TME turbo with 20g wheel (surge?)
Jan 20, 2016, 03:55 AM
#1
Newbie
Thread Starter
TME turbo with 20g wheel (surge?)
Hi all
My td05HRA with a titanium turbine and shaft is getting a rebuild - dodgy bearing - and the builder has suggested a 20g 11 blade billet comp wheel and new compressor cover. I will be using a 10.5T exhaust housing.
Do I need to be worried about running into surge issues with a 20g mated to a titanium turbine and shaft with the 10.5T exhaust housing?
stock 2.0L evo5, all supporting mods (fuel etc), stock cams.
if there is a risk, Id rather be safe and run the 16g wheel (though it would be great to have the power capability of the 20g wheel and have the titanium hot side make up for the decreased response from a larger comp wheel).
Thanks for your comments
My td05HRA with a titanium turbine and shaft is getting a rebuild - dodgy bearing - and the builder has suggested a 20g 11 blade billet comp wheel and new compressor cover. I will be using a 10.5T exhaust housing.
Do I need to be worried about running into surge issues with a 20g mated to a titanium turbine and shaft with the 10.5T exhaust housing?
stock 2.0L evo5, all supporting mods (fuel etc), stock cams.
if there is a risk, Id rather be safe and run the 16g wheel (though it would be great to have the power capability of the 20g wheel and have the titanium hot side make up for the decreased response from a larger comp wheel).
Thanks for your comments
Jan 20, 2016, 07:55 AM
#2
Evolved Member
At 0/0 camshaft dialing ( no matter what cams you choose to run, even on stock ones) you will have no compressor or engine surge whatsoever no matter how aggressively you map the setup down low using the 11 blade 20g billet wheel.
Marios
Marios
Jan 20, 2016, 05:33 PM
#5
EvoM Guru
iTrader: (1)
Originally Posted by 94AWDcoupe
the ti turbine will not last with anything bigger than original 16g
Jan 21, 2016, 03:40 AM
#6
Newbie
Thread Starter
Hi
Thanks for the reply
Are you suggesting the turbine will fail when connected to a heavier compressor side? What failure mode would be expected?
I checked the material strength properties and TiAl seems to have superior strength properties (ksi values) over standard inconel 600 however I would assume that in the structure design, MHI would have taken that into account in the design.
Would it be failure of the shaft mating between the turbine and compressor due to the incompatibility with TiAl and the brazing method which needs to be used?
Seems like there are a few suppliers who do sell a straight TME 20g
From various sources the weight differences between the 16g and 20g is only a few grams (I could only find a weight for a td05h 16g wheel which is 70g and the 11blade 20g is 76g) however I understand rotational inertia so depending on the balance, when the rotational frequencies are in the hundreds of thousands of hz, a few grams can make a pretty big difference!
Thanks for the reply
Are you suggesting the turbine will fail when connected to a heavier compressor side? What failure mode would be expected?
I checked the material strength properties and TiAl seems to have superior strength properties (ksi values) over standard inconel 600 however I would assume that in the structure design, MHI would have taken that into account in the design.
Would it be failure of the shaft mating between the turbine and compressor due to the incompatibility with TiAl and the brazing method which needs to be used?
Seems like there are a few suppliers who do sell a straight TME 20g
From various sources the weight differences between the 16g and 20g is only a few grams (I could only find a weight for a td05h 16g wheel which is 70g and the 11blade 20g is 76g) however I understand rotational inertia so depending on the balance, when the rotational frequencies are in the hundreds of thousands of hz, a few grams can make a pretty big difference!
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Jan 21, 2016, 08:50 AM
#8
EvoM Guru
iTrader: (1)
I take the 71hta is fairly light then? Since FP was selling hem on the Ti turbine..
Jan 21, 2016, 09:29 AM
#9
Remember the FP white rabbit? Old school, but worked great and was based on the TME wheel. I think you will be fine with 71HTA matched to your TME wheel. Maybe reach out to http://www.owendevelopments.co.uk/ they will now best.
Jan 22, 2016, 03:59 AM
#10
Newbie
Thread Starter
Remember the FP white rabbit? Old school, but worked great and was based on the TME wheel. I think you will be fine with 71HTA matched to your TME wheel. Maybe reach out to http://www.owendevelopments.co.uk/ they will now best.
Cheers
From what I've read, the FP white rabbit is a 20g wheel mated to a TiAl turbine and shaft and I haven't seen any comments about turbine failures with that setup
Jan 22, 2016, 09:34 AM
#11
fp has never really offered a 20g wheel turbo for evo 8. fp white didnt come with ti wheel. it would have to have been request of customer to make one like that. the compressor wheel on white rabbit was the early 5 blade design. the inducer on that wheel was just over 50mm. the 20g is 52.6mm. the later fp white (white and white rabbit were to different turbos) was the same current 71hta wheel. which is still only 51mm. the 20g wheel is closer to the current hta green wheel at 53mm.
Jan 23, 2016, 07:07 PM
#14
Evolved Member
rpm limit
I was under the impression the limiting factor was RPM. The TiAl turbines do not handle as high RPMs as Inconel. The 20g (and therefore the turbine) will spin SLOWER at the same boost as a 16g compressor.
I guess I sit on the wrong side of the camp on this one. I think it would be fine at "reasonable" boost levels.
Unless I don't understand (or know of) that TiAl turbines fail at the shaft from torque literally twisting it into failure !?
Also - I am running the 11 blade (GTX style) 20g mated to a 9-blade TD05 turbine. I have not had any surge issues. Making 375 at the wheels on my MR (Evo x = more drivetrain loss). Added 140 to the wheels so far.
~Jaraxle
I guess I sit on the wrong side of the camp on this one. I think it would be fine at "reasonable" boost levels.
Unless I don't understand (or know of) that TiAl turbines fail at the shaft from torque literally twisting it into failure !?
Also - I am running the 11 blade (GTX style) 20g mated to a 9-blade TD05 turbine. I have not had any surge issues. Making 375 at the wheels on my MR (Evo x = more drivetrain loss). Added 140 to the wheels so far.
~Jaraxle
Jan 23, 2016, 07:24 PM
#15
I was under the impression the limiting factor was RPM. The TiAl turbines do not handle as high RPMs as Inconel. The 20g (and therefore the turbine) will spin SLOWER at the same boost as a 16g compressor.
I guess I sit on the wrong side of the camp on this one. I think it would be fine at "reasonable" boost levels.
Unless I don't understand (or know of) that TiAl turbines fail at the shaft from torque literally twisting it into failure !?
Also - I am running the 11 blade (GTX style) 20g mated to a 9-blade TD05 turbine. I have not had any surge issues. Making 375 at the wheels on my MR (Evo x = more drivetrain loss). Added 140 to the wheels so far.
~Jaraxle
I guess I sit on the wrong side of the camp on this one. I think it would be fine at "reasonable" boost levels.
Unless I don't understand (or know of) that TiAl turbines fail at the shaft from torque literally twisting it into failure !?
Also - I am running the 11 blade (GTX style) 20g mated to a 9-blade TD05 turbine. I have not had any surge issues. Making 375 at the wheels on my MR (Evo x = more drivetrain loss). Added 140 to the wheels so far.
~Jaraxle
http://www.forcedperformance.net/mer...tegory_Code=SP