Homebrew rolling road

[Turbocharger]

Yellow lines are TroddenMasses's standard 200Tdi. Blue lines are my car with tweaked fuelling etc. Top curves are torque (RH axis) with no real units yet, bottom lines are power, purportedly in kW at the roadwheels. Two runs for each car, hence two sets of results.

Thoughts / comments / the usual abuse? For the people who were interested in helping with trials previously, I'm now in a position to start taking some data if they'd like to participate. PM me for details.

[will_warne]

Well, it looks like you do get differant results for differant engines, then!

The thing that jumps out at me is the torque curve, shouldn't it be peaking at low revs and then tailing off? I don't know how well it would work to give exact figures but it would certainly give you a relitive, ball park, figure.

[geoffbeaumont]

For the people who were interested in helping with trials previously, I'm now in a position to start taking some data if they'd like to participate. PM me for details.

Think I said I would, but I don't need a rolling road of any description to describe the power curve of my engine at the moment. It looks like this :

Key:

Gemima XXXX

30 |

20 |

10 |

KW/h 0 X----------------------------------------------------------------------------------------

0 3000 6000

RPM

Hmm...that worked well - looks fine if you edit it, but it once it's rendered to HTML it loses all the spacing. Can't be bothered doing a graphic so you'll just have to use your imaginations

[FridgeFreezer]

Something like this, Geoff?

[Mo Murphy]

... along with a continuous high pitched tone ?

Mo

[Hybrid_From_Hell]

"I'm sorry Sir, your diesel ...its Brocked"

"You mean Broken ?"

"No Sir Brocked, ..............as in Les Brocked"

Nige

[paradigm shift]

I have read about uprating the fuel pump and intercooler on a 200TDi as the two first steps in tuning one.. Just out of interest what are the limitations of the engine? When are you pushing the injectors to their limit and how much boost can a standard engine cope with safely? I know a lot of these questions are trial and error, but it's always handy info to have if anyone can share their experiences.

[minivin]

Well, it looks like you do get differant results for differant engines, then!

The thing that jumps out at me is the torque curve, shouldn't it be peaking at low revs and then tailing off? I don't know how well it would work to give exact figures but it would certainly give you a relitive, ball park, figure.

I'm guessing it's a fuelling issue with the injector dizzy

[Troddenmasses]

I think that it is a great idea. I now have a benchmark to start from if I want to start playing with the engine. It takes all fo the subjectivity out of it - you can prove if it has more 'go', and where in the power curve it is. Unfortunately, I don't really trust my engine enough yet to even think about playing with it.

[FridgeFreezer]

When you say "homebrew rolling road" - how exactly did you get these figures then?

I know someone who knows someone who built a homebrew rolling road, used hundreds of electric kettle elements to dump the power!

[Troddenmasses]

When you say "homebrew rolling road" - how exactly did you get these figures then?

With a GPS mouse attached to a laptop, with a piece of software that John wrote.

A bit of fiddling later, and out pop the results. I am planning to do the same test on my Passat to see how it compares

[FridgeFreezer]

With a GPS mouse attached to a laptop, with a piece of software that John wrote.

Oooo, how handy! Probably just as accurate as a rolling road, too.

[Troddenmasses]

Oooo, how handy! Probably just as accurate as a rolling road, too.

The interesting thing for me is that is shows what your vehicle does in 'real world' conditions, not the perfect condition on a rolling road. Using this piece of kit to tune your engine would lead to the vehicle being faster and easier to drive, rather than the 'max power' version, where pure power output is the intention, so that you can tell all your mates just how much (little) power you have managed to squeeze out of your 1.2 nova.

[Mark90]

I'd be interested to see how my 110 200tdi compares, totally standard, and is 'feeling' a bit down on power.

[Troddenmasses]

I'd be interested to see how my 110 200tdi compares, totally standard, and is 'feeling' a bit down on power.

I'm sure John will be on here later on, and will help you out. The problem is that you will need another standard 200Tdi 110 to compare it against. Any takers?

[paradigm shift]

Mine is standard (i think!) - conversion on a 110 and looks standard. I'm going to have it fully serviced shortly so might be a good benchmark? Not 100% sure how many miles though.

[Turbocharger]

I'd be interested to see how my 110 200tdi compares, totally standard, and is 'feeling' a bit down on power.

I'm sure John will be on here later on, and will help you out. The problem is that you will need another standard 200Tdi 110 to compare it against. Any takers?

Nope, because you know/can guess the weight of the vehicle 110 vs 90 should be comparable (neglecting the extra inertia of the longer rear prop...)

Will - my fuelling is way out but yes, I'm also surprised peak torque doesn't appear low down. The curve is flat but there might be a small issue with the way I've modelled the vehicle's drag. Keir's Passat is next on the list of tests because I can calibrate against VW's published figures for the car (aero drag, published power/torque figures etc), although I'm always going to be guessing how much is lost in the drivetrain. As Keir said earlier, the GPS records what you've actually driven though so there's no needle-wobbling flywheel figures being bandied around. It's just not as big a number, that's all

Mark, you have a PM.

John

[will_warne]

Yes, trying to model the air resistance for a Land Rover won't be easy, particularly a non standard one. You've got a blip at arround 1500 rpm which should be peak torque so I think you've got something that's been shifted by something like y = x^2.