ERA #783 - with questions

[Rickd]

If I were ordering again, with the TKO 600, I would definitely have gone with the .82 OD and I would have ordered a 3:31 rear rather than the 3:54. I really don't like the .64 with the 3:54 rear. If you are driving a lot in the 60 - 70 mph range, it is a real pain - you want to shift - but that huge drop sucks big time. My old cobra had a T5 with a .75 OD and I had a 3:31 rear - which was a nice combo.

[patrickt]

Originally Posted by Rickd

If you are driving a lot in the 60 - 70 mph range, it is a real pain - you want to shift - but that huge drop sucks big time.

Rick is right on the money with this and he's put his finger on the .64's weakness. But Mooch, don't go with anything just because someone else went with it -- you've got to choose this one all by yourself and gear it to your engine and driving speed. Whatever you do, *don't* go with a 3.54/.64 combination just because I did.

[elmariachi]

Originally Posted by patrickt

Rick is right on the money with this and he's put his finger on the .64's weakness. But Mooch, don't go with anything just because someone else went with it -- you've got to choose this one all by yourself and gear it to your engine and driving speed. Whatever you do, *don't* go with a 3.54/.64 combination just because I did.

This discussion highlights the fact that you need to talk to your engine builder about how he builds your stroker. By design, if built and cammed right it should be plenty torquey...enough to pull you out of the 2k/70mph hole if you go with 3.50/.64. But as you say, you gotta pick your cruising band and plan your setup from there. Don't listen to me either, I didn't plan diddly squat where this is concerned>>>>During my build I found a brand new still-in-the-box .64 TKO 600 on Craigslist for $1000 and made what my wife commonly characterizes as an "impulse spend."

[Mooch]

Again, another calculation with TKO-600 gear ratios through the cruising band with 26.5 inch tires. I figure there a lot of people who have been doing this calculation on their own. Hopefully they can just refer to this. I had to put it in a code box for the formatting.

RPMs         3.54w0.64od      3.31w0.82od     3.54w0.82od
 
1500              52              44              41
1550              54              45              42
1600              56              46              43
1650              57              48              45
1700              59              49              46
1750              61              51              48
1800              63              52              49
1850              64              54              50
1900              66              55              52
1950              68              57              53
2000              70              58              54
2050              71              60              56
2100              73              61              57
2150              75              62              58
2200              77              64              60
2250              78              65              61
2300              80              67              62
2350              82              68              64
2400              84              70              65
2450              85              71              67
2500              87              73              68
2550              89              74              69
2600              90              75              71
2650              92              77              72
2700              94              78              73
2750              96              80              75
2800              97              81              76
2850              99              83              77
2900             101              84              79
2950             103              86              80
3000             104              87              81

This is the equation:

MPH = (RPM*pi*d)/(12*88*g*od)

Here are the variables:
MPH = MPH
RPM = RPM
pi = 3.14159
d = Tire true diameter (inches)
g = rear end gear ratio
od = final gear reduction for overdrive


Once I talk with my engine builder, hopefully tomorrow, I'll let you know where I'm going with the gearing decision. I think I'm going to have the trunk lid finished, and I am still mulling over the seat heater and interior insulation options.