Jump to content
SAU Community

Recommended Posts

r32built26w6258s.jpg

Interesting :)

Because I spend way too much time studying dyno graphs I did pick up a few things.

Peak power for 4.11 diff ratio GTR's with that power is usually around 200km/hr or 7000rpm, the EFR's seem to make peak power at around 170km/hr. 22psi for turbos that make that power usually make peak boost at around 124 km/hr while the EFR's seem to make peak boost at 94km/hr.

So makes boost 30km/hr aka 1000ish rpm earlier and drops off peak power 30km/hr or 1000ish rpm earlier if all things are equal...

I'm assuming the diff ratios are the same?

Food for thought for you Beer Barron, your very well set up GT-SS motor makes about 190rwhp at 4000rpm and this set up makes 400rwhp. Almost unbelievable :cheers:

Edited by SimonR32

can we get a recap on this car please? cams, fuel, head work, intake plenum, exhaust size, intercooler, etc.

also, can we attribute some the gains to the new manifolds and exhaust?

and, i thought inertia was HIGHER with twins vs single

thanks

Edited by black bnr32

and, i thought inertia was HIGHER with twins vs single

I was always under this impression as well (but am prepared to be proven wrong)

2x as many bearings to drag on

2x as many turbine wheels (even though they are smaller)

1/2 as much exhaust gas per turbo

Less than ideal piping due to room constraints

Greater heat soak due to crammed space

Edited by Sub Boy32

Interesting :)

Because I spend way too much time studying dyno graphs I did pick up a few things.

Peak power for 4.11 diff ratio GTR's with that power is usually around 200km/hr or 7000rpm, the EFR's seem to make peak power at around 170km/hr. 22psi for turbos that make that power usually make peak boost at around 124 km/hr while the EFR's seem to make peak boost at 94km/hr.

So makes boost 30km/hr aka 1000ish rpm earlier and drops off peak power 30km/hr or 1000ish rpm earlier if all things are equal...

I'm assuming the diff ratios are the same?

Food for thought for you Beer Barron, your very well set up GT-SS motor makes about 190rwhp at 4000rpm and this set up makes 400rwhp. Almost unbelievable :cheers:

yeah it's pretty awesome isn't it? makes any of my set-ups look like rubbish to be honest.

but don't forget this car has a hollinger sequential 6 speed box so those figures may be a little out either way. not sure on diffs but assume 4.1 or 4.375. either way they weren't changed between the turbo set-ups. nothing was changed other than manifolds, plumbing etc.

Fuel = E85 (both set-ups)

ECU = Link

cams? yes (not sure which)

dry sump

engine built 2.6L RB26

I'm not sure we can attribute the gains to the changes in the exhaust. this car had top shelf gear to begin with when using the -5s and -10s. it had the 76mm tomei dumps (from memory it had tomei manifolds too but I'd have to double check), big front pipes and a very straight, free flowing 94mm exhaust. it still has the same exhaust but with new 3 inch dumps and the new full race manifolds.

also, don't forget this car runs semi slicks on the dyno which most definitely gives a lower figure and it was strapped down very hard (again robs some power as when you allow the car to ride up on the rollers you get a much higher reading).

sub boy, sorry I meant just the wheel inertia. bearings have little drag. obviously as you increase diameter of the wheel (and this goes for the comp and turbine) the weight increasing further from the centre line makes a big difference to inertia. so two small wheels can have less inertia than 1 big one simply due to how far out from the centre the weight is located. I could be wrong but I still maintain this. if you take 2 sets of equal turbos (as in same wheel tech, bearing type, housings etc) and use two small ones sized for 400kw and 1 large one also sized for 400kw, generally on an I6 like a GTR the two small ones will have better transient response and often better spool time too. there are lots of advantages to singles though too, easier piping, cost of one turbo vs 2, less weight (usually) and so on. and with twin scroll the gap narrows even further as you get the advantage that twins have of separating the exhaust pulses.

there is no doubt these twins so far I reckon are the gun set-up for a street/track GTR. The 9180 was awesome on the R34 but it's an RB30 and big high mount turbo with twin ext gates is not for everyone. I'm sure it'll be good on a 2.6 too but maybe for a street car if you wanted a single the 8374 would be better. But right now I love the twins. very tempted to replace my 2530s with some.

yeah it's pretty awesome isn't it? makes any of my set-ups look like rubbish to be honest.

but don't forget this car has a hollinger sequential 6 speed box so those figures may be a little out either way. not sure on diffs but assume 4.1 or 4.375. either way they weren't changed between the turbo set-ups. nothing was changed other than manifolds, plumbing etc.

