Hi anyone know the bosal or klarius exhaust part numbers for the back box section for short cat mx5 mk1’s?Â
1.8 eunos 1996 car in question.
Both the Bosal and Klarius exhausts are single piece, catbacks, of the same design as the original Mazda exhaust. MX5parts sells the genuine part.
Â
Â
Klarius and Bosal both have online catalogues; Bosal P/N is 284-567. Klarius MA374X. The 1996 Roadster exhaust, cat back, is identical to the 89-93 1.6 version (and 1994 UK 1.8 exhaust), except that the earlier exhaust has an additional mid silencer hanger bracket that was omitted on the later car.
Â
If you have a rear silencer that has a bolt on flange, its an aftermarket exhaust; probably Japanese. American and Japanese exhausts have these type of fittings (UK aftermarkets tend to favour a slip joint, and U-bolt). A lot of the Japanese after market systems from Fujitsubo are mild steel.
This one is stainless steel…
 Klarius and Bosal both have online catalogues; Bosal P/N is 284-567. Klarius MA374X. The 1996 Roadster exhaust, cat back, is identical to the 89-93 1.6 version (and 1994 UK 1.8 exhaust), except that the earlier exhaust has an additional mid silencer hanger bracket that was omitted on the later car.
I still have the original Mazda one i beleive, not bad going 16 years !
Super, now to see who’s selling cheapest…t’internet here we come. Not sure i can justify the Mx5 parts genuine one, doubt me or my car will last another 16 years !
Tempted by the Cobalt one Moss are doing, £180 delivered…
 hi all again, just to about to order a Bosal 284-567. But…all the pics seem to show an extra bracket right at the front where it joins the cat…my current one doesnt have this mount.
Post above does mention this but am i being a bit thick ?
If the one i order has it, do i just cut it off ???
You can see the bracket i dont have just at the cat join in AT’s 2nd picture.
Technically, if its attached, you can just leave it. However, a MOT inspector might decide the car is missing a rubber hanger, and fail it.
 You mean attached to the exhaust ? or my car ? theres no hanger on the car, so i should cut it off the exhaust ?
Is the part number right though ? Bosal seem to do a similar one without the front hanger (283-421)
I’d hate to order one and it incorrect…damn u Eunos.sssss
283 421
Â
Â
Â
Yes, order the 1.6 part. Hmm, different back boxes. Curious.
Â
For the record, my 1996 1.8 Roadster is fitted with a Mongoose exhaust, which I had removed from my 1991 Roadster 1.6. The extra bracket is supplied by Collins Engineering as a seperate part, so wasn’t needed on the 1.8.
Â
 1.6 part being 284-567 and just cut off the spare hanger ?
Thx for advice
284-567 is listing for the 1.8 on the Bosal website.
Â
The rusty scrap below was a 18 month old Timax, taken off a 1990 Roadster. Note the hangers.
 Hi
Got to this thread a little late.
To summarise, there are 3 different backboxes for the three different length cats. The bracket you mention indicates the wrong part for your car. These parts vary in length and are not interchangeable - I know because I sold a customer the wrong part as the Klarius listing for the later UK cars was incorrect and ended up retrieving and re-supplying.
I hope you have managed to source the correct part.
Â
Â
Â
Â
 Now i’m even more confused…3 back boxes ? Mx5parts only show 2 options one for the 370/440 and one for the 475 cat…
Mine has the round back box not an oval one and only one central hanger, nothing at the joint at all just the “plate” as per the original Mazda one.
 It may be that the difference between the 370 and 440 is brackets and not length. The 475 is two inches shorter as you would expect. Klarius listings had them the wrong way around making it extremely confusing.
Shape of backbox makes no difference - purely cosmetic. I have sent you a PM for part number reference. Â
 1996 Roadster uses the same catback system as the 1994-1995 UK 1.8 and 1990-93 UK 1.6. Except for the extra bracket. Wazza does not have a later UK car.
1 Like
Yes - it is the extra bracket that is the difference on those two parts but it would make sense to order the correct part with the correct brackets in place where possible.
 Lol, what a cuffufle !!!
I’m going to order a Bosal 284-567, and if needs be cut the “extra” hanger off. It looks more like mine in all respects, rounded back box and the angular bracket at the front.
The other one 283-421, has an oval back box, no front angular bracket…but in its favour doesnt have the extra hanger.Â
Sort of back this up as MX5 Parts website shows 284-567 as suitable for all 370 cat cars. One would assume they know whats what.
I sort of expect both would fit, if i understand what your both saying.
Thx everyone for your guidence.
 Wazza - do you read your private mail?
Don’t worry about the can shape - if you are buying a Klarius part their current can shape will be consistent. Oval may be the new version as the old round cylinder is not an attractive feature IMO.
Good luck with the fitting and be safe under that car!  Â
Â
 By way of an update… i did in the end order a Bosal 284-567 of Racedynamics2u, £77 + postage.
http://www.ebay.co.uk/itm/360612935388?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
Fits fine, as expected it does indeed have an extra hanger right at the front (at the flange) my car does not have the correspoding hanger on the body. I do have the hanger about a foot back so i guess some earlier cars just had an extra hanger. Probably just going to leave it on…or may cut it off…either way no problem.
New gasket ÂŁ2.50 from local factors part number 256-837(Bosal)
To be honest Bosal need to employ some new welders !! i think i could weld better but as it has 2 years warranty and onlt cost £77 can’t grumble too much…ofc annoyingly Moss put an 18% sale on…week after i bought it…ah well.
The Bosal exhaust does have the chrome end pipe
Some pics on link below, showing hangers, chrome end pipe and part number
https://plus.google.com/photos/110065684597189232167/albums/5880889441218808689
Â