Jump to content
SAU Community

Recommended Posts

honestly i dunno but to get around 250 and more out of a standard rb25 on anything less then 17 psi, to me sounds a big challenge, and not to mention the end result will not be reliable.

  • Replies 166
  • Created
  • Last Reply

Top Posters In This Topic

I remember freebaggin made some where up around 270-280rwkw on 17psi with his hybrid turbo using a vlt turbine housing.

The turbo specs were selected by Tim Possingham, it was an expensive bugger though, just under 3k. I suspect the comp and or turbine housings had a little bit of power porting.

The HKS int. gate housings are around $800.

Edited by Cubes

With a .63 rear housing and a GT30 comp WITHOUT zaust cam you wont get near 250rwkw under 17psi IMO. With a zaust cam gear set to 3deg advance and a HPInABox GT30 with .63 zaust housing I am hoping to get close to 260rwkw at ~20psi but not over 20psi... I think (hope) that the .63 zaust housing is good enough swollow enough to avoid serging...

With a .63 rear housing and a GT30 comp WITHOUT zaust cam you wont get near 250rwkw under 17psi IMO. With a zaust cam gear set to 3deg advance and a HPInABox GT30 with .63 zaust housing I am hoping to get close to 260rwkw at ~20psi but not over 20psi... I think (hope) that the .63 zaust housing is good enough swollow enough to avoid serging...

No work done. However I think when considdering engine life you should be right at 20 psi as long as your knock is under control. Keep in mind that this is NO race car and will only see 20psi for short periods of time. Lets face it, how many roads are there in the ACT that will allow an rb25det with 260wrkw to be going full blat for any period of time :P I think there is some risk of doing a head gasket but thats no biggy, I will get a fater one when that happens to lowwer the compression and all will be sweet.

Trust me its easier to act ignorent rather than worry about it mate :)

Edited by GunMetalR33

Yea, rb25's a good engines and I have been told a a few people that the head gaskets should last on 20psi. I think its not GOOD for your engine & an engine with less power and boost will last longer...

Things to worrie about are:

ring lands (monitor knock & A/F ratio's and all should be fine)

head gasket (no more than 20 psi / adj cam gear at 3' adv helps this)

rods (dont rev rb25's over 7000 consitantly)

Before going big boost/power get a new timming belt and water pump...

I would like to get a zaust cam to lower the boost...

rant rant rant :P

yeh i agree, coz mines pushing out about 17psi and i have been scared off by a few people telling me it wont last long.... i guess its all about how heavy ur foot is.

dude,

please correct me if i am wrong, are you running an internally gated A/R .82 housing on your turbo?

if so, what brand?

Yea, rb25's a good engines and I have been told a a few people that the head gaskets should last on 20psi. I think its not GOOD for your engine & an engine with less power and boost will last longer...

Things to worrie about are:

ring lands (monitor knock & A/F ratio's and all should be fine)

head gasket (no more than 20 psi / adj cam gear at 3' adv helps this)

rods (dont rev rb25's over 7000 consitantly)

Before going big boost/power get a new timming belt and water pump...

I would like to get a zaust cam to lower the boost...

rant rant rant :P

same me i wanna get a set of zaust cams, help boost up a little better too....

dude,

is that a genuine Garrett GT exhaust housing?

all genuine mate, only thing that aint is the dump obviously. if ur after a turbo like mine give me a pm and i can organise u someone to give u a quote, i got mine pretty cheap..

honestly i dunno but to get around 250 and more out of a standard rb25 on anything less then 17 psi, to me sounds a big challenge, and not to mention the end result will not be reliable.

Its not challenge, ive done it, as have a few others also before me :)

get a new tuner

its just that im wondering how much psi a standard engine can take and for how long?

Its not just a simple question of PSI.

Do a search and a lot of reading. There are many many things that contribute to a motor shitting itself, not just psi.

mass iv, can you confirm at what rpm you are hitting full boost and if and when your tyres start to lose traction?

You mentioned earlier that the tuner said he was losing traction in 4th (or was it 3rd) to which other including myself thought too hard to beleive.

As I mentioned previously, I'm running just over 240rwkw with full boost of 16psi at around 3500rpm and there's no way in hell my car comes close to losing traction in 3rd with newish tyres on it.

In fact, it will hardly even lose it in second, if at all.

For the record, I'm running 225 Dunlop SP3000's on the stock rims.

Maybe the stocko 16inch rims give better straight line traction?

Maybe my car is actually running 200rwkw? (no way :))

As for you guys running GT30's, being a 550-600hp unit I'd say that 250rwkw is still quite a fair whack under the efficiency range of the turbo. I have a 460hp unit on mine pulling similar power with similar boost and still haven't hit the turbos limit. Need injectors :)

Perhaps we're seeing a limit with the stock cam setup because I was actually expecting more from this turbo (GT30) considering you guys have injectors giving you enough fuel for far more than 250rwkw.

ok id like to clear up a few things, my car is at full boost by 4000rpm, which is around 17psi. secondly it spins crazy in second and does a little into 3rd, i dunno if the dyno reading is incorrect but it deffinately feels as though my car has a little more then 240rwkw... not to mention i have smoked a few big powered cars..

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

    • Hey Dave, welcome aboard! Good to see another soon-to-be Stagea owner here. The wagons are awesome — plenty of space, still got that Skyline DNA, and loads of potential if you’re into mods. Definitely post up pics when you get it, everyone here loves seeing new builds. What model/year are you looking at?
    • 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.
×
×
  • Create New...