I have been thinking about bridgeporting my 12A in the future. How much power should I expect? It will have either a holley 650 or a weber, along with all of the goodies that will go along with optimizing the system. I have also considered the option if the turbo II engine swap. What do you recommend?

 

As for as a bridged 12a. I think you could make a good 200-225 hp. with a weber. trust me if you go with the 12a then use the 48 IDA. Any ways you can't beet a simple carbed 12a.

CJG

 

200 - 225 I was hoping for a little more. What will a turbo II swap give me? What are the price differences? I really like the 12A It is a great, simple setup. But I also really like power. Is that really all you can get out of a well tuned brideport 12A with all of the goodies?

 

If it's a full bridge then you should be able to see more like 225-250, it depends a lot on your exhaust too... the quieter up make it, the less power you have. With big chokes in the carb (prob. need a 51IDA) you can see lots more than that, like 275 or so, maybe a little more depending on porting, with an open (painfully loud) exhaust.

There was one person on a mailing list who said he had 187whp measured on an Australian dyno, bridge port 12A in street trim...

 

275 thats more like it. Thanks

 

I would think a 48 would be maxing out on a bridge. Im getting a 48DCOE to go with a street port. I know, IDA's are better than DCOEs, but I still think, like PJ, that a 48 would be a restriction.

MazdaRacing.com suggests 50DCOE - DCO/SP. Thats whats in their "12A Bridgeport Intake Kit"

 

I am goint to run a 48 on my p port. The trick is BIG venturies... hahhaa. Any ways ya the 51 helps some but I am not sure if it is worth the money. I am going to stick with the 48 and I it's not enough then I will bore to 51 or 52mm.

CJG

 

What size venturi chokes will you be running?

 

I didn't get as much HP as I wanted with my bridgeport, ofcourse the engine is severily under carb'd with a Mikuni 44PHH system. IT does haul *** though easily to 120mph before I get scared. 0-60 was in the 6's and I suck at lauches and stock gearing, bad tires. But I know with a the right carb say 48mm is close to best because going to 51mm will mainly just help peak rpm but hurt midrange a little more. I am getting a better lowend engine that is due to undersized 44mm Mikuni making more midrange4-6000rpm range then a larger bore since velocity is less comprimised at lower engine speeds. I'd however gladly go to a larger bore carb when I get enough money to do so.

 

I will be running the 43mm venturies. Those are considered to be very big in the IDA world. Tell a VW guy that your running 43's on a 1.3 liter engine and he will **** his pants. Any ways you can run bigger venturies on the p ports but this is going to be driven on the street so I am going to go a little smaller. stock 48's can use up to 45mm. If this was going into a car that was going to be used on the track at an almost constant 6-8.5k then I would use bigger venturies. Any ways that where I am at. I think my 12a will make about 230-250 whp. I am realy not sure but we will find out. It is going into my rx-3 which is a very light car so it should go pretty good no matter what.



CJG

 

lol, 43's must be paper thin. I'd love to see this thing "idle" .

 

r.b claimed with a 13b bridge and a 650 holley setup they could ring 260, wit ha 51mm weber they got 285, from a 13b. i think im gonna do a bridge on a 12a i just pulled

 

so why does everyone run weber systems? Couldn't a holley flow just as much? And holley parts are easy to come by.

 

Most Holleys aren't as tuneable - you can't play with stuff like idle jets or any air bleeds.

The HP series carbs do have adjustable air bleeds - but they cost about $500 vs. about $200 for a regular carb. RB really sticks it to you when they sell you stuff, too.. they want about $200 for a pair of float bowls that you can buy anywhere else for $50. It's unreal.

Demon carbs (redesigned/reworked Holleys) can be had with adjustable everything and removeable venturis... but you're looking at over $900 for the carb!