Guest mwohaaahaahaa Posted August 30, 2013 Share Posted August 30, 2013 Hi All, I'm currently having difficulty generating more than 0.78 Bar of boost. I have recently bought the car, but it should be able to generate 1.1Bar without any issues. I have a Mines ECU, Arc intercooler with hard pipe kit, Aftermarket exhaust (not sure which make) HKS dump valve Uprated fuel pump, Blitz Dual SBC pre 2001 model The car is an auto I am using the boost gauge on the boost controller to measure boost. And the Peak and hold to see what the max boost I have generated is. I re set it after each run. I have managed to get 0.78 bar of boost with a ratio set to 35 and the gain set to 5. I have the ratio up to 70 and the gain up to 8 and could only seem to generate 0.5 bar (not what I was expecting) Something else rather strange is that between 2k and 3k rpm my boost gauge says 0.00 when I'm on the throttle (I think I may have seen it go to 0.12 but it's hard to see when driving and the peak and hold function show's a higher boost from when the second turbo kicks in). I get a negative vacuum reading when I'm off the gas, but I was expecting to get 0.7 bar from the first turbo round the 3k rpm mark when I'm putting my foot down. is this boost figure correct or am i dreaming that it should be 0.7 at this rpm? (FYI when I let of the gas I can hear the dump valve so I'm fairly sure the first turbo is spooling, even if I am not getting the full benefit of the boost.) I have been doing a lot of searching and there are people with similar problems on here. I think i have narrowed it down to the following. Exhaust is restrictive (not sure if I have the Cats in or not) A boost leak maybe on of the vacuum pipes somewhere Maybe a valve is sticking like the vsv or wastegate valve. or maybe the boost controller isn't working. Are there any easy ways to eliminate some of the options. (the Cats on is probably the easiest but I don't really know how to test the other components) I have read on here that some people put the supra in TTC mode to test some the vsv's and other valves. Below is a link to a 5 min TTC http://mkiv.supras.org.nz/articles/andy.htm Is this method any good and if this works and I get 1 bar of boost then would it mean that it is one of the valves in the sequential system or a vacuum pipe in the system? I am open to any suggestions if there are better methods of testing things. unfortunately I'm not confident enough to do this sort of work myself will have to get a mechanic to do it. As I'm not made of money, if I can reduce the labour costs by pointing them in the right direction then that would be very helpful. many thanks in advance. Quote Link to comment Share on other sites More sharing options...
listy Posted August 30, 2013 Share Posted August 30, 2013 Out of what you have narrowed it down to: 1. If you have cats in, you can easily tell by looking. If it is a straight pipe all the way from the down pipe, you have no cats. If there is a large "lump" in the middle of the car, that is the second cat. The 1st cat, you will have to look underneath and get a torch up towards the engine bay to check. 2. Change all the pipes, or do a boost leak test. (Search button is your friend here) 3. I don't really know a way to check, other than removing them and giving them a clean. Maybe someone else can help on that one. 4. Is the BC set up to boost to 1.1bar? If not, there is your problem. If you are unsure, find someone who knows what they are doing to set it up correctly. Hope this helps. Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted August 30, 2013 Share Posted August 30, 2013 Thank you that does help. When I cen get the car up on a ramp then i'll check the cats, although I still think I should be able to raise the boost to .9 or something even if they are in. I'll do a search on for a boost leak test and see how I get on with that. With regards to the boost controller. I have been doing a lot of searches on the settings and getting Manuals, I even email Blitz UK branch to get them to send me a manual (unfortunately they only have a manual form 2006 onwards) but when I look at it the functions and how to set them up are exactly the same) I have used other peoples boost setting on here but to be honest I just want it to go to .9 or something just to show that it is actually increasing the boost. When I raised the ratio the boost definitely shouldn't have gone down. Do you know much about that 4 min TTC mode? I think it bypasses the IACV and the EGCV, if I can then generate more boost then I think I can narrow it down to one of these being the problem. Quote Link to comment Share on other sites More sharing options...
Nic Posted August 30, 2013 Share Posted August 30, 2013 (edited) Exhaust is restrictive (not sure if I have the Cats in or not) The first thing you need to do is check if the car has the cats fitted. The cats are very restrictive and limit the boost level, trying to raise the boost with the cats in place will generate dangerously high exhaust gas temps. Pic of the stock cats in the foreground, the smaller 1st cat (right) nearest the engine, the 2nd longer cat (left) runs underneath the front of the car. Edited August 30, 2013 by Nic (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted August 30, 2013 Share Posted August 30, 2013 The first thing you need to do is check if the car has the cats fitted. The cats are very restrictive and limit the boost level, trying to raise the boost with the cats in place will generate dangerously high exhaust gas temps. Pic of the stock cats in the foreground, the smaller 1st cat (right) nearest the engine, the 2nd longer cat (left) runs underneath the front of the car. http://up.autotitre.com/0401f80304.jpg Thank you for that. I'll have to check when I can get under the car. I have been reading some other threads like the one below http://www.mkiv.co.uk/vbb/showthread.php?35926-The-sequential-system Could Problem 4 that Ian is talking about be part of the problem as to why I'm not seeing boost at all at low revs, also if this is the problem could a leak here also be causing me to not be able to get greater than .7 boost? Thank you all for your help so far. Quote Link to comment Share on other sites More sharing options...
skippyboyo1 Posted August 30, 2013 Share Posted August 30, 2013 Off topic, my god I'd get annoyed typing your username all the time or it my be awkward introducing yourself as that at meets. Lol Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted August 30, 2013 Share Posted August 30, 2013 Off topic, my god I'd get annoyed typing your username all the time or it my be awkward introducing yourself as that at meets. Lol Thanks. Whenever I have to give it out to companies over the phone as part of my email it usually get a laugh, and I have to spell it for them rather than just saying it. (it only really works if you say it in an evil, deep, drawn out voice) Quote Link to comment Share on other sites More sharing options...
