Question for you 4.56 guys

[HEMI LOL]

Is there a good link to a gear calculator around here?

 

[Joser281]

I wouldnt go much higher than a 4.10 with the boost. Traction is already a bitch as it is.

Wouldn't the gearing in the TR6060 sort of help in getting some of the traction back? (sort of speak)

 

[GrnBullitt08]

Yeah there is...dont know the link though

 

[GrnBullitt08]

Wouldn't the gearing in the TR6060 sort of help in getting some of the traction back? (sort of speak)

Yeah it would, and there are guys running a 4.30 with a supercharger. We ran a 4.10 with the 2.6L KB and it performed like an animal. Never tried the 4.30.

 

[tjm73]

Is there a good link to a gear calculator around here?

What are you trying to figure out? RPM's at a certain speed? Speed with a particular gear set? What cha looking for? I can quote most of the formulas for gearing.

 

[Fast64ranchero]

Couple things, all 2010 and newer GT's w/8.8 use the hi torque pinion bearing, and it's about $50 from Ford, and is a Ford only item, I hadn't seen this before so we measued it up, appears the tapper is different then the standard bearing,
as for the 4.56's I love mine, my car is a daily driver, the gear change from 3.73 to 4.56 made the car a much better car up to 75mph, easier to drive, more power, I did run into one problem, I went cheap on the gears and have a slight whine, I just purchased Ford racing 4.56's and a true trac to replace my Yukon gears and stock center section.

 

[Fast64ranchero]

Here's the formula I use
168 X gear ratio X MPH / 1/2 of tire height = your RPM in 4th gear at that speed, if you want to figure out your RPM's in overdrive X that number by your overdrive. here's my info for example

168 X 4.56 X 115mph /13.5 = 6526rpm in forth gear
I used this for figuring my rpm/gear ratio for the drags, below I changed the mph to figure rpm's at cruize
168 X 4.56 X 65mph /13.5 X .68 (overdrive ratio) = 2509 rpm's at 65 mph

the 168 is the mutiplier and the 13.5 is half of my tire height, hope this helps

 

[dysan]

I didn't see it mentioned but I would take a look at your spider gears. I've gone through 2 sets already in my car. Granted, I've got over 119k miles on it but just in case you need to replace them.

 

[iRoush]

Here's the formula I use
168 X gear ratio X MPH / 1/2 of tire height = your RPM in 4th gear at that speed, if you want to figure out your RPM's in overdrive X that number by your overdrive. here's my info for example

168 X 4.56 X 115mph /13.5 = 6526rpm in forth gear
I used this for figuring my rpm/gear ratio for the drags, below I changed the mph to figure rpm's at cruize
168 X 4.56 X 65mph /13.5 X .68 (overdrive ratio) = 2509 rpm's at 65 mph

the 168 is the mutiplier and the 13.5 is half of my tire height, hope this helps

Ok, I've been trying to figure out why, but I can't. Why exactly do we use 168? I know it's gotta be something obvious that I'm missing.

 

[GrnBullitt08]

I'm using Motive 4.56 gear set. So I don't think they would be considered cheap. My car currently has 31,000 miles on it and I will be inspecting everything during install. I bought a master rebuild kit, so I plan on replacing everything that I can to ensure I don't have to replace anything until the new axles and differential goes in.

 

[rojizostang]

engine rpm calculator
http://www.csgnetwork.com/multirpmcalc.html

 

[HEMI LOL]

Wow 3k rpm crusing at 65.

 

[GrnBullitt08]

Yup...65-70 average RPM is between 2800-3000

 

[iwaxmyjimmy]

Wow 3k rpm crusing at 65.

You do understand, it is possible to pick up gas mileage b/c more mechanical advantage right? Also your engine is further in its torque curve which means its more efficiently keeping the same speed (per say)?? Also if your trying to squeeze out gas mileage and power, just find a new hobby. Yeah some turbo cars are getting 20+ mpg's while making 800 rwhp, but also they have maybe $40k invested in them and they also don't drive it like they stole it all the time. But everyone knows once u feel the power you love the rush and so you end up spending more in gas money.

 

[GrnBullitt08]

I will be driving mine daily with the 4.56s

 

[Matt D]

I will be driving mine daily with the 4.56s

^ What a fucken G

 

[Fast64ranchero]

IRoush the 168 is the mutilpier, I'm not a math guru so I can't answer why, all I can say is it is the constant.

my car is at 2500 rpm at 65mph and 2950 or so at 75mph, as for MPG is picked up about 2 MPG in town, and dropped about the same on the highway, I'm still averaging the same MPG as I was with 3.73's (21mpg) average with a mix of in town and Highway,

my cams like the increased rpm also...

 

[GrnBullitt08]

^ What a fucken G

Word

 

[GERMANSHEPERD]

Wow 3k rpm crusing at 65.

Huh? my Auto car is 2600@65mph with 4.56's

 

[11secLX]

What kind of difference do you think the gear change from 3.73s to 4.56s will make in trap speed and ET? I was thinking 4.30s for my stock Bullitt. I'm looking for a 12.99 slip from my current 13.22. It bogs off the line on 275/40R17 ET Street radials with a 5000rpm launch.

Steve