Fuel = E85 (both set-ups)

ECU = Link

cams? yes (not sure which)

dry sump

engine built 2.6L RB26

I'm not sure we can attribute the gains to the changes in the exhaust. this car had top shelf gear to begin with when using the -5s and -10s. it had the 76mm tomei dumps (from memory it had tomei manifolds too but I'd have to double check), big front pipes and a very straight, free flowing 94mm exhaust. it still has the same exhaust but with new 3 inch dumps and the new full race manifolds.

also, don't forget this car runs semi slicks on the dyno which most definitely gives a lower figure and it was strapped down very hard (again robs some power as when you allow the car to ride up on the rollers you get a much higher reading).

sub boy, sorry I meant just the wheel inertia. bearings have little drag. obviously as you increase diameter of the wheel (and this goes for the comp and turbine) the weight increasing further from the centre line makes a big difference to inertia. so two small wheels can have less inertia than 1 big one simply due to how far out from the centre the weight is located. I could be wrong but I still maintain this. if you take 2 sets of equal turbos (as in same wheel tech, bearing type, housings etc) and use two small ones sized for 400kw and 1 large one also sized for 400kw, generally on an I6 like a GTR the two small ones will have better transient response and often better spool time too. there are lots of advantages to singles though too, easier piping, cost of one turbo vs 2, less weight (usually) and so on. and with twin scroll the gap narrows even further as you get the advantage that twins have of separating the exhaust pulses.

there is no doubt these twins so far I reckon are the gun set-up for a street/track GTR. The 9180 was awesome on the R34 but it's an RB30 and big high mount turbo with twin ext gates is not for everyone. I'm sure it'll be good on a 2.6 too but maybe for a street car if you wanted a single the 8374 would be better. But right now I love the twins. very tempted to replace my 2530s with some.

Guys,

Hollinger - correct! 4th gear in a 6sp Hollinger is not 1:1 and my diffs are 3.69 (Tomei special order). Not ideal gearing for Eastern Creek but good allround considering I travel to Bathurst every year and also do some Tarmac/Hill Climb stuff. Having a 6sp helps with 1st and 2nd gear work, having 3.69 gears helps with Conrod Straight!

Cams are Camtech 270s 10.8mm lift. Head work - yes.

Plenum is a Hypertune Multi Throttle, Intercooler is a Plazmaman 100mm job.

Everything else Rich says is correct. (most of the time anyway.....)

Also, anyone interested in Tomei Expreme Manis and Dumps, or -10's or even a Greddy Hard Pipe kit can PM me as these will definately be sold now that the EFR's are on.

cheers,

John.

Cheers for the answer Richard, I'd love to try a back to back with the twins vs a 8374 on the same motor.

I'm fizzing at the bung to get the 8374 on my new RB30....Should make my RB26 with it's -5's looks slow!

The only concern I have is if I have a big enough exhaust housing, Going by what I read around on here and other sites, the IWG .92a/r might be too small.....Time will tell, I'm not after huge HP, More small track response.:worship:

I've asked Brett if BW are looking at releasing a larger IWG housing bigger than the .92a/r, But haven't heard back yet.....But he is no doubt a very busy man!:whistling:

Edited by Sub Boy32

Guys,

Hollinger - correct! 4th gear in a 6sp Hollinger is not 1:1 and my diffs are 3.69 (Tomei special order). Not ideal gearing for Eastern Creek but good allround considering I travel to Bathurst every year and also do some Tarmac/Hill Climb stuff. Having a 6sp helps with 1st and 2nd gear work, having 3.69 gears helps with Conrod Straight!

