SirCharlesworth Posted July 7, 2004 Share Posted July 7, 2004 Couple more questions as i should be buying a GZ manual soon with any luck: I have been through the FAQ's and theres a few things which i could do with straight answers to. 1, How strong really is the bottom end? Obviously presuming correct fueling, then have many owners had rings fail worse still, pistons or even big ends? From what i could understand its a very strong engine, i'd just like to hear owners opinions too. 2, What common faults tend to occur, i've been reading this board for some time now and can't really pinpoint a single recurring failure? 3, With regard to tuning, i know you guys call it bpu, i take it thats like the cossies call stage 1 etc? On a japanese spec car, what boost is run as standard, and what can this safely be raised to without running lean or damaging ceramic blades. 4, From what i can see, boost creep is a big issue with j-spec supes once running a bigger exhaust, is it as bad as it seems? Any info will be appreciated, and i'm sure i'll think of more questions as the time gets nearer. Thanks in advance Charlie Link to comment Share on other sites More sharing options...
Jake Posted July 7, 2004 Share Posted July 7, 2004 Originally posted by SirCharlesworth 1, How strong really is the bottom end? Obviously presuming correct fueling, then have many owners had rings fail worse still, pistons or even big ends? From what i could understand its a very strong engine, i'd just like to hear owners opinions too. It's very very strong. In fact it's not at all unheard of to run over 600 bhp on the standard internals. 2, What common faults tend to occur, i've been reading this board for some time now and can't really pinpoint a single recurring failure? Not many, off the top of my head ..... Valve stem seals wearing out. Radiator plastic top tank cracking. Standard BOV leaking. Eventual turbo failure on JDM cars if running higher boost. Dude has reported front crank pulley failure on three cars. CW has seen just about every fault possible at some time or another. 3, With regard to tuning, i know you guys call it bpu, i take it thats like the cossies call stage 1 etc? yeahOn a japanese spec car, what boost is run as standard, and what can this safely be raised to without running lean or damaging ceramic blades. 0.8 bar as standard. 1.1 to 1.2 bar is generally accepted as resonable4, From what i can see, boost creep is a big issue with j-spec supes once running a bigger exhaust, is it as bad as it seems? It's not really an issue unless the car has been decatted but once decatted boost creep is a problem that needs addressing. Link to comment Share on other sites More sharing options...
SirCharlesworth Posted July 7, 2004 Author Share Posted July 7, 2004 thanks for the speedy reply that answers just about everything! So what sort of power output would be expected from a car running 1.1-1.2bar on standard setup with exhaust and air filter? Link to comment Share on other sites More sharing options...
Jake Posted July 7, 2004 Share Posted July 7, 2004 Originally posted by SirCharlesworth So what sort of power output would be expected from a car running 1.1-1.2bar on standard setup with exhaust and air filter? My '93 Auto RZ made 350.5 HP Din at the hubs. The car is stock apart from a FCD, decat and 3" exhaust. Link to comment Share on other sites More sharing options...
SirCharlesworth Posted July 7, 2004 Author Share Posted July 7, 2004 so thats on stock boost? or not fcd being fuel cu defencer i presume? would mean you have raised boost. Whats the factory fuel cut set at then? Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 7, 2004 Share Posted July 7, 2004 Originally posted by SirCharlesworth so thats on stock boost? or not fcd being fuel cu defencer i presume? would mean you have raised boost. Whats the factory fuel cut set at then? No the boost will be raised with the decatt. Realistically a JDM running 1.3 bar will make around 380 bhp at the flywheel. On the manuals the flywheel will need replacing with mileage. Also on the engine the front main oil seal can blow at high boost or high RPM. Not common by any means, but not unheard of Link to comment Share on other sites More sharing options...
Jake Posted July 7, 2004 Share Posted July 7, 2004 Originally posted by SirCharlesworth so thats on stock boost? or not fcd being fuel cu defencer i presume? would mean you have raised boost. Whats the factory fuel cut set at then? Sorry Charlie I should have mentioned that the power figures I quoted for my car were at 1.17 Bar, the increase due mainly to the Decat as Terry said. Link to comment Share on other sites More sharing options...
SirCharlesworth Posted July 7, 2004 Author Share Posted July 7, 2004 so an exhaust and decat on these cars will raise boost sufficiently without the need for a bleed valve *cough* rubbish *cough* or boost controller? And it's safe to do it this way? Sorry if i sound dumb, it's just i currently use electronic boost control to control boost and its all different on supras. Cheers guys, Charlie Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 7, 2004 Share Posted July 7, 2004 If you are decatting then a restrictor ring is the only real option to keep the boost to a reasonable level on JDM's, otherwise you may well get boost spiking issues. You should also look at upgrading the fuel pump as soon as you do the decatt. Link to comment Share on other sites More sharing options...
tDR Posted July 7, 2004 Share Posted July 7, 2004 Originally posted by Terry S You should also look at upgrading the fuel pump as soon as you do the decatt. A wise precaution on any turbo'd sportscar.... walbro item recommended. Link to comment Share on other sites More sharing options...
suprababy Posted July 8, 2004 Share Posted July 8, 2004 Sent you a PM Link to comment Share on other sites More sharing options...
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