Converter vs Gearing

[MOPARJ]

What would be a more effective boost for my situation? The motor is a 318, .477/.480 lift cam, stock compression pistons, headers, 904, stock converter, 3.21 non sure grip 8 1/4. I want to get the tires to break free a bit easier and pull a bit harder in second gear. Should I go with a 2000-2200 stall tc, or just up the ratio in the 8 1/4 to a 3.55 or 3.73 with a sure grip? I pull 16-18 mpg at 65 on the hwy now and would like to retain as much as possible, as well as getting my ets down to the solidly in the mid to high 14s. So far, my best is 15.02.

 

[mshred]

get sure grip....regardless of what you choose to do, it will definatly help alot with traction...i would go converter and gears, but i think the gears will make more a of difference combined with the suregrip as opposed to just going with a converter ( i could be wrong though)

 

[stroked 340]

If you can only do one,i'd go with a sure grip and 3.73-3.91's...

 

[MOPARJ]

If you can only do one,i'd go with a sure grip and 3.73-3.91's...

I believe I have 26.5" tall BFGs and I turn about 2750 at 65 right now. Would 3.73s create a huge increase in rpms at that speed and significantly drop milage? It turns about 3K at 74-75 mph currently. I know 3K at 65 isnt that bad, but I am still curious. The calcs I use say 3150, but that seems the tiniest bit on the high side of what I figured, which would be about 3K at 65.

 

[mr.318]

I've got 355' gears in my dart it runs 3000 rpm at 55,with 14 inch tires, had 294 gears before got 17 mpg with them, now it gets about 9 m.p.g kinda took the fun out of driving it.But the little 318 will turn mid 14's at the track guess it's all in what your going to do with it mine is a suregrip

 

[LXguy]

what kind of 60' times do you get? Do you have a lot of wheelspin?

Steve

 

[MOPARJ]

what kind of 60' times do you get? Do you have a lot of wheelspin?

Steve

Nah, not much wheel spin. 15" wheels, 26.5-27" tall tires. I think the 60 ft was 2.1 to 2.2 seconds. It pulls hard through first, then stays in second through the rest of the 1/4 mile. When in second and accelerating hard onto the frewway, the rpms do not climb as fast, signaling a need for either more gear or tc.

They are 235/70/15 rear tires.

 

[fishy68]

If I could only do just 1 it'd be the converter. It will get you in your power band allot quicker than gears. Around 22-2500 will do good. Right out of the hole the converter will have the rpm's up there. Don't get me wrong gears will help allot too but from my experience more stall helps more. That's a pretty good sized cam for a stock converter in a 318. That's where the converter would help allot.

Low gears will kill the fuel mileage fast. A loose converter will also hurt the mileage but not quite as bad as lower gears. JMHO

Oh yeah expect to have traction problems if you do either so the 60' time may not be much better.

 

[daredevil]

go converter and get some short wide 50 series tires for at the track and it will feel like a gear change

 

[pettybludart]

I think gears and sure-grip,you did say 3.21 gears with a 15 inch tire.That will bring you into 2.9??If you go 3.91 with 15 inch tires that will get you somewhere around 3.55,and i think this will help gettin into lower 14,s also 3rd gear.My 2 cents.