Cams are Camtech 270s 10.8mm lift. Head work - yes.

Plenum is a Hypertune Multi Throttle, Intercooler is a Plazmaman 100mm job.

Everything else Rich says is correct. (most of the time anyway.....)

Also, anyone interested in Tomei Expreme Manis and Dumps, or -10's or even a Greddy Hard Pipe kit can PM me as these will definately be sold now that the EFR's are on.

cheers,

John.

Makes a lot more sense now :) Hard to compare with a lot of other results from the past but it clearly shits all over the -10 set up!

thanks for posting John. :) helps clear things up. I was pretty close.

Sub Boy, I'm really keen to see what you think of the TS 8374 with IWG. all the big ones (9180 and 8374) I've been privy to have been TS EWG and to be honest I really think the big revolution is in the IWG housings with their new IWG design. I'm sure it's a big part of why the small twins are such an improvement over older design IWG twins. yes the new wheels, integrated BOV etc are cool but the IWG housings are where I reckon the big change is over previous IWG turbos.

I doubt they'll produce bigger IWG housings but they might. That market (high boost race type set-ups) is already served with the EWG housings I guess. for the less hardcore set-ups the 0.92 IWG housing should be awesome.

I'm not sure I'm quite fizzing at the bung but I am excited to see how your car goes.

Cheers for the response :) So would it be fair to say it is a bit like having GT2860-5s that punch as hard, or harder than -10s?

I've had both -5's and -10's on this setup, gotta say these respond better than -5's and make shitloads more power everywhere over either -5's or -10's.

These 6258's are the twins to have without question.

It took me a couple of sessions to get my head around how well they performed on the track. I was getting on the gas way too early (legacy of having -10's) and pushing the car offline and into either under/oversteer.

After a few more track days I'm sure I'll certainly be knocking seconds of my times......

Cheers for the answer Richard, I'd love to try a back to back with the twins vs a 8374 on the same motor.

I'm fizzing at the bung to get the 8374 on my new RB30....Should make my RB26 with it's -5's looks slow!

The only concern I have is if I have a big enough exhaust housing, Going by what I read around on here and other sites, the IWG .92a/r might be too small.....Time will tell, I'm not after huge HP, More small track response.:worship:

I've asked Brett if BW are looking at releasing a larger IWG housing bigger than the .92a/r, But haven't heard back yet.....But he is no doubt a very busy man!:whistling:

Ha! I haven't forgot about you. I had to leave a little early today, but you're .92a/r will work well for response and still net you good power gains. No word from BW on releasing a larger wastegated housing at this time. I'm talking with them again tomorrow about availability and and a few other items on my "to-do" list. bunny.gif (I don't ever use emoticons, but found that one to be to my liking)

I've had both -5's and -10's on this setup, gotta say these respond better than -5's and make shitloads more power everywhere over either -5's or -10's.

These 6258's are the twins to have without question.

It took me a couple of sessions to get my head around how well they performed on the track. I was getting on the gas way too early (legacy of having -10's) and pushing the car offline and into either under/oversteer.

After a few more track days I'm sure I'll certainly be knocking seconds of my times......

Awesome! Thanks for sharing, that simple bit of text is basically the most constructive info I've seen on these units :cheers: Thats more like what I've been hoping to hear, fingers crossed - bring on more of the same! :yes:

Too many things changed with the chassis to compare lap times sensibly. As well as a complete change in braking package, we added a cage, removed ~75kg nett, changed the track and moved to a custom center diff control unit. To make matters worse, setup time after the build was limited to a half a dozen laps the afternoon before the event and the diff maps were.... uhmmmm... not ideal... :)

What fuel were you using? Update the thread post your 2.5bar tune.

