Scott Posted September 12, 2013 Share Posted September 12, 2013 The boost controller up's the boost H. The RR is there to stop overboosting which would destroy the ceramic internals of the Jspec turbo. Uk spec's don't need a RR as the turbos have steel internals. No, it's because they have better wastegates Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted September 12, 2013 Share Posted September 12, 2013 No, it's because they have better wastegates Everyday's a school day The UK specs having steel internals is the reason for them being able to be run at a higher pressure though? ie 1.4 instead of 1.2 Quote Link to comment Share on other sites More sharing options...
Scott Posted September 12, 2013 Share Posted September 12, 2013 Everyday's a school day The UK specs having steel internals is the reason for them being able to be run at a higher pressure though? ie 1.4 instead of 1.2 Yup.... although by that point you're generating so much heat that you won't make more power. 1.2-1.3 is the max efficiency, depends on the tubby condition Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted September 12, 2013 Share Posted September 12, 2013 Have you got a Boost guage with peak hold H? Would be interesting to see what boost your actually running. After fully decatting mine, i hit 1.05 bar. I'm going full BPU next spring but I need mine mapped as I have a standalone ECU. Quote Link to comment Share on other sites More sharing options...
Kirk Posted September 12, 2013 Share Posted September 12, 2013 It hits 1.01 bar exactly, I've tested it 3 times with consistent results. Quote Link to comment Share on other sites More sharing options...
Homer Posted September 12, 2013 Share Posted September 12, 2013 The jump from 1.0 bar to 1.2 bar is as big as the jump from 0.76 to 1.0 bar IMO. You are only half way there yet H 1.2 bar is when it really comes alive in the jpsec, I never got tired of the 4k rpm kick in the backside Quote Link to comment Share on other sites More sharing options...
Havard Posted September 12, 2013 Author Share Posted September 12, 2013 Restrictor ring stops the turbos from overboosting on their own. Without that restriction there would be no control as the wastegate on the jspecs is crap. The boost controller increases boost only, if you are seeing 1.0bar of boost just now then the only way to lower that boost is to increase the restriction... ie make the restrictor ring smaller. The boost controller opens/closes the wastegate at a certain pressure. Even with the wastegate fully open the boost will increase past the safe limit if you don't have a restrictor ring in place. Here's a way of getting your head around it.... Boost controller set for 1.2 bar - Boost hits 1.21 bar - Boost controller opens wastegate and some of the exhaust gas is bypassed out of it - turbos slow down - boost pressure decreases. The above rings true for setups with adequate wastegates. On the Jspec it goes something like the following.... Boost controller set for 1.2bar - Boost hits 1.21 bar - Boost controller opens wastegate and some of the exhaust gas is bypassed out of it (just not enough) - turbos slow down (just not enough) - boost pressure continues to rise. The way to get around this is to fit a restrictor ring in order to FORCE the exhaust gas through the wastegate (easiest path with the least resistance). This means that more of the exhaust gas is bypassed and the turbos slow down MORE thus generating less pressure. Simple rule of thumb... whatever boost your car makes with the boost controller disabled is the least amount of boost your car will ever make when running as it is. A boost controller can only increase the boost levels of any given setup. Cheers Scott. I just dropped the parts off with Martin wait a few days and then eventually push the pedal and see what happens...!! I would like to understand more about turbo systems though. Quote Link to comment Share on other sites More sharing options...
Havard Posted September 12, 2013 Author Share Posted September 12, 2013 The jump from 1.0 bar to 1.2 bar is as big as the jump from 0.76 to 1.0 bar IMO. You are only half way there yet H 1.2 bar is when it really comes alive in the jpsec, I never got tired of the 4k rpm kick in the backside How much are boost controllers... Quote Link to comment Share on other sites More sharing options...
Chris Bailey Posted September 12, 2013 Share Posted September 12, 2013 How much are boost controllers... £300 for the Greddy Quote Link to comment Share on other sites More sharing options...
Homer Posted September 12, 2013 Share Posted September 12, 2013 Or a fiver for a bleed valve Not the best way to do it, but well, it is cheap! Quote Link to comment Share on other sites More sharing options...
Scott Posted September 12, 2013 Share Posted September 12, 2013 How much are boost controllers... Already told you, get a MBC, manual ball and spring boost controller. Costs less than £20, top end it's just as good as an EBC (ebc just hits harder). It get's you there till you want to up the stakes to an EBC Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted September 12, 2013 Share Posted September 12, 2013 How much are boost controllers... Just hold out for a second hand one, they're like buses on this forum Quote Link to comment Share on other sites More sharing options...
