Hi all,
looking for a little advise regarding my scrambler and gearing. I am running the stock T5, dana 300, and original 2.73 gearing. I'm now running 255/75-17 tires which makes them 32" but only 10" wide. The engine is rebuilt 4.2 running a 4.0L head, borla header, clifford intake, HEI ignition, and Howell TBI.
I live in Northern Virginia so the jeep will be used for mostly flat driving, with occasional runs out into VA, WVA, PA, and NC mountains. With this setup, the jeep runs right at 2000 RPM in 5th gear and 75mph. It has absolutely no difficulty getting there and maintaining that with my foot only 1/3 on the throttle. I have yet to get it out on mountain passes but the inclines I've experienced so far have not required any downshifting to maintain speed Means 1733 RPM for 65mph with no issues either. Considering stock 235/75-15 tires, it would run approximately 400 RPM faster across the board if I had stockers on...but it would also be running a stock engine, which as I recall, performed ok in similar situations.
Anyway, I don't believe I am lugging this engine geared this way. And it doesn't appear to need more power/revs to get to my desired speed in any situation. However, I've read on so many forums about changing out the gears to 3.73 for this setup which would raise my rpm's to 2700 at 75mph or 2340 at 65 in 5th gear. I"m not sure why I would do that, but this seems to be a theme...up the gear ratio as you get bigger tires...however, I have now provided significantly more power and torque to move them. Again, this is a 95% street scrambler...the only time this will be offroad is on mild groomed gravel roads, the beach, scenic offroading.
Can you lend me your thoughts regarding the gearing here? Am I missing something or any reason why I should bother regearing this?
looking for a little advise regarding my scrambler and gearing. I am running the stock T5, dana 300, and original 2.73 gearing. I'm now running 255/75-17 tires which makes them 32" but only 10" wide. The engine is rebuilt 4.2 running a 4.0L head, borla header, clifford intake, HEI ignition, and Howell TBI.
I live in Northern Virginia so the jeep will be used for mostly flat driving, with occasional runs out into VA, WVA, PA, and NC mountains. With this setup, the jeep runs right at 2000 RPM in 5th gear and 75mph. It has absolutely no difficulty getting there and maintaining that with my foot only 1/3 on the throttle. I have yet to get it out on mountain passes but the inclines I've experienced so far have not required any downshifting to maintain speed Means 1733 RPM for 65mph with no issues either. Considering stock 235/75-15 tires, it would run approximately 400 RPM faster across the board if I had stockers on...but it would also be running a stock engine, which as I recall, performed ok in similar situations.
Anyway, I don't believe I am lugging this engine geared this way. And it doesn't appear to need more power/revs to get to my desired speed in any situation. However, I've read on so many forums about changing out the gears to 3.73 for this setup which would raise my rpm's to 2700 at 75mph or 2340 at 65 in 5th gear. I"m not sure why I would do that, but this seems to be a theme...up the gear ratio as you get bigger tires...however, I have now provided significantly more power and torque to move them. Again, this is a 95% street scrambler...the only time this will be offroad is on mild groomed gravel roads, the beach, scenic offroading.
Can you lend me your thoughts regarding the gearing here? Am I missing something or any reason why I should bother regearing this?