8 replies to this topic

[gdcarpenter]

1990 Japanese Spec Mini Mayfair 1000 with Cooper Conversion, originally an HS4 carb per 'Guess Works' but understand Japanes Sepc Minis required the CAT I have. Have removed it for preliminary inspection and per the photo is this normal or has someone already gutted the interior it? I will be keeping the CAT to help quieten the exhaust as much as possible, though In the USA the CAT is not needed.

My plan is to replace the pipe from LCB to CAT with a new connector pipe that has the 'flex' section in order to install a sensor for an A/F Ratio Gauge, any risk of the 'flex' portion interfering with the rod change mechanism?

I then plan on installing a twin box CAT BACK Maniflow 1 3/4" exhaust system to replace the current single R40, I want this Mini as quiet as possible for a Mini as I expect to be making 200 mile runs fairly regularly.

Thanks in advance.

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[imack]

The cat is missing from that

[cal844]

That cat has been gutted, personally I'd just bin it and fit a full non cat twin box RC40.

[gdcarpenter]

Thanks for quick responses, figured someone had killed the CAT.

Will keep CAT for 'Extra Quiet' even if it costs me some slight HP, ain't as young as I once was, now that I know it won't 'Plug Up' on me down the road.

Went with Maniflow as the concensus seems to be that they are somewhat quieter than the RC's and the supplier has a set on order that should be in in about a week.

Will get the LCB pipe shipped ASAP so I can start on A/F Ratio Gauge install.

Edited by gdcarpenter, 04 May 2020 - 06:30 PM.

[DamoMini]

What AFR setup are you thinking of getting?

[gdcarpenter]

AEM 30-300, after doing my research. They have been around quite a while, and the reviews seems about the best overall. I like that the gauge also contains the 'black box' so no separate gizmo to wire in and fewer wires in total.

Looks like there is room just downstream from the LCB and before the shifter mechanism. Wiring routing TBD. It's a luxury but since exhaust parts really needed replacing now is the time to do it. At least I know the CAT bolts and all other exhaust clamps and hangers are free. Expect removing the front pipe from the LCB may enatail a bit of cussing,

[GraemeC]

An empty cat can isn’t going to provide any silencing, it’ll just mess up exhaust flow and gas speed and potentially lose you some power.

if you really want it quiet, talk to Maniflow and ask them to make you a custom system

[bartman]

if you do not need a cat to pass your country's emissions test. then replace the exhaust from the lcb back without it, much better for performance

[DamoMini]

AEM 30-300, after doing my research. They have been around quite a while, and the reviews seems about the best overall. I like that the gauge also contains the 'black box' so no separate gizmo to wire in and fewer wires in total.

Nice. I’ve been window shopping for one and the 30-0300 looks good. Like also that it has serial and 5V out for data logging.

Edited by DamoMini, 05 May 2020 - 09:33 PM.