View Full Version : Finished the differential yesterday.
1fastsedan
10-04-2011, 02:41 PM
In preparation for my kit arriving, we built my differential yesterday. It has a 31-spline Eaton Truetrac, Ford Racing 3.08 ring and pinion, and Strange Engineering 31-spline axles with c-clip eliminators. Some before and after:
http://i161.photobucket.com/albums/t225/1fastsedansrt8/33%20Hot%20Rod/IMAG0121-1.jpg
http://i161.photobucket.com/albums/t225/1fastsedansrt8/33%20Hot%20Rod/IMG_7457.jpg
http://i161.photobucket.com/albums/t225/1fastsedansrt8/33%20Hot%20Rod/IMG_7458.jpg
http://i161.photobucket.com/albums/t225/1fastsedansrt8/33%20Hot%20Rod/IMG_7459.jpg
http://i161.photobucket.com/albums/t225/1fastsedansrt8/33%20Hot%20Rod/IMG_7461.jpg
myjones
10-07-2011, 11:10 AM
[QUOTE=1fastsedan;35261]In preparation for my kit arriving, we built my differential yesterday. It has a 31-spline Eaton Truetrac, Ford Racing 3.08 ring and pinion, and Strange Engineering 31-spline axles with c-clip eliminators. Some before and after:)
308 seems kinda high, not saying it won't pull it just wondering if you plan on some top speed bonzai runs, 1 mile track maybe??
BTW you don't sign your posts, and I know you aren't scotty Q but we gotta call you something? 1FSD seems kinda plain
Dale
1fastsedan
10-07-2011, 11:58 AM
We chose the 3:08 due to the car's light weight, the high torque of the HEMI, tire size and reducing RPMS at cruising speeds. I have the same engine in a 4,400 lb car with 3:06 Getrag rear and it lights the 11" wide tires at will, so I think it will be plenty quick off the line.
Sorry about not listing my name, guess I never noticed that it was common to do so around here.
Adam :)
myjones
10-07-2011, 03:43 PM
We chose the 3:08 due to the car's light weight, the high torque of the HEMI, tire size and reducing RPMS at cruising speeds. I have the same engine in a 4,400 lb car with 3:06 Getrag rear and it lights the 11" wide tires at will, so I think it will be plenty quick off the line.
Sorry about not listing my name, guess I never noticed that it was common to do so around here.
Adam :)
Adam
I hear ya on the 4400 tire smoker my MSRT8 is/does that and runs a Buck70 thus my addy on the other boards
The tires will be a little shorter on the 33 but isn't the OD on your tranny like 0.69 have you projected RPM's at 70 yet?
Dale
1fastsedan
10-07-2011, 04:32 PM
Adam
I hear ya on the 4400 tire smoker my MSRT8 is/does that and runs a Buck70 thus my addy on the other boards
The tires will be a little shorter on the 33 but isn't the OD on your tranny like 0.69 have you projected RPM's at 70 yet?
Dale
I can't seem to find the paper, but I did the math several months ago when picking the transmission and the stall speed for the converter. From what I remember, it came out to 1950 RPMS at 75 mph. Perfect for highway cruising out here.
By the way, love the MSRT8. I have the 300C SRT8...just couldn't bring myself to buy a wagon without any kids.
Adam
britpit
10-07-2011, 05:41 PM
Is there a way to attach an Excel spreadsheet file? What I have is a calculator for rpms/speed with different tire sizes and all your transmission ratios (you enter). But it's not apparent how to attach it.
Wayne
myjones
10-11-2011, 11:46 AM
I can't seem to find the paper, but I did the math several months ago when picking the transmission and the stall speed for the converter. From what I remember, it came out to 1950 RPMS at 75 mph. Perfect for highway cruising out here.
By the way, love the MSRT8. I have the 300C SRT8...just couldn't bring myself to buy a wagon without any kids.
Adam
Adam
I just ran it through an online calculator with 27" tires 65 =1720 70 = 1850 so your 75 number looks about right.
We don't get to cruise much over 70 around here so it would be lugging in our area.
The 6.1 is the first OEM that I own that seems to need some RPM's to get up on the cam and the intake is a higher RPM design as well.
Have you thought about using the 5.7 manifold or maybe the new patriot manifold to help the port velocity in that RPM range?
Funny about the Maggie, no kids here either, they are grown and gone early i couldn't bring myself to buy the 300 without any old folks to haul around ">)
Dale
Lurkin and Learnin here too