I'm trying to decide on what gears to go with on my car.. I've been thinking either 3.89 or 4.11, but I can't really make up my mind.. My car has a C4, so I'm wondering how much rpm it would end up with at certain speeds in 3rd gear? I probably won't be doing that much highway driving with it, and the speed limit is like 50-55mph on the highway anyways.. I usually just drive it on country roads where the speed limit is around 40mph.. Any inputs?
3.55 is a good all around ratio...You wont be winding the wee out of the engine with em either. If your more interested in performance, 3.80:1 is a good choice with a 3 speed that wont rev the engine too much either.
There are calculators, where you can put in your tire size and gear ratio, and the C4 in third gear is at 1:1. So, punch them in and it will tell you what rpm you will be cruising at at whatever speed you choose. Use the Find RPM calculator here...http://www.ramblerman.com/blazer/gearcalc.htm Use 1 for transfer gear ratio, since we don't have one.
It's performance I'm going for, that's why I was thinking in the 3:89/4:11 range.. I'm just not sure if I would feel that 3:89 is enough, or that I will end up thinking 4:11 is too much It wouldn't let me put in uneven numbers though? How do you like your 3.80 gears?
3.80s with 27" tires (255/60r15) have a nice launch, cruise the freeway at 65 mph at around 3000 rpms. Not a problem. I just typed in uneven numbers, and it worked. At least I used 3.81 gear, 26.7 tires, and 65 mph. Use 1 for the transmission and gear case. It should work. Be sure you are typing it into the Find RPM calculator, second one from the bottom. You can change one thing at a time, such as cruising speed, and determine what gear you like. I have driven a 4.56 gear in a 5.0 and it felt like a MONSTROUS engine, but I never got it over 30 mph. But it got to 30 VERY quickly. My switch from 2.79 to 3.80 was quite fun, and much seat-of-pants power added. I didn't see any significant mpg loss, since the 302 likes to run at 3000 rpms cruise. Personally, I would stick a 4.11 in there, and enjoy the hell out of it, except I occasionally get on the freeway, and I think 3.80 is about the max I would like to cruise with, and I am usually cruising at or below the speed limit to keep rpms down. How you doing, by the way? Haven't heard from you in a while. Need anymore parts shipped over?
I did have a 3.70 9" with 24.65" (205/60r/15) cruising speed at 4000 rpms was 70 mph. The 3.25 took the bite out of the bark and now I'm 3100 rpm @ 70 mph. .45 more gear equals 900 more rpm
I can't really decide on whether to make a monster out of it, or just keep it a pretty fast cruiser I don't care about MPG on any car other than my daily driver My car usually only sees highway for a few mins at a time, and I don't really take it on long trips, usually just cruise down to the city and run some stop lights and stuff like that.. I have decided to go with either the 3.89 or the 4.11 gears, but I'm, still having a hard time deciding When i tried the calculator it looked like it was only a couple hundred rpms difference between the two at 60mph though I'm doing fine thank you Been very busy lately.. Besides my normal, work all my 3 cars has been in need of some wrenching.. Even my current daily driver And the car I originally purchased to use as a daily driver, turned out to become a huge project It started with putting in a bigger engine and a 5-speed manual gearbox, but now i just bought an Electromotive tec gt EFI-kit for it plus a turbo setup, so I guess it's ending up as a track car instead I definitely will be needing a few parts soon. My p/s setup has gotten a bad leak so I'll need a few things for that, plus a ton of other stuff that I feel isn't nice enough on my car Seeing as how you've helped out so much already, I just haven't had the nerve to bother you with all of my parts needs
I have 4.11s with 275/60/15s and at 70mph I'm turning 3500-3600rpm. It will get up to speed fast, but if I ever change it out, will lower to 3.70 range to gain a little cruising speed.
With the calculator scooper posted, i found out that I'll get about 3200rpm at 60mph with the 4.11 gears.. I think I can live with that
Oh, but you will get there VERY quickly. You should like them muchly!!! If i didn't mind cruising at 3200 rpms, I would DEFINITELY use 4.11 gears!!! But I spend a bit too much time on the highways going to Ed Winegar's car shows... The baby blue Challenger and Maverick belong to Ed (924 Mav).
No doubt about it, steep gear is fun. I did have a 4.56 back in the day. I could redline 4 gears crossing a 4-lane highway. Had a cop pull me over ‘cause it sound like I was laying drag. Told him my gear ratio. Lucky the cop was a carguy and he knew what happen.
Since it's for only short periods at a time, I think I'll be able to live with 4.11 gears I reckon I'll be doin 30-40 most of the time, and that was like 1600-2200rpm If I still was running 3" exhaust with just the flowmaster dumping at the rear axle, I definitely wouldn't enjoy it though Really miss the sound of it, but I would get a headache driving it for longer periods Lots of nice cars! I really like the "new" Challenger, if they weren't like 200.000$ over here I would have to buy one
