Help with rear axle ratio

yellowfever#154

yellowfever#154

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Well the "ex" wife signed the divorice papers yesterday and she didn't quite take me for all I'm worth, so I decided I should celebrate and get myself a DTS rear axle (if I can convince them to ship to Canada) and also get a set of Bogarts (front and rear) and run a 33X10.5X15 rear tire. I am going to be in the "almost" 1000 RWHP range when I'm done with my mods and looking for advice on a rear gear ratio. I'm think 4.11:1, unless anyone else has better advice. NOTE: No 1/8 mile runs he either, only 1/4. Thanks.
 
yellowfever#154 said:
Well the "ex" wife signed the divorice papers yesterday and she didn't quite take me for all I'm worth, so I decided I should celebrate and get myself a DTS rear axle (if I can convince them to ship to Canada) and also get a set of Bogarts (front and rear) and run a 33X10.5X15 rear tire. I am going to be in the "almost" 1000 RWHP range when I'm done with my mods and looking for advice on a rear gear ratio. I'm think 4.11:1, unless anyone else has better advice. NOTE: No 1/8 mile runs he either, only 1/4. Thanks.
Click to expand...

Sounds like a great setup to me :)
May even could stay 4.56 with a 33" tire :rock:
 
4.56 gears with a 33" tall tire works out to about 130.25 mph possible at 6,050 rpm in 4th gear in the 1/4 mile. A 4.11 rear would raise the theoretical speed in 4th gear to 144.51 mph at 6,050 rpm. I used 6,050 as that is the factory rev limiter setting. Your mph could be higher if you have raised the rev limiter.....for example if you raised it to 6,250...then top speed in 4th with 4.56 gears would be about 134.55 mph. Hope this helps.
 
Trainman said:
4.56 gears with a 33" tall tire works out to about 130.25 mph possible at 6,050 rpm in 4th gear in the 1/4 mile. A 4.11 rear would raise the theoretical speed in 4th gear to 144.51 mph at 6,050 rpm. I used 6,050 as that is the factory rev limiter setting. Your mph could be higher if you have raised the rev limiter.....for example if you raised it to 6,250...then top speed in 4th with 4.56 gears would be about 134.55 mph. Hope this helps.
Click to expand...

That does help, I wonder if running the 4:11 would help with traction vs the 4:56?
 
dude if you want 4.56 you can have mine i have 3.73 coming this week.. out of my DTS,

PS you do not want 4.56 they are mental 1 threw 3 usless ... Let me get my 3.73in and running and ill give you a report on 3.73 and 4.56 and give you an opinion on going 4.11.
 
yellowfever#154 said:
That does help, I wonder if running the 4:11 would help with traction vs the 4:56?
Click to expand...

With the kind of power you are building, the engine is probably going to RPM at the same speed, regardless of which gear ratio you use. Based on Trainman's calculations, you are going to need the 4.11's to get the trap speed you should be running.
 
They work in the DTS, not sure on OEM though,. I would not run a 3.55 with your setup, 3.73 or 3.90 (Motive makes the 3.90, only works with regular dana 60) would be my choice. Ive drove your setup almost exactly (950whp F1C), on the 22's with 4.10s and its a joke, 4th gear is still blowing the tires off.
Justin
 
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I would do a 9" rear end if I was doing it again period!!!!
Take my advice


Sent from my iPhone 6 while driving 100 mph on a dirt road
 
JMB Justin said:
They work in the DTS, not sure on OEM though,. I would not run a 3.55 with your setup, 3.73 or 3.90 (Motive makes the 3.90, only works with regular dana 60) would be my choice. Ive drove your setup almost exactly (950whp F1C), on the 22's with 4.10s and its a joke, 4th gear is still blowing the tires off.
Justin
Click to expand...

The 3.55's are not for me. I was curious for someone else if they fit the factory carrier or not.
 
505'sFastestViper. said:
I would do a 9" rear end if I was doing it again period!!!!
Take my advice


Sent from my iPhone 6 while driving 100 mph on a dirt road
Click to expand...

I would also prefer a 9", parts are dime a dozen, easy gear swaps, but they told me the Dana 60 was a much stronger setup. They have a bigger crown and pinion which in turn has more tooth contact.
 
yellowfever#154 said:
I would also prefer a 9", parts are dime a dozen, easy gear swaps, but they told me the Dana 60 was a much stronger setup. They have a bigger crown and pinion which in turn has more tooth contact.
Click to expand...

There is no fricken way go look at all the really fast cars they don't run 60's



Sent from my iPhone 6 while driving 100 mph on a dirt road
 
If I were doing a diff swap Tyler I would also be looking into a Ford 9" and run either 3:55's or 3:73's,you have waaaay to much power for anything lower in a gear!
 
9" FTW....I'm going to patch my Dana 60 back together for drag week and start collecting parts to build a 9" and just do ladder bars/coilovers with a fuel cell where the spare tire was.
 
yellowfever#154 said:
I would also prefer a 9", parts are dime a dozen, easy gear swaps, but they told me the Dana 60 was a much stronger setup. They have a bigger crown and pinion which in turn has more tooth contact.
Click to expand...
They are concerned about the weight of the truck, not the power level. Even with this considered, I would run a 9".
 
Rear axle

Does the 2005 srt10 have a 9.25inch or a 9.75inch rear axle?
 
Been trying to figure out if my 05 qc srt10 has a 9.25 or a 9.75 inch rear axle. Ordered parts for a 9.25 inch and nothing fit
 
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