Thread: Thinking about upgrading the turbo on RR

As some of you may now (from the old sr forum), I have a 00 G20 that has these mods :

Here is my site by the way: http://www.koojo.net/

• W10 T25 (Avenir Manifold)
• Walbro 255
• 400cc injectors (I already bought 55 lb/hr injectors, just have to install them)
• Greddy Type S BOV
• TurboXS dual boost controller
• 2.5" mandrel bent exhaust and 3" muffler
• Currently have the SAFCII but I already bought the Greddy Emanage Ultimate and will be installing it in about a month when it warms up.
• Spearco intercooler with 2" inlet/outlet and 2" IC piping all the way around.
• Wideband

I'm thinking about upgrading to the GT28RS disco potato, because I want some more power, and want a turbo that can has little lag (I drive mainly in the city and want power in the lower RPM band rather than having to beat the Sh*t out of car just to get it to move). I've seen other G20 cars run the same turbo, but the ones I've seen have been on a 99 G20, which is non RR. I want to figure out roughly the amount of money I would need to spend to upgrade safetly, and if it's even worth it.

I would have to get the GTiR manifold, correct? Could I stick with the Avenir manifold with the GT28RS? I already have the current manifold drilled for the EGT gauge so it would be a lot easier to just use the one I have. Also, the other thing I'm concerned about is the IC piping. 2" is fine for a T25, but what about with the bigger turbo? Has anyone tried? Also, I believe with the way the GT28RS fits, I'd have to chop off a part of my front motor mount and shave off a bit of the block.

BTW, the GT28RS comes clocked downward, right? My W10 T25 is clocked down, and I want the same thing, since it will be easier to route the IC pipes the way I currently have them routed. Could I use an internal wastegate with that turbo (does it even come with one), or external?

Are there any other turbo's you guys want to recommend other than the GT28RS? I've just heard such good things about this one.
Any help would be appreciated, thank you!

Personally, having had a GT28RS on a RR motor, I would go with the GT2871R. I believe you can use the avenir manifold, but doesn't it hit the block and need to be shaved (the block) down a bit for clearance?

Not that I endorse them, but the JGY version of the GTiR manifold sits out a bit further than the regular GTiR manifold (something to keep in mind, and not very expensive).

I also had the MSD 50lb injectors and loved it. Now, you do realize that the RR pistons are thin for emissions, thus, before upgrading, it would be in ur best interest to get DE or DET pistons, who cares, as long as they are not RR pistons!

Those are the most important things I can think of.

Do you mean that the RR won't hold up under boost of the GT28R or RS? If I'm only going for about 300whp, I don't think I need to upgrade my pistons if I run 93 octane gas.

The pistons suck, it's not really how much they hold, but how long they last under repeated 200+whp applications. I'm not the only person to break off that top ringland. My car was due to bad tuning (Thanks JGY) and detonation.

Ask psushoe on the other forum or b15sentra.net.

My car ran about 7 lbs of boost daily for about 16k miles. psushoe used the gt2871 made more whp (~250whp daily I believe) and ran much better afr than me and broke the piston at ~15k miles.

Its all in the tune.

I am at 26+k miles now. ~10k miles on one t25 then it started leaking a little oil, another 15k miles on another t25, and now over 1k miles on 3071r. I ran the t25s at 14psi all the time except maybe the first 3k miles which I ran it at 10-11psi. And I run the 3071r split 50/50 between 11psi and 14psi.

Not that I don't recommend upgrading the pistons, but with a good tune RR pistons are fine. It takes detonation to damage a piston.

can i ask what fuel and ignition managment are you runing? do you have some knock monitoring?

Nothing special. Most of it was stock ecu with emanage blue. Just had conservative timing map and good afr.

Now I'm running calum B14 ecu which is alot better IMO.

IMO you shouldn't have to rely on monitoring knock.

Ya especially the stock knock sensor...which is very inaccurate as engine temps start to rise

If I get the JGY Manifold or a GTiR manifold, would my current downpipe match up with the new manifold? I know that the jgy's mani moves the turbo a bit, so I'm not sure if this will have any affects with the way the downpipe sits with the jpipe.

http://www.sr20-forum.com/showthread.php?t=4541

Guess what?! RMYC is selling his JGY GTI-R manifold, that puts the turbine in the stock GTI-R location. Snatch it up!