Havard Posted September 12, 2013 Author Share Posted September 12, 2013 Already told you, get a MBC, manual ball and spring boost controller. Costs less than £20, top end it's just as good as an EBC (ebc just hits harder). It get's you there till you want to up the stakes to an EBC I have never heard of these. I just thought that EBC's were the only option beyond a restrictor ring. Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted September 12, 2013 Share Posted September 12, 2013 I have never heard of these. I just thought that EBC's were the only option beyond a restrictor ring. MarcP has/had a manual one fitted. Send him a PM, they are easy to set up apparently. I've just had a little search on For Sale section, anywhere from £150-£200 will get you a decent EBC. How many programmable settings it has increases the value but tbh you only really need one as you are at 1bar without a BC, so you just need a setting for 1.2bar. Quote Link to comment Share on other sites More sharing options...
Scott Posted September 12, 2013 Share Posted September 12, 2013 I have never heard of these. I just thought that EBC's were the only option beyond a restrictor ring. What have you been doing over 7 years and 27K+ posts lol. MBC = Manual boost controller. I ran one for years before getting an EBC. Check out my thread on it here... http://www.mkivsupra.net/vbb/showthread.php?246750-Manual-Boost-Controller-VS-Electronic-Boost-Controller Quote Link to comment Share on other sites More sharing options...
Havard Posted September 12, 2013 Author Share Posted September 12, 2013 What have you been doing over 7 years and 27K+ posts lol. MBC = Manual boost controller. I ran one for years before getting an EBC. Check out my thread on it here... http://www.mkivsupra.net/vbb/showthread.php?246750-Manual-Boost-Controller-VS-Electronic-Boost-Controller Cheers Scott. For 6 months I didn't have a car and wanted an NA. If anyone spoke about turbos I would just glaze over. After three and a half years of having an NA, I got the urge for a TT. The car has been stock and reliable for three years this month and it's only now I have started showing an interest in tinkering with it. Time to go back to school I suppose. My 27K posts mainly consist of piss taking and frequenting NWS. It's been a real roller coaster Scott. Quote Link to comment Share on other sites More sharing options...
Shane Posted September 12, 2013 Share Posted September 12, 2013 Already told you, get a MBC, manual ball and spring boost controller. Costs less than £20, top end it's just as good as an EBC (ebc just hits harder). It get's you there till you want to up the stakes to an EBC Second this. I used one on mine for a while and it worked well. The adjustment was very coarse on the one I had, but worked really well. http://www.ebay.co.uk/itm/Manual-Boost-Controller-with-Fitting-Kit-Subaru-Forester-Legacy-Turbo-/141037412213?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20d67c1f75 I picked up a cheap ebc from EPR racing last year at JAE and tbh apart from in car control and being able to set up different level settings, there are no real advantages. I guess the more complicated controllers offer more than the one I have though. Great way of getting to 1.2 though for very little outlay. Quote Link to comment Share on other sites More sharing options...
inazone Posted September 12, 2013 Share Posted September 12, 2013 All I have is the RR fitted plus the usual BPU gubbins. Depending how hard I push the pedal down I can easily achieve 1.2bar/17psi boost. Nothing beats the feeling of an Auto BPU supe, well apart from a heavily modified single or hybrid twins! Quote Link to comment Share on other sites More sharing options...
Graham1984 Posted September 12, 2013 Share Posted September 12, 2013 Did H even notice his name was changed to Harvard Quote Link to comment Share on other sites More sharing options...
Lbm Posted September 12, 2013 Share Posted September 12, 2013 He probably refuses to engage in these childish games. *sniggers* Quote Link to comment Share on other sites More sharing options...
Havard Posted September 12, 2013 Author Share Posted September 12, 2013 Did H even notice his name was changed to Harvard When? Quote Link to comment Share on other sites More sharing options...
Graham1984 Posted September 12, 2013 Share Posted September 12, 2013 When? About 30 minutes ago, lbm became Carl, I was Gayham1984 and Ben was Cheddar mong..... unfortunatly for Ben his phone lost connection and now he can't access the forum Quote Link to comment Share on other sites More sharing options...
SupraDan24 Posted September 12, 2013 Share Posted September 12, 2013 (edited) Chedder mong haha. Edited September 12, 2013 by SupraDan24 (see edit history) Quote Link to comment Share on other sites More sharing options...
Havard Posted September 12, 2013 Author Share Posted September 12, 2013 He probably refuses to engage in these childish games. *sniggers* About 30 minutes ago, lbm became Carl, I was Gayham1984 and Ben was Cheddar mong..... unfortunatly for Ben his phone lost connection and now he can't access the forum Sounds amazing. I was unfortunately watching "Educating Yorkshire" and missed the festivities. Doh. H. Quote Link to comment Share on other sites More sharing options...
Graham1984 Posted September 12, 2013 Share Posted September 12, 2013 It was even more amazing than it sounds. Quote Link to comment Share on other sites More sharing options...
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