ProtoCab

Hooray, I'm about to order my GT35R BB Turbo and was wondering what size oil feed line I need.

ATPTurbo tells me that a -3AN (no restrictor) oil feed line will do the trick, or -4AN with a restrictor.

I already have a -3AN SS line with 10mm banjo on one end (to mate with dummy oil press switch) and a 90 degree NPT fitting on the other end, for the oil inlet to the turbo.

Will this be sufficient? I'm told the GT's don't require a lot of oiling, like the KKK's do.

DonE

I use a -4 in the same manner you mention. However, I have a high volume scavange pump which is what Garrett told me I must have. They recommended this since I am not cooling the core with water or oil - it moves a lot of oil and with oil temps in the 180 - 190 range, it's done very well so far. With the BB, I can shut the car off, go inside to get a coke, come back out to the car and the turbo is still spinning down.

underpsi

I also want to get a gt35 bb, how is the spool compare to the K27? When does boost begin and when do you get full boost?? Do you really get significantly more torque at 3k compare to k27? thanks.

ProtoCab

Thanks DonE. Are you using an electric oil scavenge pump, like the Turbowerx or Westech units? I'm thinking of using one of those pumps. They move a LOT of oil!

See http://turbowerx.com/page1/page2/page2.html

underpsi, from what I've been told by another enthusiast who's using a GT35R, he reaches FULL boost at around 2700-2900 RPM's, so torque comes on earlier in the RPM band and the turbo's compressor is very efficient as it uses the latest technology GT wheels etc. You can't go wrong with the GT's.

I want as much improved spool as I can get from a turbo, since I'm restricted to using a OEM Euro Muffler (EPA regulations). I don't want to get busted AGAIN with a loud aftermarket exhaust and be fined up to $6.5k

The GT35R with Schnell headers should be a significant improvement over my existing HE, J-Pipe, K27 setup

DonE

I use the billet high capacity pump that I bought from Turbo Performance in MD.

ngoldrich

FWIW -

When dealing with the turbo longevity issues on my GT2 racecar, I finally dealt directly with one of the Garret turbo design engineers. I was running a -3 and he said that was wayyyy too much oil for their ball bearing turbos.

He recommended a tiny machined restrictor like 1/16" if memory serves; but clarify that before you do it.

He said supplying as much oil as I am is part of the cause for the end seals being destroyed on the ball bearing cartridge.

I still have not done the restrictor, but I did add oil lines to run through the cooling jackets as he recommended.

That helped a lot. Instead of replacing both turbos every 4 hours of race time, they now last 4 race weekends which is about 12 hours...

He told me if I do the restrictor they will last all season..

Again, that is just info from a Garret engineer; I have not yet tried it, but I will - once I reconfirm the restrictor size...

I have his contact info in the office (I am at the Nurburgring right now for my quarterly trip :-)


PS - I do have a huge billet scavenge pump setup...

Norm