I’m not sure whether this thread is best placed here or under track day preparation, but here goes!
There seem to be a variety of manifolds and kits available to fit individual bike throttle bodies to Mx-5s. However, it doesn’t seem to be a topic touched upon on this forum.
Jenvey seem to be the best known conversion suppliers. There is also danSTengineering, who have kit, listed as a complete kit, on eBay - item number 331781676146. This includes a replacement ECU.
If anyone has experience of carrying out this conversion, could they please provide some info on how easy/difficult it was, what the pitfalls were, whether they were pleased with the outcome.
Purchased a complete Jenvey IRTB set up just before Xmas, it is now fully fitted in my 1.6 Mk1 and at the Dyno tuners at the moment. Hopefully with it fully running it will be on show at the NEC Restoration Show on the MX-5 Owners Club stand in hall 9, 5-6th March.
Hopefully have it back tomorrow night, had a few niggles along the way, but give Jenvey their due they sorted them all out, that is what you pay for at the end of the day. See how she is tomorrow.
With a decent ECU set up they will start and idle nicely from cold and perform very well.
Be aware however, since you mentioned Bike Throttle Bodies, that a great deal if not all of bike carb conversions have a negative impact on power, economy, drivability and just about every over ility you can think of.
I did consider a Japanese carb conversion that was already set up for a 1.6 Mk1, I did think it was going backwards though from an injection set up.
So decided to bite the bullet and go full hog with the Jenvey kit, as I live close to the headquarters it was easy to pop in for the odd part or three.
although I’m a died-in-the-wool SU fan, I appreciate that carbs can be less economic than injection, and that bike carbs are set up for optimum performance at painfully high revs. But would not bike throttle bodies used with an injection system flow as well and be just as efficient on a car engine at lower revs? Particularly if the ECU is then set up accordingly, as the fuel metered to the engine would be appropriate to the engine’s characteristics and demands?
I’m sure if you have the money you can make anything work, but according to some quite heavyweight experts in Track Driver magazine about 2 years ago there was not a single benefit to them.
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!
Purchased a complete Jenvey IRTB set up just before Xmas, it is now fully fitted in my 1.6 Mk1 and at the Dyno tuners at the moment. Hopefully with it fully running it will be on show at the NEC Restoration Show on the MX-5 Owners Club stand in hall 9, 5-6th March.
Hi speedy just wondering how you have found the experience of the jenvey kit after having it fitted for a while, as i am very interested in doing this conversion as apposed to a turbo etc
just looking for some great sound and a bit extra zoom … did they fit it for you
