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Discussion Starter · #1 ·
shuffle's driving me mental.
you have to be driving a certain way to provoke it, but now i'm getting to know my local roads better, that's how i'm driving.
i ease off before the corner, and then keep a light throttle, medium revs (5kish) picking it up once visibility allows and the car takes it's set for the bend
but the shuffle is unsettling the car just when you need it to be balanced, so i'm considering a single to solve this

the obvious choice for an rb30 is a to4z, or a gt40.
but rod has talked me out of this so many times, as he's adamant that for the way the car is used, i'd lose response and ultimately be slower, and more frustrated than with my current twins (2860's, -7's i think, the ones below -10's. slightly bigger than 2530's, slightly smaller than gt-rs's.
allegedly)

so what about a smaller single, like a gt35r?
scoobyclinic claim 650 for their hybrid, which is about what i'm making atm. i've never heard of anyone putting a single that small on an (os) rb30, but rod still swears it will be less responsive and more laggy

is he right?
(he usually is)

many thanks
luvgav

ps
in the meantime i'm about to try a balanced bar manifold. how much power do you reckon i'll lose?
(260 cams)
 

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Sounds like you are running -5s - though you shouldn't really have shuffle issues with them.

In regards to your query about singles, people have funny ideas about singles, thinking you have to go a big one to make them worthwhile or thinking that they will make the car laggy. GT35Rs are awesome on RB26s, if you don't have any of the existing bits to make the change over but would like to then I'd strongly recommend getting a GT3582R with a twin scroll T4 (1.06a/r) turbine housing with twin scroll manifold. I just went for a quick blat in an EVO running such a combination and the response/spool is insane.

In my opinion you'd get better spool than you get with -5s, and a GT35R is a 600-650hp turbo so you're unlikely to be disappointed with the power it makes.

Just my 2c...
 

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Sounds like you are running -5s - though you shouldn't really have shuffle issues with them.
+1, sounds like a tuning issue more than anything

GT35r (red) 0.8x t4 rear on china manifold vs TO4Z (blue) on same setup (nothing else changed, both split pulse iirc)
Its on an RB26 - so both will come on song earlier with the 3L, but it gives you an idea of the difference in power delivery

 

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Discussion Starter · #7 ·
I will depend on what power and boost you want to run.

What boost are you running at the moment?

Richard
1.4 bar
i'm making 1 bar at about 3200rpm

thanks for all the informative replies so far
 
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sounds like the exhaust housings are too small causing shuffle due to the turbo,s being spun very easily by the 3.0ltr motor but the throttle are only open a small amount no where for the boost to go.Presume your running a management system using air flow meters?

ps
in the meantime i'm about to try a balanced bar manifold. how much power do you reckon i'll lose?
(260 cams)
waste of time I feel , hassle with gaskets blowing manifolds cracking

T04Z fitted with a 1.00 ex housing will work awesome , very very responsive. Hasnt Nismoman got a T04z fitted to his RB31?

Have you played with the cam set up on a dyno , you maybe able to retard the inlet cam right off make the motor make boost a little later , there be less energy to sppol the trubo at part throttle may then move the shuffle rpm point upwards then.

any more questions fire away
 

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Discussion Starter · #9 ·
sounds like the exhaust housings are too small causing shuffle due to the turbo,s being spun very easily by the 3.0ltr motor but the throttle are only open a small amount no where for the boost to go.Presume your running a management system using air flow meters?
i've ditched the airflow meters and am running pfc djetro

rod has several 3 litre cars with a to4z, but swears that my setup is more responsive in real-world road conditions, ie off the throttle and then back on again when visibility allows

what he's saying is that for a given horsepower it's better to use twins as opposed to a similarly rated single, as the mass of the single bigger turbo creates more inertia than in the two smaller ones, despite the power ratings being the same(ish)?

i'm distinctly unenthusiastic about the balance bar manifold, but more with regard to losing boost low down. if it's going to be unreliable as well then i really need to have another chat with him...

thanks again for all your replies, dyno charts especially :thumbsup:-
 

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Discussion Starter · #10 ·
In regards to your query about singles, people have funny ideas about singles, thinking you have to go a big one to make them worthwhile or thinking that they will make the car laggy. GT35Rs are awesome on RB26s, if you don't have any of the existing bits to make the change over but would like to then I'd strongly recommend getting a GT3582R with a twin scroll T4 (1.06a/r) turbine housing with twin scroll manifold. I just went for a quick blat in an EVO running such a combination and the response/spool is insane.

In my opinion you'd get better spool than you get with -5s, and a GT35R is a 600-650hp turbo so you're unlikely to be disappointed with the power it makes.

Just my 2c...
i think you understand where i'm coming from- i don't actually want to make any more power, i'd just like the same power and response as i have now (620-650ish) but without the shuffle/with a smoother delivery
 

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Discussion Starter · #11 ·
Here was my 3540 result accompanied by head mods etc



Was mental and about to become even more so !!
terrific result, thanks for posting

forgive my ignorance, but is that on a 2.6?
 

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-5's WILL be more instantanious than the single from lower down , but you might be talking almost un noticible amounts.
-5's really are the biz on a 2.5/6 but might be a tad small for the 3L (liken to ss's on a 26)
TBH , I would definatly try reindexing the cams (Both) and retuning, its either that or some -10's OR the Lith single or to4z
The to4z or gt35r would be what I would go for on a targa car with s 3L.
Without wanting to state the obvious, you dont want the realistically smallest single on that engine ....
You want to know how much power do I want , how do I want it delivered ....I only want a single / therefore it will be a or b ...
Aim for 700hp....you have a serious engine .



Trade Me - New Zealand Online Auctions and Classifieds

DER

I read ALL your thread ....
but rod has talked me out of this so many times, as he's adamant that for the way the car is used, i'd lose response and ultimately be slower, and more frustrated than with my current twins (2860's, -7's i think, the ones below -10's. slightly bigger than 2530's, slightly smaller than gt-rs's.
allegedly)
Slightly smaller than rs will be -7's ...
Try reindexing the cams as abbey says....
Usually you can tune that shuffle shit out ....
Does it run the intake pipe splitter ?
 

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Discussion Starter · #15 ·
$2100 for a gt3582 (3540) seems pretty good

how much will a suitable manifold cost, and will i have to replace it on a regular basis?
 
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i've ditched the airflow meters and am running pfc djetro
The throttle compensation on d jetro is pretty crap I would say the fueling at part throttle wouldn,t help your problem, normally your find the fueliing goes super rich on part throttle.
 

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Discussion Starter · #18 ·
The throttle compensation on d jetro is pretty crap I would say the fueling at part throttle wouldn,t help your problem, normally your find the fueliing goes super rich on part throttle.
that's very interesting.
so you think i should consider a 'better' ecu?
 
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that's very interesting.
so you think i should consider a 'better' ecu?

Sure, something with better throttle compensation ( fuel/igntion) together with some work with the cams will help a lot .
 
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