Divided turbine housings..
08-14-2012, 10:47 PM
#31
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My recollection is that Duke did it more as an experiment and established that they are too laggy on a 2.5 road car. Personally I don't think 3500rpm is that bad. Many other modded cars would love it that early....although they rev to 8000rpm lol...I think having a slightly laggy turbo is often quite intoxicating and that's why people like to keep them. I remember when you were first shopping for your turbo we spoke about housing sizes and you were going to get the .63 but you say that they didn't have them in stock. Personally I am with the others in saying that you should try the .63 before you contemplate going to a twin scroll.
08-15-2012, 04:34 AM
#32
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My recollection is that Duke did it more as an experiment and established that they are too laggy on a 2.5 road car. Personally I don't think 3500rpm is that bad. Many other modded cars would love it that early....although they rev to 8000rpm lol...I think having a slightly laggy turbo is often quite intoxicating and that's why people like to keep them. I remember when you were first shopping for your turbo we spoke about housing sizes and you were going to get the .63 but you say that they didn't have them in stock. Personally I am with the others in saying that you should try the .63 before you contemplate going to a twin scroll.
IMO the .82, it's not really laggy, i've gotten 15-17 psi at 3200 -3300 rpm in 5th gear.
But you're right i was looking for a .63 but no one had any in stock so i didn't have much of a choice to either wait it out (no word of how long) or go .82 so i did.
Before i do anything i'll need to get it on a dyno to see the torque curve.
08-15-2012, 04:54 AM
#33
Nordschleife Master
Yes the 3582 is larger than the 3076 but in terms of spool it is not apples to oranges.
I know I posted spool rpm's on the past and IIRC it didn't look too bad. Around 3400 rpm for 1 bar. But it's a very poor way of determining if a turbo feel sluggish or not as the transiet response is much more important.
Here's the turbo at 1.4 bar on the 2.5l 8v
I know I posted spool rpm's on the past and IIRC it didn't look too bad. Around 3400 rpm for 1 bar. But it's a very poor way of determining if a turbo feel sluggish or not as the transiet response is much more important.
Here's the turbo at 1.4 bar on the 2.5l 8v
08-15-2012, 05:23 AM
#34
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Yes the 3582 is larger than the 3076 but in terms of spool it is not apples to oranges.
I know I posted spool rpm's on the past and IIRC it didn't look too bad. Around 3400 rpm for 1 bar. But it's a very poor way of determining if a turbo feel sluggish or not as the transiet response is much more important.
Here's the turbo at 1.4 bar on the 2.5l 8v
I know I posted spool rpm's on the past and IIRC it didn't look too bad. Around 3400 rpm for 1 bar. But it's a very poor way of determining if a turbo feel sluggish or not as the transiet response is much more important.
Here's the turbo at 1.4 bar on the 2.5l 8v
you've got a good point about the response being more important to how the turbo feels.
I can say that for the size of the turbo, it's pretty good on the response side. i know the .63 would be a lot better.
08-20-2012, 06:41 AM
#35
Considering our different engine sizes, you are probably and proportionally running more ignition, on the way to 3500 rpm, than I do.
But then better spool doesn't mean the engine makes more torque...
The sweet spot is difficult to find, and if I get the same spool as you but with a bigger engine then it means you may be very well close already. Just get the 0.63 housing.
But then better spool doesn't mean the engine makes more torque...
The sweet spot is difficult to find, and if I get the same spool as you but with a bigger engine then it means you may be very well close already. Just get the 0.63 housing.
Last edited by Thom; 09-06-2012 at 09:10 AM.
08-20-2012, 07:12 AM
#36
Nordschleife Master
That is a very good point. Spool levels doesn't really say anything about power or acceleration. Especially if comparing different engine configurations.
Plus the fact that the slower the acceleration - the more time available for the turbo to spool up.
To make an extreme example, the cars accelerating 100-200 km/h in less then 6 sec accelerate so quick so that even a quick spooling turbo would spool late in the rpm range in low gears since the available time window is so short.
Plus the fact that the slower the acceleration - the more time available for the turbo to spool up.
To make an extreme example, the cars accelerating 100-200 km/h in less then 6 sec accelerate so quick so that even a quick spooling turbo would spool late in the rpm range in low gears since the available time window is so short.
08-20-2012, 01:05 PM
#37
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Pauly, I think the important thing to take into consideration here, is that you are not limiting your current horsepower, or even room to move up, by going with the .63. You will only GAIN average horsepower and have the same max power you always wanted / have. It's just a win situation.
