DjeMz Posted August 26, 2008 Share Posted August 26, 2008 sorry guys, real quick q... this is my tune: 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 More sharing options...
silva33 Posted August 26, 2008 Share Posted August 26, 2008 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? Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4093669 Share on other sites More sharing options...
DjeMz Posted August 27, 2008 Author Share Posted August 27, 2008 holds 19 still redline motor is stock Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4094093 Share on other sites More sharing options...
paulr33 Posted August 27, 2008 Share Posted August 27, 2008 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 Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4094318 Share on other sites More sharing options...
limpus Posted August 27, 2008 Share Posted August 27, 2008 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... Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4094421 Share on other sites More sharing options...
RBwhatever Posted August 27, 2008 Share Posted August 27, 2008 yeah, $300 or so for a free-er flowing 3" dump/front pipe is not expensive. It should've been one of the first things to get done. And if its its not done now then do it already. Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4094438 Share on other sites More sharing options...
DjeMz Posted August 27, 2008 Author Share Posted August 27, 2008 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 Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4096010 Share on other sites More sharing options...
R32 Driver Posted August 27, 2008 Share Posted August 27, 2008 no real quick fix but i guess a 2k engine isnt that expensive, rb25s are getting cheap these days anyway russian roulette? GAME ON! Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4096019 Share on other sites More sharing options...
RBwhatever Posted August 28, 2008 Share Posted August 28, 2008 How the heck did your dump/fronts warp? Thats the first I've head of that happening. Maybe you've got something else wrong as it shouldn't be heating up so much that it warps your dump/front pipe. Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097117 Share on other sites More sharing options...
DjeMz Posted August 28, 2008 Author Share Posted August 28, 2008 (edited) 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 August 28, 2008 by DjeMz Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097129 Share on other sites More sharing options...
RBwhatever Posted August 28, 2008 Share Posted August 28, 2008 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.... Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097160 Share on other sites More sharing options...
Pattygtst Posted August 28, 2008 Share Posted August 28, 2008 try a different brand pay a little now or pay alot later Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097211 Share on other sites More sharing options...
Al Posted August 28, 2008 Share Posted August 28, 2008 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. Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097241 Share on other sites More sharing options...
DjeMz Posted August 28, 2008 Author Share Posted August 28, 2008 (edited) ^^^ 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 August 28, 2008 by DjeMz Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097344 Share on other sites More sharing options...
RBwhatever Posted August 28, 2008 Share Posted August 28, 2008 ^^^ 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. Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097406 Share on other sites More sharing options...
DjeMz Posted August 28, 2008 Author Share Posted August 28, 2008 yeah im chasing up some already... theres one for 150.. jjr 2nd hand.. ill try that for now n save for a custom/decent one later down the track Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097450 Share on other sites More sharing options...
acsplit Posted August 28, 2008 Share Posted August 28, 2008 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. Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097630 Share on other sites More sharing options...
DjeMz Posted August 28, 2008 Author Share Posted August 28, 2008 it was much richer before on my old block, used to pump out black smoke on wide open throttle... to me this is a much better tune then the last.. Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097728 Share on other sites More sharing options...
Al Posted August 28, 2008 Share Posted August 28, 2008 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? Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097814 Share on other sites More sharing options...
Al Posted August 28, 2008 Share Posted August 28, 2008 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 Link to comment https://www.sau.com.au/forums/topic/233501-rb25det-hks2535-19psi-safe/#findComment-4097838 Share on other sites More sharing options...
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