hot side is it normal.
02-20-2010, 01:00 AM
#16
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While it is OK for a track used turbo, it is not recommended for a street car. Increased lag will decrease low end power and basic drive-ability.. If you spend most of your time driving north of 3000RPM I say go for it, and I know where you can pick up a polished magnesium cup intake too!
loss of 10% down low to pick up 5% up top only make sense in a car that is up top 95% of the time...
loss of 10% down low to pick up 5% up top only make sense in a car that is up top 95% of the time...
02-20-2010, 01:16 AM
#17
Nordschleife Master
Was the donor car a track car, or have a bigger displacement motor? If not the turbo was WAY overkill, and clipping it made the problem even more evident below 3500RPM or so...
It would best be put to use on a 2.8L or bigger motor, and even better for a track car, clipping on a street use car is almost stupid as it adds lag, and increases the engine RPM at which the turbo begins to spool up...
Better performance could be had out of a properly sized turbo than one that is too big, and clipped... but that is just my opinion.
02-20-2010, 01:19 AM
#19
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that intake was purposely done too...and probably by the same person who decided clipping an already big turbo was a good idea... not to mention it is WAY to uniform to be accidental... Yes it was purposely done... and not well IMHO...
Was the donor car a track car, or have a bigger displacement motor? If not the turbo was WAY overkill, and clipping it made the problem even more evident below 3500RPM or so...
It would best be put to use on a 2.8L or bigger motor, and even better for a track car, clipping on a street use car is almost stupid as it adds lag, and increases the engine RPM at which the turbo begins to spool up...
Better performance could be had out of a properly sized turbo than one that is too big, and clipped... but that is just my opinion.
Was the donor car a track car, or have a bigger displacement motor? If not the turbo was WAY overkill, and clipping it made the problem even more evident below 3500RPM or so...
It would best be put to use on a 2.8L or bigger motor, and even better for a track car, clipping on a street use car is almost stupid as it adds lag, and increases the engine RPM at which the turbo begins to spool up...
Better performance could be had out of a properly sized turbo than one that is too big, and clipped... but that is just my opinion.
02-20-2010, 01:23 AM
#21
Nordschleife Master
Did this turbo and the intake come off the same car? If so have you popped the head and check bore and stroke yet? If it is an elevated displacement motor you might make back what you polished away on the intake... But hey, it is all about marketing right? you can market the intake as a one of a kind magnesium intake "only one know to have EVER been polished!"
02-20-2010, 01:25 AM
#22
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Did this turbo and the intake come off the same car? If so have you popped the head and check bore and stroke yet? If it is an elevated displacement motor you might make back what you polished away on the intake... But hey, it is all about marketing right? you can market the intake as a one of a kind magnesium intake "only one know to have EVER been polished!"
02-20-2010, 01:28 AM
#23
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02-20-2010, 03:10 AM
#25
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I was always under the belief that clipping the hotside was done to improve spoolup due to less mass to move?
02-20-2010, 05:04 AM
#26
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is shave down flat or at an angle
from the center of the turbine downwards
when view from the side. This is done to
reduce back pressure"
02-20-2010, 09:13 AM
#27
Rennlist Member
Well, reducing back pressure you will be losing spool-up effectiveness.
I'm guessing reducing the mass by clipping doesn't offset the fact that less material is in the way of the exhaust gases.
I'm guessing reducing the mass by clipping doesn't offset the fact that less material is in the way of the exhaust gases.
02-20-2010, 11:45 AM
#28
Nordschleife Master
Clipped on left, non clipped on the right.
02-20-2010, 11:52 AM
#30
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Clipping
A common trick to increase the output of a turbocharger is "clipping" the turbine wheel. When the turbine wheel (on the "hot side") is clipped, the fins are cut away at a slight angle (usually between 7 and 10 degrees), thereby reducing the amount of metal that is in the path of the exhaust gasses. The reason this is done is to lower the resistance of the turbo to exhaust gasses flowing through it.
At high RPMs, clipping increases engine horsepower, since the turbo is allowing the exhaust gasses to escape more quickly (and at high RPMs, the turbo can only spin so fast). At low RPMs, clipping tends to slightly increase turbo lag, since less fin-area means that the turbocharger will take longer to get up to speed. This trade off is typically well worth the upper-range power gains.
A common trick to increase the output of a turbocharger is "clipping" the turbine wheel. When the turbine wheel (on the "hot side") is clipped, the fins are cut away at a slight angle (usually between 7 and 10 degrees), thereby reducing the amount of metal that is in the path of the exhaust gasses. The reason this is done is to lower the resistance of the turbo to exhaust gasses flowing through it.
At high RPMs, clipping increases engine horsepower, since the turbo is allowing the exhaust gasses to escape more quickly (and at high RPMs, the turbo can only spin so fast). At low RPMs, clipping tends to slightly increase turbo lag, since less fin-area means that the turbocharger will take longer to get up to speed. This trade off is typically well worth the upper-range power gains.