Td06-20g Sized Garrett Equivelant For Rb24

[kwazza11]

what you suggest by the gt30 turbine up the guts of the 2871r is basically creating a gt3071 52t right? i'm not worried about retaining the standard looking covers, all piping and manifold will be redone so no need to. was hoping i could get the 4" inlet and 2" outlet compressor cover in 52 trim but not too sure whether its available.

i'll be using the gt28 53mm rear wheel and a bored out rb25det turbine housing, i thought about the 3071r but wouldnt the small .63 ar rear choke the top end?

plus theres the whole saving $500 on buying a new garrett turbine housing...

[discopotato03]

Not really because a .63 AR GT30 housing is considerably larger than a .63 AR GT28 housing would be if it existed - closest in GT28 is .64 AR . When you go up a family in turbines ie GT28 to GT30 the matching family of housing is also larger overall - internally and externally .

Remember that a GT3071R is using a 71mm compressor rather than the higher pumping capacity 76mm wheels that GT30xx turbos usually have , so this means that the smaller AR housing (for a GT30 turbine) combination stays in sync with the compressor/housing flow wise .

I can't speak for Brett but if you buy a hybrid turbo from them this generally means you buy one turbochargers worth of parts so no unused bits to pay for , you should confirm this with him though .

Lastly you are not stuck with that Nissan/Garrett compressor cover either as you could option a .60AR TO4B truck style cover or even a 50AR TO4E cover and backplate .

Cheers A .

[kwazza11]

Not really because a .63 AR GT30 housing is considerably larger than a .63 AR GT28 housing would be if it existed - closest in GT28 is .64 AR . When you go up a family in turbines ie GT28 to GT30 the matching family of housing is also larger overall - internally and externally .

this is sort of what i'm worried about with stepping up to the 60mm rear wheel and 3071r. from looking at results with rb25 guys using the 2835pro S and seeing that they get 300rwkw and 4k spool i think it may be alittle too big even in the .64 ar housing. i know i've only got 100cc less than the rb25det but bottom of the line my head wont flow as well as the rb25det and i'm not really chasing much more than 250rwkw.

as for the turbines should use thier own garrett made housings for best efficiency arguement, what would you advise then? go for the gt28 .63 ar t28 internal gated housing and adapter flange or use the rb25det t3 integral gate housing? seems to be downsides to both, either the restriction caused by an adapter flange or the nozzle angle and shape being wrong with an rb25 housing..

Cheers

Karl

[discopotato03]

RB25DET with a HKS GT2835 Pro S spooling at 4000 rpm ? Gotta be something wrong there . A few people using that turbo in .68AR turbine housing form on their 33's say they work very well .

As for the GT3071R someone on this board has one on an RB20DET and they're not unhappy .

I get the feeling that your concerned about the torque characteristics that your engine has or that you want it to have . Putting a maximum KW figure on your build and trying to size a turbo around that figure can be very hit and miss as a wide variety of turbos can potentially achieve 250 Kw . If you really are only going to use it on the street I think you should aim for useful torque in the range that you drive it most of the time . Honestly there are no bragging rights in a street car that doesn't work too well when driven in a socially acceptable manner .

My gut feeling is that trying to get a broad torque spread on an RB20 based engine is a big ask . This is because they don't have the capacity to make good strong torque without some boost . If you size the turbo to make boost at lowish revs it will run out of gas flow potential somewhere in the upper mid range .

I think SK mentioned that RB24's with maximum effort porting and valve sizes fall short of what 2.4 litres really needs so its pointless erring on the large side turbo wise . To make the most effective use of the flow potential it has I would probably aim for something either GT2860R based (meaning the better GT28 turbine and one of the 60mm diametre compressors) or some kind of hybrid with a slightly larger turbine and a compressor with just enough capacity to make acceptable airflow . Its hard for me to say use turbo X because the result may feel great to me and terrible to you . If you really can't make your mind up the safest bets would probably be HKS's GT2530 or the GCG Hi Flow . Both are better than the std RB20 ceramic BB turbo and once you get a result you will know if its enough for your tastes . If the 2530 isn't enough there's not a whole lot you can do with it where as with the Hi flow you can play with the three different AR ratio turbine housings and a couple of Skyline type compressor covers to "tune" it a little gas flow wise .

I know of a couple of R33 owners who really like the R33 Hi Flow so if you can find someone whose done it to show you the result it would help . It won't be exactly the same as an RB24 in an R32GTST but it will give you an idea .

Cheers A .

[kwazza11]

it was full boost by around 4k, apparently a fairly awsome street turbo.

basically thats ideally what i'm after, with alittle less power, couple that with the rb20 head's poor breathing and i figure the 2871 is around what i need. i was going to just buy a 2835 Pro S but cannot afford the HKS name so am aiming for around the same or smaller minus the badge... it'll be mainly hills driving, track days, motorkhana and hill climbs so a usable power band is what i'm aiming for.

as for a high flow, if i'm going to spend $2k on a turbo i figure i might aswell go for something with the latest blade designs etc. what do the gcg high flows use? i was under the impression they use a T04 rear wheel and bored out stock housings so why would that be any different to the 2871 and 25 rear?

sorry if this is getting alittle long in the tooth but i'm hesitant on spending all my cash and ending up with an inefficient turbo..

