Gts-4 Turbo Upgrade

[discopotato03]

Actually Garrett and HKS show the "2530" compressor specs as being 63 trim where the GT2860RS is actually 62 .

I once worked out the inducer sizes and looked at factory specs so really many trim sizes are rounded to a whole number .

Regardless the GT2860RS's compressor would be the pick of the bunch and from memory the exducer tips are wider than most/all in that wheel family .

Arguably the HKS turbine housing is best for a 0.64 A/R integral (internal) waste gate type and Garrett don't make a T3 flanged one .

It's possibly acceptable to reprofile an RB25 or VG30 OE BB turbine housing though on an RB20 I'd err towards the RB25 housing .

Sometimes as a mild upgrade people fit RB25 turbos to RB20's but you still have to be mindful of that ceramic turbine and not over speed it .

If you can find a T3 flanged 2530 its probably easiest , they can be rebuilt and the only unique bit is the comp wheel and the profile of the comp housing . If you got a shagged one cheap with an undamaged turbine housing a GT2860RS slots straight in because they use the same turbine wheel . Remember its the turbine housing thats the hard bit to find cheaply .

Options are endless , ask away .

Cheers A .

[SimonR32]

don't forget that even with a 2530 rb20's dont start pulling till after 4k... no matter what the turbo

your best bet is to get the biggest turbo that is capable of making 15psi between 4000-4500 and then winding plenty of boost into it!!!

after a fair bit of research (and wanting a cheap option) i have gone a hypergear atr28g3 with 0.63 rear and going to screw over 20psi in it :-)

[hypergear]

HKS2530s that we did overhaul on, few of them needed to have comp wheel replaced. The only comp wheel in 60mm that fit perfectly into its comp housing profile was a 60mm ex with 48.3mm in wheel. Worked out to be 64.8 Trim matching Garrett T3 3D-1 Comp wheel.

Except they only comes to suit 6.3 shaft which we had to sleeve it and re-drill them out in 6mm to suit the GTRS haft and have bottom of the comp wheel machined shorter to suit the T28BB bearing housing.

We've made .64 T28 turbine housings made with T3x flange and OEM dump pattern made so that’s not a issue.

RB20 is a smaller engine so turbo should be ok to hold 20psi with a 1.6KG actuator.

[discopotato03]

Yep the bore size and backspacing is usually the drama when fitting bush type compressors onto GT BB cartridges .

If you were a bit concerned about boost threshold there is another cartridge in that family that spec wise looks the same as a GT2860RS but its tip height/width is a little less so it may bring the bost threshold down a little .

There are some mobs around that can build up custom combinations and the generic GT28R would be a good example , all it needs is the std GT28 turbine exchanged for the high performance NS111 76T turbine and you get a 60 trim 60mm comp with the good lightweight low restriction turbine . Its basically what HKS have for the SR20 specific GTSS turbo , its a different spec to the GTR RB26 specific GTSS .

I had GCG build me a hybrid turbo from the smallest BB GT2554R , swapped in that nice NS111 turbine and fitted a reprofiled S15 turbine housing because I wanted the high temp spec material and the deflector vane at the turbines outlet . I'll see if I have a pics .

A .

Edited December 19, 2009 by discopotato03

[turbolag166]

go the HKS GT-RS, its good for 250rwkw with supporting mods, and heaps better response than all those other 500hp turbos your talking about, bolts straight up to standard manifold and dump too

[OMGGTR]

Ok with all the tech talk.... comes down to the question.. which turbo will give me 230-250 ALLWHEEL KW comfortably? on my rb20

[STATUS]

Hi guys,

Wanting to strap on some real horses because 158kw isent enough coming from my gts4 and most likely less, I'm Looking at 250awkw and I duno crap about turbos or prices so! i got a quote of $1600 for a ATR43G3 520HP turbocharger with high pressure actuator and braided oil feed line.

I'm looking for criticism and any ideas...input at all with regards to the turbo i got quoted with and if there is any beta options for my gts-4 thanks!

For 250awkw they work well, just remmeber it will need intake and cooler pipe mods (only small) i would buy it or a GT3071R which requires the same mods to fit. Stao was working on bolt up rear housings (i think) as the old versions were v band only. You want to limit boost to 18-19psi NO HIGHER

GT2530 will make 210rwkw on a stocker rb20 @ 17-18psi for more you will need some more work or boost, i have three cars come in reportedly making 220-235rwkw on rb20's and on my dyno they struggled to make 210, im not saying it cant be done but the results ive found require more than just bolting it on for a genuine 230rwkw.