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Rolling around unloaded daily driver style maybe just keep whatcha got. 3.73 right?
Pretty tall on those tires tho. Works fine just picking up a Jersey Mike's #9 giant size on white bread, extra onion, and Mike's Way. Chomped on the front patio while splashed with sunshine and Pinot Grigio. Wait, where am I?
But if cost no object then a gear reduction like 4:30 will keep it very driveable in daily traffic. 4:56 if top speed and/or MPGs are no concern. Or if towing heavy, that would help a lot.
Rolling around unloaded daily driver style maybe just keep whatcha got. 3.73 right?
Pretty tall on those tires tho. Works fine just picking up a Jersey Mike's #9 giant size on white bread, extra onion, and Mike's Way. Chomped on the front patio while splashed with sunshine and Pinot Grigio. Wait, where am I?
But if cost no object then a gear reduction like 4:30 will keep it very driveable in daily traffic. 4:56 if top speed and/or MPGs are no concern. Or if towing heavy, that would help a lot.
I’m not really knowledgeable on gears and I’ve seen a lot of people recommend 4:30 for 37’s. Right now it feels a bit slow. So I guess I would want a gear ratio that would make the truck move pretty fast but would also be good for daily driving
At the moment I drive the truck to go to the gym, run errands and drive to the city on the highway
I also have a 7.3L Excursion on 35’s and it feels pretty smooth. So going from the 35’s to the 37’s feels like a night and day difference
I’m not really knowledgeable on gears and I’ve seen a lot of people recommend 4:30 for 37’s. Right now it feels a bit slow. So I guess I would want a gear ratio that would make the truck move pretty fast but would also be good for daily driving
At the moment I drive the truck to go to the gym, run errands and drive to the city on the highway
I also have a 7.3L Excursion on 35’s and it feels pretty smooth. So going from the 35’s to the 37’s feels like a night and day difference
This is how the Excursion sits. Only a leveling kit on it and 18’ wheels
Plugged some comparisons in for you. Watch for ratio changes, mph changes, and tire size differences. The first column is always “stock” as I figured this would give a baseline back to the way it was designed. Pay attention to the differences in rpm.
Biggest thing to note is seeing a “night and day” difference between the vehicles with 35s and 37s leads me to questions other setup differences and potential issues like leaking uppipes. I imagine there would be a difference you can feel but that drastic of a change doesn’t seem supported by the “small” difference in rpm. Can you share setup differences between the two? How about looking for boost or uppipe leaks?
Plugged some comparisons in for you. Watch for ratio changes, mph changes, and tire size differences. The first column is always “stock” as I figured this would give a baseline back to the way it was designed. Pay attention to the differences in rpm.
Biggest thing to note is seeing a “night and day” difference between the vehicles with 35s and 37s leads me to questions other setup differences and potential issues like leaking uppipes. I imagine there would be a difference you can feel but that drastic of a change doesn’t seem supported by the “small” difference in rpm. Can you share setup differences between the two? How about looking for boost or uppipe leaks?
Stock, current setup, 4.30’s at 70mph
Stock, 4.30, 4.56 at 70mph
Stock, 4.30, 4.56 at 55mph
Stock, 4.30, 4.56 at 80mph
Stock, 35”, 37” at 70mph (compare Ex to F250)
Stock, 35”, 37” at 55mph (compare Ex to F250)
Thanks for the info! Here goes my set ups for both trucks. Another thing too that I have noticed since I have been driving the F-250 more this past week, I can’t build up more that’s 10lbs boost, even when hammering on the pedal
Excursion:
-Fully Stock
-6 position chip (DP-Tuner)
-Cold air intake
-4 inch exhaust
F-250:
-205/30cc injectors
-KC Turbo Stage 2
-Cold air intake / 5 inch exhaust
-KC Turbo Bellowed Up-pipes
-John Woods Valve Body
My opinion? This is killing you on the 37’s paired with 3.73’s. You need MORE rpm to make that turbo work. But your effective gear ratio has pushed the rpm way DOWN.
You will need to make some setup changes to make this work IMHO.
Does it have the .84 or 1.0 housing?
The boost aspect I responded to on your other thread. I think you need to get that sorted out first then revisit this.
This will provide the best driveability and MPG. 3.73 with 37’s is miserable and renders OD almost useless at legal highway speeds. The same truck will feel like a race car with 4.56 or 4.88’s and likely return better MPG. The transmission will be much happier as well.
3.73 with tires that big will be a laggy pig. Especially on the highway in OD the RPMs will be way too low for the engine to make any power. You could lock it out of OD or just leave it in 4th if it’s a ZF6 but then you’ve essentially only got a 3 or 4 speed transmission. I think 4.10 or 4.30 were options on 250/350 with 3.73 being the standard. Mines a 3.73 too and it sucks in tougher towing conditions even with stock(ish) sized rubber on the back. 7.3’s are already underpowered pigs at stock(ish) power levels by todays standards and not having the right tire and gearing on the back can make it even worse.
