Turbo questions.....
 

1: Does anyone know which Garrett turbo is used in the Protomotive 3.2 set-up? I believe it's a T04, but I was curious as to trim. Compressor and Turbine A/R? Or the Garrett Part Number.

2: During some surfing I found that tuners are using the APC knock sensing system off the Saab turbo. They are fitting them in aftermarket turbo installations to engines with no knock sensing capability. Has anyone considered using this in a 911 turbo project?

As always any insight is appreciated.

APC knock sensing system.... http://hjem.get2net.dk/bengaard/apc-syst.htm

I wouldn't use it. I've been fiddling with APC a lot, and it's electro-acoustic system that listen's for knock with piezo-microphone.

I believe that (i cannot say "our" anymore as i sold my 930) aircooled 911 engines are too noisy for this kind of setup, generating lot's of false-alarms. Of course, it's not dangerous to try :-)

Goran, Do the newer 911 turbo appliations use any type of knock sensor?

I had the same question so I asked. Here is the reply I got:

" We use the 60-1 in a T04B on a P trim wheel, then vary the a/r of the turbine housing for either Stage 1,2 or 3 from a .58 to a .84. The Stage 1 get's the .58 for good low speed response, but it kills the power on a Stage 3, so the Stage 3 get's the .84. But this way, we don't have to keep selling new turbo's every time you want to upgrade.
The 60-1 is one of the most flexible compressors in the T04B family and has the best surge line. So, surprisingly, even though it's larger than the V series, etc. It actually can make better boost and more efficiency throughout the range.

Boost onset is approx. 16-1800 rpm's with .5 bar at 26-2800
rpm's."

I in the process of buying parts to turbocharge my 1978SC. I've picked up a T04B turbo with a V1/V2 trim compressor with a "P" trim turbine with a 0.69 hot A/R. My current project is CIS-to-EFI. This will give me the flexibility I will need with the turbo.

Tony, Thanks for the info. May I ask where you picked up the turbo. If I do stage 2 by adding an intercooler would I go to .60?
Thanks again. Rick

I picked it up on ebay. It needs a rebuild, bearings, etc, but I got a good deal on it $80US. You can get new turbos for around $400US on ebay. You just have to know what your looking for and be willing to wait for it to come up. The other problem is a lot of folks don't know what the trim is. I usually ask for dimensions of the compressor impeller to determine the trim.

Not sure what your asking about 0.6? If you have questions about Protomotive turbos, just ask Todd Knighton of Protomotive. He is very friendly and always willing to answer questions.

Thanks again Tony. If you don't mind I have a couple more questions.

<qoute><b>We use the 60-1 in a T04B</quote></b>

Do you know what the 60-1 means? Is this the compressor A/R?

Also, is it easy for the seller of a turbo to determine the dimensions of the compresser impeller? I've been looking on ebay...some P trim models but with a Tang divided turbine housing.

Rick

60-1 is the compressor trim for the T04B.

You can find dimensions for all the trims here:

http://www.bsmotor.com/turbo/tabell.html

If you click on the blue text you'll get the compressor map for that trim. If you get the ebay seller to measure *accurately* the "inducer" and "exducer" diameters of the compressor impeller, you can then determine the compressor trim by looking at the table.

Also note the "P" trim turbine diameters at the bottom. The turbo I got uses the "On-center" housing.

Lots of other useful info here:

http://www.turbofast.com.au/turbomap.html
http://64.225.76.178/catalog/Default.htm
http://www.bsmotor.com/?id=turbo/kalkuler.html

T04 w a Tial Co. 35mm billet wastegate from Slowboyracing.com and supplemental enrichment beginnning at 3lbs over.