I’ve got 3 different gear sets to choose from for my Winters quick change. If I had a 1-1 set of gears then I’d have 3.78 which is what the ring and pinion ratio of the wedgelock is. Any idea on a good street ratio for my 26 RPU Y Block, C4 and 29”.5 “ tires.
Since it's a quick change, why not start with the middle gear set and then decide wither you need to go up or down or stay the same?
I always use the rpm calculator on project33.com Put in your trans type, what gear your in, tire height, rear ratio and speed and it tells you what the rpm will be. So let’s say c4, top gear, 29.5 tire with 3.78 gear at 65mph. See what rpm you land around and play with the gear ratio to dial it in where you want it. Which is just as easy in real life with a quick change
That’s assuming 3rd is top gear on my behalf. Looks like a good around town, across the city kinda gear to me depending on where the power lands in your motor. Might want something a touch higher on an interstate 80mph drive that last more than a little while but you’ve got a quickie Edit: it didn’t have your exact ratio as an option so I got it close. So your rpm will be a teeny bit higher but probably not enough to make any difference
Popped over to a 3:31 ratio out of curiosity Should give you a good starting point. Just need to figure out how that translates into spur gears I guess
I’ll play around with it once I get I on the road. I just thought that someone might have experience with these things. With a small light little car it should get up and go pretty well, I just wanted a starting point that would give me reasonable RPMs at 60 -70 mph on the hiway. From my gear charts and the calculator it looks like 3.05 would be a starting point. By the way my rear tires are actually 29” tall.
that would be a good starting point. but you might want to play with it...as an example, I ran everything from 2.47 to 4.11 in my 55 Chevy, they each had their place.
Buy the right gear set and you can have one deep gear for running around town. Rake a couple minutes to flip them over and you can have highway gears. QC gears are cheap and easy to change. Don't be afraid to play with a few sets. SPark
4.11's and a C4 my make the fast lane a chore on the superslab. I run helical cut 4.11's in my QC, but I have a 5th gear in the T-5 to keep the flathead happy. I can tell you that my little car jumps with those 4.11's in back.
Yes I can relate. Many moons ago I had a 55 Chevy with 4.11s and a 327 with a 3 speed manual. The thing screamed on the hiway. Swapping in a 4 speed helped a little bit. The cure was a 3.23, it wasn’t as quick but much better on the hiway.
Another way of looking at it is what kind of driving do you do. I will only run up to 60mph at a stop light grand prix, and I only want to shift once. Using a different calculator, I decided that a 3.80 gets me to 60 at red line. Works for me. Yet I only run 2,000rpm at 65mph in 5th.
How would changing from a 3 speed to a 4 speed change the cruising RPM's? Unless is was an overdrive 4 speed, both trannys would still be 1:1 final drive. Shouldn't change RPM in high gear at all. Confused.... SPark
Since you are asking for a starting point, may I suggest this? Put the tallest gear you have in it. (Big gear on the bottom) If it pulls okay from the lights etc. you have that part answered. When curiosity gets the best of you, flip it over. You know you want to. That's the bad boy. My guess is that you will wind up using a gear between 3.25 and 3.50 for most of your day to day driving. I had a 2.42 in my OT shop truck. A little sluggish on the take off, but not bad for 5000+ lbs. Flipped it for 7.00. Wasn't fun even for a minute driving around the parking lot. My daily gear is 3.38.
No need to be confused, If you are it’s my fault I neglected to say that the improvement from the transmission swap wasn’t at cruising speed, the improvement was during driving and going through the gears due to a better ratio spread or match from gear to gear. As I said the final solution for the hiway RPM was a rear gear change.
Blue...they aren't called "Quick Change" rear axles for nuthin..! Geeze questions like this take hot rodding back 30 years. Your car, your driving...why don't YOU make the decision on what ratio YOU like best..?!?!?!?! Try one...if you don't like it, in about 15 to 20 minutes, you'll have another ratio installed to try..! Mike
Don't overlook the cam range for your engine. You don't want to be cruising at an RPM lower that what your cam operates at.
Yup, I know, I anticipate doing just that, that’s why I have 3 sets of gears and I may just order a couple more to play with. I just like hearing the experiences of other guys, isn’t bench racing part of the hot rod experience and history? It may even be traditional unless I’m mistaken Taking hot rodding back 30 years I guess that during that 30 years no one ever asked any of their buddies about anything, they just winged it on their own. Really?
Does your reared take standard gears? If so, I recommend keeping your eyes open at swap meets. I once bought an old ammo can full of gear pairs for about $25. Those gears don't wear out, and there were a big variety in there to experiment with. Maybe you will find a similar deal.
They absolutely DO wear out. The teeth start to pit and they crack outward from the center splines. If they were used in high HP race cars most of those get pitched on a regular basis (yearly) and/or sold to low buck teams. Break 1 QC gear set and you would never make that statement again. If they were run with cheap or really thin grease they don't last long. We found full synthetic or "red" gear lube worked best. I also wouldn't recommend polished gear sets. Raced dirt late models for years, you see them break a lot there. They should also be kept as matched sets, they develop wear patterns like any other parts that run together. We always installed gear sets with the numbers out so they were always rotating the same direction and kept the same wear patterns going. SPark
Experience based advice Perfect, my QC is brand new and I’ll stick to new gear sets and keep them in sets. I’m going to fill it with Lucas synthetic.
Put me in my place. I guess I just got lucky with a box of good gears. No pitting, cracking, or worn faces.
I run 3.89s daily and swap to 2.89s for long trips. But, you will have to figure out what you like once you have it on the road. Have fun and make sure to post some pics. -Abone.
My F100 has 350 Vortek/350 TH, 3.00 rear in Ford 9". LOVED my 3.78s, but was screaming on the hard slab at 70... Then switched to 3.54s, actually noticeable. Still too 'low' for freeway flyin'. Spiders got noisy, put one together from my son's '63.5 Galaxie. 3.00 gear works best of all, but wish I had an AOD! ...some guys are never happy...
I'm running a 3.00 8" in my 40, for what little continuous high RPM's/MPH hiway driving I do I just accept it. 3.00 are perfect for me on the surface streets.
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