Wez Posted January 13, 2003 Share Posted January 13, 2003 Hiya Guys, What would be the expected boost on a stock J-Spec if I replaced just the first CAT, would boost creep still be an issue and would a boost cut controller be needed? Regards Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted January 13, 2003 Share Posted January 13, 2003 Probably 16psi so above the 15psi fuel cut threshold. You may notice it more in colder weather and not at all in summer. Do you have any aftermarket back box system as well? I ask as the stock back section does present some restriction and the second CAT will also contribute. With both CATs gone and straight through exhaust you are likely to hit 17-18si. Regards Pete Quote Link to comment Share on other sites More sharing options...
ChrisR Posted January 13, 2003 Share Posted January 13, 2003 Originally posted by TRL Performance With both CATs gone and straight through exhaust you are likely to hit 17-18si. Regards Pete Yep and beyond like i have just hit after fitting an aftermarket exhaust with full decat. 1.5 BAR:eek: I now need a restrictor ring which is in hand. For the time being im #2 Turbo celibate. Quote Link to comment Share on other sites More sharing options...
Wez Posted January 13, 2003 Author Share Posted January 13, 2003 Thanks for the info guys, I am still running with standard exhaust so with this and the second cat still in place am I gonna hit the fuel cut? Quote Link to comment Share on other sites More sharing options...
jast Posted January 13, 2003 Share Posted January 13, 2003 Mines got no CATS and its hitting 1.0 bar max, however when it was icey its was making 1.2, so with no cats thats not 2 bad. However I may have a downsized downpipe, im not sure, still learning:stupid: Quote Link to comment Share on other sites More sharing options...
ChrisR Posted January 13, 2003 Share Posted January 13, 2003 Originally posted by Wez Thanks for the info guys, I am still running with standard exhaust so with this and the second cat still in place am I gonna hit the fuel cut? I ran with full decat and the stock cat back exhaust for 4 months. was only hitting 0.9 BAR but still had the Fuel Cut Defenser fitted to aviod stock fuel cut. Plus it was there ready for when the exhaust was fitted when i would definately need it. Quote Link to comment Share on other sites More sharing options...
Willson Posted January 13, 2003 Share Posted January 13, 2003 I have a 6 speed J-spec with front cat removed and apexi exhaust. I hit fuel cut as low as 5500 rpm, depending on weather. VFCC before the summer.............. Gordon. Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted January 13, 2003 Share Posted January 13, 2003 Thanks for the info guys, I am still running with standard exhaust so with this and the second cat still in place am I gonna hit the fuel cut? Wez, It's really hard to tell as so many Supras behave differently when removing CATS. You're changing the mechanics of the control surfaces and feedback paths so the ECU and wastegate control of boost varies a lot between cars. It's possible that you will still increase boost beyond the fuel cut threshold but I know when I changed mine I had real trouble getting any increase in boost until we changed the whole of the rear exhaust (and put in a complete Mongoose system). This is because my back box sections had collapsed somewhere. So you never can tell until you do it but chances are you'll hit it now in the winter anyway and to be honest fuel cut is not nice to experience, you'll still think you've blown something (it's a nasty safety mechanism, simple and crude but it works). Regards Pete Quote Link to comment Share on other sites More sharing options...
Snowman Posted January 14, 2003 Share Posted January 14, 2003 Here Here. Fuel Cut is evil, especially because the engine light comes on temporarily and you do honestly think, oh Christ and reach for the cheque book!!! After having a full decat with after market exhaust I was hitting Fuel cut. Hopefully the new Blitz DSBC will sort this out. Am I right in thinking that 1.2 bar is pritty much the max I show have it set at for setting 4 with a 1.25 alarm? Quote Link to comment Share on other sites More sharing options...
ChrisR Posted January 14, 2003 Share Posted January 14, 2003 Originally posted by Snowman Here Here. Fuel Cut is evil, especially because the engine light comes on temporarily and you do honestly think, oh Christ and reach for the cheque book!!! After having a full decat with after market exhaust I was hitting Fuel cut. Hopefully the new Blitz DSBC will sort this out. Am I right in thinking that 1.2 bar is pritty much the max I show have it set at for setting 4 with a 1.25 alarm? Definately 1.2 BAR max otherwise get you cheque book ready. Quote Link to comment Share on other sites More sharing options...
Snowman Posted January 14, 2003 Share Posted January 14, 2003 cool. cheers. its just a bit or reassurance that i'm on the right track. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.