What brought this up for me again was I was in need to do something about my current setup. From day one I was using a much smaller tire size than stock. The OD was 24.5" vs the +/-28" stock was. This together with the 3.73 and 3 speed early I was first running the truck made it non friendly to drive. The 3200rpm area in third was harsh as with the stock cam it sounded like it was going to rattle apart. So changed to a T5. The T5 was better as it gave me the OD and things were a bit better. Still with that 3.73 and smaller tires it would just blow thru the gears. I was in second gear within feet all the time.
Then after more stress and blowing time and money I went to a 3.23 rear ratio but not the 3.08 that was recommended. The 3.08 would need a full new rear carrier and I just never wanted to dish out for that at the time. The new 3.23 made things better. I could almost clear an intersection without needing second and the highway cruising was better. I could do 62.5 in 5th at about 2200. I Put a cam in after that and that made the engine sound like it was happy all the time with no more struggling and ran much smoother. Drove it like this for the last summer of 2015 and a bit this year.
This all really bit me in the [censored] last week or so when I just finished doing a back yard rebuild on a 57 inline that was shot in a 57 belair for a guy. I got the engine running and even with almost no compression and other items in such bad shape this thing pulled like a son of a [censored] in second and nicely in third. This got me all going about ratios again so I sat down and messed around with numbers.
I always thought I was ok with my ratios and tire sizes but I was wrong. I was fed up of my rpm gauge looking like a window wiper and me always blowing past the torque curve and needing frequent shifts. I took the plunge on Friday morning and got some new rear rubber for the truck that was almost close to the 28" stock size. Came in at 27.75" actually. I'm happy now and wish I came to this result sooner. Its amazing how it changed everything. Now with the larger size and the additional load on the engine when accelerating it goes like snot. You can feel the inline actually working and not just rev shift, rev, shift, rev...... it's even quieter and smoother also as it has load behind it when accelerating. I have such a [censored] eating grin when I drive it now and I'm no longer ashamed of it anymore as I was before. I was always happy to tell others of the work I put into it but never 100% expressed how it really felt on the road, and never really drove it hard as it never would have impressed anyone.
Now that's what brought up the cruising rpm question post. Prior to the tire purchase 5th would put me in the 2200 rpm area at 62.5. I just noticed that I accidentally used the wrong rpms and speed noted in my first post. I was currently at 2200 at 62.5 and not 1800-1900. The 1800-1900 is where the new tires were going to put me. I was tired and in bed when I made the post.
Now with the new tires on I can confirm the 1800-1900 area is where I am at and it really made a difference on the engine in 5th. I can hold a steady speed in 5th at about 65 but it's very hard to accelerate and I know I'm not doing well having to hold the pedal as low as I am to keep it going. A quick shift to 4th and its back up to 2400rpm, and then I have no issue accelerating and going way faster. I'm now on the possible hunt to find out if I can see if another T5 5th finial ratio might better be better suited then the current .72 one that the T5 has installed. Or I just ignore 5ht and use it as a 4 speed? lol.
Sorry for the mile long post but I will stand here all embarrassed in the hopes that someone else might learn from my mistakes.
