Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: B9 KLF on October 26, 2005, 08:10:37 PM

Title: How Green Is Decat
Post by: B9 KLF on October 26, 2005, 08:10:37 PM
I was thinking about decatting to go with the new performance down pipe and street porting, and I had a twinge of conscience.

I could spend out for a hi flow cat or just a straight thro pipe but wondered how much hp gain do you actually get and whether I was being irresponsible by getting rid of the cat?  :spank

Would do you think.

Keith
Title: How Green Is Decat
Post by: Carl on October 26, 2005, 08:27:33 PM
dipaands what kulour yous pain de cat mon!
regards
Carl
Title: How Green Is Decat
Post by: Red and Single on October 26, 2005, 08:31:49 PM
:rollin

FD\'s are so incredulously environmentally unfriendly, if you are thinking "green" you have the wrong car anyway !!

:rollin
Title: How Green Is Decat
Post by: B9 KLF on October 26, 2005, 09:02:35 PM
yeah I feel better now  :burnout
Title: How Green Is Decat
Post by: B9 KLF on October 26, 2005, 09:09:39 PM
thanks Carl - but wots the increase in BHP then  :p

Keith
Title: How Green Is Decat
Post by: Carl on October 26, 2005, 09:14:07 PM
You should think about a PFC ecu too.
Power increase is not a fixed figure,many factors need to be taken into account,but if you have a mappable ecu then you can get quite significant gains,40 to 50 hp on stock fuel pump and injectors is pretty achievable and safe too.
regards
Carl
Title: How Green Is Decat
Post by: oldone on October 26, 2005, 11:10:06 PM
Hey K9 ,buy a horse its crap is used to grow organic veggies,save the whale and save the enviroment crap has got no standing and place if you drive a "2 stroke motor", get the drift bud.....if you want to be part of the clean green boys then join the green peace lot....KABISH BRO.... :rollin ____________________________________________________________________________________________________________serious bud,,, if you are worried about excessive air polution then adjust your oil squrirting thingy my bob and the car will burn cleaner and you wont use as much oil and then your car will come to a standby cos it will be ****ed,then an old schooler like me comes along and runs you over cos your in the road trying to flag me down and ask for help.. :wave ______________________________________________________________________________________________________________serious thogh bro im a hippie like you but there is a slim diff.............see ya soon
Title: How Green Is Decat
Post by: Trevrx on October 27, 2005, 06:22:14 PM
Hey B9,   It\'s a fact that vehicles produce only 0.5% of the total annual global CO2 emmissions, so don\'t worry too much about your miniscule contribution, it will have zero effect on the climate whether you de-cat or not!

You must do it though, the car will feel so much happier without that ceramic furnace burning under it!
I did mine a couple months ago with a non-silenced mid pipe, I would recommend getting a silenced one though!
I\'m running on stock ECU so have set the boost controller to 0.7 bar to control the de-cat spike (upto 1.1bar).  Even running stock boost the power gain feels hefty.
Title: How Green Is Decat
Post by: B9 KLF on October 29, 2005, 12:25:26 PM
thanks for the replies (oldone - perhaps you should have stayed on at the isle of white festival  :cool )

I don\'t want to increase noise levels - but may have to accept that.

Finally some folks complain of a smell of fuel after the decat - did ya find that.
Title: How Green Is Decat
Post by: John Yorke on October 29, 2005, 02:07:23 PM
Hay Kieth

From all that I understand you will see very little difference between a full de-cat and the silenced mid pipe apart from the noise, yes you will get a smell of petrol, but not that much, as Carl has suggested doing the de-cat is by far the cheapest power mod you can do, expect +30HP :eek, not bad for what you would expect to spend to get that sort of gain. I seem to remember you having an Apexi ecu and would expect once run in it will be mapped accordingly :cool
My only recommendation is..........take your time getting used to all that extra power [sounds to me like a 300+atw] and make sure you have good rubber and brakes to match.
Title: How Green Is Decat
Post by: B9 KLF on October 29, 2005, 11:21:22 PM
thanks John

the brakes are fast street pads now with AP stoppers next year. New rear tyres aswell.

Yeah I have got an APexi ECU together with the v-mount, induction kit and cat back and once the engine is rebuilt it will be street ported too  :evillaugh. I just did\'nt budget for the rebuild this year and so have left the mid pipe as a cat. When my set up is run in and retuned I\'ll see waht power I get and if it is enough for my track day exploits, I\'ll leave the set up there for a while and if I can get by without decat then so much the better methinks - much quieter so I hear the twins.

Keith