rm2932
Probationary Member
- 8
- 0
- Dec 22, 2002
-
New Berlin,
I was doing some turbo research and I came across a Garrett turbo engineer (Rob Cadle) talking about the disadvantanges of the 60-1 compressor wheel. So I thought I would pass the word on. Here you go:
I don't know why anyone would run a 60-1 on a small-displacement high-boost engine. Many of the maps that Turbonetics has on the web site are bogus. However, most of them originally came from Garrett, and if they have not been doctored by Turbonetics, then they are pretty accurate. The map for the 60-1 that is on their website:
http://www.turboneticsinc.com/comp_maps/fig9.html
is an accurate map, but notice that none of the efficiency contours are labeled. That peak efficiency contour is about 74%, and look at how low a boost pressure it peaks at: less than 14 psi. By the time you are running 23-24 psi of boost (2.7 or so pressure ratio), you are in the mid-60's for compressor efficiency PEAK. Low efficiency means more power-robbing detonation producing backpressure and reversion.
The 60-1 does flow a lot. It flows more than the 60 trim T-04E, as Louis said. The T04E flows about 50 lbs/min versus 60 lb/min for the 60-1. However, lets look at what you have to do to flow that much.
An SR20 running 26 psi of boost, turning 7500 RPM with a 120 degree F intake manifold temperture will flow about 50 lbs/minute at 100% volumetric efficiency, which you will not achieve. At the 90% or so VE that is obtainable with headwork, cams, etc, you are talking about 45 lb/min. In order to flow 60 lbs/min you will have to run 39 psi (3.7:1 pressure ratio) at 120 degree F intake manifold temp. Even with an ice water/air charge air cooler, you will have to run 35+ psi of boost to get that kind of air flow into an SR20, at which point you'll be blowing head gaskets left and right unless you do a lot of work.
The only way you'll get that kind of airflow is through revs, and very high VE. To get high VE, you'll have to run in crossover, and that will take very high overall turbocharger efficiency, which you won't get with a 60-1.
I'm not saying it isn't possible to make good power with this turbo. But, you have to get out of the 'follow-the-leader' me-too habit of doing what someone else does just because he turns a fast ET. If the guy running the 60-1 would listen to what I say, his car would be faster. Period.
Rob Cadle
91 SE-R
I don't know why anyone would run a 60-1 on a small-displacement high-boost engine. Many of the maps that Turbonetics has on the web site are bogus. However, most of them originally came from Garrett, and if they have not been doctored by Turbonetics, then they are pretty accurate. The map for the 60-1 that is on their website:
http://www.turboneticsinc.com/comp_maps/fig9.html
is an accurate map, but notice that none of the efficiency contours are labeled. That peak efficiency contour is about 74%, and look at how low a boost pressure it peaks at: less than 14 psi. By the time you are running 23-24 psi of boost (2.7 or so pressure ratio), you are in the mid-60's for compressor efficiency PEAK. Low efficiency means more power-robbing detonation producing backpressure and reversion.
The 60-1 does flow a lot. It flows more than the 60 trim T-04E, as Louis said. The T04E flows about 50 lbs/min versus 60 lb/min for the 60-1. However, lets look at what you have to do to flow that much.
An SR20 running 26 psi of boost, turning 7500 RPM with a 120 degree F intake manifold temperture will flow about 50 lbs/minute at 100% volumetric efficiency, which you will not achieve. At the 90% or so VE that is obtainable with headwork, cams, etc, you are talking about 45 lb/min. In order to flow 60 lbs/min you will have to run 39 psi (3.7:1 pressure ratio) at 120 degree F intake manifold temp. Even with an ice water/air charge air cooler, you will have to run 35+ psi of boost to get that kind of air flow into an SR20, at which point you'll be blowing head gaskets left and right unless you do a lot of work.
The only way you'll get that kind of airflow is through revs, and very high VE. To get high VE, you'll have to run in crossover, and that will take very high overall turbocharger efficiency, which you won't get with a 60-1.
I'm not saying it isn't possible to make good power with this turbo. But, you have to get out of the 'follow-the-leader' me-too habit of doing what someone else does just because he turns a fast ET. If the guy running the 60-1 would listen to what I say, his car would be faster. Period.
Rob Cadle
91 SE-R
talk doesnt hold up in the real world. There are so many people making HUGE power on a 60-1 that its not even funny.
not boost levels..
