Please Help -9 Vs 2560

[Boostage]

I did a lot of research and the general consensus is that the GTSS/-9 is the best street setup, providing a wide and torquey powerband. but the 2560r costs a bit less here in the states and honestly doesnt seem that far off.

specs for 707160-9:

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2859R_707160_9.htm

And then the 2560r:

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT25/GT2560R_466541_1.htm

The exhaust wheel on the -9 is .8 bigger but the compressors iducer/exducer on the 2560r is 2mm bigger 1mm bigger respectivly. biggest difference I see is the A/r of the compressor housings .42 vs .60 Would getting the 2560r feel a lot less responsive and provide noticeable less low and mid range than the -9?

[Moodles2]

One turbo bolts onto a RB26DETT, the other bolts onto a SR20DET. see if you can spot the difference....

[cobrAA]

I have GTSS my friend have -5.

I could really see the difference in terms of response and kick in the butt ( maybe that's because I'm used to my car and <I have 410whp while my friend's car have 470whp) however major advantage to the gtss combo in terms of response.

If you want the ultimate quick car, I think GTSS are the way to go and I was lucky enought to find a good deal on GT-SS so I didn't think too long between the -5 vs -9 war haha! ( it made my choice a lot easier)

[Boostage]

One turbo bolts onto a RB26DETT, the other bolts onto a SR20DET. see if you can spot the difference....

I have a 1jz with custom t25 flanged manifolds, thats not an issue for me. But if you have an answer to my question, please feel free to reply.

[R31Nismoid]

As he said - one is RB26, one is SR20. Not really any other way to say that.

This is the correct one for the larger "-5" for RB26

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2860R_707160_5.htm

You'll notice the wheel combo is again, different.

I've had both -9s and -5s. For the street, -9 all the way.

[Boostage]

I didnt ask about fitment.. and none that I listed are -5's .My question is, between these two turbos would there be a noticeable difference in performance considering the MINOR difference in specs?

2560r specs

Compressor:

46.5mm Inducer 60.1mm exducer .60 trim

exhaust:

53mm .62 trim

-9 specs

Compressor:

44.5mm inducer 59.4mm exducer .42 trim

exhaust:

53.9mm .62 trim

Im not concerned about fitment and I am not asking about -5's aka 2530's aka gt2860 etc I am only asking about the performance of what I listed

Edited March 10, 2011 by Boostage

[paulr33]

as per sig, make sure you pick the right ones

[R31Nismoid]

I didnt ask about fitment.. and none that I listed are -5's .My question is, between these two turbos would there be a noticeable difference in performance considering the MINOR difference in specs?

2560r specs

Compressor:

46.5mm Inducer 60.1mm exducer .60 trim

exhaust:

53mm .62 trim

-9 specs

Compressor:

44.5mm inducer 59.4mm exducer .42 trim

exhaust:

53.9mm .62 trim

Im not concerned about fitment and I am not asking about -5's aka 2530's aka gt2860 etc I am only asking about the performance of what I listed

If noone here has used them, how do you expect us to comment?

on paper it might be ok, but given its smaller rear, larger front. it might have surge issues in twin form. you'll never know until you get them running.

for the sake of a few dollars its going to be nothing more than a gamble.

do you like to gamble?

[Boostage]

R31Nismoid that was a very educated guess and thats all I was looking for. and I agree. i will try it and post the results.

[R31Nismoid]

so basically you are buying them anyway?

or you already have them?

also you are using a different motor, this also can have minor advantage or disadvantage as its not the same as a rb26 etc.

[gtr fan]

So are you trying to fit two turbos designed for an sr20 onto an rb26?

Some people like to do things the hard way!

[Boostage]

so basically you are buying them anyway?

or you already have them?

also you are using a different motor, this also can have minor advantage or disadvantage as its not the same as a rb26 etc.

the Rb has the closest bore and stroke. I really have no data to go off of as Most JZ guys just run Single turbos. so it really is just experimenting.

[Boostage]

So are you trying to fit two turbos designed for an sr20 onto an rb26?

Some people like to do things the hard way!

no

[R31Nismoid]

the Rb has the closest bore and stroke. I really have no data to go off of as Most JZ guys just run Single turbos. so it really is just experimenting.

was more so talking about the head, but yeah i know what you mean.

could be an expensive experiment

[Boostage]

was more so talking about the head, but yeah i know what you mean.

could be an expensive experiment

I know the head is quite different, I am however building a Jenvey ITB's setup I just got the intake Plenum from Reverie in the UK

This is Next to the stock 1jz intake

In the end I expect it to be similar to an Rb26, but we will see.

