Jump to content
SAU Community

Another 25 Turbo Sizing Question

Young GT-R

By Young GT-R,
in Engines & Forced Induction

 Share

Recommended Posts

Young GT-R Proficient

Young GT-R

Posted
Posted

once this is answered by all means please delete, but I have done some research on this forum and need some good advice.

the turbo I am looking at for my 25det is ball bearing

has 0.7 A/R front

0.64 a/r rear.

62mm front wheel trim.

not sure on rear wheel yet.

it is t25 but can get a mate to make me a flange adaptor, also a dump etc.

internally gated, but would look to modify that.

Is new, is cheap for what it is.

Pics:

frontofturbo.jpg

rearofturbo.jpg

Question is that I am after streetable power to 250 or more rwkw. Is this like the GT30/40 where the front is too big for the rear and it wouldn;t be able to spool as quick as a daily driver would like? do I need more info? any help much appreciated.

My mods: Haltech ECU, 600cc injectors, subzero plenum (not a required mod I know) high flow cat and 3" exhaust.

Link to comment
https://www.sau.com.au/forums/topic/143311-another-25-turbo-sizing-question/
Share on other sites
paulr33 Grand Master

paulr33

Posted
Posted

the problem with choosing ebay turbos and other "from a friend" turbo's is that you have no idea if it will mate up correctly and how it will perform. not to mention the state of tghe bearings and other components. usually they are worse than the stocker unit, plain bearing oil cooled only.

you can take out a lot of guess work by choosing an off the shelf garrett unit. you can look at all the specs and compressor maps and even change the flange options before you order to suit. so theres no lag guess work, no power band guesswork as all the mathematics are there

too often we see peple buy "cheap ebay turbo's" or "get it off a mate cheap" only to find the suck in response and lag and are just generally crappy. sure there are some bargains, but it usually leads to shit to4 style dinosaur combos that suck. much better technology out there

something to think about

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

I appreciate that, but this turbo is ball bearing and has the 6 blade front wheel, not the dodgy 7 blade one. I have seen these before but am more concerned with the lag. I imagine power will be what I want, but do I need more info for someone to tell me how it should flow on the rb25?

discopotato03 Grand Master

discopotato03

Posted
Posted

I would stay right away from that thing if I were you , wrong turbine housing for a start (T28 flanged GT28 housing) and the 9 turbine blades usually means a 54mm GT28 turbine . Its hard to tell which compressor it uses but the comp housing looks like TO4S .70AR and too big and bulky .

Too many people buy dog turbos like that and the financial burden of replacing it with a good one is often too much . You are far better off doing some research and spending your money on something more appropriate . If the guys feel this topic is a string of repeats PM me because its only a bit of time on the keyboard , but you'd hate yourself if you went and bought a "Victim Turbo" on mates advise . Plenty of clued up victims try to sell on the sows ear and make the loss someone elses problem .

For your own sake DON'T get sucked in by that thing !

Cheers Adrian .

paulr33 Grand Master

paulr33

Posted
Posted

as i said originally, too many guys buy $900 turbo's and they are poor mans spec with crapstick housings and they just plain suck. then the person has to spend another $1500 to change it and are stuck with a crap turbo. do some research and go for a turbo where you can choose different options and see the compressor maps.

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

can someone please tell me what the problems would be using this turbo apart from the risk?

it's $3-500 vs $1800.

So if apart from blowing up the worst problem is 500rpm of extra lag because of the exhaust housing being too small??? I am not fussed over a little bit of lag but what could I expect?

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

I completely agree with you that the prices are awesome, but it's still 3-500 dollars vs 1800 dollars.

My question is will this turbo spool later because the turbine is too small for the front and if so, how bad willit be? At the end of the day for $3-500 the difference in lag is not a problem if it's 500-1000rpm.

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

indeed it's cheap. Went and saw it in real life last night and it is definitely brand new, no shaft play, bb, the 0.7 a/r front certainly is big. The guy paid 900 for it, it's not genuine garrett obviously.

So yeah, all things being equal I'd get a GT3076 or similar, but they're not equal and I am leaning towards taking the risk on this one.

So does anyone know what it roughly would act like given the details?

tridentt150v Grand Master

tridentt150v

Posted
Posted

probably work Ok, but it'll cost you shit loads of $$$ for the ventolin puffers.......lol It'd be asthmatic.

Let me know when your in the market for some other 'bargains', I reckon I've got a shed full!

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

:) hahaha,

Ok I get it, the thing will be struggling to push the air out the exhaust.

Point taken.

But as you said, it should work OK (I am not asking it to act like a 35/40 or a 3076 but something the next peg down maybe where I can achieve 250+rwkw at 16psi with a little lag - can't ask for more from a turbo so cheap)

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

ok, while I appreciate honesty....NO ONE has answered my question.

You all have your opinions which is fine, but I only asked how it would go on the 25 motor, would it have problems with lag or will it run out of puff ot what?

Simple question no one can answer it?

The Mafia Grand Master

The Mafia

Posted
Posted
ok, while I appreciate honesty....NO ONE has answered my question.

You all have your opinions which is fine, but I only asked how it would go on the 25 motor, would it have problems with lag or will it run out of puff ot what?

Simple question no one can answer it?

I'd say its going to be laggy, and might make a bit over 250rwkw (MAYBE). It doesn't look like its going to bolt on happily though.

Young GT-R Proficient

Young GT-R

Posted
  • Author
Posted

thanks for that, do you know why it'd be laggy?

I know it's not ideal, far from it.....

But I forsee it running out of puff at 6000rpm like my old t3/4 did with a .63 exhaust???

So I would have thought it would come on to boost hard and early but have nothing up top.

Am I wrong?

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • RP1421
      S15 Spec R

      By RP1421 · Posted

      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. 
    • joshuaho96
      R32 GTS (RB20DE) Injectors Replacement

      By joshuaho96 · Posted

      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.
    • perry_r33
      R34 GTR Vspec Garage Sale - All must go!

      By perry_r33 · Posted

      Pm sent 
    • Robot
      Skyline v36 350GT sedan hunting on idle

      By Robot · Posted

      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 🤣
    • GabsReDeal
      R32 GTS (RB20DE) Injectors Replacement

      By GabsReDeal · Posted

      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...