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T518Z

CWL = inducer 50.5mm, exducer 68mm.

TWL = exducer 49.1mm, inducer 56mm.

COMP HSG =

EXH HSG = 10cm2

gt3071r

Turbine

-Wheel: 60mm w/ 84 trim

-Housing: .63

Compressor

-Wheel: 71mm w/ 56 trim

-Housing: .50 ar

Its a toss up between these 2, its obvious the gt30 will make more top end power.. but lag factor also comes into it, what do you guys think? Will there be a huge difference in lag between the 2 turbos? ( If you have a 3071r with t28 shit in it dont want ur reply :D )

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https://www.sau.com.au/forums/topic/310644-t518z-10cm-vs-gt3071r-63/
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cheers status! much appreciated... also list what supporting mods on each etc.. plans are fresh s15blacktop, 740's, z32, power fc, and either the 8 or 10cm t518z :down:

i reckon i have the same car with a 8 and 10 back to back. will check.

If you can't bear GT28 based turbos you'll have to toss the OE exhaust manifold anyway if you want it to work properly .

HKS have T25 flanged GT30 turbine housings available but not in wastegated form , the 0.73 A/R one seems to be the pick on SR's .

Actually thinking about it in the States people used to get std SR exhaust manifolds and weld on mounts for external gates , could be the cheapest way to get a GT30 based turbo onto an SR20 . They sometimes picked on the GTiR std manifold because it was supposed to be the best of the factory ones - slightly larger internal passages .

I know it was a transverse engine manifold but maybe it can be made to work .

I'll see if I can find the link to the 52T GT3037 fitted to an early Sentra SE/R in the US , it has pics of it and the 0.73 A/R T housing . The fabbed manifold is something else on whats mechanically a FrWD Pulsar .

A .

interesting read disco.. was originally planning to go the hks 3037 route, but always thought lag mite be an issue? and from reading alot of good results with people using the t518z making ~260kw mark while keeping good response. So in that case, i gather your preference would be the hks 3037 0.73 a/r? i also thought, that the t2 flange would become restrictive when chasing big numbers? or do t2's with 0.73 and SR's make a realy good combo?

T2/T25/T28 mount flanges are the same size , the generic rectangular Garrett one I mean .

Do you have a power number you are chasing ie 260 Kw ?

From what I read GT3037's can be responsive on SRs but the manifold has to be a good one and the turbine housing size right , they like the 0.73 A/R one in the States .

I reckon the earlier non VCT head and the GTiR's quad throttle inlet manifold is the go , similar situation with RB25 and RB26 with the 26 being better . Expensive but goes bolt .

I must have more faith in GT28 based turbos with the larger 0.86 A/R turbine housing than you do , I really liked my GT2860RS 0.86 on the FJ20 I had years ago . Not what you want to hear but better cams and the 48 or 52T GT2871R would be much simpler to set up .

Your call but but I think it wouldn't be too difficult to end up with a GT30 based turbo and a laggy engine , the right bits are expensive and you don't have too many areas to go back to if the lag was unacceptable . The smallest GT30 turbine housing I know of is the 0.61 A/R HKS T25 (22/25/28) flanged non waste gated one . If you were going to go that small its hard to see the point of the largest compressor trim GT3037/GT3076R .

Only you can know what power level you're chasing and how much cash your prepared to burn getting there . I find that if you don't aim too high you tend to end up with a good all round result . IMO a strong mid range is where its at in a road car at least .

Individual throttles make for really good throttles response and better cylinder filling off boost . Most SR people won't do this because they baulk at the cost and prefer to sink money into big laggy turbos on fabbed manifolds with external gates .

The GTiR made significantly more power than the "ordinary" SR20 DET's and all it lacked was a more modern turbocharger . They had an orphan T300 bush bearing sort of thing with a turbine that was 10 bladed in from memory 79 trim and I cant remember what sized GT28 style turbine housing . I really can't remember but didn't they make 187 odd Kw std ?

IMO make it breathe , remove the flow restrictions and you may not need as big a turbocharger as you think .

Same old same old , budget - how much power and starting where and how is it driven most of the time .

A .

I just found something interesting whilst looking into something else .

If you look at the turbine map for the GT2860RS 0.86 A/R its not that different to the real GT3076R's one in 0.63 A/R .

This doesn't necessarily mean that the turbine response would be the same with both turbos but it does give an idea of what sort of exhaust gas flow potential that GT28 76 trim turbine has in the larger 0.86 A/R T2/25/28 flanged turbine housing .

Since you can buy the GTRS (GT2871R 52T) through Garrett with the correct compressor housing for an SR20 , the one HKS uses , and very likely option the 0.86 turbine housing which bolts to your exhaust manifold at the same time .....

Cheers A .

well mainly aiming for roughly 250-270kw, but dont want to be pushing to much or leaning out, as i will onli be using bp98... im still stuck on the t518z?.. as a few people have gotten decent numbers about the 250kw mark... but then, if you say the 3037 .73 a/r is not much difference in lag factor, but has the option to push more power, .then that turbo could be the possibly pick.

as mentioned, only want around ~350hp... street car, but occasional track days...

also, what cams would you recommend to make the most of ; a) t518z (8cm or 10cm)... b) 3037s 0.73... is there any benefit in mix and matchin cams, (ie. 256/64 or 264/272) ... and how much lift is beneficial to the goal i am aiming?

only want a fairly responsive turbo with a boot til redline, as current setup with power fc, t28bb, fmic, pod, fuel pump, exhaust - doesnt lose by much to a few sr's running gt3071r's 0.64 and 0.86s doing 330+? ... which i find weird?

Generally these GT3071R's with T25/28 flanged turbine housings are not using the full sized GT30 turbine , they use the cropped ones .

If you go to the turbobygarrett web site and look at their turbine maps their efficiency percentages are lower than you get with a GT30 turbine in a GT30 turbine housing . Croped or full sized GT30 turbines are a bad match for a GT28 turbine housing , more heat more restriction and lackluster performance . They would be better off using a GT2871R 52T/GTRS and experimenting with the Garrett 0.86 A/R turbine housing , its only available in T25/28 flange which is what SRs have std .

Maybe you should ask around and find out what results people have got from the RB specific GTRS turbo or even the GCG Hi Flow with the larger VG30 OP6 type turbine housing . 250 260 at the treads is a comom occurance .

A friendly drop in cam for the RB25DET is Tomei's Poncams , lots of peoople have used them and I haven't seen too much negative feedback .

PM Woolverine , he's had the Hi Flow and the RB type GTRS .

A .

The GTiR made significantly more power than the "ordinary" SR20 DET's and all it lacked was a more modern turbocharger . They had an orphan T300 bush bearing sort of thing with a turbine that was 10 bladed in from memory 79 trim and I cant remember what sized GT28 style turbine housing . I really can't remember but didn't they make 187 odd Kw std ?

IMO make it breathe , remove the flow restrictions and you may not need as big a turbocharger as you think .

Same old same old , budget - how much power and starting where and how is it driven most of the time .

A .

The Gtir has totally different head castings too, the std turbo had a 0.86 and was woefully laggy and responded well to an upgrade (better response and better peak) im sure they used a 0.86 for some homoglamation (spelling?) rules as it was neither here nor there for results.

this graph shows a tuned 180sx vs a GTir tuned. (the 180sx makes more torque nearly everywhere)

post-34927-1268095505_thumb.jpg

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