Edited March 10, 2011 by Boostage

[discopotato03]

I've been asked to stick my ore in which I don't mind doing because the topic interests me but always remrmber that I'm not a Skyline GTR person for my own reasons .

That said , I see an RB26 in a GTR Skyline as a very different turbo application compared to just about anything else of that era . You can't realy draw a direct comparison between the turbos suitable for RB26 twins and other single apps ie CA18 SR20 etc etc . I know they both use the same T25 style mounting flange but the packaging constraints for the two original T28s means things had to be altered to get them on the head and into an R32s engine bay .

The chief differences externally are RB26 specific turbine housings which are designed to be more compact than the CA/SR type T/GT 25/28 housings . Because these 4 and 6 cylinder engines package their turbo systems differently they can't have a turbine housing style that suits both mainly because the twins on RB26's had to be all close and cuddly , I supppose , so the body could be a drop on/over process on Nissans production lines .

The bottom line is they are different applications and there is no advantages and major disadvantages in trying to interchange the two turbine housing styles .

Now the compressor housing styles are again different for packaging reasons and unless for some reason you were doing customised plumbing , for whatever reason , I can't see why you wouldn't use an optional turbocharger thats designed to be a direct fit for your specific engines application . I strongly doubt there is the opportunity to save money because by the time you fabricate all the bits around the turbo you've burnt considerable time and money .

Now to the controvercial part , please exc spelling , checker not working and I'm struggling with a chest infection ATM so oxygen is a premium ...

People have their own views on what a well developed performance car drives like from a power delivery perspective , I like an engine thats free spinning but it HAS to make acceptable part throttle torque and I won't be waiting all day for it to happen . I HATE engines that have no usefull pulling power and you have to buzz the engine around at higher than normal revs so that when you want it to go it will , useless for a middle aged person like me on the street . While I'm being critical I DON"T belive short gearing is the answer nor that lack of low down squirt is foreplay . I take the practical approach that a road car has to drive well whout have its kneck rung ALL the time .

Basics , an R32 GTR weighs approximately 1480 Kg so I be nasty and round that to 1500 or a tonne and a half .

What lived under the lid is a 2568cc 8.5 to 1 compression ratio inline six cylinder engine . Its not really a lot of capacity or even an adequate compression ratio when it comes to moving a tonne and a half from rest . I don't know for sure but I reckon if you took the actuator rods off you waste gates valves A GTR wouldn't be mega exciting .

What this means is that they don't make the sort of torque particularly at around town revs that make cars feel nice , IMO anyway .

So we get to the hair dryers because we need more air that the atmosphere can push by itself to make some worthwhile grunt . The factory T28 turbos really don't set the world on fire until we get into the buzz the engine type revs and considering RB26's were intended to be a homologation road race engine that not terribly surprising . RS500 Sierras were the same and I'm sure many other manufactures road going homologation specials were too .

Off the top of my head I believe the early Grp A R32 GTR could make something like 600 650 Hp but I'm not sure what the boost levels or revs that was at - or even if the turbos had air restrictors on them at the time or what size they were . At 2.568 Litres and 650 Hp your talking about 253 Hp/L which is not bad going though admittedly they were not using base R32 turbos cams etc . They were using 2568ccs and it would have been an interesting prospect trying to tone such an engine down to something you could legally make and sell in a road car in 1989 .

The trouble is that there is a huge divide between a road car and a race car and even the road car basis of what works in a GT Tarmac racer won't be a 6L Chev down low because the process of making the engine have big breathing potential has to cost it torque down low at the sorts of gas speeds a road car normally uses when driven at sane speeds .

Now to GTR road cars and what has the potential to make the car nice on the street - in my opion .

I will go to the grave believing torque is everything and when you have enough of it and the control over the engine to make it deliver it smoothly and controllably it just doesn't get any better . I also believe that torque/power beyond traction is absolutely useless in a street driven car , why anyone would seek more or live with an engine in the state of tune that throws away the bottom end and lack of traction can't harness the top end is a mystery to me .

