so im thinking of getting a new exhaust including the decat for when i get my car back on the road...its a 93 r\' will it need a new ecu to take the decat? its standard apart from hks filters, blitz dump valve and will be non sequential, just dont know if its worth getting the decat or not as i dont want it to run like crap as soon as i get it back lol!
thanks in advance,
ste :cheers
Yes, it\'s going to need a a programmable ecu if you go decat and non seq. Most popular choice, and the cheapest is the apexi pfc. It wont run like crap unless there is something else wrong with the car. On the other hand, if the car is running fine now, it will run even better on a pfc right out the box because it\'s much newer 16bit technology than the 15 year old 8bit mazda ecu, then you go decat, non seq and get it remapped. You wont be dissapointed so YES, go decat, fit the pfc and release another easy 60-100bhp.
60-100 from a decat and pfc?! seriously?? i was thinking more like 10-15 max lol
I think the popular opinion is that you can either change exhaust silencer or filters but if you remove the cat you will need to remap the fuel to match the additional air through the engine. If you get a cat free exhaust and open filters you will definitely need to remap the fuel. I\'m in this process right now and I\'m looking for a cat replacement pipe.
APEXI PFC is a popular choice, that\'s what I\'ve opted for.
yeah seriously. At the time, I decatted mine, k&n air filters, 3" ss downpipe, silenced mid pipe and free flowing WGT backbox stock everything else and i got 320bhp from the stock 250bhp. Even putting the pfc on a stock car, i reckon you get about 20+bhp without getting it mapped by a pro.
lol thats mad!! i love rex\'s!! and hey i didnt know you can get k&n\'s for the rex?! are they actually made for the car or just 2 universal ones?cheeky but any chance of a pic? please? :god so for about 700 i can squeeze a fair ammount out of the rex? will it run an extra 100bhp safely? not forgetting that standard its 280ish i think?
cheers for the replies guys im now >>> :chat
Yes, they are specially made for the car. These are the same as mine. http://www.mazdarotaryclub.com/forums/showthread.php?t=51156 But mine have the blitz cast aliminium section with the twin K&N filters on the end.
The K&N ones just have a black placcy housing as standard, IIRC, but like Robbie says, they fit on the ally Blitz housings too. Catalogue piccy of them if you\'re interested;
[ATTACH]40165[/ATTACH]
ahhhh very very cool :) thanks alot for taking the time to do the pics guys, really apreciate it :D might have to look into ditching the hks\'s for some beefier looking k&n\'s!!
thanks again!!
HKS filters are just bloody nasty, chuck em in the bin where they belong! They\'re a bathroom accesory, nasty bit of foam, not a fitting filtration system for a performance engine :Giggle!
Joking aside, they\'re fine when they\'re clean, but wait till they get clogged up and filthy, and the engine starts sucking the edges of the foam in around the base of the cage cos they can\'t flow enough air through the foam any more. Before you know it, you\'ve got a lovely big gap round the edge of the mesh where loads of nice unfiltered air gets sucked in, using the course of least resistance, and taking with it small rocks, passing wildlife, fluff, spiders, loose bolts, well... you get the idea!
ive got a decat on mine, it overfuels abit but runs so much better and shoots flames
just keep in mind that upgrading it and squeezing more power will shorten ur engines life....just bare that in mind
not by much if all your doing is decatting her surely.
i\'ve found that decat exhaust and filters are enough to max out stock injectors so must be about 320-350bhp.
really? Woohoo. Lol
Quote from: Cooch;522212really? Woohoo. Lol
Maxing out injectors (ie running them above about 92%) will then make it fuel at 1/2 the amount cause the injectors can\'t keep up....so the engine will run lean at the high RPM....which is very bad lol
Quote from: Cooch;522204not by much if all your doing is decatting her surely.
A de-cat and filters
without an aftermarket ECU or some upgraded means of boost control will likely shorten the life of a good few components, the engine not least! You\'ll get boost spikes all over the place and really lean bits of fuelling just when you want them the least. Not nice, especially when it goes off like a grenade! Really best not to play roulette and upgrade the control systems as well as the breathing
Uprate all the safety mods like HT leads, fuel pump, ECU and injectors before you start pushing stock systems :) Don\'t forget to uprate the brakes and tyres before you increase the power as well
ive got a decat with k&n induction kits but also got an apexi ecu and controller, im running it on the lower boost setting, is this a safer option? just out of curousity too for those who have the apexi ecu what should the knock setting peak at usually? and what should the injector rate be to? i know its different for every car but would be interesting to see what the range should be, the only performance mods ive got are a blitz dv, k&n induction kit decat pipe and catback exhasut (so full exhaust off the downpipe) and an apexi ecu and controller running on the lower boost setting
Quote from: m1tch;522214Maxing out injectors (ie running them above about 92%) will then make it fuel at 1/2 the amount cause the injectors can\'t keep up....so the engine will run lean at the high RPM....which is very bad lol
I know thats why i said woohoo.
Cos you :WaveBye bye bye to your engine lol. Im not gona change air filters on mine im just gona run a decat with an Apexi Ecu .
I\'m running HKS filters with a decat and an Apexi on mine and she runs fine. Shoots flames when warm but is great great fun :-)
Thats what i like to hear! Cant wait. Lol
Just remember that they recomend you change the hks sponge filters every 5k-6k miles.
are apexi filters any good? i love the fact mine shoots flames not entirely sure if its a good thing or a bad thing though
Quote from: pearl_rex;521725lol thats mad!! i love rex\'s!! and hey i didnt know you can get k&n\'s for the rex?! are they actually made for the car or just 2 universal ones?cheeky but any chance of a pic? please? :god so for about 700 i can squeeze a fair ammount out of the rex? will it run an extra 100bhp safely? not forgetting that standard its 280ish i think?
cheers for the replies guys im now >>> :chat
Hello mate
I have a 96 RB Bathurst, HKS Super dragger, de cat, Apexi, HKS Racing Suction Kit ( new £380 ), ported engine, boost up by 0.5% and 350BHP on a twin turbo set up.
The day you fit a de cat and fir an Apexi with a modified map you will defo feel more power, the only way I could describe it is as if you were driving around with a passenger and then with out one, that is how much more powerfull and lighter the car feels..
Regards
Michaelb
You would be daft not to go decat really. On a 93 plate, you\'ll pass the emissions with a bit of adjustment to the pfc. If you can get away with not having one, then go for it. You\'ll pop some nice flames too, and you can sell your old cat to the scrap man for 50 notes.
I\'ve just got an Apexi and will be decatting soon, with standard fuelling, ignition and intake I\'m happy to stick to a safe 300bhp at the flywheel until the other stuff is sorted, that\'s still an approx. 40+bhp increase on standard.
Quote from: RobbieRX-7;522678and you can sell your old cat to the scrap man for 50 notes.
What? where? never knew this!
Quote from: NurburgRob;522847What? where? never knew this!
Hi Rob, off to RS5? I will be going on Sunday first thing due to the waether being cr...p on Saturday
yeb, I have sold mine within 10min in the for sale section for £40 - pick up only
Regards,
Michaelb
Hey Michael, I\'ll see you at RS5 on Sunday mate, I\'ll be there from about 10.
Nice to know I can get a bit of money for the cat :)