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Re: 4.2 Diesel GRX
Posted: 10 Dec 2015 06:21
by Peter Connan
Alex Roux wrote:Peter Connan wrote:...Oh and if you have to climb steep slopes with amputated feet, then buy a 3l Diesel....
I must have missed an episode?
Did Oscar buy a 3d? Or what happened?
At the Bapsfontein derby, Juice was the only guy who could crawl out of a hole without touching the accelerator...
Re: 4.2 Diesel GRX
Posted: 10 Dec 2015 08:03
by Alex Roux
Peter Connan wrote:Alex Roux wrote:Peter Connan wrote:...Oh and if you have to climb steep slopes with amputated feet, then buy a 3l Diesel....
I must have missed an episode?
Did Oscar buy a 3d? Or what happened?
At the Bapsfontein derby, Juice was the only guy who could crawl out of a hole without touching the accelerator...
Strange, I would have thought, besides sounding like a 72 ton truck, that this is one think the 4.2D can do better.
Re: 4.2 Diesel GRX
Posted: 10 Dec 2015 09:45
by ricster
My TD42 if I recall... may be wrong though (Peter please confirm ) came second on that particular challenge. but bear in mind the computer on a 3.0 .... anti stall ??
No computer on the td42 and still got quite far up the hill.
But yeah, each to their own, and that was basically what I was trying to say without showing any bias.
Just on a side note.... I think speed wise, the 4.5 petrol and a 4.2 diesel (turbo) on drag would be a very interesting race. I would almost hazard a guess that the diesel will take it
Re: 4.2 Diesel GRX
Posted: 10 Dec 2015 09:58
by SJC
Peter Connan wrote:Alex Roux wrote:Peter Connan wrote:...Oh and if you have to climb steep slopes with amputated feet, then buy a 3l Diesel....
I must have missed an episode?
Did Oscar buy a 3d? Or what happened?
At the Bapsfontein derby, Juice was the only guy who could crawl out of a hole without touching the accelerator...
How deep/steep was this hole?
Re: 4.2 Diesel GRX
Posted: 10 Dec 2015 11:10
by Michael
I dont think the idle test tells the story 100% on how much torque a vehicle has on idle.
As there was such a mix of Fuel injected and carburettor petrol's, 3.0 and 4.2 diesels. Some engines does not try and keep the engine from running by adding fuel when the engine is starting to take load (prbably something like a anti stall function), not sure if some Patrol engines have this?
The only real test will be to put all the engines under load on a dyno at the same rpm and compare.
I think on our next dyno day we must try and measure this? say on 500rpm, 800rpm and 1000rpm or something like that?
The drag racing in the sand was very interesting, and I wish now I could try different things when we were there.
1. I was in 4L in all the drag races which means I had to change gears like madness which makes you loose some time between changes where the auto box is just flawless and unmatched when it came to pulling away out of the sand.
2. I would love to do a running start in 4H and see how they compare, me and Tinus had an unofficial drag race at one stage when I was in 4H and it was very interesting to see that he could not escape as easy from me as before.......would love to test this properly to see the result.
Re: 4.2 Diesel GRX
Posted: 10 Dec 2015 20:18
by Peter Connan
The 3l diesel won that one precisely because the computer tries to keep the engine alive, and adds more fuel. You could hear it happening. My last Citi golf also did that, and it was amazing how well it would climb hills.
Fanus, the hole was about 1.8-2m deep and about 25 degrees. None of the Patrols had problems getting out of the hole, but the challenge was to do it without touching the throttle.
Cedric, I can't really remember who came second, but I think it was a close call between me and you.
However, the point is that although a big diesel will require less throttle control at low speeds, I have never encountered a situation where at anything over 500rpm in 1st gear low-range I could not overcome traction with throttle, and in the final analysis you can't use any more torque than that, so I really think it's a bit academic anyway.
An in-gear drag race started at say 1200rpm, the 4.2 TDI would initially pull away from the petrol, but I think above 3500-4000rpm the roles would definitely reverse. This is the power of a petrol engine: the torque curve is flatter and you still build lots of torque at higher RPM.
Re: 4.2 Diesel GRX
Posted: 11 Dec 2015 05:42
by Michael
I agree Peter, and I dont think I will ever be able to beat a 4.8 in a drag race, but my objective is just to see how well I can keep up. This is obviously why the 4.8's are killing the Dunes.......power is what you need for sand, not torque
Re: 4.2 Diesel GRX
Posted: 12 Dec 2015 09:44
by Stefan
Peter Connan wrote:There have been several tongue-in-check attempts on this forum to "prove" which is better between Petrol and Diesel.
The only thing we have managed to prove is that if you want to drag race in a river-bed, buy a 4.8, and if you want to do a rally stage, buy a GQ and stick a 4.5 in it. Oh and if you have to climb steep slopes with amputated feet, then buy a 3l Diesel.
The only competition the 4.2 TDI's have won so far is "who can sound most like a 75 tonne truck".

If you want to climb long soft dunes in the Kalahari, put a v8 in your Patrol (ala Tommie) because even a 4.8 won't make it