If I was suddenly rich beyond belief and inherited a GTR Skyline it would have 707169-9/GTSS turbos on it end of story . They help the engine make more torque at lower revs than the std , bush bearing anyway , turbos do and have a far more durable bearing system in them too . You give away the potentially unreliable ceramic turbines of the early factory T28's so it takes the form of a win all the way down the line . More torque lower , more longevity , a bit more mid range torque and top end as well I'd reckon .

Now I suppose half the people reading this are gonna say bullshit those tiny whissers are going to run out of puff and won't hold 50 pounds of boost to 8000 revs and they would be right . Where down the road can you drive like that without the riot squad pointing shot guns at you ?

Anyway a good spread of torque and some exciting mid range squirt is what make a good road car for me and I don't think this idea is lost on mobs like HKS . They obviously sat down with Garrett Japan and spent some time developing bolt on turbos that were a win everywhere over the factory ones . For those that wanted more performance and could accept the std lack of performance down low they developed the 2530's which technically are a GT2860R variant in Garretts current terminology .

Now to the innards for the propeller heads though I think I'm repeating what I typed out last year in one of these GTSS/707160-9 threads .

There are three turbine wheels use in Garretts GT25/GT28 family of turbochargers and thats forgetting for a tick the material spec .

The smallest one measures from memory 54mm in 62 trim and I think its actually a carry over from the TB25 turbos but having the shaft dimensions to suit a GT25BB center section . Its what the bush and ball bearing SR20 turbos use though in the S15 spec SR20 they are made of higher temp spec material as is the turbine housing . The turbine housing you can tell by the vane around the turbines outlet and the material is a different colour/texture than the lower spec ones . These TB25 turbines you can tell to look at because they have more blades (11 from memory ?) and they have a kind of forward rake as their straight edge blades radiate out from the turbines hub at the rear .

The next two larger capacity turbines appear to me to be the same thing but in two different trim sizes but to save confusion now I'll call them the mid and large capacity ones .

The mid one is definitely a GT28 turbine because it measure 53.8mm and its also in 62 trim but has 9 swept back and curved trailing edged blades . Its the least common of these 3 turbines and that makes me think its a bit of a special brewed up by Garrett for the then HKS only turbo options .

The large capacity one is of course the 53.8mm 76 trim GT28 NS111 turbine and it usually turns up in most of the high performance GT2860R and all GT2871R and GTRS turbos . HKS have them in the T25 flanged SR20 spec GTSS/all 2530's/all 2535's/all 2540's/all GTRS's .

When looking at turbo specs look to the turbine dimensions because some are similar enough to go almost unnoticed .

1) The major diameter which will be 53mm or 53.8mm , the smaller being the TB25 turbine .

2) The trim size because like the basic TB25 turbine the smaller of the GT28 turbines is also 62 trim . If you see 76 trim then you know its the larger of the two GT28 turbines because AFAIK there is no 76T TB25 turbine .

When you look at an RB26 with twin parallel turbochargers its plumbed on the exhaust port side like two three cylinder 1284cc engines because the hot side of each turbo is only fed by the front or rear three cylinders . Thats all the exhaust energy each turbine has to work with and this is critcal because the turbine is the turbochargers (compressors) ONLY power source . The turbine has to recover enough thermally excited and expanding exhaust gas to spin the compressor fast enough to positively charge the engines cylinders at an engine speed thats usefull . When you develope a race engine thats designed to have power at revs because the maximum performance is the goal you can size the turbines and their housings with less restriction in mind because no one races at part throttle or potters around the suburbs .

A road car obviously isn't driven flat out everywhere and needs to have adequate performance in the sorts of engine and road speeds used most often .

So HKS discovered that the TB25 turbine was the one best suited to making a GTR a better all round performer . They put them in a 0.64 A/R turbine housing which is this time one Garrett make to suit RB26 packaging . Don't quote me but I think this A/R size is a tad larger than the turbine housings used on std T28 GTR turbos but is not by much .

From what I can tell the GTR T28 compressor housings are T3 dimensions internally and in an odd A/R size I can't remember ATM . I believe the GTSS ones are similar/same .

The compressor wheel is probably the most interesting part of these 707160-9 turbos and from what I can tell is unique . I've never had one -9 turbos to measure up the tip height of these wheels but you can be sure HKS and Garrett went to a fair bit of trouble to make them work well on a road RB26 because they are afterall tailor made for RB26's and NOTHING else . They are not a generic Garrett turbo and its interesting that you can't seem to buy its cartridge separately and I did inquire a year or two back . There is actually a bush bearing I think GT20 turbo that also uses a 59.whatever mm compressor wheel but its in a different trim .

