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Biggest low mounts on stock manifolds????


JAY-R32
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As above really

At the moment i have a pair of Greddy T517z's set at 1.4 bar

264in & 272out cams

Some half decent intake & exhaust bits

and a much improved recently rebuilt bottom end etc......(still 2.6)

So far it has recorded 530hp & 418ftIb @ the hubs

on a dynapack.

The T517z's are good for around 600 - 650hp max

Are their any low mounts that can flow a lot more than this?????

Ive been told by a turbo supplier in the UK that he could build me

a pair based on GT25 housings using T3 wheels that will flow enough for just over 400hp each...........if i can supply him with some accurate specs of what will work on an RB , as they specialise in 4 pot applications and have almost no knowledge of the RB.

Cheers in advance :)

Jay

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As above really

At the moment i have a pair of Greddy T517z's set at 1.4 bar

264in & 272out cams

Some half decent intake & exhaust bits

and a much improved recently rebuilt bottom end etc......(still 2.6)

So far it has recorded 530hp & 418ftIb @ the hubs  

on a dynapack.

The T517z's are good for around 600 - 650hp max

Are their any low mounts that can flow a lot more than this?????

Ive been told by a turbo supplier in the UK that he could build me

a pair based on  GT25 housings using T3 wheels that will flow enough for just over 400hp each...........if i can supply him with some accurate specs of what will work on an RB , as they specialise in 4 pot applications and have almost no knowledge of the RB.

Cheers in advance  :thumbsup:  

Jay

Do you want higher max power or higher average power?

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twin GT2871R's w/ .63 turbines?? maybe even the .86 if you can take the lag, but if you can take the lag get the twin GT3071R's, each good for 400+, uses the standard T25 turbine flange

GT3071RWg - 450hp

Based upon the same turbo as the HIGH flowing, larger framed GT3071R, but conveniently packaged into the same style turbine housing as the popular GT28Rs/GT2871R turbos. This turbo is uniquely configured with its own turbo wheel trim, turbine A/R, and compressor housing. Unlike, the GT28RS and GT2871R, this turbo now has a much larger compressor housing to support the much higher flowing 71mm compressor wheel. Comes with T25 style inlet flange.

Turbine

-Wheel: 56.5mm w/ 84 trim

-Housing: 0.64 a/r

-Internally Wastegated (No Actuator)

-Maps: Not Available

Compressor

-Wheel: 71mm w/ 56 trim

-Housing: .50 a/r

-Maps: Not Available  

-Inlet: 2.75"

http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

www.atpturbo.com - 3071R makign 400awhp on the 1.8 audi's

www.cheapturbo.com - garretts at great prices.

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Contact Mark at Abbey Motor Sport he's probably got the best tuning shop for skylines in the UK if not Europe. They supply & tune.

Im familiar with Abbey , used them a couple of times , very knowledgable ,

and their facilities are very good......but they have in the past suggested that if you go bigger much than ive got (T517's / 2530's) then you need a capacity increase.

Im trying to find out if this is the case :P , as a 2.8 conv is WAY beyond my budget....

Do you want higher max power or higher average power?

I suppose , like everyone ..... i want both :)

But realistically , im looking for a peak @ hubs of about 650hp at a sensible (below 8000rpm) limit , without loosing TOO much power lower down.

At the moment ive got 400@hubs 5000rpm and 530@hubs at 7500rpm

Peak torque is 418@hubs at 5200rpm ,

it has very little lag and feels great on the road ,

which i like , as it's my everyday transport.

Is it a realistic target ????, i dont want to end up with a laggy ,

unresponsive car that i'll hate driving .....

twin GT2871R's w/ .63 turbines?? maybe even the .86 if you can take the lag, but if you can take the lag get the , each good for 400+, uses the standard T25 turbine flange

Sound's great ....... :) but do you know of anyone using any of these on a GTR ?

I'd like a good idea of how much lag i should expect ????

I think Cypher industries ( ive only read about their car in a magazine) MIGHT be using something like twin GT3071R's on their GTR but they are not too keen on telling everyone spec's.....

Thanks everyone for the replys so far.......

Jay

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But realistically , im looking for a peak @ hubs of about 650hp at a sensible (below 8000rpm) limit , without loosing TOO much power lower down.

At the moment ive got 400@hubs 5000rpm and 530@hubs at 7500rpm

Peak torque is 418@hubs at 5200rpm ,

it has very little lag and feels great on the road ,

which i like , as it's my everyday transport.

I have HKS 2540's with HKS 280' cams returning 600hp at the hubs

GTR V

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But realistically , im looking for a peak @ hubs of about 650hp at a sensible (below 8000rpm) limit , without loosing TOO much power lower down.

At the moment ive got 400@hubs 5000rpm and 530@hubs at 7500rpm

Peak torque is 418@hubs at 5200rpm ,  

it has very little lag and feels great on the road ,  

which i like , as it's my everyday transport.Jay

I have HKS 2540's with HKS 280' cams delivering good figures on a hub dyno

GTR V

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I have HKS 2540's with HKS 280' cams delivering good figures on a hub dyno

GTR V

Hi GTRV, am I reading your graphs right? It looks like 190 rhhp at 5,000 rpm, that seems a long way short of Jay's current 400 rhhp at the same rpm. Peak torque at 6,781 rpm on yours doesn't compare too favourably with Jays at 5,200 rpm. That's a lot to give away for an extra 50 rhhp at the top end.

