Precision Billet Turbos

[mitchum]

9 hours ago, Lithium said:

Nice - any more specifics?  Been quite curious about the SX-E turbos and a few RBs seem to have them but no dyno sheets or hardly even any numbers, yours included now haha

I haven't had it on the dyno yet, I moved from a 6870 to the S369..

The only data I have is a botched quarter mile pass on about 20-21 psi which resulted in me breaking the snout off my crankshaft!!

I trapped 137.5mph in a 3300lb car on 20-21psi and it shut off just before the end..

It spools very close to the 6870 I'm running the T4 Divided 1.0 turbine housing

[r33ryan]

Has anyone ran a 6062 on a rb25 yet and got some solid numbers? Going to change my current single scroll gen 1 gtx30 to a twin scroll 6062 twin 45mms, maybe depending on results. 

Wanting to crack the high 400kw maybe even early 500s while keeping respectable response for the street, sees a few track days. Roll racing, power cruise etc.  

 

 

[r33ryan]

Hey guys, a bit of a update to my previous post. So i went with the 6062. Mods as follows:

 

Head:

S1 rb25det 
Camtech 264 in 268 ex 9.0mm lift
Supertech valve springs with titanium retainers
1.2mm cometic headgasket
Arp 2000 head studs

Block:
Cp forged pistons 9.0:1 compression ratio
(Apparently shaved block & head for finally cr 9.3:1)
Tomei forged conrods with arp road bolts
Acl race series bearings
Acl main studs
Tomei oil restrictors
Jpc billet high volume oil pump gears
Nitto crank collar with balanced and polished crank
Ross balancer

Intake & fuel:
Plazmaman top hat
Plazmaman 72mm throttle body

Ebay 600x300x76 intercooler
Bosch 1650cc injectors
-8 braid fuel line
Walbro lift pump
2L surge tank
Twin 044 feeds
Haltech flex fuel sensor in return

Ignition:
LSA coils, custom leads
Hi octane trigger kit

Exhaust:
T4 6boost twin scroll
Twin 45mm hypergates, plumbed into exhaust
Precision 6062 t4 .84 twin scroll
Full 4inch exhaust.
Turbosmart oil pressure regulator

Ecu:
Haltech platinum pro

 

Had to stop at 25psi, ebay intercooler wasnt keeping up at all. Was jumping from 45 to 65degrees during a run. Purchased a cooling pro 600x300x100 cooler as recommended by my tuner (Matt Ashley @ Diversion Garage Brisbane. (Would highly recommend)). 

See how we go once the new cooler is on but im hoping we will be able to wind it up a bit more. See where we end up. 

So far I can say it seems to be an awesome street setup. A lot more respsonsive compared to my old gtx30 setup. 

 

I'll keep you guys updated, should be back on the dyno in the next fortnight. 

Cheers, 

Ryan.

[BK]

Hi Precision turbo fanatics. I though I would post here instead of starting a new thread since there seems to be some pretty well informed people with the use and results of these turbos. Thinking of changing turbo. Currently have a very old HKS T51 plain bearing v-band inlet and outlet 1.00 a/r exhaust housing, apparently the T51S pre dating the T51R SPL. This used to be good for over 500 wheel kW but was very laggy on the 2.6. I now am running a Nitto 2.8 and would like to know thoughts on best PT to change to with mid 9's possible, running around the 30psi and 98 ron unleaded. (Don't tell me to run E85 as it wont be happening, to much hassle in Alice Springs to obtain)

Want to keep oil only turbo and retain the v band inlet / outlet as per the HKS design. Don't want to change manifold or v band front pipe, basically want some thing that will be a bolt on replacement for the v band setup.

From my research it looks like the PT6466 or PT6870 with the v band inlet / outlet exhaust housing is the go, does this sound about right ? Will these turbos match the HKS v band manifold and front pipe ? Are the dimensions of the turbo even similar ? Looks like the v band housing is 0.82 a/r on the PT6466 and the v band only PT6870 has two at 0.81 and 0.96 a/r. What's the advice for me. Should I go away from the HKS to the PT and if so which one will meet my goals with the 2.8 ?

I was thinking the answer will be to run the PT6870 with 0.96 a/r but please give me as much info as possible on this.

[Dale FZ1]

6 hours ago, BK said:

Currently T51S good for over 500 wheel kW but was very laggy on the 2.6. I now am running a Nitto 2.8 and would like change with mid 9's possible, running around the 30psi and 98 ron unleaded.

Don't want to change manifold or v band front pipe

From my research it looks like the PT6466 or PT6870 with the v band inlet / outlet exhaust housing is the go. Looks like the v band housing is 0.82 a/r on the PT6466 and the v band only PT6870 has two at 0.81 and 0.96 a/r.

Drag application?  What does the maths say you need for hp/weight to achieve the 9 second goal?  Not a lot of info on how hard you're intending to rev the engine, or what's happening with trans etc.

For direct bolt up, forget it.  Accept you will need to make a few alterations to the dump pipe to make things fit.  Fact of life, nothing comes easy.

