The Jenvey kit certainly seems an excellent conversion.
Having contacted danST Engineering, however, their conversion kit is complete and contains all the necessary parts to get the car converted and running ready for a final map. The tapered design of the bike throttle bodies in their kit seems to contribute to the greater torque that they claim compared to the Jenvey kit. Having seen power and torque curves for engines fitted with their kits, I’m fairly convinced of their merit.
I agree that bike carbs would not necessarily suit a car, as the are set to meter fuel appropriate to a high-revving motorcycle engine. Throttle bodies, however, are there to regulate the flow of air, the metering of fuel being the job of the injectors.
I understand that danST have recently supplied a couple of their bike throttle body ITB kits to Mx5 owners, and are expecting dyno figures shortly.
I’ll be looking forward to seeing them, prior to making my final decision!