Si_s Supe Posted May 21, 2011 Share Posted May 21, 2011 I've recently bought my 1st Supra, a TT 6 speed facelift that's totally stock with 114000 kms and has never been modded. Absolutely LOVE it but have made a weird observation that I'm not sure is normal. I know potential issues are really hard to describe over a forum but I'll try my hardest! Here goes! Symptoms: 1: When gently accelerating up through the revs at around 25% throttle, the stock boost gauge climbs and you can hear the turbo spinning. At 4000 RPM while maintaining the same throttle, the boost gauge drops right off and you can't hear any turbo whistle. It stays like that to the red line. (Could this be that there is not enough exhaust flow at part throttle to spool the 2nd turbo??) 2: When accelerating hard through the revs at WOT, the car pulls hard but then at around 3700-4000ish RPM there is a momentary big drop in power / flatspot and then it all comes back as before, but I wouldn't say any harder like I'd expect with both turbos online. (Is this drop / flat spot normal during the transition between 1 and 2? If this is normal, should a standard car pull noticeably harder after the transition than before?) I've read loads of threads through the search function but none seem to specifically match my 'problem' if there is one. Have I read these threads and talked myself into thinking I have a problem? Before owning my 1st Supra, I'd only ever been out in an auto TT and I'm sure that didn't have the flat spot on transition but then it was some time ago so I may not be remembering correctly!? Hope I've made my explanations clear enough and I'm sorry if I've rambled on! Thanks in advance for any input on this. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 21, 2011 Share Posted May 21, 2011 There's probably a leaky small hose, or a solenoid issue with the sequential system. I have now made a rig to test the whole set up for leaks, and it is something I should have done years ago, as it is saving me a lot of aggravation Quote Link to comment Share on other sites More sharing options...
aman00123 Posted May 21, 2011 Share Posted May 21, 2011 The dip in power is normal, but when the tubbies come back on power there is usually quite a big and noticeable difference - more power.... As for problem number 1, probably not enough gases as you said, if you put your foot down a bit more do you get boost? As mr Wilson has said, check for any leaks first up, if it does turn out to be one of the solenoids I have both sitting spare in my garage Quote Link to comment Share on other sites More sharing options...
Si_s Supe Posted May 21, 2011 Author Share Posted May 21, 2011 That sounds ideal Chris. Shame you're so far away from me! Can you not move closer?? :rolleyes:Is there a good way to check for leaks or is it a case of going through each and every hose and visually inspecting? Is it maybe worth me getting a length of fresh silicone hose and just replacing them all to be sure? They are 15yrs old after all! How should I test the solenoids? Aman...I'll try sqeezing the throttle some more next time I'm out in it and see what happens. If it turns out I need a solenoid, I'll give you a shout. I take it they're known to be working? Quote Link to comment Share on other sites More sharing options...
aman00123 Posted May 21, 2011 Share Posted May 21, 2011 Yea bud came straight off my car which was 100% before everything was taken out for a single conversion Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 21, 2011 Share Posted May 21, 2011 Don't use silicone, it's nothing like as good or as reliable as decent "rubber" hose for this application. Get some Gates or similar quality hose on a reel and cut lengths to suit, Some hoses will need to be bought from Toyota as they need to be a moulded shape, trying to use a straight hose bent to a tight enough radius will probably see it crimped closed, or its flow substantially reduced. Small bore silicone hose hardly ever has a braided liner, so splits, plus it's slippery, and that's not what you want for push on hoses.... You never see it in that application on any proper race engines, only in larger bore sixes with a textile braid moulded in for things like IC and rad hoses. Quote Link to comment Share on other sites More sharing options...
Si_s Supe Posted May 21, 2011 Author Share Posted May 21, 2011 Don't use silicone, it's nothing like as good or as reliable as decent "rubber" hose for this application. Get some Gates or similar quality hose on a reel and cut lengths to suit, Some hoses will need to be bought from Toyota as they need to be a moulded shape, trying to use a straight hose bent to a tight enough radius will probably see it crimped closed, or its flow substantially reduced. Small bore silicone hose hardly ever has a braided liner, so splits, plus it's slippery, and that's not what you want for push on hoses.... You never see it in that application on any proper race engines, only in larger bore sixes with a textile braid moulded in for things like IC and rad hoses. OK, thanks for the heads up! Is it worth me just getting all new hoses from Toyota or will that just be silly expensive?? If I'm going the route of the Gates hose, what diameter will I need? Quote Link to comment Share on other sites More sharing options...
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