chilly Posted June 19, 2007 Share Posted June 19, 2007 How much would it cost and what bhp gains can be expected?? Also where do you stand on emissions for the MOT? Cheers Quote Link to comment Share on other sites More sharing options...
Konrad Posted June 19, 2007 Share Posted June 19, 2007 BHP gain will be around 10 bhp (?) It will not get through emission test in 99%. You can always keep second cat and put it in at MOT time, this should be enough. Both decat pipes costs around 130 - 150 pounds. Be warned - decatted NA sounds like hells thunderstorm! Quote Link to comment Share on other sites More sharing options...
chilly Posted June 19, 2007 Author Share Posted June 19, 2007 Both decat pipes costs around 130 - 150 pounds. Be warned - decatted NA sounds like hells thunderstorm! Is that £130 - £150 each? I ready have an aftermarket exhaust on which sounds quite loud. (It has set off car alarms when using high revs!) Not worth doing then? Quote Link to comment Share on other sites More sharing options...
CarlT67 Posted June 19, 2007 Share Posted June 19, 2007 Can you also have problems with the loss of back pressure, as don't n/a cars need a bit of back pressure (read that somewhere before)...? Quote Link to comment Share on other sites More sharing options...
Thorin Posted June 19, 2007 Share Posted June 19, 2007 Can you also have problems with the loss of back pressure, as don't n/a cars need a bit of back pressure (read that somewhere before)...? No, it's a myth. Quote Link to comment Share on other sites More sharing options...
chilly Posted June 19, 2007 Author Share Posted June 19, 2007 No, it's a myth. I produce plenty of my own back pressure...and that is no myth!! Quote Link to comment Share on other sites More sharing options...
chilly Posted June 19, 2007 Author Share Posted June 19, 2007 So is it worth doing then? I dont know whether I have a problem with one of the cats anyway... Theres a slight blowing sound coming from under the drivers door area and when on idle after warm up theres a slight crackling sound. Any ideas. Quote Link to comment Share on other sites More sharing options...
CarlT67 Posted June 19, 2007 Share Posted June 19, 2007 No, it's a myth. Ohh really, glad thats been cleared..... As far as is it worth doing, I de-catted my n/a MR2 and there was a small noticeable difference in throttle response and the engine seemed to climb revs more freely.....could have just been my imagination though lol Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 19, 2007 Share Posted June 19, 2007 If you decat just to see a power rise, you might be disappointed. Time the car a few times on a local stretch with an accelerometer and then time it again after the decat. If the ambient temperature is similar, don't expect to see much difference, apart from noise. Quote Link to comment Share on other sites More sharing options...
kieren1234 Posted June 19, 2007 Share Posted June 19, 2007 Decatting the n/a seems alot of hassle for very little power gains, if any. Quote Link to comment Share on other sites More sharing options...
Al Massey Posted June 19, 2007 Share Posted June 19, 2007 you may lose a bit of torque when fully decatting,thats why i put one back in Quote Link to comment Share on other sites More sharing options...
SupraJim Posted June 19, 2007 Share Posted June 19, 2007 i have fully decatted my n/a supra, the previous owner had bought the cats but never put them on, thought it was a waste so i had them put on! i also have a HKS super dragger exhaust and with the full decat the noise is awsome!!!! loud! but really shows what the 3.0l straight six engine sould be sounding like!!! i noticed a considerable difference to throttle responce and did notice more power. It really is worth doing if not for power but for the sound of it driving down the road turning heads before u have even passed them lol! as for the mot anything before 1992 is fine mine is a 1993 so was borderline tho for 5 mins to unbolt the mid section to put a cat in is well worth it! Jim Quote Link to comment Share on other sites More sharing options...
naybad Posted June 19, 2007 Share Posted June 19, 2007 Where’s the best place to get your decat from ??? was looking into getting a new manifold but might just decat it instead. Quote Link to comment Share on other sites More sharing options...
Dave Posted June 19, 2007 Share Posted June 19, 2007 done mine and im well pleased you only need to put your cat back in come mot time ,or not if you know what i mean . anyway if i was to do it again id have one of those manifolds [8-12 bhp increase]from nic -import pimp cause they replace the front cat anyways and just a bypass pipe for the mid section .my exhaust is not that loud either perhaps it depends on what system your running do it mate well worth it Quote Link to comment Share on other sites More sharing options...
Dave Posted June 19, 2007 Share Posted June 19, 2007 you may lose a bit of torque when fully decatting,thats why i put one back in have you any solid proof of that matey i.e rolling road ??? Quote Link to comment Share on other sites More sharing options...
Al Massey Posted June 19, 2007 Share Posted June 19, 2007 no just what i had noticed and the previous owner noticed, trying to pull away and its a bit hesitant Quote Link to comment Share on other sites More sharing options...
R3DG3CKO ROB Posted June 19, 2007 Share Posted June 19, 2007 I'd love to do full de-cat and fit a nurspec to an n/a it'd sound awesome is anyone already running that? Quote Link to comment Share on other sites More sharing options...
Scooter Posted June 19, 2007 Share Posted June 19, 2007 Just to clarify if its worth it a quote from Chris wilson "They make a surprising difference to performance, the engine responds well to the cats being removed, more than I thought it would, to be honest." Quote Link to comment Share on other sites More sharing options...
Nic Posted June 20, 2007 Share Posted June 20, 2007 The other option would be to fit a tubular exhaust manifold, this replaces the stock cast manifolds AND the first cat. You should see around 8-12hp increase, response is better and makes the engine sound a lot 'revvier' http://img98.imageshack.us/img98/8473/p1030161sa4.jpg http://img89.imageshack.us/img89/1831/p1030162uk1.jpg http://img143.imageshack.us/img143/7632/dsc00305dl3.jpg http://img242.imageshack.us/img242/1738/dsc00307xs0.jpg http://img142.imageshack.us/img142/3957/dsc00312gm4.jpg http://img83.imageshack.us/img83/1491/dsc00313hh4.jpg Quote Link to comment Share on other sites More sharing options...
AndyT Posted June 20, 2007 Share Posted June 20, 2007 That's really rather nice Nic. Great pics too. Quote Link to comment Share on other sites More sharing options...
R3DG3CKO ROB Posted June 20, 2007 Share Posted June 20, 2007 I wish you'd stop posting those pics Nic! I'm struggling to stop my wallet from flying open I've removed the stock air box on mine so would really look amazing Quote Link to comment Share on other sites More sharing options...
hoff Posted June 20, 2007 Share Posted June 20, 2007 Lol. Know what you mean mean Rob. Is it worth risking doing an mot with the 2nd cat removed. Mine is due soon and I am picking a 2nd decat up from Brett on Sunday at Japshow. Shall I wait to put it on? I have a 1994 supra. (I think, its on an M). Quote Link to comment Share on other sites More sharing options...
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