Nice chart ed.
Fusion Ed
Active Member
The 3071 was Steve Pudneys.
I can't do an any more accurate than that one right now, However against RPM it would look 99% the same. I could have labeled it either as the data run was in the same gear, and both to 6000+ so its valid as one agianst RPM as well, even if not technically correct.
I can't do an any more accurate than that one right now, However against RPM it would look 99% the same. I could have labeled it either as the data run was in the same gear, and both to 6000+ so its valid as one agianst RPM as well, even if not technically correct.
Fusion Ed
Active Member
I'll do that when the data exists, you can be sure of that. But as mentioned it wouldn't change the graph too much if anything the stock T28 would be shifted to the right slightly. I can give specific values on the response vs rpm if there is anything you want, but due to the way the logs were taken I don't have enough date over enough RPM points to make such a nice graph. (the two graphs don't compare well to rpm when the rpm points are different on each one, time however remains a constant). I may be able to interpolate the data later and produce a boost/rpm graph. It would be for approximate comparison only however.
Ed
Ed
Phil, I've done some G-tech plots that calculate the torque curves on my old T28 and my new 3071. Althought the plots were taken a year apart and its a bit like comparing apples and bananas, you can see my 3071 is matching my old T28 up to about 3250 at which point the gap starts to open and by 4000 the 3071 was around 20% more. Its pretty unscientific when you consider the variables but it broadly reflects my experience. I was going to analyse it again for here given yesterday's RR experience.
Jim
Jim
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Here is a comparison from my G-Tech 2.0 software taken a year apart but the only major difference being the turbo and the boost level.
Key points:
1. The plots are real world horse power so are the result of everything including wind resistance (2nd gear to minimise) slopes, transmission losses, wheel friction etc.
2. The charts are far from a normalised enviroment but they were done on the same road!
3. The basic engine configuration is the same.
4. The T28 was re-built with 360deg bearings so isn't standard
5. On these occasions, the T28 was at 0.9Bar (Red), the T3071 was at 1.4bar (Black)
My conclusions:
From this and confirmed on my my recent RR experience making 377hp at 1.7Bar, it demonstrates the "standard turbo elbow" is really restricting the performance of the T3071. I had half expected this but thought I may as well wait until the RR to confirm it more scientifically before I specced my new custom exhaust.
Performance is more than just fitting a bigger turbo.
My advice to anyone else is not to uprate your turbo to a 2871, 3071 or larger without changing the exhaust elbow. You will eliminate any hint of boost surge on the standard elbow but IMO it loses around 10% power at high revs.
Its only cost me a gasket so I'm not fussed, the new exhaust AND elbow will get fitted in the next weeks.
Jim
Key points:
1. The plots are real world horse power so are the result of everything including wind resistance (2nd gear to minimise) slopes, transmission losses, wheel friction etc.
2. The charts are far from a normalised enviroment but they were done on the same road!
3. The basic engine configuration is the same.
4. The T28 was re-built with 360deg bearings so isn't standard
5. On these occasions, the T28 was at 0.9Bar (Red), the T3071 was at 1.4bar (Black)
My conclusions:
From this and confirmed on my my recent RR experience making 377hp at 1.7Bar, it demonstrates the "standard turbo elbow" is really restricting the performance of the T3071. I had half expected this but thought I may as well wait until the RR to confirm it more scientifically before I specced my new custom exhaust.
Performance is more than just fitting a bigger turbo.
My advice to anyone else is not to uprate your turbo to a 2871, 3071 or larger without changing the exhaust elbow. You will eliminate any hint of boost surge on the standard elbow but IMO it loses around 10% power at high revs.
Its only cost me a gasket so I'm not fussed, the new exhaust AND elbow will get fitted in the next weeks.
Jim
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Fazz
New Member
Interesting info thanks Jim.
Helps me get prepared for my mapping session in Jan so think I'll try get an elbow in then too!
Are there any aftermarket straight fit jobs or is this going to be a custom job ? ?
Are you sure its teh elbow and not the downpipe? Do you think the downpipe would restrict if the elbow was replaced - I suspect you are changing both at same time whilst getting made up???
Helps me get prepared for my mapping session in Jan so think I'll try get an elbow in then too!
Are there any aftermarket straight fit jobs or is this going to be a custom job ? ?
Are you sure its teh elbow and not the downpipe? Do you think the downpipe would restrict if the elbow was replaced - I suspect you are changing both at same time whilst getting made up???
My downpipe is 2.5" to a 2.5" system and back box. The elbow is pretty shocking and I've always just stuck with it as the replacement was looking a bit expensive. My front section will look like Wayne's as its done by the same bloke.
Here is the post : http://www.gtiroc.com/forums/showthread.php?t=42861
IMO its definately the elbow and probably the down pipe. The custom solution means I don't have to worry about either ;-)
Here is the post : http://www.gtiroc.com/forums/showthread.php?t=42861
IMO its definately the elbow and probably the down pipe. The custom solution means I don't have to worry about either ;-)