Gearing

Yarrowman · Veteran Member

Gearing

73SC · A Poncho Legend!

What engine and transmission are you using ?

Yarrowman · Veteran Member

461 ci 500 hp 500 ft lbs torque TH400 with a 2800 rpm stall and 12 bolt posi rear end which at the moment has 4:11 in it and a 28" tall tire

427carl · A Poncho Legend!

You have lots of grunt switch to 3:08 and have both power and economy

Do you race the car a lot?

unburt · Guru

Nice combo brad the 4 series gear would make that car launch hard and lots of fun.
The first question is how far would you drive it and at what speed?. Do you take it to the track regularly and are you concerned with time slips.
The power that you make with that combo would allow you to drop down to a mid 3 series gear and still blow the tires off the rims.
I am upgrading my posi/axels and im doing a 342 with a 28 tire this will equate to a 330 ratio. This gear and tire will put me at 25 to 2600 at 60 mph.
Going to a 355 might be a nice setup but it still depends on distance/speed.
With a torque monster big block, gearing can be more street friendly.
I like using automotive calculators so that effective gearing can be figured out. I use Wallace racing site, really good to plug some numbers into.

Yarrowman · Veteran Member

427carl wrote:
You have lots of grunt switch to 3:08 and have both power and economy
Do you race the car a lot?
No not at all I might go to the track this summer just for fun and it would be the first time. The car is just going to be a street car with some growl and bite!

Yarrowman · Veteran Member

unburt wrote:
Nice combo brad the 4 series gear would make that car launch hard and lots of fun.
The first question is how far would you drive it and at what speed?. Do you take it to the track regularly and are you concerned with time slips.
The power that you make with that combo would allow you to drop down to a mid 3 series gear and still blow the tires off the rims.
I am upgrading my posi/axels and im doing a 342 with a 28 tire this will equate to a 330 ratio. This gear and tire will put me at 25 to 2600 at 60 mph.
Going to a 355 might be a nice setup but it still depends on distance/speed.
With a torque monster big block, gearing can be more street friendly.
I like using automotive calculators so that effective gearing can be figured out. I use Wallace racing site, really good to plug some numbers into.

Thanks, I will check that site out and crunch some nimbers!

ak 67sd · Poncho Master!

Do you plan on alot of freeway/highway driving? or mostly lower speed city cruising? I used 4.56's for city use, and they were a ton of fun on a car that i spun to 7500rpm... and occasionally highway use, maybe 30-45 minute max a few times a year... the cam in the engine, and what you plan to trap speed at will help you determine optimum 1/4mi gearing, you had it dyno'd right? at what rpm did peak hp come in?... with the 4.10's I'm guessing you will run out of motor before the traps... of course borrowing some taller slicks for the track would also help that out! I'd run the 4.10's for a while and have some fun with them, but you will probably be happy with a 3.73...pretty close!

ak

edit: let us know what the calculators came up with! and what you decide...it'd be fun to do back to back 1/4 mile tests in the summer with the gears...

-- Edited by ak 67sd on Tuesday 3rd of January 2012 11:22:47 PM

2drpost · Uber Guru

performance, some hiway, 3.55s

4SPEED427 · A Poncho Legend!

69 belair wrote:
performance, some hiway, 3.55s

Dave and I think very much alike on that one. 3.55 is a very nice combination gear that is liveable on the highway especially. With today's high speed limits, steeper gears than that can get tiring.

73SC · A Poncho Legend!

Wouldn't an overdrive transmission with some 3.73's be ideal.

427carl · A Poncho Legend!

73SC wrote:
Wouldn't an overdrive transmission with some 3.73's be ideal.

Thats the best route except he has a 400 turbo now

4000.00 for a trans to save 400-500 worth of gas is well .. sounds.. like the government lol

73SC · A Poncho Legend!

Well excuse me but to be blunt the whole concept of a 461 Cubic inch, 500 HP, 500 ft lb engine with 4.11 gears trying to save fuel sounds more like the Government to me.

427carl · A Poncho Legend!

wink Exactly actually he asked about highway speed vs perf vs rmp

my 468 500/500 with 2.73 would run 160km in 2nd gear All depends on your pocketbook

65wagon · Poncho Master!

i used to run 256 but it was hard on the small block while towing, right now ive got 336 but when the o9 goes back in so does the 256 posi

73SC · A Poncho Legend!

Big Blocks and all the torque they make are better suited to high gear ratios. On top of that it gives you pretty much unlimited top end.

dualquadpete · Canadian Poncho Superstar!

This all depends on his driving plans. Lots of Hwy. trips,or long runs I'd be going Hwy.gears [high 2's to 3:38's] B/Block as stated has the torque to handle these gears & still "melt" the tires. If city & short runs then go for the "stump" puller gears & have fun but pay for the fuel used!!! I dropped from 3:42's to 2:67's in the Catalina & it will still "fry" the tires in 1st.& 2nd [turbo 350trans] but can get 17MPG on the trip to W.V. You can't have both but you can come close!!!!!

seventy2plus2 · Canadian Poncho Superstar!

Your gearing will be determined on how you like to drive. I like to be able to cruise on the highway at 80 mph, and can easily hit 100 mph when passing on a 2 lane road. As such, my 2.73's suit me fine. While 4.10's might be nice for around town, I don't think I could handle them as I like some top end speed.

73SC · A Poncho Legend!

I'm with Pete and Clint, I like my 2.73's with the 454. Clint your car must behave just like an RCMP Strato Chief back in the day, pretty much could haul down anything out on the open road. I think they may have used 2.56 gears, probably good for 140 mph at least.

65 SD L79 · Canadian Poncho Superstar!

my 69 corvette M21 small block had 308 and I changed to 355. Didn`t know I was driving the same car

Paulish · Guru

I have a 461 that's 406 hp at the rear wheel, 460 fpt.

I also have a turbo400 and a 3000 stall converter.

I have a 9inch rear end with 355's in it.

I find the 355's a lot more practical then my old 411's. The 411's made hyway driving a nightmare. Car is loud as hell at 3500 rpm and was still barley doing the speed limit. With the 3.55's ive had it at 150km. Still ripps off the line too. No complaints about my gear choice.

-- Edited by Paulish on Wednesday 4th of January 2012 07:59:52 PM

Yarrowman · Veteran Member

Thanks for all the great input guys, from what you have all contributed and my own research I think I will go with the 3:55 gearing, I will be mostly cruising around the farm roads of the Fraser Valley and a little bit of highway driving, it will be up and running on the road in March so I will let you know how it all turns out!

Yarrowman · Veteran Member

To answer one of your questions AK this motor cranked out 500 ft lbs torque at 3600 rpm and 500 hp at 5500 rpm I cant wait to fire it up and drive!!

seventy2plus2 · Canadian Poncho Superstar!

73SC wrote:
I'm with Pete and Clint, I like my 2.73's with the 454. Clint your car must behave just like an RCMP Strato Chief back in the day, pretty much could haul down anything out on the open road. I think they may have used 2.56 gears, probably good for 140 mph at least.

yup the convertible still has the 2.73's from when it was a 350 car. I can run down and pass anything on the road (with the exception of a supercar), and have buried the speedo more than once. the 454 Laurentian has 2.56's, and while I haven't had it up to speed, I'm sure it can easily bury the speedo. (keep in mind I just re-did the poor brakes late in the fall)