Jump to content
SAU Community

Recommended Posts

sorry guys, real quick q...

this is my tune:

dynoula220708.jpg

my hks adjustable actuator only goes down to 19psi... we tried all methods, its the lowest it will go... im running a stock dump/front... some ppl say its overboosting coz of that, some say it wont matter im sick of hearing bs, all i would love to know is if running 19psi n the occasional limiter bash at winton drifts next sat will be safe?

i ran this exact setup for a year n a half n a couple of weeks ago cracked first n 6th piston (looks like an over time thing)... i would rather not have a repeat of this if boost was the cause.

thankyou in advance!

emz

Link to comment
https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/
Share on other sites

I used to have the same setup on my R33 and to be safe I would turn the boost down on track days ad also run a quality octane boost.

Does it hold 19psi to redline? if it falls off towards the end of the rev range then it may not be to bad.

Is the motor built for 19psi?

why on earth would you run a larger turbo with std front and dump pipe?

no wonder you cant lower the boost, its trapped in the housing!!

change the front pipe/dump pipe even if you dont want more boost

We'll all heard this so many times from you...the solution to your overboosting is your stock dump...it has been told to you several times...whether or not it holds to redline is beside the point at this moment...

Now...as for 19psi at winton...its probably not the best idea...especially if your high boost is a result of a restriction...people usually wind boost down a few psi for safety at the track...couple of laps at WOT will have EGTs through the roof as well...and then risk of detonation will be another issue...its a bad idea if you ask me...and is an accident waiting to happen...

i had 2 different 3" dump/fronts

both different brands (i wont mention on the forums) one was the split n other the bellmouth design and both warped.. one from the turbo/dump n the other from the front/cat.

f**k buying cheap 300 shit.

does that answer ur question? sorry i dont mean to be rude but as a student i cant just go off n buy expensive shit, especially not a week before winton lol.

im just really after a quick fix for next weekend, then might sell my recaro seats n buy a proper jap dump/front.

cheers guys

first one was kinda my fault..

every1 warned me that the gaskets that came with the kit WERE SHITHOUSE... but some people said they will be fine. so instead of going to nissan n getting some, i just used the ones that came from the kit... my fault coz i got lazy.

2 weeks later, gasket failed, exhaust leak for a day or 2... ordered gaskets off nissan, pulled the dump off n realised the metal warped, no chance it was going back on so i returned it.

different brand kit, used the nissan gaskets... this time warped from the front/cat... looks like it was caused by shitty welding.

till this day i havnt heard anything bad about the jjr items... can they be trusted?

Edited by DjeMz

Well, I bought the Xforce bellmouth in mild steel and its been a treat for the almost 2 years i've had it.

Maybe get one fabbed up for you at a reputable exhaust shop. Shouldn't cost you a great deal more and at least you know the quality will be good. But yes being a student and funds and stuff etc etc....

That boost and those a/f ratios at the top end; you're asking for trouble.

RB25's are known to have weak ring-lands and the boost and leanness of the tune will generate more heat which can cause issues. I personally wouldn't risk it.

I consider anything over 12:1 a/f ratios, on a std RB25 and doing track days a BIG risk.

I ran 18psi, with 11.5:1 a/f ratios and still managed to crack a ring-land, pics below. All other components were in top nick, even the piston top, bore, etc of the cracked piston where completely undamaged.

Don't worry about split pipes or stainless; just get a custom made bell-mouth mild steel dump from a good exhaust shop. Should not cast you too much.

post-1811-1219909462_thumb.jpg

post-1811-1219909476_thumb.jpg

^^^ thats exactly wat happened to my old 25...

"I consider anything over 12:1 a/f ratios, on a std RB25 and doing track days a BIG risk."

drifting at winton isn't as bad as circuit, we do a few corners n line up for 5-10 mins then go out again...

i need something asap before winton, im not going to risk my new motor over it..

Edited by DjeMz
^^^ thats exactly wat happened to my old 25...

"I consider anything over 12:1 a/f ratios, on a std RB25 and doing track days a BIG risk."

drifting at winton isn't as bad as circuit, we do a few corners n line up for 5-10 mins then go out again...

i need something asap before winton, im not going to risk my new motor over it..

If your short of the $$, maybe someone close by to you would be willing to let you borrow one for a short time. Otherwise, maybe you'd want to check the for sale threads, there's cheap second hand goodies in there.

That boost and those a/f ratios at the top end; you're asking for trouble.

RB25's are known to have weak ring-lands and the boost and leanness of the tune will generate more heat which can cause issues. I personally wouldn't risk it.

I consider anything over 12:1 a/f ratios, on a std RB25 and doing track days a BIG risk.

I ran 18psi, with 11.5:1 a/f ratios and still managed to crack a ring-land, pics below. All other components were in top nick, even the piston top, bore, etc of the cracked piston where completely undamaged.

Don't worry about split pipes or stainless; just get a custom made bell-mouth mild steel dump from a good exhaust shop. Should not cast you too much.

Its not the afr's that kill the engine ................... it doesn't matter if you have a "richer tune" if it detonate's it will do more damage with rich tune than a lean tune.

Maybe your solution is to fit a better dump pipe then check / retune or not fit the dump and get a safer tune ?

I am not suggesting your tuner did not tune it safe but if you don't want to blow another cheap shit rb25 then get it detuned.

Its not the afr's that kill the engine ................... it doesn't matter if you have a "richer tune" if it detonate's it will do more damage with rich tune than a lean tune.

