Dale, Makes sense to me too that speed has nothing to do with it. My guess is that they chose 45 MPH because that works out OK for most applications and they don't have to worry about people not understanding gearing. Plus, I think the computer controlled cars use a vehicle speed sensor for lockup. I have evel lower gears, 2.73:1 which is even more pronounced. I never use 4th/OD in town. The car sometimes shifts into OD at 30 mph if I'm cruising light throttle, and this is way too low to be able to drive. Heck, the car can go faster than that at idle!
Brad Waller > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Dale McIntosh > Sent: Wednesday, July 30, 2003 1:21 PM > To: [EMAIL PROTECTED] > Subject: RE: [Chevelle-list] 200R4 success stories? was: Trans cooler > > > Now here's some good news. My rear gear right now is pretty high as > well (3.07) so lockup below 65 or 70 isn't practical. I'll probably > change the rear gear at a later time as even at 75 with O/D > it'd only be > turning 1900; 3.55's would bring that up to 2200. I wonder where B&M > came up with 45MPH since MPH has nothing to do with RPM?. Example, at > 45MPH with a 4.10 gear, you'd be turning 2300 in drive or 4th gear. > Given the same tire size at 45 MPH and a 3.07 gear, you're > only turning > 1700 PRM. Big RPM difference at the same speed. > > Dale McIntosh > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of > > [EMAIL PROTECTED] > > Sent: Wednesday, July 30, 2003 1:34 PM > > To: [EMAIL PROTECTED] > > Subject: RE: [Chevelle-list] 200R4 success stories? was: > Trans cooler > > > > > > I put a 2004R in my 67 in place of the Powerglide with no > > real problems. > > > > I could reuse my driveshaft with no modifications. > > I had to move the crossmember back to accommodate the new > trans, but > > there were holes already drilled in the frame at the right > > place. My cooler lines required minor re-bending, but the > > length was ok. I did need to buy an aftermarket shifter > > because the column one wouldn't fit. I needed to buy an > > aftermarket lockup converter controller. I was > > offered a non-lockup converter by the trans shop, though. > > I needed to buy a longer TV (throttle-valve, aka detent) cable. > > > > However, I'm running a 250-I6. I can't speak for > durability, because > > the trans came from a 90 Caprice with a 350 TBI. My > rearend gear is > > too high - lockup isn't really practical until about 60 > MPH, and B&M > > recommends it be set no higher than 45 MPH. OD isn't practical in > > town, as the speed limit here is about 30 MPH, which translates to > > approximately 1500 RPM. Apparently a set of 3.42/3.55 rear > gears is > > about ideal for cruising/all-around general use. > > > > Talk to your local trans rebuilders and see what they have to say. > > Many here said they weren't able to guarantee their work > for anything > > other than a stock-type rebuild and use, but I found one who would > > happily do so and was familiar with building and modifying them for > > racing. > > > > Hope this helps, > > Dave. > > > _______________________________________________ > Chevelle-list mailing list > [EMAIL PROTECTED] > http://chevelles.net/mailman/listinfo/chevelle-list_chevelles.net > _______________________________________________ Chevelle-list mailing list [EMAIL PROTECTED] http://chevelles.net/mailman/listinfo/chevelle-list_chevelles.net