[mokompri]

i would recommend the Garrett GT2871 - 52 trim. The HKS GTRS equivalent, which has the ability to put down 250rwkw on an sr20det, and still has very good response. although a different motor, it should work even better on your motor since you have the extra 400cc capacity. its the next step up from the gt2530 in the silvia world, the gt2530 will only give you 230rwkw - but has awesome response, extremely streetable and a very nice mid range, i know because im running one on my sr20

although it should be noted that, the .64 turbine housing (GT2871 - 52 trim), starts getting choked in the top end on SR's, it may be even more evident on your motor. but for 250rwkw, its the smallest option, which should give you the best response..

Edited May 14, 2006 by mokompri

[discopotato03]

Yes well unfortunately a GT2871R won't bolt up . One last time , IMO the 48 comp trim version of that turbo is the one to have . It can make 39lbs of airflow . If you want it to have a T3 flange you need a HKS exhaust housing . The Garrett marketed GT2871R 52T will not have the exact same characteristics as the HKS one because its modelled off their SR20 S13-15 specific turbo not HKS's RB20/25 specific turbo which uses different compressor and turbine housings to either the SR20 2871R or Garretts generic GT2871R .

You may need to consider a slightly taller ratio final drive as the one to suit the std RB20 may be a little short for the RB24 .

Your call .

Cheers A .

[mokompri]

Yes well unfortunately a GT2871R won't bolt up .

The Garrett marketed GT2871R 52T will not have the exact same characteristics as the HKS one because its modelled off their SR20 S13-15 specific turbo not HKS's RB20/25 specific turbo which uses different compressor and turbine housings to either the SR20 2871R or Garretts generic GT2871R .

haha oops forgot about the different flange...

yeah i was referrering to the sr20 version of the GTRS, although i thought it was the same one for the rb20, and only the rb25 one was different with a .84 exhaust housing ?!

[grim32]

My vote goes to the GT3071R. Boost gauge moves into the + at 3000rpm and is all in at 4. Its power range is 3500-7000rpm on a standard RB20, i love this turbo setup on my car and i dont think you would be disapointed either.

[kwazza11]

My vote goes to the GT3071R. Boost gauge moves into the + at 3000rpm and is all in at 4. Its power range is 3500-7000rpm on a standard RB20, i love this turbo setup on my car and i dont think you would be disapointed either.

hey grim, you wouldnt happen to have a dyno graph thats got boost plotted would you? have been looking for some real world figures for a long time but no one seems to have any..

2871r will bolt up with a machined up rb25det exh housing.

Your confusing me disco, in your initial post you recommended the 52t, whats changed your mind?

Cheers

Karl

[crack]

disco,

is this the 3071r you are talking about?

are the compressor and turbine maps suitable for the rb24 and rb25? i have an rb25 and want approx. 260 rwkw with bucketloads of torque.

[discopotato03]

No that one and the other similar one at turbobygarrett are the ones to avoid . The real one you can see at -

Garrett GT3071R : atpturbo.com . The Garrett exhaust housings are shown up top where the rest are some of ATP's alternatives . The top ones are genuine GT Garrett .

As I've said in the past the propper one has a GT30 turbine and GT30 turbine housing . The simple way to check is does it have a T28 flange and integral watsegate ? No deal . Does it have a T3 flange and .63 or .82 or 1.06 cast in the exshaust housing - in the ball park . If the housing has .64 or .86 cast into it its a GT28 housing so a dodgy .

Acid test . Check the ID tag on the turbos bearing housing . It must say 700177-0023 or -5023 . If it says another number after the "-" ie 700177-XXXX its not the genuine article . Don't let any turbo shop tell you its not available either . At risk of sounding like a walking ad for GCG turbos try them if you have no luck . I know Brett deals with Garrett overseas so would track one down if you were having trouble finding one . If he could not find one he would probably make one up to suit your needs .

Cheers A .

[discopotato03]

I have no idea why the confused icon is in above post - not my doing ...

[kwazza11]

Well i've finally got the car finished, ended up going with the 2871r 56t using a machined out rb25 rear and a hks low mount. being tuned atm so will report back on how it goes next week. Very keen to get back driving it again!

some pics

[silver gts-t]

very nice..

im going the exact opposite route to what u want.

[R31 POWER]

Get a ext gate on there

[silver gts-t]

this is how im going to be running my crossover pipe

[rb26s13]

so how'd the tuning go kwazza that setup is fat looking forward to seeing the dyno sheet

[kwazza11]

external gate? meh, been there done that!

Silver, what made you choose to run it like that? i'm assuming your intercooler to throttle pipe runs under the cooler? reason i did it that way is the intercooler exit comes out just between the battery and radiator so it basically made the cold side approx 1.6 metres, and meant i could run 3" without loosing much if any throttle response! Had a small issue with bonnet clearance though...

Car gets tuned hopefully tuesday then cold start needs to be done so hoping to be driving it wednesday morning.

Edited June 10, 2006 by kwazza11

[Cubes]

Mine runs the same as Silver GTS-T, except I have retained the std cross over pipe.

Basically the hot air from the turbo runs via the stock piping route then slightly under/behind the fmic core to the drivers side where it enters the fmic.

Its easy to do this with my core as the cooler piping enters the core in the center of the core unlike the majority of the fmic's on the market that enter the core at the bottom.

The cool air then leaves the core and has a very short route to the cross over pipe.