I'd aim at the 6466CEA for mid 500kW, so V band inlet means you get a 0.82 housing.  But I'd sell off the current manifold and get a T4 split pulse, run a 1.15 housing.

But before I did anything, I'd speak with a person who knows and plays in this area.  Call Boost Automotive in Launceston.

[SiR_RB]

I think to get the most out of the 6466 u would need e85

6870 with correct size rear should make easy power with lower boost on 98 and reach your goals

[Dale FZ1]

1 hour ago, Dale FZ1 said:

But before I did anything, I'd speak with a person who knows and plays in this area.  Call Boost Automotive in Launceston.

Probably not the case of getting the best out of whatever turbo.  Wants to run 9s, less lag than T51S

[r33ryan]

2 hours ago, Dale FZ1 said:

But before I did anything, I'd speak with a person who knows and plays in this area.  Call Boost Automotive in Launceston.

+1 for Brad @ Boost Automotive Launceston. When I was living in Tasmania, I used him to tune my car a few times. He is great at what he does and is very knowledgeable.  

[BK]

Ok would really like want some people that are actually using these turbo's, not just "talk to so and so" or your opinion if you don't run a Precision. People that are familiar with the exact v band housing flange dimensions, or ideally someone who has went from a HKS T51 to a Precision on a GTR. Not opinions, actual users running PT6870 or PT6466 v band housings ideally.

5 hours ago, SiR_RB said:

I think to get the most out of the 6466 u would need e85

6870 with correct size rear should make easy power with lower boost on 98 and reach your goals 

That's what I was thinking SiR_RB. Dale FZ1 I won't be modifying an HKS 4" stainless v band front pipe thank you very much, I would make a new one from scratch before that happens. Same with manifold, keeping HKS v band. Not going to chop an HKS kit up to fit a turbo. The v band gear really is great when your working on your car a lot and think they are superior to bolted flanges so I'd like to stick with them. No gaskets, just a clamp.

The info I guess I'm really after is the dimensions of a PT6870 v band turbo compared to the HKS T51. Mark from Godzilla motorsport assured me that Precision should have a direct swap turbo for the HKS T51.

[NEO25T]

They list all the dimensions in the catalogue on the precision website

[BK]

Yes quite aware of their catalogue. No they don't have ALL dimensions of EVERYTHING in it. Was on the site and pdf catalogue as I'm typing this and still hasn't answered my questions on size, and it's all in stupid imperial making this a bit harder. (Please don't mention how to covert to metric either)

Has flange sizes but not width of housings and CHRA, which I would need to make an informed decision on housing selection if anything is compatible. You would think they would make something that would be comparable to Garrett wouldn't you ?

T51 has exhaust housing v band inlet at 99.1mm (3.9") and exhaust housing v band outlet at 115.5mm (4.55"). Unless I'm missing something I can't find an exhaust housing that has these measurements.

[iruvyouskyrine]

Ok would really like want some people that are actually using these turbo's, not just "talk to so and so" or your opinion if you don't run a Precision. People that are familiar with the exact v band housing flange dimensions, or ideally someone who has went from a HKS T51 to a Precision on a GTR. Not opinions, actual users running PT6870 or PT6466 v band housings ideally.
That's what I was thinking SiR_RB. Dale FZ1 I won't be modifying an HKS 4" stainless v band front pipe thank you very much, I would make a new one from scratch before that happens. Same with manifold, keeping HKS v band. Not going to chop an HKS kit up to fit a turbo. The v band gear really is great when your working on your car a lot and think they are superior to bolted flanges so I'd like to stick with them. No gaskets, just a clamp.
The info I guess I'm really after is the dimensions of a PT6870 v band turbo compared to the HKS T51. Mark from Godzilla motorsport assured me that Precision should have a direct swap turbo for the HKS T51.

Why not ask the guy who told you it would work then?

[BK]

"The Guy" is Mark Jacobsen from Godzilla Motorsport in Qld. He is generally pretty busy and hasn't got back to me about it yet. I know he's in the know with things of this nature as he was (might still be) fastest RB GTR doing 7s, but stuffed if I can find the v band flange dimensions in the Precision catalogue that suits. Everything seems to be smaller v band flanges. I'm starting to think the T51 HKS flange size is different than everything. Don't know if its worth doing new manifold, front pipe and gate arrangement to gain a few extra kilowatts with the PT6870 over the HKS. Really thought someone on SAU would have already done a similar swap and wanted some feedback on the changeover results if possible. Doesn't look like that is the case. I will report back if I get something concrete on direct swapping HKS to Precision.

As this thread is 137 pages what approx power is everyone getting with PT6870s ?

[iruvyouskyrine]

Most people who have done the swap are doing it from old school HKS/Trust T4 manifolds rather than V-Band. And as you would know T4 is a standard size, so wack on a new turbo, new dump pipe and away you go.

[acsplit]

I think the HKS vband was a specific size when they patented the manifold

[BK]

3 hours ago, acsplit said:

I think the HKS vband was a specific size when they patented the manifold

yep i think so after having a look.

