Jump to content
SAU Community

Recommended Posts

On 1/11/2022 at 12:50 PM, The Mafia said:

Just an update. I have the 8474 on the engine now (8374 previously)

It's about 100-200rpm laggier and makes an absolute sh$t tonne more power up top. The 8374 topped out at 650rwhp at 30psi. 

This 8474 is just f$c%ing dumb. At 26psi, it's making well and truly over 750rwhp and just keeps going. It doesn't fall over. 

RB28 with Vcam (264/272), 6boost manifold, 3.5inch exhaust, E85, Emtron KV8 etc etc 

Which rear housing with 8474?

The issue with my 8474 was it did fall over in the top end it was struggling thats the only reason i removed it, I do recall the car had some odd rough running the more i drove it which i mistaked for the turbo, or drop in exhaust cam hurting flow so couldn't really get it to run how it should, but response wise I could get it on almost right off the lights with a gradual clutch drop most wow factor out of any EFR turbo i've tried zero lag getting back on throttle this was 1.05 rear great turbo for fast street driving

Edited by RB335
2 hours ago, RB335 said:

The issue with my 8474 was it did fall over in the top end it was struggling thats the only reason i removed it, I do recall the car had some odd rough running the more i drove it which i mistaked for the turbo, or drop in exhaust cam hurting flow so couldn't really get it to run how it should, but response wise I could get it on almost right off the lights with a gradual clutch drop most wow factor out of any EFR turbo i've tried zero lag getting back on throttle this was 1.05 rear great turbo for fast street driving

Would have been an awesome comparison to see how it went throwing on the 1.45 turbine housing. Presumably that would have given you more top end but obviously at the expense of a bit of response.

When you say falling over in the top end, at what power was that?

Had twin Tial MV-S 38mm gates with Y pipe plumbed back into a 3.5" dump EFR9180 held power fine 8474 began dying up top, I had limited time to do more dyno runs so only did one test but quite a bit of street driving on both turbos.   OK no problem i will try vent them to atmosphere next time see how it effects it will have much more sensors all over the engine on next motor too for monitoring stuff on manifold.

I have no access to an engine or dyno at the moment Mafia you are interested i can send you my 9180 then cover freight back to me you can test it lots of tech talk etc but test ok.

Edited by RB335

a 3.5" plumbed back exhaust with an 8474 on kill would have had sky high EMAP.

screamers would add loads of power through VE improvement and pumping loss reduction.

at that kind of compressor power you'd be at expansion ratios of 3.5:1 or more on the turbine, so every PSI of backpressure would be 3.5+psi in the manifold.

Edited by burn4005
12 minutes ago, RB335 said:

Had twin Tial MV-S 38mm gates with Y pipe plumbed back into a 3.5" dump EFR9180 held power fine 8474 began dying up top, I had limited time to do more dyno runs so only did one test but quite a bit of street driving on both turbos.   OK no problem i will try vent them to atmosphere next time see how it effects it will have much more sensors all over the engine on next motor too for monitoring stuff on manifold.

I have no access to an engine or dyno at the moment Mafia you are interested i can send you my 9180 then cover freight back to me you can test it lots of tech talk etc but test ok.

I would say the 74mm turbine would have been at it's limit and the pressure ratio across the engine would have started to go up. 

The 9180 has the bigger rear which will flow a lot more before choking up. 

haha do you trust me enough to send me a turbo? I have access to a dyno but it's a bit of a big job to swap them over

  • 5 months later...
On 29/04/2023 at 1:47 AM, SLVRBAKSLPZ said:

Any recent dyno results of a 9180 or 9280??

Not an RB, but the nost recent result I've seen, and one of the more impressive is this 3litre VVTi 2JZGTE making 1130hp @ hubs with 30psi by 4000rpm on an EFR9280:
https://fb.watch/kiHcr8Bydb/

Edited by Lithium
  • Like 3
On 4/28/2023 at 6:47 AM, SLVRBAKSLPZ said:

Any recent dyno results of a 9180 or 9280??

EFR turbos have largely been unavailable for the last 18 months so until BW resumes production its likely going to be pretty quiet

  • Like 1
On 05/05/2023 at 5:42 AM, Full-Race Geoff said:

EFR turbos have largely been unavailable for the last 18 months so until BW resumes production its likely going to be pretty quiet

Any idea if some of the SX-R upgrades are going to flow over the to EFR range?  The compressor map for the S200SX-R 7670 (/ S258SX-R?) looks like a cracker and could only imagine similar aero would make a worthy and needed update for the EFR7670:
image.thumb.png.7d5de5ff319e3e334d7d91ca0bf259b7.png

  • Like 2

Hi, 

Me again. Long time between drinks Any chance anyone would have a 1.45 ar rear housing interested in swapping for a 1.05 to suit a 8474? Turbo is choking Uptop and keen to see with a gearbox change how a 1.45 would respond. 

