Foxbuster Posted June 30, 2010 Share Posted June 30, 2010 (edited) Hello, I have a Toyota Supra RZ 1994 J-spec with the following specs : 1st decat 2,5 with RR 2nd decat 3 HKS Two stock bafflers (restrictive?) Blitz nur spec After fitting the downpipe, boost didn't raise at all? Is it true that the two bafflers before the blitz are also very restrictive? I have a thorsen FCD, but not connected yet It should raise the boost now, or am I wrong? And yes I've read the FAQ about BPU This is the only thing that came across my mind 1) Aftermarket cat-back exhaust The stock cat back (the pipe after the 2nd decat pipe) is extremely restrictive. In order to allow a good free flowing system this needs to be replaced with an aftermarket system. There are a huge amount of systems available, but any good quality aftermarket system will be suitable for a BPU level of modification. Thanks Edited June 30, 2010 by Foxbuster (see edit history) Quote Link to comment Share on other sites More sharing options...
jackso11 Posted June 30, 2010 Share Posted June 30, 2010 No, you will have a restrictor ring in there between the decats so boost will be about standard. You need to now fit a boost controller which will allow you to up the boost. Also, fit your FCD before boosting more. Quote Link to comment Share on other sites More sharing options...
Mcgoo Posted June 30, 2010 Share Posted June 30, 2010 (edited) If I've read this right, you have decatted it but have a stock baffle/s after the decat pipes, and a NUR spec back box? If so, the stock baffle/s will be too restrictive to allow your boost to rise much above stock. Yes, you need to get an aftermarket cat-back system fitted. You will also need a restrictor ring fitted ( normally between the two de-cat pipes) to stop it over boosting. Edited June 30, 2010 by Mcgoo (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted June 30, 2010 Share Posted June 30, 2010 I think "RR" means restrictor ring folks, just in case you missed it Every system is different buddy, some will hit 1.2bar with a 1.2bar restrictor ring (Rare as hens teeth though) and some won't. I hit 0.9bar with a 1.2bar restrictor ring, I then used a manual boost controller to up the boost to a nice 1.1-1.2bar (Depending on load/gear). If you are seeing 0.8-0.9 I would try a manual boost controller to see what happens. I would advise getting an exhaust gas temperature gauge though, so that you can monitor the temperatures to make sure the restriction isn't causing too much heat. Hope that helps. Quote Link to comment Share on other sites More sharing options...
jackso11 Posted June 30, 2010 Share Posted June 30, 2010 Quote Link to comment Share on other sites More sharing options...
Foxbuster Posted June 30, 2010 Author Share Posted June 30, 2010 (edited) If I've read this right, you have decatted it but have a stock baffle/s after the decat pipes, and a NUR spec back box? Yes this is correct I think "RR" means restrictor ring folks, just in case you missed it This is also correct No, you will have a restrictor ring in there between the decats so boost will be about standard. You need to now fit a boost controller which will allow you to up the boost. Also, fit your FCD before boosting more. And what will happen if I remove the RR now? Nothing since I still have the two restrictive bafflers? Also I will connect my FCD tomorrow, it's a thorsen as far as I know Edited June 30, 2010 by Foxbuster (see edit history) Quote Link to comment Share on other sites More sharing options...
jackso11 Posted June 30, 2010 Share Posted June 30, 2010 And what will happen if I remove the RR now? Nothing since I still have the two restrictive bafflers? Also I will connect my FCD tomorrow, it's a thorsen as far as I know Who knows. It might not change as the baffles may keep your bost down....but if the baffles are not effecting it you may wind up peaking at 1.5 bar and screwing your turbos. Quote Link to comment Share on other sites More sharing options...
Foxbuster Posted July 1, 2010 Author Share Posted July 1, 2010 I am getting a boost controller and I will connect the FCD... I will also make one open freeflowing exhaust so I am sure I have no retrictions and I will also buy myself a exhaust gas temperature gauge After all that, ill let you guys know Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted July 1, 2010 Share Posted July 1, 2010 dont run your car without the boost controller and no RR.. or your turbos will be a russian roulette as to how long they last. leave RR on and turn boost via controller, also what size dia is RR as this is sometimes the problem on level of boost Quote Link to comment Share on other sites More sharing options...
Foxbuster Posted July 1, 2010 Author Share Posted July 1, 2010 The RR is from whifbitz, this is normally 1 bar RR Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted July 1, 2010 Share Posted July 1, 2010 The RR is from whifbitz, this is normally 1 bar RR i have had one or two from paul and had to make them large to boost more.. each car is different.. you can increase its size and it will increase the boost or use a boost controller Quote Link to comment Share on other sites More sharing options...
Foxbuster Posted July 1, 2010 Author Share Posted July 1, 2010 Ok, I thought I had the right wiring diagram, but I doesn't seem to match my J-spec Supra... Can someone add some information to make it happen I need to cut the wire to fit the FCD from the MAP to ECU. Input from ECU goes to blue for thor FCD and the other side goes to green wire for thor FCD... But which one is my MAP, cause the colours don't seem to match with the j-spec pinout diagram.. ? Quote Link to comment Share on other sites More sharing options...
Foxbuster Posted July 3, 2010 Author Share Posted July 3, 2010 (edited) Been busy today, The stock whifbitz RR is 50mm, i've now gone to 52,5mm and nothing special so far happened, maybe increase from 0,76 to 0,8 but it's hard to tell... I still have the restrictive stock bafflers Also I am still looking for the correct FCD wiring diagram for a j-spec car If you are seeing 0.8-0.9 I would try a manual boost controller to see what happens. I would advise getting an exhaust gas temperature gauge though, so that you can monitor the temperatures to make sure the restriction isn't causing too much heat. Hope that helps. Where to fit the exhaust temperature sensor? Cause the manual doesn't say anything about the exact place... The manifold? If so, it isn't gonna be an easy job Edited July 3, 2010 by Foxbuster (see edit history) Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted July 3, 2010 Share Posted July 3, 2010 your best bet is to stick a boost controller on.. if the boost controller does not move the boost you have a leak somewere.. leaks do happen very often, yours might be small as your seeing 0.8 Quote Link to comment Share on other sites More sharing options...
Foxbuster Posted July 3, 2010 Author Share Posted July 3, 2010 (edited) FCD connected and the stupidest thing ever tried -> drive without RR ring... still 0,8 bar and absolutely no peaking. I will put the RR back off course, but now I am sure the baffles are way too restrictive... I've found the correct FCD wiring diagram here http://www.mkivsupra.net/vbb/showthread.php?t=39084 It didn't overboost at all. Jurgen I've send you an email Edited July 3, 2010 by Foxbuster (see edit history) Quote Link to comment Share on other sites More sharing options...
Jurgen-Jm-Imports Posted July 3, 2010 Share Posted July 3, 2010 FCD connected and the stupidest thing ever tried -> drive without RR ring... still 0,8 bar and absolutely no peaking. I will put the RR back off course, but now I am sure the baffles are way too restrictive... It didn't overboost at all. Jurgen I've send you an email FCD is only needed when you hit higher boost 1.1 1.2 so if your hitting 0.8 you need a boost controller to control the boost. once you have boost controller set it to 1 bar and check your boost.. if its not boosting to 1 bar YOU HAVE A LEAK SOMEWERE (very small i think as its still boosting quite good 0.8) once you got to 1.1 bar boost etc make sure you fit FCD properly otherwise you will hit fuel cut and your ENGINE light will come on. once all done dont go beyond 1.2 bar. Quote Link to comment Share on other sites More sharing options...
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