Garrett T51r Vs Garrett Gt4202(r)

[KISIN]

what is the difference between these two turbos ? I thought they were the same, yet i can see both being sold under those names with a different price tag ?

[The Mafia]

I don't know much about them but I can tell you that HKS like to make improvements with housings etc.

[sleeper7]

HKS almost always uses Garrett turbo housings then change the bearings, fins ect. The T51R is a hyped up version of the garrett equivelent ( as u could prob judge from the price difference ).

[datsqik]

The Garrett t51r (spl) is basically the same as the hks t51spl. The gt4202 is a different turbo, basically has a gt42 turbine wheel and a 74/102mm comp wheel. Garrett also sell another turbo sometimes called a gt4502 which is the t51 spl, uses an old style ta45/51 turbine wheel (not the gt45 turbine as used in like the gt4508) and a 76/102mm comp wheel like the hks t51spl.

I recently bought in a few borgwarner turbos around the same size and bigger. These are cheap and strong with a good range of comp/turbine wheels.

[shanef]

The Garrett t51r (spl) is basically the same as the hks t51spl. The gt4202 is a different turbo, basically has a gt42 turbine wheel and a 74/102mm comp wheel. Garrett also sell another turbo sometimes called a gt4502 which is the t51 spl, uses an old style ta45/51 turbine wheel (not the gt45 turbine as used in like the gt4508) and a 76/102mm comp wheel like the hks t51spl.

I recently bought in a few borgwarner turbos around the same size and bigger. These are cheap and strong with a good range of comp/turbine wheels.

ive been starting to see a few results using the borg warner turbo's. from all reports though they love BIG boost 2.5bar+

[discopotato03]

Its all Garrett stuff cartrige wise but the T51R is a large frame BB version using the 11 blade T51 76T turbine .

The GT4202R uses an 84mm GT42 turbine .

Often you'll find the old T series turbines like the T04P and T51 are in 76 trim size where the GT series turbines tend to be more like 84T .

I used to have some pics of a T51 and if I can find them I'll post them .

[discopotato03]

Sorry about that , I haven't posted any pics for a while and a bit rusty .

Anyhow as you can see the turbine is not a GT type and that particular turbo from memory is a bush bearing one , the give away is generally the lack of water coolant holes .

The HKS housings are very different to a GT42R as you can see by the V band turbine housing fittings . The comp cover looks like a one off and similar in some ways to their T04Z housing - minus the glitzy drilled ported shroud . You would have to look down the air outlet to see if they've enlarged its diffuser section .

Cheers A .

Edited February 14, 2008 by discopotato03

[datsqik]

Hers a pic of the b/w 76mm comp wheel in the background.

[datsqik]

T04r/z v bw76 v bw80

[The Mafia]

ahh, I love port shrouded compressor covers..

They sound soooo damn good when pulling in 20+psi of boost..

[KISIN]

interesting.

Well i guess the next question is, which is better, as both t51r and gt4202 are capable of 1000hp ? Assuming they are used on the same setup, which would be more efficient ?

Is there any other differences in the 4202 and 4202R other then 1 is non BB other is ?

Im interested to contact someone who had these turbos on an RB30DET to see how they behave, but im having trouble contacting such people...can anyone help me out ? From what ive seen a couple of the 31's had this (SLO 031 and JET R31 from memory?) Would be nice to see their dyno sheets !

[datsqik]

The t51 can flow more than the gt4202

[discopotato03]

Well the theory is that T series turbines are not really up there with GT ones but in this case I think the T51's were probably available from Garrett/HKS before the GT4202R went on sale .

Garretts larger frame ball bearing cartridge seems to be an evolution of the large frame GT bush/plate bearing type centre section , I've only been inside the GT plain bearing type and I suspect that the shaft dimensions and compressor backspacing is the same so that they can both use the same wheels and housings . Makes economic sense and its handy to be able to use a direct fit BB cartridge in place of a plain bearing one if required .

Garrett usually fits truck type compressor and turbine housings where HKS often do specials to suit petrol performance type applications . If you have a look in the turbobygarrett site they have comp and turbine maps for the GT4294R and GT4202R .

ATM places like Forced Performance in the US are cooking up hybrids using Garrett cartridges with alternate compressors in an effort to get better spool for little or no peak power losses . Their HTA35R is one example of this .

Also BTW turbo manufacturers like Borg Warner seem to really push twin scroll turbos but without BB cartridges - they also seem to like 7/14 blade compressor wheels .

I go to lots of sites in the US and the drag race fraternity in Honda's and Evo's etc tend to stay from HKS spec turbos I suppose for cost reasons . They at times use GT42R's and I don't remember ATM if they get 1000 horses out of them or something else .

One problem you will get with really big turbos is huge housings and they get hard to package . This could be a case where twins may be a little easier to fit in because a 500 odd hp turbo is considerably smaller in diameter housing wise . I'm sure I remember seeing pics of Japanese GTR drag cars with twin GT3037's and twin GT3240's .

Cheers A .

Edited February 14, 2008 by discopotato03