ardasaliah Posted July 25, 2006 Share Posted July 25, 2006 Hi- just curious to who runs higher boost with the cats still in. I know all about the associated problems that may result from doing the above e.g high EGT etc- but just wanted to know if anyone takes the risk. What psi/bar do you run? How long for? Any problems? Quote Link to comment Share on other sites More sharing options...
wkdtime Posted July 25, 2006 Share Posted July 25, 2006 Dont think many really do mate, TBH you can keep the second cat in and remove the first one (nearest one to the engine) and it should pass MOT's without emmission issues, this way you can safely increase the boost to 1.2 Bar, But 1.2 Bar fully decatted feels quite a bit better than a single Decatted running the same boost, turbos spools up slighlty quicker too. You have stated the issues running high boost with Cats in place, but if you really wanted to you could use a Bleed valve or EBC and run the Boost to a Max. 0.9-1.0 Bar. Somecars here have been known to boost to 0.9 Bar with cats in place, plus exhaust. Quote Link to comment Share on other sites More sharing options...
ardasaliah Posted July 25, 2006 Author Share Posted July 25, 2006 Hi so you think removing the 1st cat would have no effect on emmisions. Has anyone pass the MOT with their 1st cat out? Whats the 1st cat for ? Quote Link to comment Share on other sites More sharing options...
wkdtime Posted July 25, 2006 Share Posted July 25, 2006 It will have an effect on emmisions but as long as the second Cat is in good nic then the probability is that it will pass. Quote Link to comment Share on other sites More sharing options...
Angarak Posted July 25, 2006 Share Posted July 25, 2006 Hi- just curious to who runs higher boost with the cats still in... Im pretty sure the Jap Chap who had my car before it was imported did (he installed FCON-V ECU and Boost Controller with both cats inplace) - and I think he may have killed the stock turbo's as the ones on it now (which work fine) look like they are 2nd hand, unless all stock turbos come with some kind of serial number written on them with black marker pen. Quote Link to comment Share on other sites More sharing options...
mikeyb10supra Posted July 26, 2006 Share Posted July 26, 2006 Im pretty sure the Jap Chap who had my car before it was imported did (he installed FCON-V ECU and Boost Controller with both cats inplace) - and I think he may have killed the stock turbo's as the ones on it now (which work fine) look like they are 2nd hand, unless all stock turbos come with some kind of serial number written on them with black marker pen. raising the boost with cats in place is just asking for trouble IMO!! you can end up melting the cats from the inside out for starters, best to have them out if you want the boost up Raised boost comes at a price....HEAT and lots of it Quote Link to comment Share on other sites More sharing options...
Angarak Posted July 26, 2006 Share Posted July 26, 2006 raising the boost with cats in place is just asking for trouble IMO!! I agree. The first thing I did was to make sure the boost controller was zero'd out. I've since decatted and Im seeing 1.0 bar on the boost guage which im happy with. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 26, 2006 Share Posted July 26, 2006 The dirst cat is there to pass the emissions test in countries where CO and HC's have to be below a ceratin level within 10 seconds of a cold start. being small, and near the engine allows the fist cat to come up to operating temperature very quickly. However, being small means it's also very restrictive. Quote Link to comment Share on other sites More sharing options...
Supradan Posted July 26, 2006 Share Posted July 26, 2006 I am going to fit an hks ti to my 94 Gz TT i want to leave the cats in for a while as i am skint now lol,will this cause any problems with boosting/melted cats etc Quote Link to comment Share on other sites More sharing options...
Stonkin Posted July 26, 2006 Share Posted July 26, 2006 I am going to fit an hks ti to my 94 Gz TT i want to leave the cats in for a while as i am skint now lol,will this cause any problems with boosting/melted cats etc No mate, you are fine fitting a cat back exhaust without removing cats, you just wont benefit as much from the exhaust upgrade with them still in place. The problem is only if you increas the boost too much with cats still in Quote Link to comment Share on other sites More sharing options...
Wez Posted July 26, 2006 Share Posted July 26, 2006 I use to run 1.1bar with first cat in and second out, no noticable power above 1.1bar but extra heat recorded on the EGT. Quote Link to comment Share on other sites More sharing options...
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