Originally Posted by James @ M Developments.

I was just being honest really,
Sure the weber ECU can be used and I have mapped plenty that have worked fine, but at the end of the day you are making brackets using different sensors for different jobs etc, I've also seen plenty arrive for mapping with issues that can be time consuming to trace and fix.
So if asked what would I do, if I was building one of these I would be using an aftermarket ECU that is fully configurable,( we can fit and map these too!) and would more than likely end up more cost effective for the owner in the long run, especially when you can end up paying £50-£80 per hour to diagnose and fix issues. I think the last 3 that have come in for mapping have had sync issues and hit a limiter at 5500rpm which is not the rev limiter, the customer assumed the car was running totally fine.
I've seen quite a few knock out crank (phase) sensors as the gap has to be so small, and the bracket moves, then there's the fact you have no workshop settings to follow, so how does somebody set them up?


Many people think its the cheaper option which is why they go this route, but often its not, by the time you have purchased all the weber stuff second hand, then fixed the broken bits, purchased a new loom if needed, then headed into the errors you get from phase and crank sync issues, using a crank sensor instead of a phase with a tiny gap, spent time timing it all up, fitting brackets here and there, at the end of it all you then are very limited to tuners for Weber mapping of good quality, and at the end of the day it does come down to budget and what you get for the money,
which is why If I was going this route with an RST I would go straight to aftermarket where you can decide what you want to do, what sensors you want to run, and its far easier to get great results from.