Jump to content
SAU Community

Stock Ceramic Turbo And Boost Surge/spike

reNEGaDe88

By reNEGaDe88,
in Engines & Forced Induction

 Share

Recommended Posts

reNEGaDe88 Proficient

reNEGaDe88

Posted
Posted

Hey guys.

I have read up on how much boost a R33 stock RB25 turbo can handle. As I have one.

I had my car tuned at 13psi making a generious 291 rwhp. I have a AEM Electronic boost controller.

So I run it on 12 psi seeing as I gather that 14+ the turbo is likely to fail.

So I was driving my car this morning at 9am. I let it idle warm to 70 deg C and then took it for a drive. Air was super cold from yesterdays rain.

When I was boosting the car was reading 15 and 16 psi a few times and then as I continued to drive for 10 minutes it would level out at 12psi again.

So I am wondering if my turbo surges or spikes to 15-18psi every so often on cold mornings or nights, up hills or in high gear. Will the turbo explode soon?

Cos I don't want to feed my turbo some compressor wheel peices.

Thanks in advance

Berny

reNEGaDe88 Proficient

reNEGaDe88

Posted
  • Author
Posted
its not ideal. Id get it sorted out.

And your turbo wont be fed a compressor wheel. It is the compressor wheel :P Maybe you mean engine haha.

hahaha yeh, typo. Meant, I don't want to feed my engine compressor wheel pieces.

Ultimategtr Proficient

Ultimategtr

Posted
Posted

I used to get that on my stock turbo.. MS-IBC boost controller set to 7/10psi.

On low boost on a cold night/morning it would creep up to around 9psi initially but settled to 7psi spot on..

on high boost it would initially creep to 13psi but it would settle down to 9-10psi rock solid once the ebc discovered it was creeping.

The other thing i used to do was decrease the gain a wee bit to help.

If your turbo creeps to 14psi and STAYS there, then possibly you havent fine tuned it and thus would need to decrease the GAIN/Start boost.

You def dont want to run 15-18psi otherwise:

1) Turbo's exh wheel WILL break

2) You will hit mass over-run and the ecu will do weird shit to save the engine

reNEGaDe88 Proficient

reNEGaDe88

Posted
  • Author
Posted

Oh. The boost controller must be allowing the wastegate to open later to run higher boost. But when the air is cold/dense and the intercooler has not soaked up heat, then the boost creeps. The EBC then realises it and settles it back down to correct setting.

How do I decrease the gain?

Nah for like 5 or so full gear runs the boost was at 16ish. Then it got better and sat at 12psi.

Turbo's explode purely due to hoop stress if they are ceramic, not because of heat or dirty oil. Just because they are spinning too fast and to much energy.

So if my ecu stops the car from leaning out. The turbo can still explode cos the ECU won't stop the turbo spinning too fast

reNEGaDe88 Proficient

reNEGaDe88

Posted
  • Author
Posted

Any other input into this?

I wanna know how serious it is running 15-18 psi when engine is cool and if turbo will explode. Or not.

Otherwise I will definitely get a 2535 or 2835 or GTRS really soon.

Dammit, so much money :D

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

    • Turbodoc
      Noobie Stagea owner..

      By Turbodoc · Posted

      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?
    • GTSBoy
      Duncan's V37.......race car?

      By GTSBoy · Posted

      See if you can thermal epoxy a heatsink or two onto it?
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      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.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      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
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      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...