Rear axle ratios, tire size, trans and engine combos

[RJacobsen]

I just posted this link on another thread but thought it should have its own. If you are trying to decide on rear axle ratios, transmission types, tire sizes, and engine combinations this will come in very handy. http://www.gtsparkplugs.com/GearCalc.html

[Naumoff]

Thanks Rod. Great site
**will have to edit later. Our forum tightens everything up****Happy Easter
Here is my set up

*******************************
Final Gear Ratio : 3.31
Tire Size : 295-55-15
Max Power RPM : 6300
Limit RPM : 7000
*******************************
*********************
Gear Ratio Compound
*********************
1 2.320 7.679
2 1.690 5.594
3 1.290 4.270
4 1.000 3.310
***************************************
Gear MPH/1000 MPH @6300 MPH @7000
***************************************
1 10.77 68 75
2 14.78 93 103
3 19.36 122 136
4 24.98 157 175
********************************************
MPH RPM (in Gears)
********************************************
1 2 3 4
********************************************
5 464 338 258 200
10 929 677 516 400
15 1393 1015 775 601
20 1858 1353 1033 801
25 2322 1691 1291 1001
30 2786 2030 1549 1201
35 3251 2368 1808 1401
40 3715 2706 2066 1601
45 4180 3045 2324 1802
50 4644 3383 2582 2002
55 5108 3721 2840 2202
60 5573 4060 3099 2402
65 6037 4398 3357 2602
70 6502 4736 3615 2802
75 6966 5074 3873 3003
80 5413 4132 3203
85 5751 4390 3403
90 6089 4648 3603
95 6428 4906 3803
100 6766 5164 4003
105 5423 4204
110 5681 4404
115 5939 4604
120 6197 4804
125 6456 5004
130 6714 5204
135 6972 5405
140 5605
145 5805
150 6005
155 6205
160 6406
165 6606
170 6806
175 7006
********************************************
Gear Change RPM drop (change @6300) RPM drop (change @7000)
************************************************** ***********
1->2 -1711 (To 4589) -1901 (To 5099)
2->3 -1491 (To 4809) -1657 (To 5343)
3->4 -1416 (To 4884) -1574 (To 5426)
************************************************** ***********

[RJacobsen]

I'm not sure why the copy/paste turns out that way but the charts on the site are interesting to look at.

I was trying to decide between the 2 rear axles I have (4.09 or 3.54) for my 289 HIPO- 5 speed combo and came up with 200 mph at 6500 rpms with the 4.09 rear end, not that I think the engine will be able to do it but I'm going with the 4.09 now because I know I'll be short on torque and high on rpms.

[RJacobsen]

Tony, Looks like your good to 160 mph, Hang on

[Naumoff]

Rod,

I will want to put the big brakes up front before I attempt 160.

In the 1/4 mile I can run through the traps in third gear with my set up when I do a soft launch.

What is the redline on your smallblock? 9000? I guess a 4.09 wouldn't be bad.
I ran a 4.10 in my Galaxie.

[RJacobsen]

Tony, I'm not sure about the redline, I'm going to limit it to 7000 for now and see how it acts, that should be plenty to get into trouble with. I have a different cam now than what I used when the engine was in my Mustang but 7000 was not a problem before.