12a bridgeport 6port with flatside carbs
 

hi guys just a update. as said in my other thread i have a 12a 6port full cut bridgeport. was using factory nikki carb rejetted. changed to a 48mm ida. still i wasnt happy with the out come around town... as i work in a motorbike shop we had a set of flatslide carbs off a 87 suzuki gsxr750 on the shelf....had me thinking.
i made a manifold (10mm plate and exhaust tube and 10mm plate for flange to mount carbs to.) took ages to shape etc. with the carbs i added a fuel supply to other end of fuel rail so its gettin feed from each end. blocked up the primary jet and rased the needle etc (bit of mucking around) sorted my jetting out to stop the flat spot i had. i rased the needle so its running on the main jet all the time even at idle (idle is 2000rpm) as couldnt jet enough on primary to get a nice lumpy idle. made stroke on acc pump bit longer and bolted it all up... in testing it was great, heaps of responce and pulled stronger than the nikki or ida through 1st and 2nd gear. top end of 3rd etc running out of fuel..... at moment im making 1.5 inch spacers to increase fuel bowls and lowering the main jets so i should have no more fuel troubles.. ill let you know... looks hard case with four flatslides hanging off a 12a. next is air cleaner set up

pics ....
sounds like a cool idea

i think it is, ive seen them on a escort before but never on a rotary... cant wait to test with more fuel. ill take video of it and put on youtube when i get it sorted. here are sum photos of then as i found them at work.... they are keihin 36mm flateslides

awesome carbs, flat slides are awesome, i am bookmarking this and cant wait to see how they turn out on the 12abp.

as soon as its all up and going and finished ill put up a video and photos of it and a dyno run... to see if its better than the ida

hi guys. just a up date, manifold nearly done and carbs nearly ready. ill have photos up soon

This is great! I love it when other people aren't afraid to think outside the box. I'm always thinking of shit, people usually tell ya to stick to what works. But if you make something new and different work, everyone benefits! Good Luck! I'll be keeping up with this.

cheers. ive already had it going but the fuel bowls wernt big enough. ive neary finished the spacers and tidying up the manifold. Found sum air filters of a new lta450 quad bike that suit my needs. (they a bit ugly but will work for now) . during the first round of tests it was great, so crisp and reponce was great when compared to ida or my nikki... just was running outa fuel at top end... (i know it was fuel not air flow as i fitted fuel psi gauge to far end of fuel rail and was droping to .5psi during flat out run) Bigger fuel bowl and fuel rail and feeding it from both ends im hoping will fix this... ill keep ya all up dated soon with photos. time is hard to find at mo due to work and family dutys etc... wont be long tho

oh and i dynoed my 6port 12a full bridgeport a week ago and got 169hp and with a bit of fine tuning on timing and a 170main jet in the nikki got 177hp at rear wheels... not bad i dont think for home mods.. carb venturis are factory untouched. only carb mods are jets.
after my flat slides are fitted and tuned ill c how much they make and then ill fit up my expansion chambers in the headers and retune to see how much extra they make ... made a big diffrence on friends 13b pp race rx3 so im keen to see how they work on a bridgeport..
( may be in for a dissapointment) but ya have to try

if your fuel pressure is dropping it usually means you need more fuel pressure. aka an aftermarket fuel pump. are you running the stock fuel pump?

im running a holley blue pump and reg... the fuel rail feeding carbs are only about (4mm id)max and floats are ment for zero pressure i have tryed to pump about 3psi into carb but floats cant hold it (it pisses out main jets at idle)(they hold about 1.5psi max). as normaly they have a gravity feed fuel supply. im hopeing that by getting more low psi fuel there that it will help

sorry guys..... ill be posting video and photos of finished running rx7 with flatsides in 10 to 12 days. got a week off work then so going to get stuck in and finish it.... had it running tonite but got a fuel leak to sort... by bowl spacers arnt sealing like they should

Any updates on the carbs? I'm very curious in this setup. I have a late 90's suzuki katana sitting in my shed and would like to attempt something like this in the future cuz I don't have the money for a weber.

ill put up photos and video soon as i can