3 hours ago, iruvyouskyrine said:

Most people who have done the swap are doing it from old school HKS/Trust T4 manifolds rather than V-Band. And as you would know T4 is a standard size, so wack on a new turbo, new dump pipe and away you go.

yeah I suppose so. Just throwing it out there if it will actually be worth the trouble. Remember I I have to travel 1500 - 2500km one way for a tune, hence want to be absolutely sure if I decide to go down this Precision path.

[Lithium]

On 11/10/2018 at 2:02 PM, BK said:

I now am running a Nitto 2.8 and would like to know thoughts on best PT to change to with mid 9's possible, running around the 30psi and 98 ron unleaded. (Don't tell me to run E85 as it wont be happening, to much hassle in Alice Springs to obtain)

From my research it looks like the PT6466 or PT6870 with the v band inlet / outlet exhaust housing is the go, does this sound about right ? Will these turbos match the HKS v band manifold and front pipe ? Are the dimensions of the turbo even similar ? Looks like the v band housing is 0.82 a/r on the PT6466 and the v band only PT6870 has two at 0.81 and 0.96 a/r. What's the advice for me. Should I go away from the HKS to the PT and if so which one will meet my goals with the 2.8 ?

I was thinking the answer will be to run the PT6870 with 0.96 a/r but please give me as much info as possible on this.

It's hard to tell from all this what your knowledge level is and what exactly you need from the turbo, so I'm going to be difficult and ask a few questions - though as others have alluded to, some of this should be between you and your tuner/builder partly for these kinds of reasons.

1) The difference in power, power delivery etc etc required to run a mid 9 can very HUGELY depending on what the chassis is setup like, what tyres are involved, how good the actual dragstrip/driver are, how heavy the car is (or even what drivetrain - is it a GTR?) etc.   Using 98RON with ANY Skyline GTR chassis is a big big ask for mid 9s, but if you are running a full weight h-pattern GT-R then this is a *very* serious ask.   Can you give us an idea of what the rest of the setup outside of the engine is like?

2) How serious is this 2.8?   When you say 30psi and mid 9s on 98 it makes one imagine a very "big" head setup but I don't want to assume anything. If you have a power target in mind that would help things.

3) Your post suggests you want less lag than the T04S, as well as mid 9s etc - have you ever hit the strip with the T04S?  And HOW laggy is it?  The T04S really isn't that large of a turbo, when I think of GT-Rs which will need to make the power to run mid 9s on pump gas I do not think of things which will be more responsive than a T04s.... the extra displacement may even things up, IF you are hoping to have a more responsive 2.8 setup than what your 2.6 T04S one was but the turbo itself is going to be larger.

Any result most people in here are familiar with for getting into the 9s will NOT apply as so much is achieved from pumping craploads of boost through a smallish cam setup on E85 which results in fat torquey power curves with decent response and capitalising on the fact that you don't really have to dance around knock at huge boost pressures/high EMAP.    All assumptions I am making about what you're trying to achieve is vastly different to this, I am inclined to think you are going to need a much larger turbo and are going to end up with a laggier setup than you expect if you are serious about shooting for mid 9s.   

You're going to need as much VE as possible and keep the rpm spinning at the dizzy end of the tacho so the cylinder pressures required to make the power you need are as low as possible.   This will mean big cams and a large turbo, though the exacts of this may vary depending on what the answers to my above questions are.  You are right, there are lots of people with results with these turbos - but when you are talking about a high strung pump gas setup you may as well completely disregard the results unless you are also going to go E85.

Edit: Oops, for some reason I read "T51S" as "T04S" - my bad... still not a huge turbo, going to something modern and ball bearing with the stroker may still improve usability a bit but you will still likely need something with bigger wheels to supply the significantly higher amount of power needed to do mid 9s.

 

Edited November 11, 2018 by Lithium

[Lithium]

15 hours ago, BK said:

I know he's in the know with things of this nature as he was (might still be) fastest RB GTR doing 7s

Also, he never was the quickest/fastest GT-R.  HKS had the record at 7.67, Heat Treatments was the first to beat that with a 7.57 and it's been gradually dropped since.   I'm pretty sure Mark's best was 7.6, after HT got in the 7.5s.   

[Nismo 3.2ish]

That’s a long way for a tune 2500klm  , where do you live, Alice Springs?

I would definitely make sure that I did my homework, hope you get it right ?

[ido09s]

How much power does the car make now?

have you raced it yet and what mph did it run?

I personally think you are asking for magical things to happen and they wont. You will find it very hard to swap brands and have it simply bolt up. You will need to change something. Get used to the fact you will need something done to make it all work.

As for tune, Mark Jacobsen hasn't been on the scene for a very long time. If you want to talk to someone who knows what they are doing speak to either Anthony @ Maatouks or CRD. If they cant give you reliable info then nobody can. I would also be flying someone in to tune the car than towing it 5000klm round trip just for a tune. At least you know its tuned in your weather conditions and wont be a ticking time bomb once you get it home