Hi Jay, personally I don't favour much bigger than 2530/N1/T517 size turbos on 2.6 litres. Not if you want to maintain decent response, anyway. That's why the RB30 bottom end is so attractive to us. With 3.1 litres we can run 2 full sizes larger turbos (or a big single) and have better response, higher average power and more max power. We make more power at 7,000 rpm with the 3.1 litre than the 2.6 litre makes at 8,500 rpm. With the 2.6 litres we find that we are chasing more and more rpm, which costs money and shortens life dramatically. Plus the gearing becomes unuseable when the rpm gets so high, we have to change diff ratios and that's not cheap either.

:)

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Jay,

You've seen my car when it had low-mounted 48 trim GT2835s (still have the manifolds) and was 2.6l - once it was mapped it wasn't bad on the road. T618Zs must be the easiest route, and you haven't had the problems with your 517s everyone was talking about, or you could sell your bottom end and go RB30 like a few others are doing...

Phil

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tomei arms b9046. 720ps, straight bolt on kit, most powerful low mounts on sale, the trust items mentioned above r not ball bearing if that concerns you.

if u wanna argue, buy GT-R magazine no.059 and email them with your concerns

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Hi Jay, personally I don't favour much bigger than 2530/N1/T517 size turbos on 2.6 litres. Not if you want to maintain decent response, anyway. That's why the RB30 bottom end is so attractive to us. With 3.1 litres we can run 2 full sizes larger turbos (or a big single) and have better response, higher average power and more max power. We make more power at 7,000 rpm with the 3.1 litre than the 2.6 litre makes at 8,500 rpm. With the 2.6 litres we find that we are chasing more and more rpm, which costs money and shortens life dramatically. Plus the gearing becomes unuseable when the rpm gets so high, we have to change diff ratios and that's not cheap either.

Hi Sydneykid, Unfortunatly i cant afford to go bigger capacity yet.....thats gonna have to wait another 18months or so , you say you dont favour MUCH bigger than what i have , one of the reasons im considering changing is the 270* bearing on the T517z's is restricting the amount of boost i can safely run.....

so rather than just get them rebuilt with 360* jobbies i thought about going a teeny bit bigger :) with decent bearings........ like a pair of these ......... http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

but i have the feeling they might fall into the "too big for 2.6" catagory , but not knowing a great deal about turbo characteristics , im a bit lost....

You've seen my car when it had low-mounted 48 trim GT2835s (still have the manifolds) and was 2.6l - once it was mapped it wasn't bad on the road. T618Zs must be the easiest route, and you haven't had the problems with your 517s everyone was talking about, or you could sell your bottom end and go RB30 like a few others are doing...

Hi Phil , hows it going ???? Can you send me ( PM me or Email [email protected] ) your dyno graph , while your at it , let me know whats happening with your car :rant: , if its not a secret :P

Jay

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Hi Sydneykid, Unfortunatly i cant afford to go bigger capacity yet.....thats gonna have to wait another 18months or so , you say you dont favour MUCH bigger than what i have , one of the reasons im considering changing is the 270* bearing on the T517z's is restricting the amount of boost i can safely run.....  

so rather than just get them rebuilt with 360* jobbies i thought about going a teeny bit bigger  :( with decent bearings........ like a pair of these ......... http://www.atpturbo.com/Merchant2/merchant...tegory_Code=GRT

but i have the feeling they might fall into the "too big for 2.6" catagory , but not knowing a great deal about turbo characteristics , im a bit lost....

 

Hi Phil , hows it going ???? Can you send me ( PM me or Email [email protected] ) your dyno graph , while your at it  , let me know whats happening with your car  :cheers:  , if its not a secret  :(  

Jay

Hi Jay, I strongly suggest you have a look at the T25 compressor map, that should help you decide if a pair is the right way to go for your purposes.:)

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Thanks .... but i dont know what any of this means :confused:  :D  

The first one is the comp map for a GT25r

The second one is for the GT28RS

gt25rcompressormap.gif

gt28rscompressormap.gif

Hi JAY-R32, you realy need to know something about compressor maps or have complete trust in your turbo supplier, have discussed your requirements with them and agreed on the selection. If you want to select turbos yourself. buy them site unseen from people you have never met, then I strongly suggest you get a hold of one (or more) of the turbo books around. I prefer Corky Bell's books but there are others.

My comments on the 2 compressor maps you have attached;

* Personally I wouldn't touch the GT28RS, it has a very complex surge line between boost of 1.2 and 1.8 bar (pressure ratio 2.2 and 2.8). This is where your engine will mostly operate. At that boost, the power levels 145 bhp and 260 bhp (13 lbs per minute to 23 lbs per minute) are also very common transient power levels.

* In my opinion the GT25R simply doesn't produce enough airlfow to satisfy your requirements, its top airflow of 26 lbs will mean it won't make any more power than a 2530. The surge line is much more user friendly than the GT28RS and it does produce good airflow at low boost levels.

My suggestion is to keep looking, I don't think either compressor is suitable.:P

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