  • 2 weeks later...
  • 1 month later...
On 31/05/2023 at 3:24 AM, Full-Race Geoff said:

Full Race stocks the 1.45 a/r turbine housing, can ship immediately if you're in need.  

Hey mate, any specials for the SAU team? I have an EFR 8474 Black series on my RB28 and it has the 1.0AR rear. I think it's choking up. 

Do you have any back to back dynos / comparisons of the smaller and larger rears? 

16 hours ago, The Mafia said:

Hey mate, any specials for the SAU team? I have an EFR 8474 Black series on my RB28 and it has the 1.0AR rear. I think it's choking up. Do you have any back to back dynos / comparisons of the smaller and larger rears? 

Depending on how high you rev the 2.8, and your boost level - choking can happen with 1.05 a/r. If you can log turbo speed and backpressure it's insightful into making a change.

The 1.45 a/r back to backs are deceiving - on the steady state dyno they look like identical spool.  but on the street, its anywhere from 150-400rpm later spool depending on gear.  

I'd be happy to crunch the #s for a match if you wanted to know what the calculations show?  




 

4 hours ago, Full-Race Geoff said:

Depending on how high you rev the 2.8, and your boost level - choking can happen with 1.05 a/r. If you can log turbo speed and backpressure it's insightful into making a change.

The 1.45 a/r back to backs are deceiving - on the steady state dyno they look like identical spool.  but on the street, its anywhere from 150-400rpm later spool depending on gear.  

I'd be happy to crunch the #s for a match if you wanted to know what the calculations show?  




 

It would be massively appreciated if you could please fudge the figures to make it look like spool up is 1500 rpm later and it only makes 2 HP difference?  That would instantly save me spending $1600 for something that will sit on a shelf for the next 2 years....

  • Haha 1
9 hours ago, Full-Race Geoff said:

Depending on how high you rev the 2.8, and your boost level - choking can happen with 1.05 a/r. If you can log turbo speed and backpressure it's insightful into making a change.

The 1.45 a/r back to backs are deceiving - on the steady state dyno they look like identical spool.  but on the street, its anywhere from 150-400rpm later spool depending on gear.  

I'd be happy to crunch the #s for a match if you wanted to know what the calculations show?  




 

At the moment I am running 20-24psi and rev it to 7,000rpm on the circuit. I have a Holinger 6speed so there isn't a great need to rev it hard, only keep the rpm above 4500rpm or it bogs a little. 

It's a 9.75:1 compression ratio with a HKS Vcam. 264/272 cams. 

It's a hard one for me. 150rpm I can live with, but 400rpm would hurt a little in two corners that I know. 

I plan to put it in the dyno soon and measure the back pressure through one of the EGT ports. I have plenty of logs and data, and I mean lots of data. I also have turbo speeds. Running between 104,000rpm and 108,000rpm. 

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

    • Sadly I can confirm if you are actually seeking to drift, you will quite easily spin up one wheel. Even if you're going in a straight line. I am not entirely sure of the metrics/terminology here but there's only a certain amount that the helical will actually spin both wheels. I've seen it on video with my own car where two lines of smoke switch over to just one after you really get in to it. Unlike with a clutch diff where you can keep your foot planted until the car regains grip, in my experience with the helical you want to be utilizing traction control allowing LIMITED slip or lifting (partially) when you start to spin up both tyres with a Nissan helical. Which makes them pretty sub optimal for drifting duty. That said... this is probably a helical on numbers alone. Just put the Kazz in
    • Let's just fix the problem by f**king the rest of the gearbox.
    • Unlikely, as per Greg's post. This is not helical diff behaviour unless one wheel is up off the ground. Shimming what? You don't "shim" a mechanical LSD. Probably not in the sense that you have heard of people "shimming" a diff. And the process that Nissan f**kwits call "shimming" a diff involves super-preloading a VLSD cartridge against the side of the diff to create a friction/wear point (in a place that it wasn't supposed to have one) to make the sloppy, useless, viscous diff into a hybrid viscous/mech abortion. In case it isn't clear, I consider the process to be stupid. Nike.
    • How much does the shifter move when the car is in gear with the engine off? If it is more than about 1cm you need to replace your shifter bush. Your shifts will just get crunchier, not faster, with a short shifter unless you also rebuild the whole box
    • I should video mine, will prob do it tomorrow    Between 1st and 3rd, you could fit another two gears. That is how loose and wobbly it is   horrible:(
×
×
  • Create New...