Maybe your solution is to fit a better dump pipe then check / retune or not fit the dump and get a safer tune ?

I am not suggesting your tuner did not tune it safe but if you don't want to blow another cheap shit rb25 then get it detuned.

That's right, but a lean tune creates more heat, more boost creates more heat, this setup has both. What can promote detonation? You guessed it..................HEAT.

May be alright on the dyno, but on the track and under the car's own load, detonation may occur. I would consider that top end tune unsafe for a "built engine" let alone a std one. Holding 19psi to red-line ain't doing it any favours too.

Just a second thought though :(

-If the dump is restrictive doesn't that slow down the exhaust gasses, so shouldn't the turbo be creating less boost than expected or at least dropping off dramatically?

- Just thinking whether the car may have another issue :)

Personally i would give this event a miss, knowing my car is not running properly. Can you afford possibly blowing another rb25? Is this event that important to risk all?

Just saw you sig, so obviously this Winton day is important to you.

Having my car at DECA, on my 30th B'day was important to me too, but that didn't happen; knowing now that my car is 100% ready and working perfectly is more important. There will be other events and other B'days, hell i was glad i didn't have it, as i would have had to drive it back the next morning :(

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

    • I just got this system but haven’t installed yet I got a Moroso sealed box (defect reasons) which will be set up same as their pic The quality is high grade, the correspondence I had with the owner (former head designer for Rockford Fosgate) was unbelievable, guiding me with what I needed. Even told me not to buy some things as it could be sorted in a different way at his loss. Just a bit of a bite with the exchange rate and don’t purchase gear in 1 hit that goes over $1,000 au, lol I forgot!  
    • Thanks mate for that reply. Very helpful.    it’s a 2022 400R so would most likely lose those features as you say.     I did a quick compare of a rv37 nav and heading for sale in Japan to q50 model. I’ll pop pics below. Seems  Japan spec head into top, nav unit second below it   below pic Q50 aud delivered     differences seem to be Aus delivered has a different plug top left hand side of head unit- not sure what and where it goes.   and nav unit Japanese tv37 had an extra plug put    Again I’m really not sure what each of these differences mean!       the actual plugs on a v37 and q50 screens look identical on both screens… pics below for comparing. (One screen was is a us delivered one) but should be same gps signals etc as Australia.    If it were as simple as swapping a nav unit from q50 aud delivered im interested -just want to figure out what the missing plug is for before spending big $ on a second hand part for it to not work, and I guess with the head unit, if the band expander does the job (I got a 20mHz so should get the range I’m after) so should narrow my issue down to nav unit only.  I’d love to know what the extra cable on rv37 does and if I eliminate that part what it’ll do to the setup,    and also, if I can figure out what that head unit plug difference is, what does that cable do and where does it got can it be altered or re-plugged?! Excuse my ignorance what is ACP/AA, what does that stand for? (Apple car play? Android air play)? so If I swapped head units to save using a band expander, I’d likely lose those better features to have an oem Unit operational. Better to use a band expander and retain AirPlay options and newer version of head unit     provably best to band expand it, and focus on the nav unit. th isn’t  a big deal/ would be cool to have it working  from what I can tel we use a PAL Signal and Japan uses a NTSC signal  I don’t know if there’s a co better or if the screen only reads NTSC, or if it’s the tv module that needs replacing… no big deal don’t need it but more of a curiosity thing on that!   Thanks for the info re tyre sensors, helpful and great to know.  I was reading the online manual off Japan website and it seemed to make it sound more confusing than it is  I guess a rim replacement would require the sensors to be moved to a new rim to carry that option over?!     Thanks for the info regarding diagnostic mode. I appreciate your help mate. Trying to brainstorm here to find a solution to get as much gadgets as I can working! I plan to get my local Nissan tech to have a look too who used to be at an Infiniti dealer back in the day to see if any thing they have or idea can find a soliton. But hoping anyone here has gone down the same route to make life easier!!   i guess identifying the cable/plug differences and what they do would be a great way of finding out if the units are transferable    thanks again 
    • No idea about the remote start part. If the V37 nav is anything like other Nissan JDM vehicles, you can't get the factory Japanese nav working in australia, a card from a different car almost certainly won't work, those cards are usually matched to the serial number of the DCU.  You could be possibly swap out the components from a AuDM Q50 to get it working, but if this is a new model (2021+) 400R, then you will lose the newer features like ACP/AA.  That said, if you have ACP/AA, just use google maps.. I assume a band expander would be required to get the local radio stations, but don't forget the Japanese FM band is narrower than ours, so you still might not be able to receive all Australian stations. I can't see any reason the tyre pressure sensors won't work here, there is the sensor unit inside the rim and the receiver nearby in the wheel well.  I have never had to change the batteries on my 2015 Q50, so I assume they last quite a while.  A straight battery change shouldn't need them to be re-registered as they are the same unit, that should only be required if you replace a sensor with a new one.   Word of warning, if you ever go into the 'secret' diagnostics mode on the main screen, DO NOT EVER do a 'reset' in this menu, it will erase all of your model specific data in the DCU and you will need a trip to a dealer to re-program it all, which would be particularly painful being an import.  This applies to the AuDM Q50 too.
    • There is a known issue with the mix door motor on the Q50 which causes these symptoms, not sure if it is common on the Y51 though.
    • That ring thing is interesting how it's holding everything together 
×
×
  • Create New...