RB25DET turbocharger "stock" a/r.63 or "oversized" .70?

[JC71 0]

hello all,

98 R34 GTT RB25DET NEO engine with front mount Greddy intercooler, APExi intake, and kakimoto N1 3 inch full exhaust system , spec clutch, two stage boost "eliminated" (set to 7 )and a walbro 255 pump, nothing crazy.

looking at replacing the turbo with a fresh one as current one is original and definitely worn...

I would like a "bolt in"  type that utilizes all current mounting, connections , stock exhaust manifold and piping, looking at a "stock" bolt in replacement a/r .63

https://www.ebay.com/itm/153337361041

OR

a/r .70

https://www.ebay.com/itm/392114863244

 

what would be the advantages or disadvantages if I go with the .70, instead of a .63?

is there something else that would need to be changed to actually gain anything when putting in the .70 unit?

 

thanks

Edited June 25, 2020 by JC71

[Ben C34 2,504]

Second on won't bolt on.

 Im not sure why you would even bother with first option 

[Dale FZ1 185]

Both of those units are a long way from a stock bolt in option and would probably perform well below expectations compared to the OEM turbo especially without ECU tune changes.

OP - 0.7A/R comp housing does not provide any basis for comparison of 0.63 turbine housing on the other unit.  There's some very good resources out there in internet land if you want to get your head around turbos.

There are some decent replacement turbos out there that will bolt in and do the job you want.  Try an experienced supplier like Hypergear and see what can be done cost effectively.

[KiwiRS4T 772]

Cheap turbos don't last. For a decent upgrade that will bolt in see Hypergear.

If you want to make more than 300kw you will need as a minimum a Nistune chip, better AFM ,  injectors and  fuel pump .. so a few thousands of dollars rather than a few hundred.

[GTSBoy 2,589]

13 minutes ago, KiwiRS4T said:

If you want to make more than 300kw

The number is a lot lower than that. Not even getting to 190rwkW without all those things.

[GTofuS-T 1,976]

2 hours ago, KiwiRS4T said:

If you want to make more than 300kw

I didn't see OP say anything about 300kW?

6 hours ago, JC71 said:

looking at replacing the turbo with a fresh one as current one is original and definitely worn...

Unless you're actually planning on building the car or the turbo is literally pissing out oil, just leave it until it blows which it likely won't at 7psi...otherwise hiflow it, which will give you an actual and reliable improvement over stock while remaining as stock as you can get, and add a few extra grand for ecu and tuning as stated above

[KiwiRS4T 772]

5 hours ago, GTofuS-T said:

I didn't see OP say anything about 300kW?

 

OP was looking to buy a turbo that promised 430hp which is just over 300kw

He was also looking at at TD06 promising over 400hp and asked

"is there something else that would need to be changed to actually gain anything when putting in the .70 unit?"

so I told him what would need to be changed...

 

[JC71 0]

16 hours ago, Dale FZ1 said:

Hypergear

I will check out Hypergear, thanks

probably not be a possibility as they are in Melbourne and I am in the US, but ill get their input.

Edited June 26, 2020 by JC71

[JC71 0]

are the stock turbocharger on the rb25det neo ball bearing or journal bearing type?

 

what would be a good brand and model for a stock replacement?

Edited June 26, 2020 by JC71

[GTSBoy 2,589]

24 minutes ago, JC71 said:

are the stock turbocharger on the rb25det neo ball bearing or journal bearing type?

Ball, like all RB singles.

24 minutes ago, JC71 said:

what would be a good brand and model for a stock replacement?

There is no such thing off the shelf. All Garrett, BW, etc turbos are intended to be MASSIVE upgrades on the shitty 1950s technology that defines the stock Hitachi turbo.

No turbo that you will find on eBay from the usual scumbags is worth the $400 they want for them.

If you want a good "slight upgrade" replacement, then Hypergear's lowest end highflows are the closest sort of thing you can buy. Oh, and there is no problem buying from HG all the way from the US. You do realise that the world is round, right? And it is therefore possible for planes to fly all the way around? It's amazing what they can do with cardboard boxes these days.

Edited June 26, 2020 by GTSBoy

[Murray_Calavera 127]

If you still have the stock ecu and stock injectors, a good replacement would be their "G2" profile 

https://hypergearturbos.com/product/nissan-rb25det-turbocharger-standard-high-flow-service/

Maybe consider using one of their donor turbos to save you posting them your current turbo. I'm sure they can post a turbo to the states. 

[GTofuS-T 1,976]

Imagine the cost of shipping during coronatimes, Surely in the 300 million+ population of the united states there is someone who can rebuild a turbo locally...

 

22 hours ago, KiwiRS4T said:

OP was looking to buy a turbo that promised 430hp which is just over 300k

based on everything else the OP has stated he's looking for a stock replacement on a stock ecu not a 300kW upgrade...

[TurboTapin 12]

As already mentioned, do not under any circumstance purchase a cheap ching chong meow turbo off of ebay. You will regret it. 

[Dale FZ1 185]

1 hour ago, TurboTapin said:

As already mentioned, do not under any circumstance purchase a cheap ching chong meow turbo off of ebay. You will regret it. 

The location of manufacture is not the issue.  But the spec of the unit (dimensions, bearings, quality of castings and machining) is.

I've run a Kinugawa on RB, generally it was fit for purpose especially at the price point.