mrgee2jz Posted November 4, 2010 Share Posted November 4, 2010 Ok today i set out about increasing the boost on the first turbo, something ive been meaning to do for a while now and today i got round to doing it. I set it up using the info found here as i could not really find a proper guide on this forum and yes i did use the search option before anybody asks, LOL http://www.max-boost.co.uk/max-boost/supra/boosting_the_beast.htm I used the "Stealthy version of this mod" at the bottom, but i can not get anything above .9 bar of boost on the first turbo, is this the max we can run on J-spec turbos or is there something wrong???? Quote Link to comment Share on other sites More sharing options...
Scott Posted November 4, 2010 Share Posted November 4, 2010 I was hitting 1bar without any mods done to mine. Not sure why though lol. I think I might even have seen 1.2bar at one point. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted November 4, 2010 Author Share Posted November 4, 2010 I was hitting 1bar without any mods done to mine. Not sure why though lol. I think I might even have seen 1.2bar at one point. On the first turbo below 4k rpm??? Quote Link to comment Share on other sites More sharing options...
Scott Posted November 4, 2010 Share Posted November 4, 2010 I did read your question, yes Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted November 4, 2010 Author Share Posted November 4, 2010 I did read your question, yes is yours a j spec? Quote Link to comment Share on other sites More sharing options...
Scott Posted November 4, 2010 Share Posted November 4, 2010 Yup. I have a video somewhere. I'll have a look. Quote Link to comment Share on other sites More sharing options...
Lude Posted November 4, 2010 Share Posted November 4, 2010 sorry if im wrong, but isnt the 1st turbo only suppost to take aroun 0.9-1.0 bar? then the second turbo spools? Quote Link to comment Share on other sites More sharing options...
Scott Posted November 4, 2010 Share Posted November 4, 2010 1st turbo will normally be 0.7 to 0.8 in BPU. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted November 5, 2010 Author Share Posted November 5, 2010 after taking her for a proper drive, it does feel a lot more powerfull while driving around town so im happy with the setup Quote Link to comment Share on other sites More sharing options...
mwilkinson Posted November 5, 2010 Share Posted November 5, 2010 after taking her for a proper drive, it does feel a lot more powerfull while driving around town so im happy with the setup So you have installed this mod with the addition of the MBC? In addition to your normal EBC? I have never heard of this before. My car is a J-Spec and the first turbo on BPU only goes to 0.7 to 0.8 bar. I would love to get more power lower down in the rev range. Scott - What boost controller are you using and how do you have it set? Quote Link to comment Share on other sites More sharing options...
Scott Posted November 5, 2010 Share Posted November 5, 2010 MBC, ball and spring type, for the 2nd turbo to make 1.2bar. I haven't made any alterations at all to the 1st turbo. It just does it for some reason. Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 7, 2010 Share Posted November 7, 2010 MBC, ball and spring type, for the 2nd turbo to make 1.2bar. I haven't made any alterations at all to the 1st turbo. It just does it for some reason. What was detonation like at that much boost on the first turbo? I know if the second one doesn't come online you'll start getting det above 4500rpm as #1 overspeeds and overheats the air, and I'm fairly sure that's below 1.2bar. Quote Link to comment Share on other sites More sharing options...
Scott Posted November 7, 2010 Share Posted November 7, 2010 What was detonation like at that much boost on the first turbo? I know if the second one doesn't come online you'll start getting det above 4500rpm as #1 overspeeds and overheats the air, and I'm fairly sure that's below 1.2bar. Why would the 2nd one not come online? I see 1.0bar till around 3800rpm and then the 2nd turbo kicks in and I get 1.2bar. I have seen 1.2bar for a short amount of time on the first turbo, more like a spike than anything. More often than not I see 0.9-1.0 bar. Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 7, 2010 Share Posted November 7, 2010 Why would the 2nd one not come online? I see 1.0bar till around 3800rpm and then the 2nd turbo kicks in and I get 1.2bar. I have seen 1.2bar for a short amount of time on the first turbo, more like a spike than anything. More often than not I see 0.9-1.0 bar. The second turbo can sometimes be late due to leak/vsv/actuator/electronics issues. I figure if #1 is unhappy and causes det at 4500rpm @ 1bar, it'll be just as unhappy at 1.2bar. I read your "I might even have seen 1.2bar at one point" as you were running that as target boost for a while, not that you saw brief spikes to it I still wouldn't run 1bar, I know I experienced a marked power loss when upping the boost on mine years ago - I guess timing was being pulled. They only run 13:1 afr's under 4000rpm, so it's dicey. Quote Link to comment Share on other sites More sharing options...
Scott Posted November 7, 2010 Share Posted November 7, 2010 AFR's seem ok. Maybe it's the Mines ECU taking care of it. I definitely feel more torque lower down the range than I used to, so it's a performance gain to me. It would hit 1.2 for a second then settle at 1.0 bar just before tubby 2 coming online. Doesn't do that now, 0.9 to 1.0bar is the norm. My car had been lying a while so could have been sticky valves/actuators causing the brief spikes. Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 7, 2010 Share Posted November 7, 2010 Ah well, obviously I was on about stock ECUs Who knows what witchcraft the MINES jobbie performs. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted November 8, 2010 Author Share Posted November 8, 2010 Ah well, obviously I was on about stock ECUs Who knows what witchcraft the MINES jobbie performs. I suppose you can make it do whatever you tell it to do I used a ball and spring type valve (made by me) and put it right in the back next to the firewall, The how too is in a link in the first post of this thread near to the bottom Quote Link to comment Share on other sites More sharing options...
mwilkinson Posted November 11, 2010 Share Posted November 11, 2010 I took mine for a spin the other day. I get 0.9 to 1.0 bar on first turbo without the need for the additional MBC mod. I always thought it was 0.7 bar but I was wrong. I think I need at the least to get a piggy back ECU to sort the fuelling now. As Ian C says I am concerned about the fuelling, I might also increase the injector size as my 440cc injectors will by crying at full chat. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted November 11, 2010 Author Share Posted November 11, 2010 im going to try another boost gauge and try it then Quote Link to comment Share on other sites More sharing options...
mwilkinson Posted November 11, 2010 Share Posted November 11, 2010 im going to try another boost gauge and try it then I have a Defi BF series boost gauge which reads of the same plenum as my Greddy Profec B Sec II boost controller. The Greddy unit reads 0.1 bar below the Defi. I tend to go by the Defi as its on a pillar pod by my face. It's safer and I can record it via the control unit. Quote Link to comment Share on other sites More sharing options...
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