overspent Posted April 13, 2006 Share Posted April 13, 2006 Can anyone help me? I get a drop in boost pressure once I get to 4000rpm it climbs fine till I get to this point then from 1.25 it drops to approx 1.1 and from 1.5 it drops to 1.3. There is no significant drop when the EVC5 is switched off. I am running stage 3 hybrids and it has been suggested that the actuators may be at fault ? ? ? ? However if this is the case where can I get some new ones, Toyota only sell them with new turbos (no go on that one) and have had no success from any other sources. Your thoughts please guys. Link to comment Share on other sites More sharing options...
Jake Posted April 13, 2006 Share Posted April 13, 2006 "There is no significant drop when the EVC5 is switched off" Doesn't that indicate a problem with the EBC rather than an actuator problem? Link to comment Share on other sites More sharing options...
overspent Posted April 13, 2006 Author Share Posted April 13, 2006 That is an idea that hasn't been endorsed by two tuners. The problem was initially diagnosed on Thor's dyno (August), their suggestion was removing the front cat, nothing more only an invoice, I purchased a front de-cat pipe, fitted it and took the car back to go on the dyno again (September), fault still there and another invoice, they had no constructive solution to offer and the car then ran terribly, they did not suggest the EVC5. Car than went to Hyper who have remapped it and removed all the problems that were installed in September and again have made no connection to the EVC5. It is only that other people I have spoken to have had the same problem (not Supras) and the actuator has been at fault. Link to comment Share on other sites More sharing options...
Jake Posted April 14, 2006 Share Posted April 14, 2006 Let me get this right. With the Boost Controller turned on the car loses boost pressure when the second turbo is supposed to kick in. But it's fine when the boost controller is turned off. Is that right? If so, I would take the boost controller off and put the plumbing back to stock (10 mins work) and then see if the problem persists. If the problem goes away then surely the actuators are fine? This seems too simple. Am I missing the point here? Link to comment Share on other sites More sharing options...
overspent Posted April 14, 2006 Author Share Posted April 14, 2006 Thanks Jake. Have only gone on other peoples suggestions, but will give it a try, will let you know what transpires. Link to comment Share on other sites More sharing options...
Jake Posted April 14, 2006 Share Posted April 14, 2006 It's a test you can do for free at least. Also make sure the hoses to and from the EBC solenoid have a really good seal on the pipe they go onto - both ends. Link to comment Share on other sites More sharing options...
Nic Posted April 14, 2006 Share Posted April 14, 2006 HKS do replacement actuator kits (no kit for Supra), which I can get modified to fit the Supra, I had these fitted on my own car when I was having similar problems. See HERE Link to comment Share on other sites More sharing options...
JohnA Posted April 14, 2006 Share Posted April 14, 2006 Can anyone help me? I get a drop in boost pressure once I get to 4000rpm it climbs fine till I get to this point then from 1.25 it drops to approx 1.1 and from 1.5 it drops to 1.3. There is no significant drop when the EVC5 is switched off. .....Your thoughts please guys. I take it that your turbos are NOT in sequential mode, right? do you get appreciable boost below 3Krpm? Link to comment Share on other sites More sharing options...
Nic Posted April 14, 2006 Share Posted April 14, 2006 I take it that your turbos are NOT in sequential mode, right? do you get appreciable boost below 3Krpm? Correct, I get positive boost from around 2800rpm. Link to comment Share on other sites More sharing options...
overspent Posted April 14, 2006 Author Share Posted April 14, 2006 Hi JohnA - Not sure why Nic is answering about his car but NO my turbos still run in the sequential mode and the power curve does exactly what would be expected, a strong rise with the first turbo a slight dip as the 2nd comes in and then a strong rise again until it reaches 4,000rpm. Link to comment Share on other sites More sharing options...
Nic Posted April 14, 2006 Share Posted April 14, 2006 Hi JohnA - No my turbos still run in the sequential mode and the power curve does exactly what would be expected, a strong rise with the first turbo a slight dip as the 2nd comes in and then a strong rise again until it reaches 4,000rpm. Just a thought what blow off valve do you have fitted? Is teh boost dropping off at a certain pressure? Just wondering if your BOV is not holding the pressure. Link to comment Share on other sites More sharing options...
overspent Posted April 14, 2006 Author Share Posted April 14, 2006 Was running the stock recirculating valve but has now been changed for a BOV, would not think that they would both have a problem. Link to comment Share on other sites More sharing options...
BURT Posted April 14, 2006 Share Posted April 14, 2006 hey there bud , like the others are saying it sounds more like te boost controiller, the hks evc isnt the best for reliabilty either.. i had one on my skyline played up all the time... 0n the other hand pm supraman he may be able to help you on the actuator front..... See you at the soon bud.... on the eurotunnel;) Link to comment Share on other sites More sharing options...
JohnA Posted April 14, 2006 Share Posted April 14, 2006 ...my turbos still run in the sequential mode and the power curve does exactly what would be expected, a strong rise with the first turbo a slight dip as the 2nd comes in and then a strong rise again until it reaches 4,000rpm. In that case how about disconnecting the boost controller and puting everything back as stock. It shouldn't be too hard, as all VSVs are still functional. If you still get erratic boost then you know that it's not the boost controller at fault. Since you run hybrids they will probably have stronger actuator springs so the max boost might be higher than stock. But it should build up nicely. If it doesn't, then you're looking at eliminating leaks, aren't you? PS A decent garage should be able to pressurise the actuators one by one and see if they work as they are supposed to work. They could even hook a boost gauge before each actuator and verify that they are pressurised properly with the engine under load. That alone would eliminate quite a few factors. Link to comment Share on other sites More sharing options...
Angarak Posted April 14, 2006 Share Posted April 14, 2006 Apologies if this is a stupid question, but is it possible to pressurise the whole system without running the engine to identify leaks (and is it safe to do so)? I've currently got a similar problem, boost drops around 4k rpm when tubby #2 should come online...car doesnt pull as strong as usual. Having read this thread, I've visually inspected the vacuum hoses that I can access (without getting it up on ramps) and can't see any splits or loose hoses anywhere. I'll be pressure checking the actuators over the weekend as per the Technical Manual I purchased from CJ. I have a mate who built a Cossie for racing, and he diagnosed boost leaks on that car by getting a baked bean can, sticking it on the end of the air intake pipe and feeding xx PSI of air into it. It sounds like a Blue Peter project, but it worked for him. Not sure if its possible/feasible to do on the Supra. Cheers Link to comment Share on other sites More sharing options...
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