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456's and rpms

P

projectTK

NAXJA Forum User
Location
Swantucky
I went to my mechanic that is going to setup the gears and rear true trac for me. I told him i wanted 456's and he said that is to deep for the streets your motor would be spinning to high on the streets. What rpm's use guys get going 60mph? 70mph? My jeep is going to be a daily driver only in the winter when it is shity out. Anywhere else will be local trails and trailered. 5spd b10peugot.

thanks
 
my 89 5sp(peuguot) with 31" tires and 4.10 is perfect for a DD, IMHO

if i had 33's, i would want 4.56 gearing
 
mine isnt a dd only in winter down country roads at 60mph. What is ur rpm at 60mph. thats what i plan to do is after the 31's wear out ill put 33's on.
 
AX-15 with 33s and 4.56 gears=2750 at 65mph. Keeps me in the torque band so I can actually pass in 5th. I am happy with the setup although it does like to drink the gas a bit more on the freeway but I think mileage is actually better on the streets. No numbers to prove it.
 
projectTK said:
31's for now
Click to expand...


Your RPMs will be high with that size tire. But you only want to do the gears once not twice so go for it. I have 456s and 32"s and love them.

Generally Mechanics that arnt into off-roading have that response of 'WOW thats way to low why would you ever want that.'
Just tell him to do it.
 
he has a full caged baracuda sitting in his garaged with a dana 60rear end. He is into dragging not offroad. So what would it be at 60mph 3000rpm's?
 
The 4 liter likes to spin a little fast more than it likes to work a little hard.. especially when its approaching 20 years old like yours.

I ran 4.56 and 32's, would sit just over 3,000 rpm's on the highway and got better than 20 mpg, in my 87.
 
projectTK said:
mine isnt a dd only in winter down country roads at 60mph. What is ur rpm at 60mph. thats what i plan to do is after the 31's wear out ill put 33's on.
Click to expand...

You'll love 4.56's....Even with 31's and a 5 speed....Especially if you only plan on doing 60 mph....definitely if you plan on larger tires.
 
sounds good thanks guys for your help i appreaciate. When i get the 456's and rear true trac done ill right a big review to maybe clear up questions like this and for gearing in generel. Thanks again
 
i get that response on occasion when talking to other mechanic friends. the problem often times is that they're running V8's and also not into offroading. one of my mechanic friends that gave me the same response about "wow that's gonna scream high rpms", was very impressed how clean it was with 4.56, 5-speed manual and 33's.

generally they're not used to the calculations of bigger tires, gearing and specially the nicer crawl ratio which alot of us go for with taller gears.

for 31's it'll be a little high, but nothing major. and then when you go to 33's it'll be perfect, and still "doable" with 35's.

i'm on 33 and going with 4.88's because i want the extra gearing in 4lo, and on the street it'll be fine/nice. and then i have the option of going with 35's if i ever want to.
 
projectTK said:
I went to my mechanic that is going to setup the gears and rear true trac for me. I told him i wanted 456's and he said that is to deep for the streets your motor would be spinning to high on the streets. What rpm's use guys get going 60mph? 70mph? My jeep is going to be a daily driver only in the winter when it is shity out. Anywhere else will be local trails and trailered. 5spd b10peugot.

thanks
Click to expand...

Get the 4.56 and don't even consider anything else. You will be fine running any size tire up to 35s. I'm an old guy, been wheeling for many years, I've never once heard anyone say they went too low, but I've heard lots of guys say they should have gone lower. Also, 4.56 is perfect for 33s, so there's your next goal.
 
Mike H. said:
I'm not sure where some of the numbers above are coming from.
I have ax-15 (same ratios as b10-'cept for 1st), 4.56's, and 31" tires.
In 5th (0.79:1);
2250rpm = 60mph
2500rpm = 65mph
2500rpm = 70mph

check out this site to play with gear ratios and such
http://www.grimmjeeper.com/gears.html
Click to expand...


Some AW4's (early models) are .70:1, later model AW4's are .75:1, and the ax15 is .79:1 ..

Not everyone uses the exact same speedo gear too. Some people may be a tooth off one way or the other based on different charts or calculators.
 
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