also, does anyone have a ballpark figure for the kind of horsepower a mod like this could add, if I were to use the stock hicrappy carbs?

If a stock EA81 has 78 max housepower, my dual carb EA81 would have about 85 to 93Hp I would reckon. I think EA82's are 83hp or something like this. And seems my EA81dc has just as good flow characteristics as a EA82 I would think somewhere around 92hp. But i am only guessing.

 

As for the tool: I've never seen one and have no idea what they do... sorry.

 

_______________

Dual carbed EA81

http://www.offroadingsubaru.com

hmm... maybe a sort of a scale, with a kind of a flat chute type thing in the mouth of each carb - if one carb sucks more air than the other this'll make the scale tip, and I can adjust it to compensate...? of course, the two carbs won't be sucking at the same time, but I could just take an "average" so to speak of the scale position?

 

or is the difference in airflow not that apparant?

go for it i guess. at least you dont live in california and have to go through the pain of smog testing.

luckily yeah...

 

I'm wondering, should I put up a diary or something of progress?

 

As it stands at the moment, all I need is to go build prototype manifolds out of wood, digitize the design and send it off to my friend to construct them for me... then it's just trying to find a second carb and hooking up all the vaccuum lines.

 

As for the coolant, I was thinking hacking off the thermostat/temperature sender housings, welding them to a block with three nipples on it (one for each manifold + the heater core), welding nipples to the new intakes for the coolant, and fixing this new coolant supply thinger to the engine by the same mounts as the PS pump.

 

Quick question though: why does it squirt coolant onto the base of the carb (from below), and will I need to do this?

Also - to sync the carbs, can I pull the idle screw on the slave pretty much all the way out, crank the throttles all the way open and then link them?

I think they run coolent thru the manifold and around the carbs to cool the manifold so it doesn't heat the air going into the engine. If you have very short manifolds you won't need this I wouldn't think.

sweet I'm aiming for a manifold length of around 2 to 3".

 

Looks like I'll be having to make hood scoops anyway at least I can do fibreglassing to some extent...

you are exactly right about the scale thingy that sounds exactly like how they do it to tune the twin Strombergs on the V8 Rover(spit)

Actually, the purpose of the coolant flow is just the opposite. It's to warm the intake charge for better vaporization and to prevent icing.

The JDM dual carb EA81 was 108 HP. (should mention that it has a different compression ratio, heads, and y-pipe too).

 

Stock EA81 single carb is 78 HP up to '82, and 83 HP for '83+. Difference is the larger intake valve, and cam profile.

 

Stock EA82 single carb is 95 HP, Turbo is 110 or 115 depending on year.

 

GD

^^^

If my dad's car has 95hp, mine must be 108hp... Hmm, I don't think so, maybe when it was new. My dad's 85 wagon would have around 85hp (its burning a little oil) and my dual carb would have somewhere near 100hp, maybe. It feels gutless becuase I run 27" tires on it. But it was a lot of fun with the stock wheels. Those turbo's were pretty **i*, huh? I can see why people want to get 180hp out of them.

 

 

Actually, the purpose of the coolant flow is just the opposite. It's to warm the intake charge for better vaporization and to prevent icing.

That makes sense too. Although many cars do not have this and it sounds like something that is not necessary. If it is getting vapor-lock after the mod I would suggest using some acetone. It helps to vaporise the fuel.

Even porsche gave up the dual carbs a looooong time ago on a 4cyl boxer. Upon some reading, there was absolutely *zero* benefit to this setup, and even hindered low-end..The benefits of an single intake achieving the same cfm, better tuned and balanced for the four cylinders to stay smooth is much better. Unless your creating a conversation piece, Try a better injection on say a spider intake, etc. Would love to hear one run, it would no doubt sound interesting.

hmmm... any idea where I could get my hands on such a tool, or how I could make one myself?

 

Here's an article on dual Webers on a VW. It also mentions the UniSyn Carburetor Syncronizer tool. I used something else, but this is the same sort of tool, looks like $25 or so.

 

Monte

hmmm... any idea where I could get my hands on such a tool, or how I could make one myself?

Here's an article on dual Webers on a VW. It also mentions the UniSyn Carburetor Syncronizer tool. I used something else, but this is the same sort of tool, looks like $25 or so. You'll have to Google it to find more information on the tool.

 

Monte