GT3071 Turbo @ 2.4bar on a YB engine gives 514BHP!
#41
Certianly looks like less boost on your one given that its only making 460lbft.
Also made 50bhp/lbft (490 vs 440) less at 5250 than Dougs did despite the larger turbo.
What boost was that on then? 1.8 bar or something like that I guess?
Last edited by Chip; 20-10-2010 at 11:31 AM.
#42
Doug's still on hyrdaulics and its a road car, so massive rpm isnt really what he is after.
For big rpm and still as or more responsive than your T4, a 3076 would be a better bet.
#44
Surprised its only a couple of people TBH, there are certainly far more idiots on here than just 2, so I'd have expected a lot more tags from them than that if anything.
I'm sure there will be more once the bandwagon is rolling, but at least its not cluttering up the thread which so far is mainly just people with a genuine interest in YB's which makes a nice change on PF, lol
I'm sure there will be more once the bandwagon is rolling, but at least its not cluttering up the thread which so far is mainly just people with a genuine interest in YB's which makes a nice change on PF, lol
#45
He certainly seems to have done a good job of it as its not had any issues at all since Dave built it and NMS mapped it again.
Not something he does for a lot of people I dont think, although I know he has been building his own big power YB's for years of course.
#47
Combination of the turbo size and the low compression mate, at higher rpm the 3071 simply cant fill the cylinder enough to really get the engine to work hard, and is also starting to be restrictive on the exhaust side as well so increasing pumping losses etc.
For higher rpm, without any doubt the 3076 is the one to go for.
If you look on the before and after graph above, you can see that dougs engine was just starting to dip below the old 3076 at the very top end, but obviously the extra 100lbft for most of the rev range is at a cheap price if it only costs you half a dozen lbft at the top for literally only a few hundred rpm.
If the compression was a little higher it would hold on a touch longer, but even then it would still not be going strong at 8K on the 3071 for example
Last edited by Chip; 20-10-2010 at 11:55 AM.
#48
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At 5250 it has just on 2 bar boost, the difference is less than 40ft/lb as far as I can see (depends which graph you're using), what boost is 5250 at on your graphs? I should have done a really high boost run just to see.
Last edited by Martin-Hadland; 20-10-2010 at 11:56 AM.
#49
Oh, as much as that, I wasnt expecting it to need quite that much on the 3076 TBH at 5250 is pretty much where those turbos really love to be for starting to make good torque versus the 3071 IME
Yes on the earlier graph it was 40lbft, I was looking on the later one.
It was 2.4 bar peak and 1.9 bar held on that graph IIRC from what Doug said, not sure on the exact value at 5250 though, but would imagine its in the 2.2/2.3 ballpark based on those peak and held values, I'll try and find out for you mate.
Yeah it would be a bit fairer comparison then I guess as at the moment it looks like this 3071 is absolutely anhiliating your 3076 for most of the rev range and im sure that playing field could be brought more level with a bit more boost from the bigger turbo.
For track use in a RWD car, I'd take your one for what its worth though mate, better power at the very top end of the rpm scale is useful on track and if its rwd you dont want big torque spikes on track of course.
More isnt always more, but for dougs application he certainly seems to have a great spec now.
the difference is less than 40ft/lb as far as I can see (depends which graph you're using), what boost is 5250 at on your graphs?
It was 2.4 bar peak and 1.9 bar held on that graph IIRC from what Doug said, not sure on the exact value at 5250 though, but would imagine its in the 2.2/2.3 ballpark based on those peak and held values, I'll try and find out for you mate.
I should have done a really high boost run just to see.
For track use in a RWD car, I'd take your one for what its worth though mate, better power at the very top end of the rpm scale is useful on track and if its rwd you dont want big torque spikes on track of course.
More isnt always more, but for dougs application he certainly seems to have a great spec now.
Last edited by Chip; 20-10-2010 at 12:03 PM.
#50
1st to 200 without NOS
iTrader: (2)
Yeah it would be a bit fairer comparison then I guess as at the moment it looks like this 3071 is absolutely anhiliating your 3076 for most of the rev range and im sure that playing field could be brought more level with a bit more boost from the bigger turbo.
For track use in a RWD car, I'd take your one for what its worth though mate, better power at the very top end of the rpm scale is useful on track and if its rwd you dont want big torque spikes on track of course.
More isnt always more, but for dougs application he certainly seems to have a great spec now.
