dexnfx Posted January 13, 2007 Share Posted January 13, 2007 Hello there everyone, i have abit of a tech question. I have used your brill search engine to find previous topics on this subject but non of them were specific to my problem (Please prove me otherwise) I have recently become the owner of a starlet glanza and working on stats i've picked up from here about the cars i've noticed that my pressure on my boost gauge (Swoosh) is only running 0.6 bar. And thats all the way through the rev range. It definately wasnt in low boost mode. And i wasn't in 1st or 2nd gear. Now i have an adjustable boost knob but i didnt want to start playin with that just yet. Is it ok to just turn it up bit by bit to see if it is that. Assuming i dont see a result from that it means i could have a boost leak from somewhere (Please correct me if im wrong) Everything else on the car is sound. Apologies i am a noob, but you gotto start somewhere Quote Link to post Share on other sites
scutch0 Posted January 13, 2007 Share Posted January 13, 2007 well mine only boosts to .6-.65 bar and mines on a greddy boost gauge.i thought that was the correct boost pressure?i think if you have a boost leak you'll find it will over-boost, well thats the problem i had anyway. Quote Link to post Share on other sites
lobotomy Posted January 13, 2007 Share Posted January 13, 2007 No that's about right mate:LO boost mode should run about 0.35BARHI boost mode should run about 0.65BARIt could be where you've plummed in your gauge. The fact it's holding that boost all the way through the rev range is actually quite a good point. It means you're not suffering from boost creep and it's building full boost quickly.Right now since I've fitted my FMIC (due to the slightly longer piping and pressure drop across the core) I'm only running 0.3BAR in LO though. Quote Link to post Share on other sites
paul w Posted January 13, 2007 Share Posted January 13, 2007 Don't go upping the boost too much without fueling mods or you will have a problem! A very expensive problem! Quote Link to post Share on other sites
dexnfx Posted January 13, 2007 Author Share Posted January 13, 2007 Yeah fair enough, these are the things i really need to know. I think i can get my head round boost creep, but what is over boost and why does it happen? Quote Link to post Share on other sites
lobotomy Posted January 13, 2007 Share Posted January 13, 2007 Overboost is basically when you near the factory set fuel cut limit -- 0.93BAR(approx) If you go over this point you'll hit fuel cut unless you have an FCD installed.As paul says, get your fuelling mods sorted before turning up the boost. If you're going over fuel cut you'l need a higher flowing fuel pump, RRFPR (rising rate fuel pressure regulator) or some other device to add fuelling. Quote Link to post Share on other sites
scutch0 Posted January 14, 2007 Share Posted January 14, 2007 what you you guys say is a acceptable amount of boost to run without fueling mods? .75bar?i assume having a gutted cat/ decat would increase the boost pressure slightly too wouldnt it?as mine was running .9 bar when i first got it! Quote Link to post Share on other sites
paul w Posted January 14, 2007 Share Posted January 14, 2007 Anything below fuel cut should be fine without fueling mods,boost pressure will increase with a decat/gutted cat (less of an increase with a gutted cat i believe)as theres less backpressure. Quote Link to post Share on other sites
lobotomy Posted January 15, 2007 Share Posted January 15, 2007 Yep I concur with Paul -- The car is mapped up to Fuel cut so you can boost up to there fine. Quote Link to post Share on other sites
dexnfx Posted January 15, 2007 Author Share Posted January 15, 2007 Im just suprised that bypassing the hi-lo boost setting up the boost by that much. Dont understand it. I've not touched anything else Quote Link to post Share on other sites
scutch0 Posted January 15, 2007 Share Posted January 15, 2007 what, do you mean increasing the boost? apparently it does increase the boost slightly. Quote Link to post Share on other sites
lobotomy Posted January 15, 2007 Share Posted January 15, 2007 Yeah I've heard like 1-2psi (0.06-0.1bar) Quote Link to post Share on other sites
dexnfx Posted January 16, 2007 Author Share Posted January 16, 2007 As soon as i swap those pipes around to bypass the hi-lo and get full boost in first and second gear the boost gauge read 0.85 bar and when there piped correctly it sits at a nice constant 0.65. When i swapped the pipes over i was quite overwhelmed at the diffrence but when i accelerated hard the engine started stuttering, feels like a limiter (Which i bored down to being the fuel cut) Quote Link to post Share on other sites
ecksjay Posted January 16, 2007 Share Posted January 16, 2007 mine was the same mate, when i bypassed it i gained a huge amount of torque, and some good bhp due to the increased boost (mine was boosting to around 0.8bar also).now i have a blitz access ecu i boost happily at between 0.9 and 1bar all day long, accompanied with a blitz decat and a blitz dual-sbc electronic boost controller (wow, that sounds like i have a proper blitz fetish ).now mine's permanently bypassed and controlled via the electronic boost controller (configurable within the car at the touch of a button), and i've actually removed the original boost solenoid completely as its not needed.If your MBC is plumbed up correctly then tweak it slightly and see what happens - you have fuel cut (and obviously hit it previously) so you wont have to worry about damaging anything as the ecu will cut the fuel and save the engine from any serious harm (whereas i could easily blow something up big style as i have no limiters of any kind with my ecu, so i have to use an electronic boost controller with an automatic boost limiter set before i even start playing with the boost, that way if something does happen then the dual solenoids of the boost controller will stop the engine from going into self destruct mode ). Quote Link to post Share on other sites
dexnfx Posted January 16, 2007 Author Share Posted January 16, 2007 cheers for that bud, explains alot. On the an aftermarket boost gauge what would you expect it to read when the engine is idling? To me logic says that when you hear the turbo spool up that the boost gauge would read above 0. Mine starts to boost while its still just below 0. My boost gauge is tapped off the hose that leads off the end of the BOV and back to the engine somewhere. I assume this is right as it came that way when i bought it. here is a pic Quote Link to post Share on other sites
paul w Posted January 16, 2007 Share Posted January 16, 2007 My gauge is in psi for boost (above 0) and in inhg (below 0),at idle mine reads 20inhg. Quote Link to post Share on other sites
dexnfx Posted January 17, 2007 Author Share Posted January 17, 2007 From the picture can you see if the pipes are in there correct places for the standard hi-lo solenoid? I seem to be getting in hi mode the usual restriction on first gear but full boost in 2nd gear which i didnt think was possible unless you by passed that hi-lo solenoid. Confused!?!?! Quote Link to post Share on other sites
Guest Enzo Posted January 17, 2007 Share Posted January 17, 2007 yea everything seams to look correct here, had my old glanza running at just under 12psi(fual cut) with the use of a hks actuater every day with a guted cat and manifold, really wished i had the thing dyno'd as it felt fast overtaking...... Quote Link to post Share on other sites
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