GT28RS what ar to pick .86 or .64

[Grambos13]

You red the title. I have a redtop w/600cc in injectors/z32 mafs/greddy front mount.... in the end I want a 300whp track car/drift car. What do you guys think?

[Grambos13]

the ar I am talking about is on the turbine side .64 or .86

The reason I ask is I just got one for a good deal and the AR is 0.60 on the compressor and 0.86 on the turbine.

[DawgMode]

.86 for crazy topend...but laggy.64 will spool quicker for good low end

[Grambos13]

Thanks. Is there any way to change it? or do you have to get a completely different shaft/wheel/housing?

[Nicksemianiw]

You can add some things onto your car to reduce the lag for the .84 A/R i dont see a problem with the .64 A/R though. You can add a catback exhaust,test pipe,down pipe,turbo elbow,turbo manifold,hotpipe,smoother flowing intake and get some nice tuning done and that can lower the lag considerabully, because the smoother the flow and bigger piping will reduce back preasure which will help your turbo spool faster. And if you want a big differenct go with a smaller i/c core a 12x9x2.5 if you dont want that much power then that would be good. will all of that you would notice a big differenct in the lag.

[Grambos13]

Good deal...I'm just gonna go ahead and use it then. I allready have all the stuff you are talking about besides the smaller ic but I want to keep my greddy. The only thing I do not have yet is a good boost controller. Can you adjust a electronic boost controller to make it hold the wastegate shut in the lower rpms then have it back off when it gets up to full boost speed?

[PhoenixTurboEric]

IMO, i would go with the .86 a/r just so you dont limit the flow of your turbo, remember people always want more power!
Modified by PhoenixTurboEric at 9:07 PM 5/21/2005

[Grambos13]

It just came in the mail today it is the .85 ar. Do I need any type of oil restrictor? I am using my stock t25 lines that I was using on my previous t28

[PhoenixTurboEric]

It just came in the mail today it is the .85 ar. Do I need any type of oil restrictor? I am using my stock t25 lines that I was using on my previous t28

No need for the restrictor

[s13sr20chris]

whoa, whoa, whoa...the .86 is laggy? maybe on a turbo with a big compressor. check the specs on the gt28rs. it has a little compressor(a good one though). i would never ever get the gt28rs in .64. you have to special order it from most places because they only stock the .86.gt2871r, whole nother story. that is a compressor wheel over 10mm bigger.

[Grambos13]

Thanks for clearing that up. I'm glad I got the .86. I'll let you guys know how it works out for me after I get it running tomorrow. All I have left to do is fab up a new peice of intake tubing for my air filter and I should be good to go