#51
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As i mentioned it was a bit of an evolved spec, so Im not sure how much say Karl really had in its totality, for example I dont know if it was Doug that choose the .63 housing on the 3076 to cut down lag or Karl, and the .63 is proven to be a bad combination on the GT30s IME, so if that was a decision Doug made and Karl had to map around it for example then it wouldnt really be fair to say the results reflected on Karl etc
So I am sure that this didnt represent Karl at the top of his game.
Anyway, I really dont want an NMS vs MSD thread as personally Ive got a lot of respect for both of them anyway.
So I am sure that this didnt represent Karl at the top of his game.
Anyway, I really dont want an NMS vs MSD thread as personally Ive got a lot of respect for both of them anyway.
when i spoke to karl about my engine he metioned this car in conversation regarding the .63
karl told me doug was melting the tips off spark plugs when doing high speed runs and when he investigated the egt there where far to high over 1000c i think) but doug still did'nt want to use the .82 housing as he did'nt want any more lag.
so what karl had to do was to add more fuel at the top end to bring the temps down but this was'nt he choice of the way to do it.
#52
The exhaust side was massive in particular on dougs previous setup.
The 3076 can work well without a doubt, you only have to look at Deanos from MAD to see that, on a very similar spec engine to Dougs, he made 560bhp IIRC and that was still on an old intercooler with high intake temps.
I personally like the 3076 and was telling doug to keep it and go to marks cams and intercooler setup and the vipec etc but then I didnt realise at that point that mark was going to make 520bhp our of the 3071 TBH, Ive never heard of any other YB managing that yet.
#54
when i spoke to karl about my engine he metioned this car in conversation regarding the .63
karl told me doug was melting the tips off spark plugs when doing high speed runs and when he investigated the egt there where far to high over 1000c i think) but doug still did'nt want to use the .82 housing as he did'nt want any more lag.
so what karl had to do was to add more fuel at the top end to bring the temps down but this was'nt he choice of the way to do it.
karl told me doug was melting the tips off spark plugs when doing high speed runs and when he investigated the egt there where far to high over 1000c i think) but doug still did'nt want to use the .82 housing as he did'nt want any more lag.
so what karl had to do was to add more fuel at the top end to bring the temps down but this was'nt he choice of the way to do it.
Anyway, the good thing is now he has more power and less lag at the same time
#60
Surprised its only a couple of people TBH, there are certainly far more idiots on here than just 2, so I'd have expected a lot more tags from them than that if anything.
I'm sure there will be more once the bandwagon is rolling, but at least its not cluttering up the thread which so far is mainly just people with a genuine interest in YB's which makes a nice change on PF, lol
I'm sure there will be more once the bandwagon is rolling, but at least its not cluttering up the thread which so far is mainly just people with a genuine interest in YB's which makes a nice change on PF, lol
#61
Would still be good for search engines when they are used properly, and would still be ok for good natured humour, but would stop the spineless wallys hiding behind them?
Last edited by Chip; 20-10-2010 at 01:49 PM.
#67
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On the subject of GT3071.82 turbos on an internal gate, my Dad's car made 444bhp and 420lbft at the wheels (4x4) on a Dyno Dynamics rolling road using one of these turbos. Peaks at 40psi (2.75 bar) and holds 37 (2.55 bar) on a 7.2:1 C/R, BD14 inlet and custom exhaust cam.
I don't have the graph to hand so can't tell you where it makes the power and how long it makes it for but it is still pulling up to 8.2k.
I don't have the graph to hand so can't tell you where it makes the power and how long it makes it for but it is still pulling up to 8.2k.
#68
On the subject of GT3071.82 turbos on an internal gate, my Dad's car made 444bhp and 420lbft at the wheels (4x4) on a Dyno Dynamics rolling road using one of these turbos. Peaks at 40psi (2.75 bar) and holds 37 (2.55 bar) on a 7.2:1 C/R, BD14 inlet and custom exhaust cam.
I don't have the graph to hand so can't tell you where it makes the power and how long it makes it for but it is still pulling up to 8.2k.
I don't have the graph to hand so can't tell you where it makes the power and how long it makes it for but it is still pulling up to 8.2k.
Cause when im quoting hold, im saying what the boost has dropped to at the limiter.
would be good if you could dig out the graphs, especially one with boost and power on it?
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If I can find the graph later on this evening I'll post it up but I'm not sure if it shows a boost curve. Only power and torque. It was about 18 months ago now.
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The tags were the best thing ever! Be it ones coming my way, or dropping T bombs myself. They always brightened up the day.
Shameless plug time, we have tags on the FF forum.
Plug and tears of sorrow over....something about YB's was being discussed i believe