8.8 3.55 to 4.10 Gas Mileage

[4.0B2]

what's your plans for the truck, seriously?
leave it as it w/ lower gears? larger tires? lift? lowered? drag?

 

[GoGoggansGo]

I have 4.10s and 225/70 R15s on my truck and at 65-70 I'm right around 3K... That's higher than you want to be with a 4.0.

With a 4.0 and 4.10s you're set up for 31s.

I do have 14 inch rims though this truck is a really a daily driver/ car show driver, not a highway cruiser so in someway the high RPM dosen't bother mean and at 70 I am right around 2300-2450 don't quote me. My master tech at school said most of the time in the swap I am doing it will jump 150 to 200 RPM. Hell I have no idea, and as far as I can tell this swap will be interesting

 

[GoGoggansGo]

what's your plans for the truck, seriously?
leave it as it w/ lower gears? larger tires? lift? lowered? drag?

street/ maybe strip

 

[Gotta_gofast]

(2400/3.73)4.10 = 2638rpm

 

[GoGoggansGo]

(2400/3.73)4.10 = 2638rpm

you sir are right on target thanks for the help

 

[Sunk]

You have 14 inch rims, so you tires are even smaller. That means at the same speed your RPMs will be higher.

Let's do some math.

4.10-3.55= .55.

3.55/.55= 6.454

100/6.454= 15.49% difference between gearsets.

Let's say that you're right when you said 2300-2450 RPM at 70.

2450x1.1549= 2829 RPM with 4.10s

 

[GoGoggansGo]

I'm suprised you don't have a hard time with traction now with them small tires. My truck with the larger tires and a rear locker lights em up effortlessly.

But basically first and second will feel strong, but as you approach the right side of your tachometer in any gear (which will come quicker with deeper gears) the truck will get less exciting. The 4.0L OHV makes a great motor for towing and offroading where the motor spends most of its time below 3000rpm. Most guys who look to improve the truck to "go faster" will swap to an entirely different drivetrain because the 4.0L just doesn't cut it.

In its simplest form, you are gaining a lot of acceleration down low at the expense of top speed and fuel mileage. You might find with the 4.10s that a better set of tires will be required. A wider tire on a 15" rim will regain that traction to launch.

On very slick surfaces like a parking lost drag strip she rips them up easy, but on tarmack hell no I do have hankook that are sticky so that dosen't help either. In some ways I can't figure it out either thats one reason why I want 4.10s

 

[Gotta_gofast]

street/ maybe strip

If you really want to hit the strip, you are honestly wasting your money on the 4.0L OHV. If you are patient, you can source out all the required parts to swap in a small block ford v8. I've seen dyno charts of 4.0 OHV engines running 8psi supercharged with ported heads and comp cams 422 camshaft and supporting mods make just over 200hp (but made over 300rwtq). A mild 302 with GT40 iron heads and a mild cam backed by a c4 auto will easily make 275-300hp with room to grow. When I swapped in a V8 in my old 93, I ran a carburetor for ease of tuning and cost. Every dollar spent was researched and stretched to go as fast as I could.

Its all about being honest with yourself and your goals. The 421 banshee you see in my avatar took a whole year to build (all by myself). The results are impressive, but they only come after an immense amount of hours researching and patience during assembly (and a few brewskis to calm the nerves).

 

[GoGoggansGo]

You have 14 inch rims, so you tires are even smaller. That means at the same speed your RPMs will be higher.

Let's do some math.

4.10-3.55= .55.

3.55/.55= 6.454

100/6.454= 15.49% difference between gearsets.

Let's say that you're right when you said 2300-2450 RPM at 70.

2450x1.1549= 2829 RPM with 4.10s

correct, and yes the mileage will go down somewhat, but from what I have heard the performance change in the truck is worth it. Thanks for the info

 

[GoGoggansGo]

If you really want to hit the strip, you are honestly wasting your money on the 4.0L OHV. If you are patient, you can source out all the required parts to swap in a small block ford v8. I've seen dyno charts of 4.0 OHV engines running 8psi supercharged with ported heads and comp cams 422 camshaft and supporting mods make just over 200hp (but made over 300rwtq). A mild 302 with GT40 iron heads and a mild cam backed by a c4 auto will easily make 275-300hp with room to grow. When I swapped in a V8 in my old 93, I ran a carburetor for ease of tuning and cost. Every dollar spent was researched and stretched to go as fast as I could.

Its all about being honest with yourself and your goals. The 421 banshee you see in my avatar took a whole year to build (all by myself). The results are impressive, but they only come after an immense amount of hours researching and patience during assembly (and a few brewskis to calm the nerves).

Hell I know the only reason the 4.0 is still hear is because this was my father truck, and it's been in the family since 92, and that alone is the only to keep the stock motor. It might not be stock anymore, but hell my dad name is on the damn block. He was at Chicago Stamping Plant for 32 years.

 

[4.0B2]

didn't i send you that grimjeeper calculator sight in a different thread? that site is good stuff for figuring out speed at RPMS.

http://www.grimmjeeper.com/gears.html

 

[GoGoggansGo]

didn't i send you that grimjeeper calculator sight in a different thread? that site is good stuff for figuring out speed at RPMS.

http://www.grimmjeeper.com/gears.html

wow cool thanks

 

[Gotta_gofast]

So pull the motor, clean/polish it up and put it on display in the garage. lol this WAS your father's truck. Its in your name, in your garage, and that means its your decisions. My wife purchased a car from her parents last year and they tried telling her what can/cannot be done. I picked up a second set of wheels and mounted some winter tires for her to use in the snow. They told me the tires weren't rated for the same speed as her factory tires.... she's not going to exceed 100mph ever, let alone in the snow lol. As long as the car sits in my name and my garage and I do the maintenance its my decision.

 

[4.0B2]

wow cool thanks

enter your stock info on one side, enter what you want on the other side... and compare.

 

[GoGoggansGo]

So pull the motor, clean/polish it up and put it on display in the garage. lol this WAS your father's truck. Its in your name, in your garage, and that means its your decisions. My wife purchased a car from her parents last year and they tried telling her what can/cannot be done. I picked up a second set of wheels and mounted some winter tires for her to use in the snow. They told me the tires weren't rated for the same speed as her factory tires.... she's not going to exceed 100mph ever, let alone in the snow lol. As long as the car sits in my name and my garage and I do the maintenance its my decision.

That old girl dosen't have any rust on the body the frame is OK I need for coat it real soon. I love this motor though it sounds like nothing else, and ur right if see ever dies, and I will pull her out and use the block as some type of display. I have been looking at higher gear for a while, and I am going to do them. On the ranger militia they couldn't believe that it was my fathers and heres the real kicker. I have the windows sticker she got some bad dents I would love to get rid of, and that means a new paint job