cheekymonkey Posted June 12, 2007 Share Posted June 12, 2007 Hi Guys Right, still in Japan but dying to get back to doing stuff with my Supe! As some of you know I have a full custom stainless steel exhaust system from the first cat, and it's pretty loud. To go BPU I would need to fully de-cat but it may end up being too loud. Would a high-flow first cat help me, or would high-flow still mean it's going to be too loud? And is such a thing made for the first cat section? Quote Link to comment Share on other sites More sharing options...
bodilx6 Posted June 12, 2007 Share Posted June 12, 2007 I just got the first cat installed again. From there backwards i have a fully custom 3" exhaust with a straight through stainless 3" muffler. I don't think it is too loud but that is probably more up to the muffler than anything else. BUT the point here is that the sound almost hasnt change from running no cats to having the first cat reinstalled. Only change in sound I notice is at high rev where it seemed to be a bit louder before. Are complete de-cat need for BPU? Couldn't you just install a Boost Controller and push to 1.1 bar or so? Quote Link to comment Share on other sites More sharing options...
cheekymonkey Posted June 12, 2007 Author Share Posted June 12, 2007 Mine's the same but without the muffler. I guess I could try with the full de-cat. Out of interest why did you put the 1st cat back in again? You do need to de-cat for full BPU else you're EGTs will get too high, this is what I've heard... Quote Link to comment Share on other sites More sharing options...
bolarbag Posted June 12, 2007 Share Posted June 12, 2007 You do need to de-cat for full BPU else you're EGTs will get too high, this is what I've heard... p*sh! BPU is a term not a set achievement, I ran 1.1bar with first cat still on and 391 at fly, I always remember first coming on this forum(afer a year of supra ownership) after doing most of my research on the U.S forum and being slated for referring to something as bpu, no one knew what it meant, it was referred to as American Now it seems as if everyone needs to achieve this set formula to bpu, you can be single turbo and still have first cat in! Removing first cat will increase performance, but its not essential, especially for reliability Quote Link to comment Share on other sites More sharing options...
bodilx6 Posted June 12, 2007 Share Posted June 12, 2007 Out of interest why did you put the 1st cat back in again? explanation here: http://www.mkivsupra.net/vbb/showthread.php?t=114261 Quote Link to comment Share on other sites More sharing options...
cheekymonkey Posted June 12, 2007 Author Share Posted June 12, 2007 explanation here: http://www.mkivsupra.net/vbb/showthread.php?t=114261 Hmm OK - I responded but I think you're just using the first cat as a RR, you still need the rest of formula for BPU Quote Link to comment Share on other sites More sharing options...
cheekymonkey Posted June 12, 2007 Author Share Posted June 12, 2007 BPU is a term not a set achievement, I ran 1.1bar with first cat still on and 391 at fly, Well, that's good for you. I probably *could* do the same, but until I get my gauges installed I'd be running blind. Once I do, I can keep an eye on things, and if my EGTs stay at a sensible level with the first cat still in, then great Quote Link to comment Share on other sites More sharing options...
Homer Posted June 12, 2007 Share Posted June 12, 2007 p*sh! BPU is a term not a set achievement, I ran 1.1bar with first cat still on and 391 at fly, I always remember first coming on this forum(afer a year of supra ownership) after doing most of my research on the U.S forum and being slated for referring to something as bpu, no one knew what it meant, it was referred to as American Now it seems as if everyone needs to achieve this set formula to bpu, you can be single turbo and still have first cat in! Removing first cat will increase performance, but its not essential, especially for reliability Thats going against the opinions of pretty much every tuner and engine builder on the forum. If you leave the 1st cat in place and raise boost, your WILL get higher EGT's. It is strongly advisable to remove the first cat when raising boost to help take some of that heat away from the turbo's and engine back. bodilx6, for the same reason you're going it raising boost the wrong way. Quote Link to comment Share on other sites More sharing options...
Soop Dogg Posted June 12, 2007 Share Posted June 12, 2007 Thats going against the opinions of pretty much every tuner and engine builder on the forum. If you leave the 1st cat in place and raise boost, your WILL get higher EGT's. It is strongly advisable to remove the first cat when raising boost to help take some of that heat away from the turbo's and engine back. bodilx6, for the same reason you're going it raising boost the wrong way. Plus the fact that you could run the risk of overheating the cat. Quote Link to comment Share on other sites More sharing options...
AndrewOW Posted June 12, 2007 Share Posted June 12, 2007 Would a high-flow first cat help me, or would high-flow still mean it's going to be too loud? And is such a thing made for the first cat section? Have a look at this thread. Nic's looking into prices. http://www.mkivsupra.net/vbb/showthread.php?t=112967 Quote Link to comment Share on other sites More sharing options...
bolarbag Posted June 12, 2007 Share Posted June 12, 2007 So having a first cat in running at 1.2bar is going to raise exh. gas temperatures to dangerous levels? I agree the temps will be raised due to the restriction of the forces on the turbos, but they wont be catastrophic, I have defi x6, I'll report back on the decrease of my exh. gas temp when I go single, perhaps I'll be pleasantly surprised 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.