Change a/r housing - difference?
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Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Change a/r housing - difference? Thinking about another turbine housing for the street and another for race day. Current turbine housing is a t4 1.1, BW offers a .9 also. Is there enough difference in spool to justify the $180.00? Wondering if anybody ever tried this. Alot of the PT and TC turbos have smaller a/r's - wonder if this is why they come online faster than mine.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
This turbo spooled the same with an LS6 cam, 216/220 113lsa cam, then a 6.0 with the LS6 cam, then a PTC converter - no change at all in spool with all those changes.
Seems like some people have full boost by the time mine is starting. Any suggestions??
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From: Norn Iron
I've only tested a couple of cars with turbine housings. Just like Jesus says, it really did make very little difference to spool, if at all.
But smaller housings did affect performance by a noticeable amount, and not for any good.
I'd stick with the larger housing.
But smaller housings did affect performance by a noticeable amount, and not for any good.
I'd stick with the larger housing.
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Verdad Gallardo My data logs show boost starting around 3500 RPM's, and with 3.25 rear gears puts you at a higher speed playing around on the street
I didn't get any paper work from FI, but I think mine was an S475 with a
92 turbine-if I can fit a 4L80E (now 400) in it, I will switch rear gears to 3.70's, still spool same RPM's, but cut the speed I am in boost earlier
If I stay with the 400, then I might look at a smaller housing also
I wont get the feel I had from Prochargers down low, but get closer, lol
I didn't get any paper work from FI, but I think mine was an S475 with a
92 turbine-if I can fit a 4L80E (now 400) in it, I will switch rear gears to 3.70's, still spool same RPM's, but cut the speed I am in boost earlier
If I stay with the 400, then I might look at a smaller housing also
I wont get the feel I had from Prochargers down low, but get closer, lol
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From: THORNTON, PA (NEAR PHILLY)
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From: Norn Iron
Here's how it seemed to me, on the engines it was tried on.
Off boost...if there still isnt enough energy to help drive the turbo...all the smaller housing does is choke the engine's normal breathing.
So it wont help anywhere.
And likewise on boost, it simply restricts the engines breathing further at the top end
Transient response, off/on throttle there was no measurable change between the two housings even at over 30 psi boost ( 4cyl car )
Obviously not every application will be the same, but that was what I found testing with 2 different turbos, and 2 turbine housings on each on the same car.
I'll be trying another larger housing soon to see how that responds. Hopefully it'll be as good low down, and even better up top.
Off boost...if there still isnt enough energy to help drive the turbo...all the smaller housing does is choke the engine's normal breathing.
So it wont help anywhere.
And likewise on boost, it simply restricts the engines breathing further at the top end
Transient response, off/on throttle there was no measurable change between the two housings even at over 30 psi boost ( 4cyl car )
Obviously not every application will be the same, but that was what I found testing with 2 different turbos, and 2 turbine housings on each on the same car.
I'll be trying another larger housing soon to see how that responds. Hopefully it'll be as good low down, and even better up top.
Looking at rpm vs boost is for the most part pointless on an unlocked auto, especially a PTC 9.5
The converter stall speed moves directly with TQ input. And in the case of a 9.5 is is nice loose down low so the stall rises easily without much TQ rise
You can't make say 15lbs at 3500rpm on that converter, it is impossible, doesn't matter what turbo you put on or even if you spray it with nitrous. Because as the boost comes in and so does the TQ from it, rpm rises in direct relation to this
Let's say your motor makes 750ftlbs on 15lbs.... And sitting against the converter in stall it rides at 5000rpm...... You will never see rpm lower than that ever at that boost/TQ level
If you want more (more and useable) boost at a lower rpm aa you need a different converter, something more traditional like a normal companies 10"..... But then again you would be missing out on the whole point of the PTC 9.5
If you put a manual behind your combo you could make 15psi by 3200rpm.. Guaranteed
It is pointless to look at rpm vs boost on your combo though. Post a log rolling 2500 rpm and flat foot it in high gear
The converter stall speed moves directly with TQ input. And in the case of a 9.5 is is nice loose down low so the stall rises easily without much TQ rise
You can't make say 15lbs at 3500rpm on that converter, it is impossible, doesn't matter what turbo you put on or even if you spray it with nitrous. Because as the boost comes in and so does the TQ from it, rpm rises in direct relation to this
Let's say your motor makes 750ftlbs on 15lbs.... And sitting against the converter in stall it rides at 5000rpm...... You will never see rpm lower than that ever at that boost/TQ level
If you want more (more and useable) boost at a lower rpm aa you need a different converter, something more traditional like a normal companies 10"..... But then again you would be missing out on the whole point of the PTC 9.5
If you put a manual behind your combo you could make 15psi by 3200rpm.. Guaranteed
It is pointless to look at rpm vs boost on your combo though. Post a log rolling 2500 rpm and flat foot it in high gear
Thread Starter
Joined: Nov 2009
Posts: 1,621
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From: THORNTON, PA (NEAR PHILLY)
Looking at rpm vs boost is for the most part pointless on an unlocked auto, especially a PTC 9.5
The converter stall speed moves directly with TQ input. And in the case of a 9.5 is is nice loose down low so the stall rises easily without much TQ rise
You can't make say 15lbs at 3500rpm on that converter, it is impossible, doesn't matter what turbo you put on or even if you spray it with nitrous. Because as the boost comes in and so does the TQ from it, rpm rises in direct relation to this
Let's say your motor makes 750ftlbs on 15lbs.... And sitting against the converter in stall it rides at 5000rpm...... You will never see rpm lower than that ever at that boost/TQ level
If you want more (more and useable) boost at a lower rpm aa you need a different converter, something more traditional like a normal companies 10"..... But then again you would be missing out on the whole point of the PTC 9.5
If you put a manual behind your combo you could make 15psi by 3200rpm.. Guaranteed
It is pointless to look at rpm vs boost on your combo though. Post a log rolling 2500 rpm and flat foot it in high gear
The converter stall speed moves directly with TQ input. And in the case of a 9.5 is is nice loose down low so the stall rises easily without much TQ rise
You can't make say 15lbs at 3500rpm on that converter, it is impossible, doesn't matter what turbo you put on or even if you spray it with nitrous. Because as the boost comes in and so does the TQ from it, rpm rises in direct relation to this
Let's say your motor makes 750ftlbs on 15lbs.... And sitting against the converter in stall it rides at 5000rpm...... You will never see rpm lower than that ever at that boost/TQ level
If you want more (more and useable) boost at a lower rpm aa you need a different converter, something more traditional like a normal companies 10"..... But then again you would be missing out on the whole point of the PTC 9.5
If you put a manual behind your combo you could make 15psi by 3200rpm.. Guaranteed
It is pointless to look at rpm vs boost on your combo though. Post a log rolling 2500 rpm and flat foot it in high gear
So really what is one to do to bring boost on sooner for a street ride - supercharger lol!!!!