe the flywheel figures when they're estimated from the wheel figures which you don't believe? Because they're "about right"?

How can you believe the filter gains of around 4 bhp, when the wheel losses altered by 3-4 bhp between runs? Who's to say the dyno over- or under-estimated the gains?

If the readings are inconsistant, how can the results be? Surely this Maha dyno is not the only one in your area- I live in the arse-end of nowhere yet I'm within a 30 mins drive of 3 completely different dyno's.

I'm not slagging you off- I just can't blindly believe in any of the figures.

 

[D4nny8oy]

What i find interesting is that:
a) the BMC panel filter gives less torque than standard below 3000 rpm

I mentioned this in post#18, but everyone seems to have ignored it (bar you ).

Depends whether loosing 8 lbft at the bottom end is worth the 5-6 lbft gain at the top.