Turbos running out of steam
Originally Posted by Guard dog
Then go 7268 with the 0.81 A/R in the T series. I wonder if they could put together a 6668 in the T series?
Something you might consider.
Test the accuracy of your IAT.
In ice water and boiling water.
I noticed mine is off a bit and I'll do this test when the car is back together.
Not sure what eng management you are using, but There are cal coefficients in HPT to adjust.
I'm using the same sensor.
Test the accuracy of your IAT.
In ice water and boiling water.
I noticed mine is off a bit and I'll do this test when the car is back together.
Not sure what eng management you are using, but There are cal coefficients in HPT to adjust.
I'm using the same sensor.
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From: Norn Iron
What pressure ratios are you seeing ?
Certainly moving the a larger compressor say 66/67mm ( nice billet ) would help your charge temps and should offer a good power increase.
Originally Posted by stevieturbo
Why do you feel you're running out of turbine ?
What pressure ratios are you seeing ?
Certainly moving the a larger compressor say 66/67mm ( nice billet ) would help your charge temps and should offer a good power increase.
What pressure ratios are you seeing ?
Certainly moving the a larger compressor say 66/67mm ( nice billet ) would help your charge temps and should offer a good power increase.
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From: Norn Iron
I'd be surprised if the turbines themselves are a major issue though.
One good thing, now that you've driven it with the glide and those smaller that expected turbos...you're in a much better position to say whether you could go much larger or if spool was terrible and a large jump might be bad for you.
Originally Posted by Guard dog
Just assume there is a boost leak and prove to yourself that there isn't before you change stuff.
It's very possible they are spinning hard, that doesnt mean the turbines are out, it more likely means the compressor cant cope, likewise with excessively hot air.
I'd be surprised if the turbines themselves are a major issue though.
One good thing, now that you've driven it with the glide and those smaller that expected turbos...you're in a much better position to say whether you could go much larger or if spool was terrible and a large jump might be bad for you.
I'd be surprised if the turbines themselves are a major issue though.
One good thing, now that you've driven it with the glide and those smaller that expected turbos...you're in a much better position to say whether you could go much larger or if spool was terrible and a large jump might be bad for you.
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Verdad Gallardo 9 Second Club
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From: Norn Iron
On mine essentially 6468 if we can compare numbers in that way, 382ci.
Up to either 25psi or 5500rpm, pre turbine pressure vs manifold pressure are pretty much bang on 1:1
Only over either 1 of those ( or of course both ) did it rise above 1:1 and even then only by a small margin.
Even at 28psi boost over 1km and top end of 6k I'd say it's only around 1.2:1
I'd have thought the 68mm turbine ( T4 0.88 ) would have been worse than that, but quite pleased to see it isnt an issue at all
It isnt to say a larger turbine may not still perform better, I'd actually like to try, but I'm not going to spend any money to try.
I'd think going to your original choice of 6665 or thereabouts would still be a good call, or better if they're offering billet wheels ( not sure if they have a range of turbine wheels ? )
Up to either 25psi or 5500rpm, pre turbine pressure vs manifold pressure are pretty much bang on 1:1
Only over either 1 of those ( or of course both ) did it rise above 1:1 and even then only by a small margin.
Even at 28psi boost over 1km and top end of 6k I'd say it's only around 1.2:1
I'd have thought the 68mm turbine ( T4 0.88 ) would have been worse than that, but quite pleased to see it isnt an issue at all
It isnt to say a larger turbine may not still perform better, I'd actually like to try, but I'm not going to spend any money to try.
I'd think going to your original choice of 6665 or thereabouts would still be a good call, or better if they're offering billet wheels ( not sure if they have a range of turbine wheels ? )
Originally Posted by stevieturbo
On mine essentially 6468 if we can compare numbers in that way, 382ci.
Up to either 25psi or 5500rpm, pre turbine pressure vs manifold pressure are pretty much bang on 1:1
Only over either 1 of those ( or of course both ) did it rise above 1:1 and even then only by a small margin.
Even at 28psi boost over 1km and top end of 6k I'd say it's only around 1.2:1
I'd have thought the 68mm turbine ( T4 0.88 ) would have been worse than that, but quite pleased to see it isnt an issue at all
It isnt to say a larger turbine may not still perform better, I'd actually like to try, but I'm not going to spend any money to try.
I'd think going to your original choice of 6665 or thereabouts would still be a good call, or better if they're offering billet wheels ( not sure if they have a range of turbine wheels ? )
Up to either 25psi or 5500rpm, pre turbine pressure vs manifold pressure are pretty much bang on 1:1
Only over either 1 of those ( or of course both ) did it rise above 1:1 and even then only by a small margin.
Even at 28psi boost over 1km and top end of 6k I'd say it's only around 1.2:1
I'd have thought the 68mm turbine ( T4 0.88 ) would have been worse than that, but quite pleased to see it isnt an issue at all
It isnt to say a larger turbine may not still perform better, I'd actually like to try, but I'm not going to spend any money to try.
I'd think going to your original choice of 6665 or thereabouts would still be a good call, or better if they're offering billet wheels ( not sure if they have a range of turbine wheels ? )
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From: Norn Iron
Spool is very subjective.
If I load the engine up in say 5th from 3000rpm, I can easily make decent boost by say 3500rpm.
But nobody would ever drive like that so largely irrelevant. For most part I can easily make 15psi by 4000rpm, lower gears with less load against the engine threshold would of course be higher, but car is accelerating hard anyway despite that so again no big deal
With your trans setup now, I'm sure under load you'd rarely be below 4k anyway ? So plenty of scope to shoot a bit bigger.
If I load the engine up in say 5th from 3000rpm, I can easily make decent boost by say 3500rpm.
But nobody would ever drive like that so largely irrelevant. For most part I can easily make 15psi by 4000rpm, lower gears with less load against the engine threshold would of course be higher, but car is accelerating hard anyway despite that so again no big deal
With your trans setup now, I'm sure under load you'd rarely be below 4k anyway ? So plenty of scope to shoot a bit bigger.
Here is some data that I came up with 2 years ago. The Garrett cores are far superior to the treadstone stuff.
Got results from the Garrett swap. Went from a Treadstone 25x9x3.5 to a Garrett 24.25x10x4.5. I used two garrett cores welded together part number 703521-6003.
Treadstone
17psi it gained 50* on a pull to 150mph
24psi it gained 80*
Garrett
18psi it gained 18*
26psi it gained 27*
31psi it gained 30*
Got results from the Garrett swap. Went from a Treadstone 25x9x3.5 to a Garrett 24.25x10x4.5. I used two garrett cores welded together part number 703521-6003.
Treadstone
17psi it gained 50* on a pull to 150mph
24psi it gained 80*
Garrett
18psi it gained 18*
26psi it gained 27*
31psi it gained 30*
Thanks for all the help guys. DB that's great data there. FF i agree.. im going with the 66/68'd and i found a really cheap A2W core that ZB uses. im going to modify it a bit and go A2W.. The car should be whole new animal when i'm done.
