Shifter23 Posted March 12, 2010 Report Share Posted March 12, 2010 Just starting a thread and seeing what people have studied or even used on upgrading their TGPs. Stock crossovers and downpipes are not a limitation to input here either. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted March 12, 2010 Report Share Posted March 12, 2010 All I want is a GT2871R Then Ill be a happy guy Quote Link to comment Share on other sites More sharing options...
Shifter23 Posted March 13, 2010 Author Report Share Posted March 13, 2010 True that would be nice! But what about the idea altering so you can run a more common line with more options? I have been pondering if I can come up with a crossover/down pipe set-up that can be a kind of conversion kit for us TGP folk. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted March 13, 2010 Report Share Posted March 13, 2010 Anything is possible with a welder... I want a 3" downpipe but Im not sure if Ill really gain that much from it. Probably just a faster spool but thats not a problem with a t25 Quote Link to comment Share on other sites More sharing options...
Shifter23 Posted March 13, 2010 Author Report Share Posted March 13, 2010 This is true. I have a T28 hybrid already and and going to experiment with a T3/T4 set-up next and see how it goes. With the larger set-up a 3" down pipe would be ideal I think. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted March 13, 2010 Report Share Posted March 13, 2010 you can kind of funnel it out an start with 2" to 2.25" to 2.5" to 3". jump up one size on each bend. there is an article on this topic by an engineer from garrett who recommends doing it this way. I am still working on my 3" dp for my gt2871r and it starts off with a 2" mb ss 30 degree bend on a 3/4" t-25/28 flange. at the outlet of the turbine the pipe only really needs to be a little wider than the diameter of the exposed turbine. then you can funnel it out anywhere from 7 to 14 inches downstream and be fine. Quote Link to comment Share on other sites More sharing options...
Shifter23 Posted March 14, 2010 Author Report Share Posted March 14, 2010 Interesting... Is that to regulate at least a minor sense of back pressure? No back pressure would be horrible but that suggestion is very logical. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted March 14, 2010 Report Share Posted March 14, 2010 I guess backpressure is not needed with a turbo, but its still good to have it funneled out to a big exhaust. the stock exhaust is pretty small already but as we know it is still pretty good and decent power can be made. 2" mandrel bend on that first bend is still going to be bigger than the stock dp. Quote Link to comment Share on other sites More sharing options...
GhrarhG Posted March 26, 2010 Report Share Posted March 26, 2010 I had a 3" DP on my T25, there's a few flanges for the t25 shape that allow a crushed 3" pipe to fit. It's this style of flange: with essentially this pipe: I just used a 3" mandrel bend and a vice because of the master cylinder location, but you get the idea. You could even use something like this: But clearance around things may be tight. Back pressure is not needed after the turbo. The engine sees plenty, if not too much back pressure from the turbo, so there's no worries there. Any backpressure after the turbo essentially lessens the work done by the turbo, decreasing efficiency. I'm in the process of building a T3 setup. I have a strange setup so I'm not sure if I would have gone the same route with a TGP, but for my 3x00 hybrid 2.8 it turned out that the best T3 turbo for me was a GT3271. If I had the extra displacement, I could probably have run a T3/T04e 50 trim, but I was pushing too close to the surge line with a 2.8. At any rate, I will be fabbing a T3 crossover to TGP manifolds shortly (As soon as parts arrive). I'll probably post progress either here or on TGP forums as it happens. FWIW a GT2871r would have been a great upgrade too, but too $$$ for me. Plus I needed to fab a new x-over anyway because stock turbo location was giving me trouble with my 3400 top swap tb location, and completely prevented me from running the 3500 UIM with LX5 tb. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted March 26, 2010 Report Share Posted March 26, 2010 after reading this I may just throw my GT2871R on one of my TGPs and just fab up another DP and crossover then for my 88 when I turbo it. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted March 27, 2010 Report Share Posted March 27, 2010 You wanna sell it instead? Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted March 27, 2010 Report Share Posted March 27, 2010 no I haven't even had a chance to try it out yet. Quote Link to comment Share on other sites More sharing options...
94GPGTP Posted March 28, 2010 Report Share Posted March 28, 2010 I had a 3" DP on my T25, there's a few flanges for the t25 shape that allow a crushed 3" pipe to fit. It's this style of flange: with essentially this pipe: I just used a 3" mandrel bend and a vice because of the master cylinder location, but you get the idea. You could even use something like this: But clearance around things may be tight. Back pressure is not needed after the turbo. The engine sees plenty, if not too much back pressure from the turbo, so there's no worries there. Any backpressure after the turbo essentially lessens the work done by the turbo, decreasing efficiency. I'm in the process of building a T3 setup. I have a strange setup so I'm not sure if I would have gone the same route with a TGP, but for my 3x00 hybrid 2.8 it turned out that the best T3 turbo for me was a GT3271. If I had the extra displacement, I could probably have run a T3/T04e 50 trim, but I was pushing too close to the surge line with a 2.8. At any rate, I will be fabbing a T3 crossover to TGP manifolds shortly (As soon as parts arrive). I'll probably post progress either here or on TGP forums as it happens. FWIW a GT2871r would have been a great upgrade too, but too $$$ for me. Plus I needed to fab a new x-over anyway because stock turbo location was giving me trouble with my 3400 top swap tb location, and completely prevented me from running the 3500 UIM with LX5 tb. Where can these flanges be purchased? also the 3" pipe adapter thing.. lol I would like to make a DP for my car and thats a nicee flange.. better than what i have seen Quote Link to comment Share on other sites More sharing options...
Shifter23 Posted March 28, 2010 Author Report Share Posted March 28, 2010 This is what I was trying to do with this thread. Hopefully even more input can be obtained. Quote Link to comment Share on other sites More sharing options...
GhrarhG Posted March 31, 2010 Report Share Posted March 31, 2010 The two flanges can be bought from a variety of vendors online. I can't remember where I got mine personally, but I know ATP turbo has them, though their prices may be high. http://www.atpturbo.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=ATP-FLS1 As far as the transition pipe, I'd go with the 3" pipe in a vice method. That's what i did, and it's very cheap. Hammering it to be reasonably round takes some time, but overall not hard at all. They do exist pre-made, but again just check the internet, i'm sure lots of vendors have them. Edit: ATP has that transition too bottom of the page: http://www.atpturbo.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=ATP-FLS2 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.