Jump to content
SAU Community

Recommended Posts

IMHO the 3071 w genuine housing is definately the best turbo choice for an RB25 in the current climate (2835 being number 1 but cost prohibitive these days)

BUT..........

if i had my time again i would be going a twin scroll 3076 with a 6 boost manifold and GTR plenum

I thought the consensus from discopotato was that the twin scroll didnt have a big effect on 6 cylinder engines, more 4 cylinders.

The 6 boost manifold is probably a bit separate as it would help all of the turbos we are discussing.

If you plot your current turbo against the 3076 you have more area under the curve.

  • Replies 139
  • Created
  • Last Reply

Top Posters In This Topic

hence the twin scrol idea.... i thought it would get me a little more under the curve but not much, hence why i wouldn't change over to that setup, it's just what i'd look at doing if i had my time again :P

actually if i had my time again, i'd probably have just done an LS3 conversion

yeah the reason disco said twin scroll is more suited for 4 cyl is because the firing order and the engine is optimized to suit the firing order

like the 4g63 and sr20 are more suited for twin scroll as the firing order matches the manifold split setup

i wonder how complicated a properly twin scroll manifold on a rb20/25/26/30 footprint would look

and perform with a properl twin scroll manifold with the correct firing order match and turbo to suit

Twin turbo does not follow the firing order (in terms of GTR), where twin scroll is meant to given the parted collector/rear housing

difference - who knows, maybe a few hundred RPM?

You aren't talking 1000's of RPM of response either way.

I got 254kw at 3200rpm with r33 gcg high flow turbo. Im very happy with the response and power i have with this turbo. I only paid $850 for gcg from SAU forums and sold my stock turbo for $300. So only cost me $550. i still retain factory air box and car looks very stealth. Best bang for buck turbo.

I know of people on this forum who have run 12.3s quarters with this power on semi slick street tyres.

Invest in some mickey thompson full race slicks on 15inch chaser rims and a jim berry full monty race clutch and you will run 11s with around 250kw.

Its not always about all out power. Many other factors to consider...

hey mate 254 RWKW yeh? if so thats not bad at all for a highflow especially for that price!, what injectors do you use? also how much did you get charged for installing the new highflow turbo, did it need anything different to fit it or did it slot straight in like before?

sorry for the hundreds of questions.. but with my wage, id much rather 254rwkw for $850 or $550, as opposed to 300rwkw for $3000

cheers.

Twin turbo does not follow the firing order (in terms of GTR), where twin scroll is meant to given the parted collector/rear housing

difference - who knows, maybe a few hundred RPM?

I'm not sure what you mean by that? The front 3 and rear 3 alternate so with twins each manifold collects the same as a properly designed twin scroll manifold...

hey mate 254 RWKW yeh? if so thats not bad at all for a highflow especially for that price!, what injectors do you use? also how much did you get charged for installing the new highflow turbo, did it need anything different to fit it or did it slot straight in like before?

sorry for the hundreds of questions.. but with my wage, id much rather 254rwkw for $850 or $550, as opposed to 300rwkw for $3000

cheers.

I sourced most of my parts from SAU second hand from good honest people, thats why i love this site..spread the love.

Paid $850 for GCG high flow only 2 years old checked by gcg , sold my stocker for $300 so cost me $550 and installed it my self, piss easy took about 5 hours and everything bolted straight back on. True direct bolton , nothing to change. If i can do it , any one can.

Apexi power fc=$950 second hand SAU

Nismo 550injec=$600 second hand SAU( need injectors to max out turbo potential)

Bosch 040 in tank fuel pump=$50 second hand SAU(needed to meet fuel demands)

Splitfire coils=$450 second hand SAU(needed to run bigger gap on my plugs, went from .7 to 1.1 coppers when i upgraded coils.

JJR return flow coooler=$450 new

3 inch exhaust turbo back full stainless=$650 wreckers

Greddy profec b EBC

Run stock air box.

