RB30DET turbo choices

[Bl4cK32]

U just confirmed what the opinion of a few people told me Thats great - looks like i chose right the first time...HKS 3037s it is. Power was wanted to be 330 ish so that make me happy

So running with a 3037s (0.87 A/R) and the 25 psi in mind how large an external wategate? (on a cast tubular HKS manifold)

[Skyrine-Dave]

RS500,

You seem to know your turbo's.

Can you tell me .. do you think a GT35 with .82 will be able to produce 500hp@wheels and if so approx what boost? i would expect it at around 25-30psi, true?

or would it be a better option to buy a 1.06 housing?

i am also contemplating purchasing a 1.06 exh housing and utilising both maps in my ecu (EMS Dual sport) 1. for .82, 2. for 1.06.. have them tuned accordingly.. but just an idea.

thoughts, comments?

[RS500]

U just confirmed what the opinion of a few people told me Thats great - looks like i chose right the first time...HKS 3037s it is. Power was wanted to be 330 ish so that make me happy

 

So running with a 3037s (0.87 A/R) and the 25 psi in mind how large an external wategate? (on a cast tubular HKS manifold)

dude,

i'm glad i could be of help.

what engine is it going on?

fyi, did u know that garrett make an equivalent turbo in their GT30 range?

wastegate;

most people with large turbos are running larger sized wastegates, so i'd recommend the turbosmart 45mm external gate. works a charm.

[Bl4cK32]

Specs:

R32 RB25DE NA Head - $750 (purchase) + $880 (Rebuild/Work)

Stock cams

Inlet 240dur 7.8mm Lift

Exhaust 232dur 7.3mm Lift

Very mild port & polish job mainly concentrating on the bowl area of the exhaust port.

Inlet valves deshrouded

Inlet valve seats have had a 3 angle seat job done.

Exhaust valves have had another type of seat job that is best for the airflow direction.

Head, manifolds & plenum port matched.

Stainless Steel Headgasket with built in O-Ring (Looks like it has 3 layers?!)

Series II VL Commodore RB30E NA Short Motor - $3450

Crack Tested - Crank, Rods & Block.

87mm RB25DET Wiesco forged pistons ~8.5:1CR

RB20DET oil pump

Nissan Rod bolts

Nissan Head bolts

King Performance Bearings

Blue printed

Os Giken twin plate & flywheel.

Balanced using the Heinz Balancer to 1 gram

This one

[RS500]

RS500,

You seem to know your turbo's.

Can you tell me .. do you think a GT35 with .82 will be able to produce 500hp@wheels and if so approx what boost? i would expect it at around 25-30psi, true?

or would it be a better option to buy a 1.06 housing?

i am also contemplating purchasing a 1.06 exh housing and utilising both maps in my ecu (EMS Dual sport) 1. for .82, 2. for 1.06.. have them tuned accordingly.. but just an idea.

thoughts, comments?

Dave,

first of all, what engine is it going on and what are the specs of the engine and support systems?

fyi, 500rwhp is ~373rwkw, so it's a bit of power, but i believe this power is able to be achieved with the GT35R (A/R .82), although it will need to be pushed on the higher side of 25psi.

i have seen a few of these Garrett GT35Rs on RB30ETs and they've had no problem making ~320-330rwkw on ~20psi. Of course, there were other engine mods to help make this power.

with the A/R 1.06, the power will be made easier and more efficiently as there will less backpressure in the turbine side, but i guess this will depend on what your application is.

if the car is for street/strip use, go the A/R .82 even 1.06 (as they're not all that laggy compared to the .82), or if it's for drag/dyno comps, then definitely go the A/R 1.06.

give this link a go, it'll help u with your decision.

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

good luck.

[Skyrine-Dave]

hmm interesting calculator. It recommended a GT42 if i wanted 26psi, a GT30 for 22psi and a GT35 for 24psi

My engine is very similar to Bl4ck32's setup.

