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Hey all, I was wondering if I could get some pointers on carbs. I've done some research into them, but I'm looking for the opinion of board members so I can get a better fix on what's good for a T motor. So for starters, I have a mostly stock 3tc in an '80 wagon (w/T50 5sp). Only thing I've changed thus far is a new exhaust, as the old one rotted and fell off (literally). My new system is a 4-1 header, 2.5" crush bent pipe all the way, glass pack resonator (no cat), and a twin loop style muffler. I was planning on doing carbs first but fate forced my hand. Anyways, I'm looking to do a twin side draft set up (all the rage, i know), but the volume of info is a bit foreboding, especially because I am 20, and inexperienced with carbureted cars (only driven EFI before this). I plan to do simple daily driving (and pizza delivery) in the wagon. I don't need tons of power or giddy'up, just a little more pep and hopefully MPG. I have no plans to turbo it, or build the motor for performance.

For those who TL;DR'd

'80 wagon
stock 3tc
2.5" exhaust
daily driving intended


So here's what I've sort of gathered.

Webers:
Popular because of current production and parts
Easy to come by and versatile
Spanish made ones aren't as good as Italian made ones
40 DCOE's good for stock 1.8, or 45's with small venturis

Mikunis:
Popular for period correctness (especially with Datsun crowd)
Harder to find parts for and rebuild
Somewhat easier to tune than Webers (largely opinion based from what I can tell)
Mikuni Type T's were OEM for some Toyota motors (eg, 18rg)

SUs:
Popular for ease of tuning, reliability, and efficiency
Work based on needs of motor moreso than needs of driver
Not as performance oriented
Harder to figure out sizing (for me anyways)
Harder to find info for non-Datsun or European applications

So provided I have my facts straight I was thinking that twin SUs might be for me, but it seems pretty hard to find solid info for Toyota applications. Would it be best to use Datsun SUs? Where might I be able to find a manifold for such carbs? Would I need to have it custom fabbed? Any thoughts, concerns, or interjections would be greatly appreciated. Feel free to correct me if I've gotten something wrong.

If you're going to keep the engine stock. I would just throw a 32/36 on there. Twin side drafts are a chore to tune and expensive. They sound cool though. I have some myself but not on my daily driver.
You're not going to gain any mpg by adding multiple carbs.
Single side draft is a little more streetable and still looks cool. Just my opinion.

Have one of those too. Lucked out and got mine for $15 at pick n pull.....score.

Thanks for your input. I've heard that single side draft setups are rich in the 2 & 3 cylinders, and lean in the 1 & 4, do you know anything about that? Moreover, I'm currently getting about 21 MPG city on my stock carb. Mind you I think it needs either a good cleaning, or a rebuild because it bogs at about 75% throttle. How significant of a loss in efficiency would I see from, say, a single weber DCOE vs a double? Moreover, lower MPG is one of the main reasons I was looking into SU's since they are supposedly more efficient (and easier to tune to boot).

Estebot wrote:If you're going to keep the engine stock. I would just throw a 32/36 on there. Twin side drafts are a chore to tune and expensive. They sound cool though. I have some myself but not on my daily driver.
You're not going to gain any mpg by adding multiple carbs.
Single side draft is a little more streetable and still looks cool. Just my opinion.

Have one of those too. Lucked out and got mine for $15 at pick n pull.....score.

You wrote: "If you're going to keep the engine stock. I would just throw a 32/36 on there...

Single side draft is a little more streetable and still looks cool. Just my opinion.

Have one of those too. Lucked out and got mine for $15 at pick n pull.....score."

My stock carb is worn out and in need of replacement. Though I have put 32/36s on engines before, the DCOEs are better carbs. I only want one, though. Is your single side draft manifold a cross-over design? Is so, may I persuade you to sell it?

Thanks,

Bill
wmeastman@aol.com

Get a 45 side draft and the intake mani for a single side draft.

To get my 2TC running I opted for the Weber 32/36. Another option is the 38/38. The engine was installed in an AE86 used for drifting/track purposes. As a daily driver, the carb worked well. As soon as I started to throw the car around it would starve for fuel.

Since then I've swapped in dual OER racing carbs, 45mm. I'm able to drift without the engine stalling. The engine is more responsive and the sound is to die for. I'm unsure of the cam sizing but she seems to scream after 2500rpm all the way up to 7000.

I would recommend what the other 2 are saying and find a single side draft intake manifold and have some fun.

It bogs at 75% throttle now? Maybe is because you put a big a$$ exhaust on it! I personally dont know anybody with su on their cars. But most of us have some kind of weber. (more help for you) If you dont want a headache but want a decent carb to play with, I would suggest to start with a 32/36 or single 45. That way you will learn how to work with carbs and learn how they work. Start with one then with two From what I hear the su are the ones that work for what you want. If you go down that road you should let us know how that goes.

It bogged at 75% even before, I put the larger exhaust (crush bent mind you) in preparation for other upgrades. I was going to do it afterwards but it literally fell off the car so I figured I might as well replace it with something more in line with my final vision for the car. I think it had something to do with the secondary barrel being way out of whack, because the car would load up and then back fire when pushed at WOT.

Anyways, I ended up going for a single 40 DCOE with a crossbar linkage, and a pre EGR head with bigger valves, couldn't be happier with it! My MPG high score is 27.5, average is between 22 and 24, and the car is WAAAYYYY more street-able now.