SupraTT Posted November 21, 2001 Share Posted November 21, 2001 Hi Guys There seems to be so many different opinions out there, that i just want toask on here and see what opinion is the most common. What i am trying to find out is...... 1) I have an Import TT with a MINES ECU and cat back Abflug Hyper Muffler Exhaust ( big bore )and want to de-cat the car, but have heard about the boost creep problems / uncontrollable boost etc. I would like your opinions on whether its best to remove BOTH cats or just the first / second and also if so, what downpipe to use / from who and what size is best to control flow to an extent if need be. 2) With having stock turbo's and a MINES ECU / Exhaust, will i need to add a Fuel Cut Defenser, and if so should i get a Pete Betts one which "ups" the limit or an HKS one which i "think" removes it totally ? Been contemplating this for months now but i just want to know the best answers to each Thanks for all and any help people ! Cheers Michael Quote Link to comment Share on other sites More sharing options...
Alex Posted November 21, 2001 Share Posted November 21, 2001 Hi there, Firstly, The MINES ECU, de-limits speed, uprates the fuel map, raises if not defeats the fuel cut, and can be easily used in conjunction with the MINES 540cc injectors...you may wish to check your car for them though it will rewuire you to remove the intake manifold. The MINES fueling is good for about 1.1bar after that you'll probably start to run lean. The MINES ECU is mapped to Jap fuel this means its happiest at about 100Ron...you can only theoretically reach this using Optimax from Shell and Millers Octane Booster. If you fit a replacement Down pipe but still leave the front pipe stock with the 2nd cat in it the you will not suffer boost creep. It is only when you remove both Cats that you can suffer boost creep or higher boost than the fueling or Turbo's can really deal with. 1.2bar is as high as you really want to go...but its your choice some people have had no problems running 1.4 bar for a long time....but be careful and fit a boost gauge if there isn't one already as the current cold days/nights will allow the car to boost higher than in the Summer. If your just going to remove one pipe make it the down pipe as the first cat after the exhuast manifold is the most restrictive. Blitz can sort you out with a 3" down pipe...talk to www.torqueic.com who are members of this BBS. Or the other chap to speak to is Chris Wilson he's is on this list aswell. Chris does a complete 2.5" De-cat solution for about £260 I believe...the pipes are that size as they put just enough restriction in the system to keep the boost sensible with both Cats removed but as some have found extra restriction is often nessecary even with these pipes inplace....this can be done with a restrictive gasket. The Abflug Hyper Muffler is not one I know a great deal about....if you measure the diameter of the pipe work between the back vox and the front pipe it will be fairly easy to work out how restrictive it is compared to say the HKS Hiper Muffler. I've got a MINES ECU...and have been doing some research on it....so any other questions either search the BBS or drop me a line. One thing I can tell you is that its not supported in this country...and the Blitz one is no real improvement in the UK market either as we just can't get the fuel to cope with its demands. Currently I have boosted to 1.34bar (19.5psi ish) but I get some hesitency but I don't know if this is lean-ness or fuel cut or the ECU barging in and trying to stop it going so high what ever happens it can't hold high boost for long hence I'm sticking with 1.1bar for day to day driving to be safe. Standard fuel cut is 15psi so as you can see the MINES let me waltz straight past that barrier! So the anser to your questions would be 1) Just change the down pipe and leave the second cat in...and fit a Boost controller (Blitz DSBC is the industry standard) 2) You don't need one! PS Stock Turbo's are out of their efficiency range above 1.1-1.2 bar..so no need to go higher... laters, Quote Link to comment Share on other sites More sharing options...
SupraTT Posted November 21, 2001 Author Share Posted November 21, 2001 OK so now for my next question.... If i just replace the first CAT nearest the turbos, how does this work in terms of removing only one ? Is the downpipe a separate pipe from the 2nd cat ? it looks like its all one big section, so does this need split somewhere to join / mate up with the new 1st Cat replacement downpipe ? Also ......to try and give you an idea of the Abflug Hyper Muffler exhaust, my friend has a 96 N/A MKIV and he took a look under the car for me. When he saw the exhaust he reckoned that it was the biggest bore he has EVER seen on an aftermarket MKIV exhaust !! It basically has TWO pipes coming off the backbox, probably about 70-90mm approx in diameter each, then they go back into one at the join / flange for the next section......big piping i guess !! So, after all that, i basically need to know what is required to fit a 1st CAT replacement only i.e. Cutting / Joining or are the CATS actually in 2 sections..... Sorry about all the questions..... Cheers Michael Quote Link to comment Share on other sites More sharing options...
eyefi Posted November 22, 2001 Share Posted November 22, 2001 cats are in two separate pipes. is the abflug just a muffler or is it from the cats back? Quote Link to comment Share on other sites More sharing options...
SupraTT Posted November 22, 2001 Author Share Posted November 22, 2001 The exhaust is from the Cats back and splits into two huge pipes and then back into one at the back box Quote Link to comment Share on other sites More sharing options...
Alex Posted November 22, 2001 Share Posted November 22, 2001 The second Cat is pretty obvious and is in the Front pipe...using a normal exhaust connection it is joined to the down pipe which basically hangs vertically from the manifold down to the front pipe. No special tools are required. A skilled exhaust mechanic will be able to change them quickly with out having to destroy the original pipes. Quote Link to comment Share on other sites More sharing options...
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