GT2871R Intake Pipe - 3" or 2.5" - Which is preferred?

[Pepperoni]

As some of you know, i'm working on an aluminum intake pipe for the gt2871r, disco potato, etc. turbos. They come with a 3" inlet.

I've been trying to work with 3" piping to match the inlet. However, there's very little space to work with. I fabbed up a pipe where it won't touch anything at idle (or at least from what is heard) but during boost I think it's tapping on something.

I'm still working on it, but i'm wondering, for those of you with this/these turbos, do you really want a 3" intake? 2.5" would allow more room, but I don't know if the 0.5" makes that much of a difference on the dyno. I haven't personally seen any dyno charts comparing intakes sizes. I really want to minimize clearance issues, but I don't want to sacrifice performance by doing so... it's a toughie

Any opinions?

[fliprayzin240sx]

Well the inlets 3" and most people who run this turbo are running a Z32 MAF which is also 3". So 3" would be your best bet. Id buy it 3". Im actually looking for one.

[mjjstang]

3 inch for sure, plus id imagine it would cost more for 2.5 with all the converting.

[AllenRPS13]

if turbo, 3 inches for sure!

[fliprayzin240sx]

Pm me when your done with it and ill prolly buy one from you. Assuming that I dont sell my car by then. If you wanna make it easier on some people, sell it with the 3" couplings too since some of us are too lazy to go to home depot for couplings.

[Pepperoni]

actually it would be a bit cheaper for both me and the buyer for 2.5" but not by too much i think. And yes this will be a complete kit with couplers, clamps etc. any more opinions? thanks guys

[s13rymos]

Make a 3 in. intake pipe and ill prolly buy one.. I made my own but its kinda ghetto and would like a better looking/performing option.

[<^> ^_^ <^>]

i would also be interested in a 3 in pipe for the disco potato

[240trainee]

I have a friend with a GT2871r on his S13 SR, he is also running a Z32 maf. I have already told him about your intake pipes, and I think he is going to contact you about making a 3" one for him, lol. Then I saw this thread. so yea.

[decksy]

lol i was going to ask about the 3" from you also...i'm sure everyone wants the 3"... so when you have one fully fabbed, i'm down for one

[D1champ]

Yes, If you make it they will come.

[Nismo180]

if your getting a GT2871 .64 A/R you can get it with a T28 "style" T04B compressor housing. Then you just need the different angle intake elbow and you can run any stock intake kit you please, for example an Apexi super suction kit, like me :) Best of all looks like your still running the stock turbo.

[Pepperoni]

Thanks guys,

I have a few other projects coming along but these should be available in a few weeks after I get enough people to test fit these.

[fliprayzin240sx]

if your getting a GT2871 .64 A/R you can get it with a T28 "style" T04B compressor housing. Then you just need the different angle intake elbow and you can run any stock intake kit you please, for example an Apexi super suction kit, like me :) Best of all looks like your still running the stock turbo.

Umm...no intake will work with it. You gotta custom fab the piping for the intake since its such a tight fit between the turbo, powersteering pump and the reservoir. I had to put together some pipes that goes from the 3" Z maf down to 2.5 pipe, then back up to 3" and mate with the 3" compressor housing. With that 2.5 inch retriction, im pretty sure im loosing some HP cuz of it. 3" would alleviate that issue for sure. People dont need or want 2.5" so why make it? Make the 3" since alot of us need and are looking for it. Just make sure the elbow bend from the turbo inlet will clear the power steering and have enough room to play with when the engine torques to the side.

[Pepperoni]

Ok, intake coming out probably next week.

It will consist of a silicone coupler elbow for more clearance of power steering, aluminum intake pipe, silicone coupler for MAFS, and clamps. All 3". Would any of you be interested in upgrading to t-bolt clamps? Not sure if i want to add in this option since it will increase the price significantly. It will be a bit more expensive than my current t25/t28 intakes mostly because of the size of everything.

I'll also add options for BOV and catch can bungs.

Anyone got any last minute suggestions?