What Is The Best Turbo For 300rwhp With Minimal Lag?

[Roy]

Agreed 100%. Sounds like he is out there and doing it. Incidentally how do you find your 32 deals with heat loadings?

Well at 230rwkws with std radiator and a 19 row oil cooler i can get about 4 laps out of it before the water gets over 95 and oil nudges 100 deg C. I stop at that level because its a std motor. But as soon as i wind 19psi and 260rwkws into it i can only get around two laps out my car at full noise and 8,000rpm. Of course if i run a tad lower boost and only use 6,800rpm por so instead of 8,000rpm then i can circulate pretty comfortable on the std radiator.

So, borderline and ruins the fun as you can get into a rhythem and work up to a lap, but still fun. I have shrouded up the std radiator so any air through the front bar has to go through the intercooler and the radiator. I have new electirc thermo fans, low temp thermostat, and tossing up between a PWR or Race Radiator setup to go with my Billion thermo controller. But yeh, lots of agro for a lousy 50hp, woudl probably be quicker doing more consitant laps at lower boost with more running then winding it up boost and revs wise and being messy

[PM-R33]

Maybe I took the OP's comments a little differently, but I'd think he's generally looking at the "drag" between turns, not a 1/4 mile? Don't under-rate how fast and easily a 300rwhp Skyline can cover ground...

I'm not, however remember that it isn't to hard to have a setup that can make more power and be more responsive than the stock turbo setup is. Just because the stock turbo is small, doesn't mean that is is the most responsive and has the best low down power possible, because that simply aint the case.

But yeah you are right, he probably did mean out of corners on a bit of a straight or something because out on the street driving along and putting your foot down, no way in hell.

Edited May 1, 2010 by PM-R33

[Sheriff Wan]

Think I'm able to comment here...

I have a 32 with 25DET and its running a 2530, it was a legacy from the RB20 I used to have.

Just had it tuned by Trent (Status) and it made 231rwkw @ 15psi.

It makes full boost by 2750 and pulls nicely to redline and picks up from anywhere and in any gear. I cant say it feels like it needs more, especially if any street driving will be done. More than capable of lighting up 3rd in the dry with 235's on the rear...

[PM-R33]

Thats very good power out of a 2530 on 15psi. Did it have more left in it on more boost?

[fubar]

Maybe I took the OP's comments a little differently, but I'd think he's generally looking at the "drag" between turns, not a 1/4 mile? Don't under-rate how fast and easily a 300rwhp Skyline can cover ground...

Agreed 100%. Sounds like he is out there and doing it. Incidentally how do you find your 32 deals with heat loadings?

That spec high flow was mine Adrian. 300rwhp @ 12psi. Max boost by 2700rpm. Easy, reliable power and because it made power early it was very easy to drive fast point to point. Not really a drag strip weapon, but in terms of getting power down early out of turns it could get the jump on 260-300rwkW cars and generally punch above its weight.

I've not seen anyone else run with that turbo spec, but it certainly worked. Not sure, but I don't think it would do much more than 300rwhp, cranking more boost should yield bigger mid range stick though. I often wondered if an OP6 housing would have allowed it to make torque as the rpm went over 6000, but not have a major impact on torque between 2000-3000rpm.

Given that this is a proven unit, I'd go this way. Really very similar to the unit I had built, with the advantage of some extra flow capacity if desired. Back it in this should produce the 300hp @ 12psi as mine did, but with the ability to make another 40hp with a few more pounds. Possibly some differences in boost response right down low in the rpm, but I'd be certain Stao could supply the 48T cartridge if it was an issue.

Cheers dale for the comments sounds like you have a good set up just what im after, what ecu and set up are you using?