Back at the GTR road car . Now I reckon you can make all sorts of incrimental improvements to RB26's without giving up any paultry low down squirt the things have std . I reckon you can gain a bit with porting and MILD cams and a bit higher CR wouldn't go astray with the fuels available today . Maybe smooth up and match the manifolds and fit proven dump and exhaust pipes and a low restriction cat . The beauty of building medium rev torquey engines is that NOTHING has to be big and the work involved can be quite straightforward you're basically enhancing what the factory spent the millions on producing .

The things you MUST avoid is huge ports/big valves/huge manifolds/huge cams/and huge exhausts cause the engines only gonna break off and rattle down the pipe ...

You have to remember that enhancing torque means having adequate air and exhaust gas velocity to make the engine volumetrically efficent and make strong torque without the huge increase in engine revs .

Don't even bother trying to convince me that you can't make strong pulling power without a bootfull of revs because Mitsubishi , well Ralliart , cranked 650 Nm of torque out of their two liter four cylinder rally engines and did it under 5500 revs - with a turbo air restrictor .

An RB26 should be easier because it has the extra nearly 600cc's and it isn't like an R32 weighs 25% more than say an Evo 6 GSR , 1360 and 1480 the numbers are from memory .

The real power delivery differences are that one was designed to be the basis of a Group A Rally car and the other a Group A tarmac racer . It's old news that rally car power ranges are more closely aligned with road car power ranges than tarmac racers are because road and rally have to have power from lower engine speeds . This is really driven home with air restricted turbo race engines because the builders are forced to make best power , read torque , in a limited rev range and cieling .

Anyaway if anyone is still awake I think its entirely possible to build an RB26 capable of maybe 330-350 kw and a real good spread of usable torque . You just have to remember that turbo/s are just one part of a system and if you keep that in mind and keep thinking torque rather than kw/hp and high revs then you'd end up with a pretty sharp roadie in a GTR .

My opinions only , cheers A .

A .

[Boostage]

Thats an extraordinarily Interesting point of view on the subject, however I would still like your opinion on the feasibility of the 2560r being able to mimic the power curve/production of -9's. also to addres your comment about not saving much money, I can assure you the initial cost of the 2560r's is at a minimum $600 less. which is enough left over change to accommodate other useful components.

[discopotato03]

Giz a tick , I have to have a look back through my Garrett notes because my head is full of Misty turbo stuff ATM .

A .

[Scooby]

Hi A / Disco

That's a great read. Sorry to go OT briefly but can you give us your views along the same lines on street turbos for the 26/30 please? Maybe here:

http://www.skylinesaustralia.com/forums/topic/349467-5s-vs-rss-on-a-larger-then-stock-motor/page__st__160__p__5663461__hl__bigger+then__fromsearch__1#entry5663461

Cheers

Edited March 11, 2011 by Scooby

[discopotato03]

Really shitty ATM , lost a detailed post explaining about the differences of the OPs linked turbos in his original post .

Brief version .

The GT2560R you linked is one of two almost identical OE turbos for SR20DETs . 446541-1 and 446541-4 and the difference is the -4 has a higher temp spec turbine and turbine housing . The more temperature resistant version costs more to make and to buy .

All the GT28 ball bearing based aftermarket turbos Garrett make for RB26's use the better materials and that would make them more expensive to buy than a lesser temp spec GT2560R .

Probably the best way for anyone to prove to themselves that SR style turbos wouldnt fit is to painstakingly remove the std RB26's turbos and compare them to SR ones on the bench . That way you'll realise why such customisation was needed in the first place for Nissan to get twin parallel turbos on an RB head .

The other sad thing about RB26's and GTRs is that because so much of the both is unique that rarely does cost cutting come into it . They are such a complex and time consuming thing to pull apart and put back together that few want to risk scrimping on bits and have to go through the whole painfull exercise twice if it doesn't work .

Your call , I'd just get the best new price for -9 turbos and do everything to the engine at the same time .

Do it once do it properly and have piece of mind for a long time . Expensive ? Yes but then thats the nature of doing virtually anything to a Skyline GTR and probably the the main reason why I wouldn't own one . An Evolution Lancer by comparison is a piece of cake by comparison but thats another non related story .

Cheers A .