| Re: The old 3.73 vs 3.53 debate |
Subject: Re: The old 3.73 vs 3.53 debate by BeachBum on 2009/4/22 4:26:25 I personally do not like to gear a 700R4 transmission with the traditional 1-1 gear vs rpm as being done here.... I don't think it works, in part due to the rpm limit on the TPI motor coupled with the steep 1st gear.... I think you instead look at speed vs gear..... too much gear in a TPI motor and you're hitting 2nd gear so early in the speed the car loses inertia. Its just hard to lug 3200 lbs in 2nd gear at 30 mph. I switched from a 3.07 to 3.45 gear and unfortunately, was rewarded with no et improvement. The 3.45 gears were theortical the better gear that was supposed to improve my et based upon it being closer to my peak HP rpm in the 1-1 gear.... my results were similar to a few others back a few years that did the same. There are other things involved with this as well, but I won't go into right now. I do think more gear would help a TPI motor if it was running a th350 or a manual transmission dependant on the gear ratio. I think for the OP in this thread...... as somebody else had said, I think you'll get the biggest bang for the buck with a good torque converter. They are always good for a 2-4 tenths et gain it seems..... but I will say, if you have the original 85 torque converter, it was a little loose from the factory and I believe rated at somewhere around 2100 rpm..... thus its not bad, but you could still improve with a jump up to a 2500-2600 converter. good luck with whatever you decide ! |
