openinverter forum

Thanks for the heads up- might have to look into this and try to find one...

Edit: Found and ordered one!

Unfortunately I had no luck even with the module wired in- still the same behavior- if I gently put pressure on the pedal the pedal sinks in to breaking point, if I stomp the pedal it gets hard for a splitt second, then goes soft down to the breaking point...

itiuk wrote: ↑Sat Dec 28, 2024 1:31 pm For the master cylinder itself, I'm using a Bosch 0 204 854 799 (got mine from a Vauxhall/Opel Grandland X), which has a 1" bore vs the stock MX5 (Sport) 15/16" bore and with the outlet ports on the more favourable side to mimic stock MX5 packaging.

Hi, how did you find the right MC? Unfortunately my OEM MC has an 89mm bolt spacing whereas the one uses in the ibooster I have is 100mm. I could fabricate am adapter plate and extend the pushrod but something using the right bolt spacing, bore, hydraulic ratio and brake line connections would be a lot nicer.

Jacobsmess wrote: ↑Thu May 15, 2025 7:43 am Hi, how did you find the right MC? Unfortunately my OEM MC has an 89mm bolt spacing whereas the one uses in the ibooster I have is 100mm. I could fabricate am adapter plate and extend the pushrod but something using the right bolt spacing, bore, hydraulic ratio and brake line connections would be a lot nicer.

Honestly, it was trial and error by ordering cheap used ones off eBay and seeing which ones fit... I have a box full of old an not-suitable master cylinders I'm trying to sell back on eBay . To be honest I might have more luck using them as scrap to do some ally casting...

I do wish Bosch had a catalogue with bore, port details and such but I can't find anything.

Chris