Tuning a carb for 1st gear performance

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XakEp

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Ok... This isnt as stupid as it sounds I promise. I've finally gotten the damn car to stay running, and its got another issue. Off the line its pathetic. I mean, I realize its a 318 but DAMN, if i hit the gas it should go SOMEWHERE. It doesnt sputter or anything, it just doesnt really go anywhere until I get to 30mph and then it just goes like hell. I mean its a totally different car.

How do you setup a carb for jumping off the line? Gimme your ideas and after I tear this damn carb down tomorrow I'll give your ideas a shot.

Yes, its fun as hell to get this thing on the road again. A huge shout out to everyone who helped.

Edit - What rods/jets should I be using? I think I may have massive jets in, and I'd imagine running rich would cause this problem. What are the stock rods/jets so I'll have somewhere to start?
 
Your problem is probably more with the combination rather rhan the carb. If you aren't belching black smoke or fouling plugs hold off on the carb a sec. A few things before you go buy a new converter or change cams that will fill in the low end hole:
1. Make sure you are running as much initial timing as the engine will allow and then shorten the curve to limit total advance. Use weak but not sloppy advance springs so you have steady deliberate timing advance.
2. Add an "H" or "X" pipe crossover on your exhaust if you don't already have one. You will be amazed at the difference in low end performance.
3. If you are usung a single plane intake switch back to a high rise dual plane and if you have the room add a 2" four hole spacer.

All these things add to gut wrenching torque and drastically improve low end performance.

BD :thumbup:
 
how about a little more info on the engine. My 318 goes 60ft in 1.9sec at 5000+ ft with OPEN exhaust...Which isnt too shabby, i wouldnt start recommending that atleast. What carb do you have, is it an auto? gear ratio? intake? ignition? manifolds/headers? converter? ...
 
More info would be nice like auto or manual, what gear you are running, cam, etc.. Your timing could be off right now.
But mguner suggestions are the keys for low end torque. If you have a automatic then I see a higher stall converter coming and maybe a set of 4:10,3:91 gears. :thumbup:
 
need more info about the engine!!!What carb.,intake,cam.,exausts,trans. are you using on your 318.
 
http://www.aquaterramotors.com/ebay/2007-donzi-43zr/2007-donzi-43zr_59.jpg
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I r dum

Here's the lowdown. Eddie 600cfm carb, M1 single plane manifold, FBO whole she-bang ignition (electric, no points for me!), dual exhaust with headers, 8.25 rear end with 2.73 gears (came with the car) and Comp cams XE262 something or other cam.

When you floor it in first, its got a hesitation, pops and then goes slowly. Once you get to about 30 and you nail the gas and the tranny shifts down it takes off like hell. I can get video of it tonight so you know what I'm talking about.
 
LowDart said:
sounds like carb. is not working properly !Is Automatic transm?
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Yeah its an auto. I have no idea whats wrong with me - should have put that in the first post.
 
XakEp said:
I r dum

Here's the lowdown. Eddie 600cfm carb, M1 single plane manifold, FBO whole she-bang ignition (electric, no points for me!), dual exhaust with headers, 8.25 rear end with 2.73 gears (came with the car) and Comp cams XE262 something or other cam.

When you floor it in first, its got a hesitation, pops and then goes slowly. Once you get to about 30 and you nail the gas and the tranny shifts down it takes off like hell. I can get video of it tonight so you know what I'm talking about.
Click to expand...

Sounds like it needs more gear.
 
This is true...2.73 gear is not good for the hole...Sounds like timing is to slow though for it should not pop when u step on it...One of the best things u can do to a 318 is advance the cam 2-4 degrees, which will be 4-8 degree advance for the crank...This will give the 318 more bottom end with a stock convertor.
 
The carb doesnt know what gear your in. The problem is rpm related. You can gear it and make it easier, of fix the problem. Your tune is off. The intake is mismatched. Teh XE262 is a killer cam, but you need a dual plane for your current setup. It should be roasting a tire, not sputtering. In my experience, Edelbrocks are naturally lean, and the step up spring is too heavy for a larger than stock cam. Buy the track kit, and follow the instructions for setting the carb up. My guess is one step lighter springs will cure it.
 
With the single plane intake your velocity will be low at slower engine speeds so this could cause your stubbling. The carb may not know directly what gear is in the car but the carb does know lack of velocity which is rpm related. A lower gear will get the engine up in rpm quicker to gain velocity quicker. Change intakes first then gear. The carb setup is probably off like moper said but since the intake is the wrong one for the package there is no sense in setting up the carb for that intake because when you change the intake to a two plane you will have to set up the carb again.


Chuck
 
I dont think I'll have the money for a new intake or gears for at least another 2 months (I owe on taxes) so I'll just get the carb working on the setup for now. I'll be tearing into the carb tonight, so I'll report back then what I find.
 
I feel for you, I'm in the same boat. I owe now for the second year in a row and to be able to pay the tax man I have one of my Mopars on ebay for sale to pay him.

Chuck
 
Well, we pulled the carb apart, and nothing looked out of the ordinary. I'm using .104 primary jets and the .068 x .042 rods. Its pretty damn rich, so I dunno if thats going to do anything for me. My friend thinks it might be the base timing is off, but I dunno.

THoughts at this point? I'll toss the carb back on and see what happens.
 
Yea that jetting/rod is a bit tight. I'd go back to stock and work from there. Don't expect much, thats a pretty mix-matched combo. Your hole shot is still going to be pretty bad, even at top tune, imo.
 
Ok, got the carb back on and it likes to stall if you floor the gas. I'm gonna get the WD-40 out and hunt for vacuum leaks. Any other ideas?
 
Is it warmed up? are you trying to free rev and it stalls? under a load? where is your accellerator pump shot at? (highest to the carb hole, middle, or furthest. on drivers side, top, front corner.) Got a vacuum gauge?
 
GoodysGotaCuda said:
Is it warmed up? are you trying to free rev and it stalls? under a load? where is your accellerator pump shot at? (highest to the carb hole, middle, or furthest. on drivers side, top, front corner.) Got a vacuum gauge?
Click to expand...

Its warmed up, and it stalls when I floor the gas - not when the revs come down. The pump shot is at the lowest I think - but I'll have to check. Do not have a vacuum gauge, where would I hook it up at? I can get one.

Edit - I mean, if I floor the gas hard, the car just stops instantly. Doesnt even sputterm, just dies. Rather strange.
 
was the cam degreed when installed?
timing chain wore out?
check tdc against balancer marks.
daul plane will make a big differents as will gears
and some stall.
 
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