Nic Posted August 30, 2013 Share Posted August 30, 2013 Thank you for that. I'll have to check when I can get under the car. I have been reading some other threads like the one below http://www.mkiv.co.uk/vbb/showthread.php?35926-The-sequential-system Could Problem 4 that Ian is talking about be part of the problem as to why I'm not seeing boost at all at low revs, also if this is the problem could a leak here also be causing me to not be able to get greater than .7 boost? Thank you all for your help so far. Before assuming there is a problem, check if the cats are fitted. A completely stock TT Supra - with both cats fitted and no boost controller - should start to make positive boost at around 1.8K rpm, then between 3.5-4K rpm you should feel the 2nd turbo come online and the boost pressure should peak at around 0.8bar. If the cats are still fitted, start by adjusting the boost controller so it has no effect on the turbos (so it's just acting as a boost gauge) and test to see if the car is behaving as above. Let us know if the cats are fitted or not and what sort of boost pressure it is making at what rpms. Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted August 30, 2013 Share Posted August 30, 2013 Before assuming there is a problem, check if the cats are fitted. A completely stock TT Supra - with both cats fitted and no boost controller - should start to make positive boost at around 1.8K rpm, then between 3.5-4K rpm you should feel the 2nd turbo come online and the boost pressure should peak at around 0.8bar. If the cats are still fitted, start by adjusting the boost controller so it has no effect on the turbos (so it's just acting as a boost gauge) and test to see if the car is behaving as above. Let us know if the cats are fitted or not and what sort of boost pressure it is making at what rpms. The boost controller was completely off and it was set like that, but I had this problem and I thought the boost controller would solve it. So we connected it up and to be fair the spool up for the second turbos coming in did improve. This is with the boost controller set up with 0 for all the ratios on all channels To keep the boost stock and even then it only had 0.74 bar of boost. I have had a look and the vsv had a pipe which was connected to the waste gate blocked off (due to the boost controller) but the other one is also blocked off. I'm not sure why. I think the other end should connect to the line next to the pressure line to the EGCV VSV. I'm not sure what you call that line. But that line too is blocked off is close to the other and looks like that is what it should connect to. Could my problems be because this isn't connected up? Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted August 30, 2013 Share Posted August 30, 2013 I have looked around and I think it is connected up to the exhaust bypass valve. If this is just capped off will the valve always be open or closed? Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted September 2, 2013 Share Posted September 2, 2013 I have looked around and I think it is connected up to the exhaust bypass valve. If this is just capped off will the valve always be open or closed? Does anyone have an answer to the above. should both pipes on the vsv be blocked off or just the one that originally went to the waste gate? Cheers Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted October 18, 2013 Share Posted October 18, 2013 Hey guys, I have an update, but I still don't seem to be getting boost in the rpm range of 2k to 3k. I have done the following: put decat pipes in and a restrictor ring (now without upping the ratio on the boost controller I get .9 bar of boost in 3rd gear in TTC mode. which is good yay!) I have replaced both of the turbo link pipes. one was slightly warped on the inside but nothing too major, so i'm not sure if this made much difference. I have also replace the IACV vsv and put the turbos back into sequential mode. unfortunately the boost gauge on my boost controller is still reading 0.00 bar of boost when I have my foot down and am between the 2k and 3k rmp range. and the car doesn't seem that much faster between 2k and 3k rpm. There is a difference in sound between TTC and sequential. the car is more throaty in TTC mode when idling. Any ideas as to what else i can try? can you move actuators by hand when they are still fitted (and the engine is off) to see if they are seized or not? thanks in advance again for all help. Quote Link to comment Share on other sites More sharing options...
mellonman Posted October 18, 2013 Share Posted October 18, 2013 what i would surgest is to get a noraml boost gauge and plumb the all the vac pipes back to stock and the go from there using this link to help diagnose http://www.mkiv.co.uk/vbb/showthread.php?35926-The-sequential-system Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted October 18, 2013 Share Posted October 18, 2013 what i would surgest is to get a noraml boost gauge and plumb the all the vac pipes back to stock and the go from there using this link to help diagnose http://www.mkiv.co.uk/vbb/showthread.php?35926-The-sequential-system I have done this (only I used the boost gauge on the boost controller to measure boost. But the actual bit of the boost controller that is hooked up to the waste gate was not plumbed in. Instead it like stock going to the vsv.) unfortunately even at this stage I still didn't have boost showing on from the first turbo. Maybe it was the boost controllers gauge, but this was still showing a vacuum when there was not much power and when i getting boost it does show the correct positive setting, so i thought it was unlikely that the boost controller that was the problem. The rest of the set up is stock. (not including exhaust or inter coolers etc...) Quote Link to comment Share on other sites More sharing options...
Guest mwohaaahaahaa Posted October 18, 2013 Share Posted October 18, 2013 Could it be the EBV vsv that is not letting boost build on the first turbo? Quote Link to comment Share on other sites More sharing options...
heckler Posted October 18, 2013 Share Posted October 18, 2013 well, what I would do is... 1 - Remove the boost controller from the system all together 2 - Put the Sequential system back to should be 3 - Check the Boost Gauge is connected to the correct place, from what I remember is off the inlet manifold This is to prove the sequential system is working and producing the correct boost levels. Other wise you trying to fix the issue by adjusting 2 variable (BC and vac lines) and you end up getting in a mess as you don't know what is effecting what! Quote Link to comment Share on other sites More sharing options...
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