I already have a GT35 with .82, application will be daily driven, and i would really love to go to willowbank and punch out a good time... low 12, high 11 in my dream world.

Rev limit would be 7500rpm absolute max! maybe even 7000rpm for safety

[RS500]

Specs:

R32 RB25DE NA Head - $750 (purchase) + $880 (Rebuild/Work)

Stock cams

Inlet 240dur 7.8mm Lift

Exhaust 232dur 7.3mm Lift

Very mild port & polish job mainly concentrating on the bowl area of the exhaust port.

Inlet valves deshrouded

Inlet valve seats have had a 3 angle seat job done.

Exhaust valves have had another type of seat job that is best for the airflow direction.

Head, manifolds & plenum port matched.

Stainless Steel Headgasket with built in O-Ring (Looks like it has 3 layers?!)

Series II VL Commodore RB30E NA Short Motor - $3450

Crack Tested - Crank, Rods & Block.

87mm RB25DET Wiesco forged pistons ~8.5:1CR

RB20DET oil pump  

Nissan Rod bolts

Nissan Head bolts

King Performance Bearings

Blue printed

Os Giken twin plate & flywheel.

Balanced using the Heinz Balancer to 1 gram

This one

nice specs dude.

what's the application of the car?

the reason i ask is that for a 3.1L engine with twin-cam head, you'd probably be better off going for something a little bigger (eg, GT35R with A/R .82) as you'll be able to reach your power target easily & efficiently and yet still have heaps more headroom to be able to make more power again.

Although, again, it all depends on what the purpose/application of the car is.

[RS500]

hmm interesting calculator. It recommended a GT42 if i wanted 26psi, a GT30 for 22psi and a GT35 for 24psi

My engine is very similar to Bl4ck32's setup.

I already have a GT35 with .82, application will be daily driven, and i would really love to go to willowbank and punch out a good time... low 12, high 11 in my dream world.

Rev limit would be 7500rpm absolute max! maybe even 7000rpm for safety

so, another one with an RB31DET, nice.

dude, i think you should be fine with the GT35R (A/R .82) if it will a street driven car, and with the specs of the engine (if the same as bl4ck32) and turbo, i would be looking more along the line of a low 11 if the car is setup right and has good traction.

[Sydneykid]

Hi guys, I have no idea where these boost figures are coming from. We have an RB31DET (RB26 top end) that makes 637 bhp on the engine dyno (around 550 rwhp on the chassis dyno) using a GT35R at 20.5 psi. There is no way it would ever get to 24 psi, there is simply not enough resistance in the (modified) RB26 inlet system. The GT35R (1.06 turbine) doesn't have enough air flow to make that sort of power and still have 24 psi of resistance.

Put another way, the engine swallows all the air flow that the GT35R can make, so there is no airflow left to make more boost.

Our experience basically confirms what RS500 posted and what Ray Halls online calculator shows.

[Steve]

Bl4cK32, I am with SK and RS500 on this one. I have seen the GT35R produce some very good results with a 2JZ in WA, I would think for an RB31, you wonldnt want to go much smaller. I dont think a 0.8 housing will be big enough either.

If it were my engine, I would go the 1.06, esp as you are doing head work and match porting. I find with 0.87 on an RB25 (no port work, not matched) it really isnt too laggy for the street. Boost starts just on 2000rpm, although it really doesnt kick until close to 4000rpm, but it does pick up the bottom end/midrange enough that it feels quite lively, more so than it did with the stock turbo. Remeber also that you have a MUCH torquier (if there is such a word) engine, and you will find the bottom end/midrange is fine for putting around the street.

Lastly, when I had a 0.61 housing on mine, it was too small and meant that I could only run low boost on the street or the car would go sideways at the most inopportune times - like heavy traffic. Not fun. With a larger housing, throttle control is excellent. You can run higher boost and control it with the right foot, not on/off as it is with too small a turbine housing.

At the end of the day, it will be a nice package which ever way you go, I just think anything smaller than a GT35 may be selling the potential a bit short - you have a tough engine there by the sounds, enjoy it.