Tune=$750 unigroup engineering

My set up is begging for a garrett gt3071 or 76r bolton replacement and retune but this exercise will cost me between $2500 to $3000 , to gain an extra 30kw atw on my current set up. The only way i would justify this would be to take a ride in a gtst making 280kw + . If blown away by the difference then i would do it.

For now im at peace with what i have.

Hope i helped.

No offense - do you know how to read a dyno sheet?

You have 254rwkw @ 6750rpm. Not 3200rpm.

You have ~135rwkw @ 3200rpm

You also have boost control issues.

I stand corrected

Thankyou for teaching me to read a dyno, thats why i love this site, you never stop learning

What i should have said is that you will have full boost 16 to 18psi by around 3200rpm with this turbo

Thanks.

I'm not sure what you mean by that? The front 3 and rear 3 alternate so with twins each manifold collects the same as a properly designed twin scroll manifold...

Cool, yeah I was scratching my head but didnt have the knowledge to go against the president haha

So it seems a big waste to go to all the effort of twin scroll on an RB20/25 when an RB26 with twin turbos already has everything done from the factory.

So is this the major reason that twin turbos on an RB26 will have more low down power/torque then the equivalent sized single turbo conversion?

The only way i would justify this would be to take a ride in a gtst making 280kw + . If blown away by the difference then i would do it.

where you live?

i'm happy to er... "help" :(

Hey guys, similar question i thought you may be able to answer:

One turbo, running in a 220kw tune (injector and afm limited), vs the same setup, but with injectors and obviously a bit more boost (profec b) for 270kw.

Obviously off boost performance is identical, and full boost performance is waaay better, but what's the "in between" area like?

I used to have an MR2 years ago, and when boost was turned down, it was linear and boring, and with boost up, it was epic fun, but felt like it had a shitload more midrange. So i'm wondering, when i get injectors and a tune, is it likely to be a lot more midrange, or just top end stuff, it's a really laggy turbo i can't afford to replace yet (KKR560). I'd imagine it would seem more "responsive" as the wastegate would stay shut for longer before hitting full boost?

I'm just poor at the moment, but think i can afford injectors and a tune by the end of the year, as a present to myself, and want to make sure that the performance jump is as epic as i am expecting it to be :( Gavin Woods will be doing the tune, as he's a champion :(

Hey guys, similar question i thought you may be able to answer:

One turbo, running in a 220kw tune (injector and afm limited), vs the same setup, but with injectors and obviously a bit more boost (profec b) for 270kw.

Obviously off boost performance is identical, and full boost performance is waaay better, but what's the "in between" area like?

I used to have an MR2 years ago, and when boost was turned down, it was linear and boring, and with boost up, it was epic fun, but felt like it had a shitload more midrange. So i'm wondering, when i get injectors and a tune, is it likely to be a lot more midrange, or just top end stuff, it's a really laggy turbo i can't afford to replace yet (KKR560). I'd imagine it would seem more "responsive" as the wastegate would stay shut for longer before hitting full boost?

I'm just poor at the moment, but think i can afford injectors and a tune by the end of the year, as a present to myself, and want to make sure that the performance jump is as epic as i am expecting it to be :( Gavin Woods will be doing the tune, as he's a champion :(

Midrange will jump mainly but you will still get a nice top end bump.

Midrange is where its at anyway, how often do you hit 7000 revs?

So it seems a big waste to go to all the effort of twin scroll on an RB20/25 when an RB26 with twin turbos already has everything done from the factory.

So is this the major reason that twin turbos on an RB26 will have more low down power/torque then the equivalent sized single turbo conversion?

Equivalent sized SINGLE ENTRY single turbo, yes - and no its not a waste on a 20/25 as you only have to buy one turbo etc... imho. You have far more choice with single turbos, less plumbing, etc. Try working on a Skyline with a big single versus low mount twins haha.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
    • Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...