Liam_D Posted February 25, 2010 Share Posted February 25, 2010 Hey guys, Just wondering is it really worth getting a de-cat for a N/a? Or does it cause a loss of power, due to backpressure? Just wondering because im looking at getting my exhaust done this month, and im unsure wheather to do a de-cat while im there. Any help will be appriciated. ThanksLiam Quote Link to post Share on other sites
ste91 Posted February 25, 2010 Share Posted February 25, 2010 Theoretically a decat should give gains. I am told "back pressure" is nonsense.When you say you are getting your exhaust done, do you mean a full system? Quote Link to post Share on other sites
lukEp Posted February 25, 2010 Share Posted February 25, 2010 this might help http://www.uucmotorwerks.com/html_product/...etorquemyth.htm Quote Link to post Share on other sites
Liam_D Posted February 25, 2010 Author Share Posted February 25, 2010 Yes mate looking at getting a Custom manifold, decat and new middle pipe and keeping my current backbox. Have any gains ever been proven from a de-cat as i dont want to spend the money for no reason. Quote Link to post Share on other sites
ste91 Posted February 25, 2010 Share Posted February 25, 2010 Basically you want as much flow as possible without losing velocity, or something like that.A cat is a restriction, it serves no performance purpose. Have a read up on exhaust scavenging aswell. Quote Link to post Share on other sites
lukEp Posted February 25, 2010 Share Posted February 25, 2010 and another inc volocty http://www.thumpertalk.com/forum/showthread.php?t=659727 Quote Link to post Share on other sites
Craig_N Posted February 25, 2010 Share Posted February 25, 2010 I going to get one made prob sometime in March so i can let you know.But i have spoke with a few people who have decats on there n/a's and everyone one said they they noticed a difference.Craig Quote Link to post Share on other sites
BAZ2CRAZY Posted February 25, 2010 Share Posted February 25, 2010 I would say big wins with a manifold 4-2-1?Mitch Quote Link to post Share on other sites
rob_bower Posted February 25, 2010 Share Posted February 25, 2010 im going to try and get mine finished off this month so we can all share notes!!! lol Quote Link to post Share on other sites
DavidAshton Posted February 25, 2010 Share Posted February 25, 2010 I noticed a nice difference when i put a de-cat on my n/a. But i kept the middle box and SR backbox. Maybe a full system would not be such a good idea with a de cat, it will be silly loud. Quote Link to post Share on other sites
rob_bower Posted February 25, 2010 Share Posted February 25, 2010 that depends if you still running a middle box!!! Quote Link to post Share on other sites
Amjad Posted February 26, 2010 Share Posted February 26, 2010 Craig & Rob do let us know how you get on I'm thinking of getting a decat too Quote Link to post Share on other sites
Starlet__SR Posted February 26, 2010 Share Posted February 26, 2010 I wasn't running a midbox on the SR in its last few months, sounded kinda like a supersprint system lol, you'll notice the engine revs alot freer and easier than when the cat was fitted, but you'll lose a bit of the bottom end torque.Damien Quote Link to post Share on other sites
Amjad Posted February 26, 2010 Share Posted February 26, 2010 Damien did you remove the mid-silencer AND the cat? Quote Link to post Share on other sites
Craig_N Posted February 26, 2010 Share Posted February 26, 2010 I dont have a middle box on mine and yeah does rev alot better than my old exhaust but it is load, i have been given quotes of like £85 for one so will let you all know when i get it done and i will be getting a printout at the rolling road meet so i will see if it does make any difference. Quote Link to post Share on other sites
Starlet__SR Posted February 26, 2010 Share Posted February 26, 2010 Damien did you remove the mid-silencer AND the cat?Nope, kept the cat, just used a section from behind the cat all the way to the backbox, alot louder and raspier, was worth doingDamien Quote Link to post Share on other sites
Liam_D Posted February 26, 2010 Author Share Posted February 26, 2010 Think im just gonna get the manifold done and get a new middle pipe, because i really dont wanna lose the low down power and i dont want it to be any louder. Those that know my car know that it is silly loud already. Would be nice to see any RR print outs that show noticable gains. What about if i get the mani and de-cat done and leave the middle pipe in place? Quote Link to post Share on other sites
Starlet__SR Posted February 27, 2010 Share Posted February 27, 2010 And what are you gonna do come mot time when it comes to the emissions test? Keep the cat, ditch the midbox, the newer free flowing manifold will outweigh any restrictions the cat makes, possibly a sports cat with fewer cells per inch?Damien Quote Link to post Share on other sites
Liam_D Posted February 27, 2010 Author Share Posted February 27, 2010 Mots wont be a problem dude, but i am starting to think i want the cat in there as i still want the car to be legal just incase. Think im just gonna get the mani and then get the Middle box removed like you said, and then maybe some sort of sports cat in the future. I really dont want the car to be any louder as its quite rediculous now. lol. Going to get this priced up sometime next week!! Quote Link to post Share on other sites
Starlet__SR Posted February 27, 2010 Share Posted February 27, 2010 Mots wont be a problem dude, but i am starting to think i want the cat in there as i still want the car to be legal just incase. Think im just gonna get the mani and then get the Middle box removed like you said, and then maybe some sort of sports cat in the future. I really dont want the car to be any louder as its quite rediculous now. lol. Going to get this priced up sometime next week!!There is that too, it is illegal to drive without a cat, a sports cat is the best option, most standard cats are 400cpi, as with a sports cat, they're around 200cpi, better flow but still legal, the cat will suppress the sound, but the main exhaust volume is controlled by your backbox, Damien Quote Link to post Share on other sites
b4d1sy Posted February 27, 2010 Share Posted February 27, 2010 I did have a de cat made a nice difference and change the sound a little 2 Quote Link to post Share on other sites
Liam_D Posted March 3, 2010 Author Share Posted March 3, 2010 Been to get this priced up today, im going to be looking at £400 for a full custom Manifold and a decat pipe, which i dont think is too bad considering that this guys work is top quality. Think ill be booking that in next month Quote Link to post Share on other sites
Dean @RW-Developments Posted March 4, 2010 Share Posted March 4, 2010 liam get an interchangable decat thats what i had but i must say i didnt have any middle box and when i had the decat in the power gain wasnt noticable till high end power ... the interchangable decat/cat was mint though i was always swapping it took like 10 mins to chage over! only cost £60. also try www.mijperformance.com they do all my work and aint too far from you! Quote Link to post Share on other sites
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