[Steve]

Having said that, the 3037S will give an awesome midrange when tacked on a RB31, when they come on boost at WOT its a very nice thing:) If you want more, just go twins.

Sorry, gotta dream.

[Bl4cK32]

Well as it stands, I can get the HKS 3037s 56t (0.87 exh) with a HKS cast manifold...or I can get a GT35/40R turbo with a 0.8 exh. housing with the same cast manifold....

Now Im confused...so the GT35/40R would be ok for 330 ish rwkw on an RB31DET? Not too laggy? How would it go with the 0.8 ex.housing?

By the way steve i got some 265's im trying to squeeze in there As for application...well how about till im satisfied

[SE-Rfornow]

Please forgive my ignorance to this subject... I'm just a yank trying to learn some info:).

What about twins? Could the rb26 setup (manifold etc.) be used successfully? I don't know what the limit is on the stock turbos but I've heard some really nice hearsay. Would the twin setup with smaller turbos really help lag compared to a larger single?

I'm getting better versed on the rb30, but still trying to comprehend the turbo choices. Would the rb30det be similar to a 2JZ in turbo choice? Is the rev'ing ability the same as the rb26 or is that lost with the change in block?

[Steve]

Bl4cK32, if you are not too sure, go the 3037, you can always sell it later and get the GT35R if you want a bit more, and make sure you have good rubber on the rear and a good wheel alignment:).

I do think a 0.82 housing will be a bit small, even 0.87 on the 3037 will be a bit small. Unfortuneately, it can be a bit hard to know exactly what you want as it is different for different people - but dont underestimate the torque of the 3L.

SE-Rfornow, technically twins will spin up a bit quicker than a similar sized (as the two) single - but you have twice the cost involved, two wastegates, AFMs, dumps etc as well as problems of trying to fit two large twins on. The RB30 has a longer stroke, so not as friendly towards high revs. Also there are other problems with RB30 (nissan as opposed to OS Giken) and higher revs, but there are others that could tell you alot more than I, sorry. 2JZ has a similar stroke and bore size to the RB30.

[Bl4cK32]

Bl4cK32, if you are not too sure, go the 3037, you can always sell it later and get the GT35R if you want a bit more, and make sure you have good rubber on the rear and a good wheel alignment:).

Well...Im going for the Garrett GT35/40R now....I think. I can get it brand new for $1950, where as the HKS 3037s is closer to 3k mark. Brand new the turbo sells for like $5k from BD4's (Yes i know the whole kit is $10K Steve )

It comes down to cash i suppose...even though like u said Steve, u probably end up paying the same in the end anyway:(

PS - Rubber and a wheel alignment are no problemo compared to choosing this turbo and actually FINDING someone who can supply one for a decent price

[Steve]

If you want someone to source it for a decent price, a couple of years back Per4manz turbocharging in WA were doing a kit for well under 10K with a GT35R. Might be worth giving them a call.

[Bl4cK32]

I think thats whats stopping me Steve. he fact that its up to 10g's up in one hit. I have just put the deposit on the GT35/40R + manifold (cheaper than the 3037s by itself!) so we'll see how that goes...

So seeing as i got this now...the weakest item is the conrods i presume now? What sort of power level is safe for the std RB30 rods?? Anyone??

[Steve]

RIPS has had over 440rwkw from an internally standard RB30DET - seems to be quite reliable. They are ALOT larger than the RB25 ones - if you can break (bend) one with 350rwkw you will be doing very very well:)

[Bl4cK32]

Thats what im afraid of. I want it to be reiable, so less than 350rwkw say 330 rwkw - would this stop banana rods? :bananaman

[Steve]

You would be the first that I know of if you did it with 350, I have 320 with skinny little RB25 rods (ok different rod ratio, but still applies to some degree) and dont have a problem. Like I said, RIPS has 440rwkw+ running nos and no probs.

Your engine will be quite tough with the right tune.