Help Selecting Single Turbo For RB26DET(T)

[nocab72]

Car: '95 GTR R33 V-Spec, RB26DETT

Miles: 24,000

Current Condition: Bone Stock

Have ordered most of the STD goodies to prepare for this buildup:

* Nismo TwinPlate

* PFC w/Commander & Datalogit

* Fuel Rail, Pump, Lines

* HKS Type R Intercooler

* 264 Cams, Cam gears, etc

etc, etc, etc...

Just finished my RX7 single project, Large Street Port 13b w/Garrett GT35/40, put down 420rwhp @ 16psi (94 Octane pump) and just over 500rwhp @ 22psi (100 Octane). Get excellent spool for my driving habits, starts boosting by 3800rpm, full boost by 4500 - 4800rpm & 9000rpm redline.

Would like to have similar spool and performance caracteristics on the GTR and looking for insight on a single turbo choice for it. The car will be 98% street driven, with a current power goal of 600awhp (US Dynojet). Am currently looking at the Garrett GT40R or GT42R. Will the GT40R take me to 600awhp? Are there other singles I should be considering?

Thanks for your expertise, opinions and advice!

K

[Gav]

Just my personal opinion, having driven both big single and twin high mount versions, I much prefer twin terbs for the street. They tend to be more responsive and give a broader torque curve.

Also, there is no sound on earth like a GTR with two large highmounts spooling up!

[wreckedhead]

my personal opinion , sorry to say this to you GAV but ive also had both twin turbo and single turbo set up in my gtr's and i can honestly tell you that there is no beter feeling, then driving a gtr with single conversion, (eg t78 or t88) waiting for the boost to kick in and hearing the external wastegate open up will serioulsy demolish any thoughts of twin turbo set up being beter, sorry no offence its just my 5 cents.

[Morgs]

He said twin high-mounts

Im figuring a GT40R would be size enough for that power output...

[wreckedhead]

ah yeah i didnt read properly, sorry my mistake, is not my fault i read every 3rd word.

[PurpleR32]

HKS T04r cut back, or the new HKS T04z.

Both support around 600hp, although the T04z is newer and is supposed to spool up quicker due to the holes drilled in the compressor cover.

Trust T-78 either 33, or 34D.

thats for high mount single.

However, it would be very hard to achieve (on an un-stroked RB26) 600hp and have full boost hit by 4500rpm. thats with any turbo.

I know two people who have made 320rwkw on thier R33 GTR's with HKS 2530's. These are a low mount bolt on application.

They have a great spool and would hit full boost around 4500rpm.

how much does 320 rwkw equate to in HP?

[Sumo]

429.1271

[Morgs]

Don't forget we use Dynodynamics and DynoJet is the standard in the US

[Butler]

if u r aiming for 600ps or less then the best option would be to go 2 lowmount turbos ..maybe twin trust t51z's or twin hks 2540's or gt-rs's ..that way it will give the best response and torque ..however if u want to go down the single turbo path ..maybe a to4z cutback ..or trust t78 or even a t67 for good response ...there are other things we need to know like are u going to rebuild the engine and gearbox options!

[nocab72]

Took a few minutes and crunched some #'s with .xls.

Do these calculations looks close for a stock RB26?

http://flathat.woodstream.net/R33/rb26comp...sormaptech.html

If so, they line up very nicely with a GT40R...

K

[RS500]

nocab72,

according to Ray Hall's turbo match app, it seems that with a rev limit of 9000rpm and 26psi on an RB26, you will require a GT42 with A/R 1.22 exhaust housing which would give you ~700bhp and 64lb/min worth of air flow.

http://www.turbofast.com.au/TFmatch.html

yeah, it sounds all good and sweet but then again, i'm not too sure how this turbo would be for a street GTR, i would dare say that it would be quite laggy down low but with a monstrous top end power band.

[Sydneykid]

Hi nocab72, my suggestion would be a Garrett GT35R, good for 700 bhp less around 60 hp for losses on a 4wd hub dyno. However I wouldn't be aiming for that sort of power on standard RB26 internals, particularly pistons and conrod bolts.

As for spool up, being a 3.9 litre 6 cylinder 2 stroke, 13B rotaries have a lot of exhaust gas flow. If you want that sort of boost build out of an RB26, I would suggest around 2.7 litres with 9 to 1 compression ratio, porting and a good dose of ceramic coating.

Hope that is of some help.

[Harry]

Just had my build finished using a Garrett GT35/40 (admittedly using a 2.8L setup)

On 106RON fuel dyno results (from dynapack hub dyno) below

http://web.onetel.net.uk/~bluem/Rebuild/Dy...Dynodataweb.jpg

[DoughBoy]

Nice graph there Harry, how is the car to drive? Happy with it?

[Merli]

Wow... that's an awesome power curve and boost response you have there Harry!

Excellent work!

[B-Man]

A bit OT - but why does Torque always drop off a bit at the end ?? I noticed nearly everyone's dyno graph does that.

BTW - Nice one Harry !

[Sydneykid]

Hi Harry, looks awesome. What else have you done, other than 2.8 litres of course?

PS; Why di they stop the run at 7,000 rpm?

[Harry]

Hi Harry, looks awesome. What else have you done, other than 2.8 litres of course?

Full spec here

PS; Why di they stop the run at 7,000 rpm?

run went to 7500rpm - chart updated now (my mistake) - limited as no need to run further - engine was set up for max torque on or around 4000rpm onwards

Nice graph there Harry, how is the car to drive? Happy with it?

Excellent!!! and v happy so far - havent really had a chance to drive it in anger yet - still a bit wet here