when I talked to John about him trying these I told him from the compressor map reading and research and calculations I'd done these "should" give -10 power with -5 response. Now it seems it's more like -10 (GTRS) power with -7 (GTSS) response. as simon pointed out they shit on my GTSS down low and murder John's own -10 set-up up top. that's a good thing in anyone's books. My guess is John will reap the benefit of being a pioneer with these (and my god he's been pioneering!) and will get some good on track results against other GTRs with -5s and -10s until they get sick of him shooting out of corners so much faster and buy their own 6258s.

when I talked to John about him trying these I told him from the compressor map reading and research and calculations I'd done these "should" give -10 power with -5 response. Now it seems it's more like -10 (GTRS) power with -7 (GTSS) response. as simon pointed out they shit on my GTSS down low and murder John's own -10 set-up up top. that's a good thing in anyone's books. My guess is John will reap the benefit of being a pioneer with these (and my god he's been pioneering!) and will get some good on track results against other GTRs with -5s and -10s until they get sick of him shooting out of corners so much faster and buy their own 6258s.

Well they don't murder your GT-SS set up down low, the diff ratio was wrong for that calculation :)

Very hard to compare with anything besides the -10 graph because scale is in km/hr not RPM and god knows how that translates with that box/diff set up...

By my fairly educated guess they appear similar in response to -5's with about the same top end, maybe a tad more responsive down low :)

Personally looking at their packaging, price and engine bay mayhem I would lean towards still using -5's. Actually no I wouldn't I'd be going a single every time but hey that's just me :cheers:

Edited by SimonR32

Get the gear ratio it was run in, the diff ratio, rim size and tyre + sidewall details and I can calculate the rpm scale vs kph scale if you want. Will make comparisons much easier.

There are guides on google if you want to do it yourself as well.

By my fairly educated guess they appear similar in response to -5's, maybe a tad more responsive down low :)

This is what I was getting, too...

.. with about the same top end ...

Where do you get that from? It looks to deliver more everything than the -10s on less boost?

Guest
This topic is now closed to further replies.



  • Similar Content

  • Latest Posts

    • See if you can thermal epoxy a heatsink or two onto it?
    • The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1780, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
    • Also, I logged some data from the ECU for each session (mostly oil pressures and various temps, but also speed, revs etc, can't believe I forgot accelerator position). The Ecutek data loads nicely to datazap, I got good data from sessions 2, 3 and 4: https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-2?log=0&data=7 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-3?log=0&data=6 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-4?log=0&data=6 Each session is cut into 3 files but loaded together, you can change between them in the top left. As the test sessions are mostly about the car, not me, I basically start by checking the oil pressure (good, or at least consistent all day). These have an electrically controlled oil pump which targets 25psi(!) at low load and 50 at high. I'm running a much thicker oil than recommended by nissan (they said 0w20, I'm running 10w40) so its a little higher. The main thing is that it doesn't drop too far, eg in the long left hand fish hook, or under brakes so I know I'm not getting oil surge. Good start. Then Oil and Coolant temp, plus intercooler and intake temps, like this: Keeping in mind ambient was about 5o at session 2, I'd say the oil temp is good. The coolant temp as OK but a big worry for hot days (it was getting to 110 back in Feb when it was 35o) so I need to keep addressing that. The water to air intercooler is working totally backwards where we get 5o air in the intake, squish/warm it in the turbos (unknown temp) then run it through the intercoolers which are say 65o max in this case, then the result is 20o air into the engine......the day was too atypical to draw a conclusion on that I think, in the united states of freedom they do a lot of upsizing the intercooler and heat exchanger cores to get those temps down but they were OK this time. The other interesting (but not concerning) part for me was the turbo speed vs boost graph: I circled an example from the main straight. With the tune boost peaks at around 18psi but it deliberately drops to about 14psi at redline because the turbos are tiny - they choke at high revs and just create more heat than power if you run them hard all the way. But you can also see the turbo speed at the same time; it raises from about 180,000rpm to 210,000rpm which the boost falls....imagine the turbine speed if they held 18psi to redline. The wastegates are electrically controlled so there is a heap of logic about boost target, actual boost, delta etc etc but it all seems to work well
×
×
  • Create New...