Mazda Bridgeport Rotary - Dyno Tuning (Weber Carby)

Mazda 12A rotary engine, bridge port, with Weber IDA 48 carb on the dyno. We run you through the process.

[@michellelabuschagne1683]

Thanks so much for the clip . I can't wait to sort my car

[@benrobertson7855]

Hi ,got recommended from the comments on rad potential,this is just so much fantastic info for my 13b na bp rx4 coupe.I can’t thank you enough.appreciate you giving such a clear honest,open vid. Best regards from New Zealand.

[@petercrisp2573]

Thanks for a great clip. You know how a Weber works and adjustments made were spot on. Timing as well and it was great to see the before and after effects on the graph. Really enjoyed this, subscribed now.

[@TURBOTRISTO]

Great to see a video on tuning carbys you don’t see that anywhere on youtube!!! Awesome

[@ehpunka]

This is the type of video I have been looking for

[@TURBOTRISTO]

Love an old school rotor carby they sound awesome

[@daveferranda9379]

Awesome insight into what goes into the process. I went from 4 barrel to 48 web and was disappointed. Obviously took it to the wrong shop!

[@unigroupengineering]

Thank you Dave!

[@darwonboyful]

Fantastic and informative video mate you really know your stuff

[@unigroupengineering]

Thank you Andrew!

[@Ghost-gw2ue]

I desided to keep my 12a for more reliability reason. Glad I seen this video . Maybe later I’ll upgrade but for now $$$$

[@oldstyleanalog6459]

Bro.u need a 45.mm venturi a 235 main jet and f11 emulsion tube or f8 tube and a 110 to 110 air jetaq celebratory pump 0 and make sure the discharge nozzles are drilled a bit.Idle jet run a 70 to 75 for racing.and when ur gona drive normal stick a 65.and ur motor will drive and sound beautiful.thats what I did.if u drive it with 70 idle or bigger ur gona foul plugs.so carry 2 sets of idle jet in ur car.With this combo u will be very happy my man.Try it out and let me know what happens.If u run a air cleaner put a 230 main

[@smash12a]

Sweet 808 an great info.

[@str8o.g241]

Great video, have u got any videos setting up the mixtures

[@johncuthbert5320]

Keep up the good work.

[@markc1456]

Another informative video mate

[@oldstyleanalog6459]

I assume u have some nice porting.But let me tell u.i had a 12a that made 200+at the wheels full bridge with a 51 ida carburator.Sorry but ur 48 is too small and u need to lock ur distributor and put some msd boxes and a aluminum flywheel.Ur squirters were fine but u need a 00 pump jet.I learned that the weber carb likes a big idle jet for more responsiveness.I ran a 65 and when it was time to race I took it out and ran a 75 or a 80.A 70 would work but will foul plugs on.street driving.so carry a extra set of jets.It will be more responsive with bigger idle jets.I never had 20 degrees of advance either.Ur on ur own on that one.Good luck.nice car nice motor

[@richardstanley7288]

Great video 👍

[@unigroupengineering]

Thanks Richard!

[@nickkiofetzis5667]

i am suprised he didnt check the needle seat size first up upon removing the lid and checking it everybody knows you change it if it's only a 2mm, a 3 mm is the norm for any performance application what was he thinking?

[@brendondaniel8638]

What size emulsion tubes, main jets and air corrector sizes did you end up with? And also idle jet sizes?

[@unigroupengineering]

Hi Brendon, apologies it's been a while since this video was shot. I'll give it my best shot. From memory tubes were F2, mains were about 220, airs were near 140. Cheers, Evan.

[@brendondaniel8638]

@@unigroupengineering Thanks Evan, also what choke sizes do you recall? Cheers

[@unigroupengineering]

@@brendondaniel8638 These were modified from memory, hence don't know the exact size. You'd want at least a 40 on a healthy engine...👍

[@brendondaniel8638]

@@unigroupengineering Thanks Evan, I have 45mm chokes ready to try once the engine is built with F2, mains 220, airs 135. Dean Bradley is building the 12A

[@unigroupengineering]

@@brendondaniel8638 45s!! What a combo. Post up a vid when you've got it going.

[@golfy808]

Great video! Have u ever tried leaning out to a 13.0 to see if it picks up power?

[@unigroupengineering]

Hi! Depends, every combo is a little different. What I can confirm is this: A rotary engine has a very broad range of mixtures where it makes best power. Typically 13.3 to 12.5, some will even go as rich as 12:1 and not lose any power. I find that appreciable loss starts outside of 13.8 to 11.7. Not that you'd ever aim to be there, more a case of sometimes being unavoidable due to compromise in jetting...🙂

[@golfy808]

@@unigroupengineering thanks for the info!

[@ricardobarnao369]

Who’s best for a similar tune in Brisbane?

[@juanmelissagarcia5981]

Is it possible to run the vacuum advance on a setup like this?

[@unigroupengineering]

Yes, with a suitable vacuum canister.

[@CRILIKk]

Where do you get blank jets from please?

[@unigroupengineering]

Usually, get the smallest size jet to have enough meat to modify into what you need.

[@markc1456]

What about doing an extended fuel bowl...

[@unigroupengineering]

Hi Mark! On a car with bigger power I have seen them used. However I've never needed one. Because as long as the feed to the carb can keep up with the flow rate the engine is using the fuel there will be no problems and no need for one. Also larger bowl (extended) can cause fuel surge by having larger space for the fuel to slosh into when cornering, accelerating, etc.