Thread: t2 flanged 2871r or 3071r??

Ok, guys I need to make a decision here. I was planning on buying a gt2871r, but have now been thinking about a gt3071r. The only issue here is I am sticking with my t2 flanged gti-r manifold, so I know alot of people suggest a t3 flange when running anything over the gt2871r. I am looking for a daily driven 350whp and i know a 28 will give me that, but at a higher psi then a 30 would. I also know that the 30 will give me more topend and a little more lag then the 28, but maybe that is better for both the street and track??

People with experience on both please help me make this decision. I also am assuming I will be using a .86 a/r on both turbos too.

thanks

btw I have a stock gti-r block.

I run the gt28rs and make 342whp at 15psi. I like the gt2871r but have been looking at the t2 based gt3071r. If they are the same price I would take the gt3071r with a .86 turbine housing. The gt2871r is not worth in my mind. I jumped from a s15 bb t28 to the gt28rs. If I were to upgrade the 3071r would be my choice especially in a t2 housing. Also a gtbb37 would be a great choice. I would strongly recommend going external gate with a large t2 based turbo.

Now i currently have a gt28r and want to upgrade and thats why i am now thinking about the 3071r because I don't think the 2871r is a big upgrade over the 28r. I mean I know the 2871r can make 400whp if really pushed, but I am thinking with a 3071 i won't have to run as much of a psi to make 400.....?????

your in the same spot I was in I had a choice between the gt28rs and a gt2871r both were the same price. The problem was the gt2871r had just come out and not much was know about it. I also did not want 20psi on my 9:5:1 motor. I have been looking at the 3071r for myself since a gt2871r does not make much more power over what I have. the 3071r shouldmake more power at a lower psi. I tuned a gti-r motor that made 300whp and 300lbft on the stock turbo setup at 17psi. the only thing that was chaged was the ic was relocated to be a front mount.

I just couldn't see myself installing a GT30xx with a T2 flange. Not sure if that helps you any though... =(

if its externally gated whats the difference. Most of the issues of running a big t2 based turbo is the turbulence caused by the waste gate and the turbine dumping in the same small space. I picked up 40whp just by going external gate and alot more control over boost. Not that I don't like bigger turbos (sc6262:bigthumbup

All else being equal, a T3 flange is intrinsically less restrictive, and promotes more laminar flow (important post-collector). I know it all goes to the same place and to the same size hole in the end (turbine blade), but how it gets there matters too.

i am a big hater of the t2 .86 gt3071 as i have mentioned before

3071 ftw

personally i think you will be very pleased if you run with it

^I agree. If you go this route, there should not be a "what if" in the turbo game because you chose the bigger of the two. I have not personally ran either, but I would go with the 3071 for your personal case.