Are N1 the best upgrade for r32 GTR

[Matty George]

Hi all, was just wondering if N1 are the best upgrade from the stock ceramics on my GTR? Thoughts? -5 are laggy I hear?

[KiwiRS4T]

Depends on your budget and ultimate power goal. check this out:

http://www.goodezilla.com/rb26dett-skyline-gtr-single-turbo-vs-twin-turbo

[djr81]

No N1's arent. If you want stock twin bolt up style turbros (And not a single) Garrett do some good work.

Have a look at the Garret range 2860's.  707160-7, 707160-9, 707160-5 in order from small to large.  By way of random shops.

https://justjap.com/garrett-gt2860r-7-twin-turbo-kit-nissan-skyline-gtr.html

https://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=GRT-TBO-074&Category_Code=RB26

https://justjap.com/garrett-gt2860r-5-twin-turbo-kit-nissan-skyline-gtr.html

[Matty George]

Watched the video and those lads do great stuff. I’m not interested in going single I want to remain original with low mount twins. I’ve heard n1 are the best upgrade for twins bud just wanting others advice.

[BK]

Basically -7 are R34 N1

-9 slightly larger is essentially HKS GT-SS and -5 is larger again and essentially HKS 2530.

Essentially....doesn't seem much difference between -7 and -9 from all results.

Get the -9.

[Matty George]

Why do you say -9 bk? 

[BK]

Slightly bigger than -7, but no real world noticeable difference in spool and slight top end better flow.

I have HKS GT-SS twins on the 33 and I don't think any other twins spool better.

-5 has a lot more top end but a lot more lag, more than a lot of single setups

[Duncan]

Also, there are at least 4 different specs of n1 turbos

R32 n1 were bush bearing only and about as laggy as -5 but make probably 20% less power. You would only choose them if you were racing in a class that required the factory turbos for example

R33 n1 were ball bearing and a little smaller, and in R34 there were smaller and larger rear housing options. Either way these are roughly equivalent to -7 and -9 respectively, but more expensive

The "best" turbo always depends on your power target and how responsive you want them to be. For road driving where you are looking for a little more than standard (say 20-30%), -9 is a great compromise.

BTW there is a really long thread with  people's actual experiences with rb26 dyno results, suggest having a skim if you want a range of experiences.

[GTSBoy]

The more I think about it, the more I think that the best "twin" setup is a v.large turbo + an Eaton screw supercharger.

[niZmO_Man]

What is your goal though?

[Matty George]

I’m not looking for any more than 350kw. Just looking for a nice street car.

[Duncan]

350 awkw (australian wheel kilowatts) will require -5 and will come with a bit of lag. 300-330 is a better sweet spot and would still move you around town ok.

[joshuaho96]

If you want the absolute fastest spooling bolt-on twins the best are still the stock ceramic turbos. With the ceramic turbine. The R34 ball bearing ceramics are the fastest spooling of the three gens.

If you want more power and more durability the GT3-SS is the next step up. It spools faster than the -9s despite the journal bearings but you give up high-end power, an honest 300 awkw should be possible with good fuel and tune. If the engine flows enough at the midrange it will be a better option than -7s which trade a little bit of top end for not much faster spool.

-9s are going to deliver more power than GT3-SS and if you don't have a VCAM step 2 or step 1 with 50 degree advance the RB26 just doesn't breathe enough for a really substantial difference in spool vs a GT3-SS.

Beyond that just go single turbo. Honestly the only reason to stay with bolt-on twins is to avoid getting defected and to have a well-understood setup that tuners have done many times over the decades.

[BK]

Joshua you seem to be pushing the new Mitsubishi core HKS gt3-ss turbos like they are a better turbo than the ball bearing Garrett units already available. Spool faster than -9 ? Really ? Do you have any actual experience with them directly ? Or are you just quoting the HKS propaganda ? Of course HKS is going to say their new non Garrett stuff is better than their old Garrett based turbos.

Lot of GTRs in Australia and I am yet to hear of anyone purchasing a set of these, using them and publishing results here. Same goes for the GTIII-4R and GTIII-5R - no one is using them. If these new GT3 HKS units are so good, why isn't anyone down here using them ?

Matty George, again Garrett -9 mate. You'll be happy as Duncan said with the 300 - 330kw they'll provide. Also see below.

Check this table, has a good reference for the twins. You'll see -9 and HKS old GT-SS is identical.

[joshuaho96]

You are correct that the GT-SS and GT2859R-9 are the same turbo, I never argued that. I'm just looking at the data that I can see and making assessments from there. As far as turbo spool goes the GT3-SS with VCAM step 2 looks like this vs stock:

The -9s with the same VCAM step 2 looks like this compared to stock:

This is from U.P. Garage in Washington. Maybe the guy has a vested interest in selling HKS turbos? What stands out to me is the GT3-SS is pushing 10 psi by 2500 RPM while the -9s/GT-SS are closer to 3000 RPM. The huge overboost from like 3000 RPM to almost redline is maybe overselling the capability of the turbo but clipping the boost to be 1.3 bar flat would just flatten the torque curve even more.

He also had some other neat charts like this VCAM step 1 stock ceramic vs GT3-SS:

This one shows to me that the stock turbos ultimately build boost the fastest, so if the power goals are maybe 250 kw then stock turbos are as good as it gets.

[Matty George]

Going to stick with Garrett just unsure of bolt on options. Will continue to ponder -7,-9 .

[BK]

I have owned and/or driven rb26 motors with stock turbos, R34 N1, -7, -9, -5, -10, GT-SS, 2530, 2540 low mounts over the years. My conclusion is based only on what I've had a chance to drive, hence recommending -9, and settled on HKS GT-SS ball bearing turbos myself. Garrett -9,-7,-5 ect weren't out then and came later, as HKS still had the exclusive Garrett aftermarket rights back in the mid 2000s.

I do love the SS / -9, but wish there was something that spooled like them, but had the top end of the -5. -5 top end was pretty good I thought. That would be an ideal combo but without more like a 3 litre bottom end with -5 it doesn't seem possible with twins to get it.

[joshuaho96]

-7s and -9s is a pretty simple answer. If you want more power get the -9s, they have a more efficient if narrower compressor map, especially at high boost. If you're ok with less in return for a touch better response get -7s. I agonized over this for a while but after seeing the prices for a full -9 kit vs GT3-SS I think I'm going with the GT3-SS.

[BK]

Prices AUD for a pair

Garrett -9 / -7 ball bearing are $2500 -$3200

HKS GTIII-SS are $4400-$5500 for plain bearing.

I think I know which ones most people are going to buy....

[BK]

Actually probably none of the above as they have already gone to a single