Yeah i do beat up on the car alot and the temps stay fairly good. say when im drifting it sits at 7000rpm for about 5 to 6 laps (dependging on how long the tyres last) and the water temp stays below 100 deg but the oil temp can climb up to the 120 to 140 mark depending and the ambiant temps. i have a oil cooler and big alloy radiator and never had overheating issues even on a 38 deg day, On track days i have done 15 laps straight driving it real hard and its fine, just the tyres that give up:)

So you would reccommend hi flowing the standard turbo?

[Dale FZ1]

With that spec, I ran a PFC, 040 pump, and the brown 450cc manual trans spec S15 injectors. Basic, cost effective and sized appropriately to the job.

If you want to consistently bang up around 5000-7000rpm, it sounds like you need to make sure the turbine housing isn't such a restriction. Ask yourself where you want the peak torque band to sit in the rev range, and check the turbine options. As much as anything, it's how/where you make the 300rwhp as what the ceiling is. I found the stock R33 spec housing started to choke as revs rose, and it had well done its best by 6500rpm. I don't know if the OP6 Neo spec housing is the same as Hypergear's 0.63 A/R casting.

You've seen a post on this thread from a reputable SAU trader with his recommendation. I'd probably be getting on the phone to Stao and discuss what options he can give you to tailor the equipment to your needs. Running high revs/load and with excessively high turbine inlet pressures aren't good for power production, and can lead to engine problems with excess heat retained in the combustion chambers.

140 degree oil temps don't sound great, I would be consulting for technical advice and make sure you are running an oil spec that can survive that treatment too. My guess is that Roy has been down that path already.

[perzn_34]

http://www.hksusa.com/images_products/1674.jpg

[jono2jz]

disco potato would be insane to drive with on a rb25

[GTScotT]

i think a disco, despite being a nice turbo, is too small for the 25.

[Sheriff Wan]

Thats very good power out of a 2530 on 15psi. Did it have more left in it on more boost?

Maybe a little, Trent tuned it - I haven't posted the Dyno yet, but I can if you want.

Initially its was 14 psi and ~225 kw, so it had a little more, but standard injectors (90% duty), so didnt want to push that hard. But it seemed to respond well to more boost

I was only really after a streetable package, dont care about the numbers, just want good powerband and response - which I have in buckets now

[Munkyb0y]

thats good news ^^, coz i have a hks 2535 sitting here with 480cc injectors and a z32 afm to go into my r33, most likely on a nistune, when i eventually get my ass motivated, and other more important crap stops coming up!

and like you, i'm not interested in numbers. i just want response, low/mid range torque, and a totally useable street car. oh, and a few spare sets of tyres

i would imagine close to 250rwkw at 18psi or so?

Edited May 3, 2010 by Munkyb0y

[The Dan]

disco potato would be insane to drive with on a rb25

Yes they are insane. They are the most responsive turbo in their fram size. Including the GT25 range. I don't think anyone here has actually compared the flow charts for them to a 2530/35 otherwise they would reliase the Disco is a much better turbo for the job. Like was said above, smaller doesn't always mean better. And there is somthing to be said for MATCHING the right turbo to an engine, not just getting some tiny thing and saying 'oh it's sweet, it comes on hard at 2700' when the last part of that sentence ends like this: 'yeah but it drops off very quickly at 6000rpm'

Disco will come on at the same time, gives you the potential for moe power when you want it and will pull all the way to redline.

[Dale FZ1]

Is the HKS GT2530 not using the same cartridge as the Garrett GT2860RS aka Disco Potato?

Is the real difference between those two units that

1. GT2530 uses a RB friendly T3 flange pattern that allows it to bolt up?

2. GT2860RS uses a T25 flange pattern, and a larger 0.86A/R housing vs the 0.63 for HKS?

There was a comment passed on a particular spec high flow, which happens to use the next size UP compressor and therefore with greater flow potential. It was good in its intended environment, and the experience shared with someone who wanted to know.

Best practice is to match turbo to engine to intended use. For that reason I'd still advise fubar to consult with the supplier and find what turbine housing sizes/options are available for that given turbine size. If he wants to make the thing able to breathe at higher rpm, go for the bigger housing.

