Mazda Rotary Club

Ive got a kakimoto cat back zorst at the mo, if I changed it to say, a Apexi N1 or GT, would there be enough difference to warrant a re-map?

Im guessing it would be ok on current map, but I thought I\'d better check with the experts  ;) :god

why u changing it dude? I love my kakimoto... sounds awsome :D

Difference would be minimal, no need for re-map. Just keep an eye on the boost.

I would say that unless your current map is very rich, you\'ll want to remap for safety - I believe the N1 and GT catbacks are 2 of the highest flowing systems available. It doesnt take much to reduce back pressure enough to the point that overboost and spiking occur, you hit a lean spot then and \'ping\' it and its :(

You should really get it checked as a matter of course whenever you change any thing, esp. \'zortst-related IMO.

The diffrence between to after market exhausts will not be that great, especially on just a cat back. After all you still have the cat.
Yes less back pressure, will increase the pressure differential across the exhaust turbine blades and increase velocity, therfore allowing the heat to be absorbed quicker  by the turbine blades, in turn increasing the boost pressure created by the compressor wheel, and therefor potentailly giving the wastegate a harder time of controlling boost. However as stated above its only a cat-back, so I honetsly wouldn\'t worry about.

I dont think a catback is necessarily a catback; compare an HKS dragger with an N1 or GT-spec for e.g. By swapping the above I went from spiking to 1.1-1.3bar and over boosting to 1.1-1.2bar consistently to struggling to make 1bar with the HKS can. I would check and remap if required, a few quid getting it checked over isnt much for peace of mind.

I know someone who has a catback can\'t remember the make and a host of other mods. When he put on a blitz catback instead because he liked the noise it produced upon hearing mine started to overboost also. Was quite suprised the difference a catback can make. The 99 spec onwards cars Mazda used a thinner metal for the down pipe and slight difference in the back box which resulted in 10% less back pressure. Your neccesaruly going to need a remap you\'ll have to keep an eye on your boost gauge though once you\'ve changed to make sure all is well.

rgds

Cheers Guys, so basically if I change them keep an eye on the boost gauge. If boosting normally I should be ok, if not get a re-map.
I don\'t mind paying to get a re-map done as its money well spent IMO its just there all so damn far away, makes it such a hassle, we need an Essex based Apexi tuner :)

Andy, do like the sound of my kakimoto, but ive got a bit of an apexi fetish plus I want a shiny new box under there:) and i hear the apexi\'s are rather loud...;)

Mmm yours must be diff setup to mine then, mine kinda collapses weak buildings as I go past :D

Thought my mates sk2 with his twin hks was loud till I put mine in the same tunnel (http://homepage.ntlworld.com/robert.pogmore/dartford.mpg) , just drowned him out :D

(his is the high pitched motorbiky type sound - notice the way you can\'t hear it at all inside his car while i\'m side by side at the start hehe)

well i\'m sure you\'ll be able to sell it, worth quite a lot those I think

lol at that video all you need is a cop car & you have the beginnings of a "getaway in dartford tunnel" series lol
Si

hehe funnist thing was waiting for him to turn the camera on.. we were driving from the toll gates blocking both lands at about 10mph getting beeped :rollin