Shame that the GT2860RS is spec'd with the T25 pattern because otherwise it would probably have been used in plenty of RB25 engine bays already.

[discopotato03]

No time ATM but .

GT2530 = 446179-5021 CHRA , from memory GT2860RS = 446179-5066 .

The real original spec DP turbo uses a 0.86 A/R T25/28 flanged GT28 turbine housing .

I reckon the 48 and 52T GT2871Rs are better sized unless you want a std replacement in the form of a Garrett GT BB turbo .

Yeah Dale an OP6 housing on your Hi Flow looks like a good idea ....

A .

[Black_CSR]

I Have Hi Flow Spec Turbo in GT2860RS on a 0.86A/R Housing. on 58T I have a RB25DET.. I plan running it on 17-18PSI n they've increased the Max RPM to 8000RPM.

It's gettin tuned tommorrow wif Sard 550cc injectors n Z32AFM.

Hypergear made it for me :-)

[GTScotT]

keen to see your results mate, dont forget to post em up

[discopotato03]

Actually the original form of the GT2860RS was with the 0.86 A/R turbine housing . Many at Garrett in the US reckoned that if it didn't have the larger ratio turbine housing it wasn't a real DP turbo . They also said that HKS was silly not to have had a 0.86 A/R turbine housing available for the GT2530 .

Anyhow like most things in the GT25/GT28 families the hard bit is finding a T3 flanged turbine housing to make them bolt onto RB exhaust manifolds . HKS have them in 0.64 A/R and Garrett don't do any T3 flanged housings for them at all .

A .

[D_Stirls]

It seems ATP offer T3 housings for the GT25/8 range, external gate though.

http://www.atpturbo.com/mm5/merchant.mvc?S...tegory_Code=GRT

[discopotato03]

I think if you really wanted to run a GT2860 family BB turbo the go would be to find a second hand "GT2530" designed for an RB engine and run that . If not enough you can run a GT2871R in its turbine housing because they use the same turbine wheel .

Something to think about is the fact that HKS GT2530s seem to work well on RB20's so you'd think an RB25 could use something with a bit more airflow .

I'm just looking at the maps for the GT2860RS and the GT2871R 48T , the RS hit the wall airflow wise at about 36 pounds and the 2871 48T at about 39 pounds by mass of air .

JC put together the original RS turbo for an 1800cc four and while they also work well on 2L fours I think the airflow from them is a bit lacking for a 2.5L six . An RB25 isn't exactly lacking at low revs so it doesn't need boost for torque at 2000 revs . From memory std RB25 turbos have a compressor that's around 68-70mm OD so I wouldn't want to be going smaller than that .

Possibly what the original poster needs to think about is what turbo would give OE like power delivery and have a bit more squirt without any loss of response or torque - anywhere .

I can see where people think the lowest possible boost threshold would be good but instant torque at low revs can actually be tiresome to live with because you end up getting boost when you don't want it and it always feels on/off with little in between .

Dale do you have the link to your hi flow thread ?

A .

Edited May 5, 2010 by discopotato03

[hypergear]

I've built few different housings in T3x bolt flange with a OEM 6 bolt dump pattern that is made to suit a GT2xBB and T2x sleeve bearing housings. available in .63 T3 and .82 T3 as well as modified T28 turbine housings rated at .64 and .86.

My main concern would be high back pressure running the small .64 rear housings. I believe its wise to run .86 modified T2x / .63 T3x rears to maintain similar response, while picking up better torque with lower back pressure.

My self is currently running a 2871 52T profiled sleeve bearing turbo in T3x .63 rear with OEM dump pattern. The driving ability is exactly same as the stock OP6 turbo with about 25% more power and torque through out all rev ranges.

It does not have this strong "pull feel" as my previous 3586 or 3076 profiles in .82 rears did but far more responsive then any of them.

I'll be seeing dr.drift for a tune tomorrow and see what it makes