when it comes to final ratio, when is to low to low

i'm swapping in a toyota truck rear axle into my mighty max truck mainly for the mass after market avalible for the toyota rear ends. and my last decision is gearing. I can go from a modest 3.90 to a masively deep 5.71s. i know it all depends on your power out put and torque.

my motor seems to like the upper end more rather then trying to pull longer gears so lower gears you would think would be better. but with that you are shifting i would think a lot more.

I'm down to either running 4.88s or 5.29s. I just can't make my mind up on which one to do. I have looked at the numbers on a chart, but with out having the set in your car on stage it's still just numbers and means squat.

so what do you think, how low is to low?

---

"Rally racing makes a heroin addiction look like a vague craving for something salty"

what are your gear ratios?

http://www.fatboyraceworks.com/gears/

---

Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/

Jon Burke Wrote:
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> what are your gear ratios?

Hey those mean nuthin without knowing what the normal tire diameter.
Box is box and the spread from peak torque to peak HP generates the demands for the box ratios, but tire diameter and max safe continuous revs generates the final drive ratios.

So dude, what's tire diameter and max safe continuous rpms?


Note well: your truck first gear ratio is probably somewhere around 4:1, almost anything you do will make first silly short.
Can you train yourself to skip 1st?
That will allow you to consider ratios like 5.29

Comprende muchacho?


>
>
>
> Jon Burke - KI6LSW
> Blog:
> 'Holy Shit!' @ 4:10

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

john vanlandingham Wrote:
-------------------------------------------------------
> Jon Burke Wrote:
> --------------------------------------------------
> -----
> > what are your gear ratios?
>
> Hey those mean nuthin without knowing what the
> normal tire diameter.
> Box is box and the spread from peak torque to peak
> HP generates the demands for the box ratios, but
> tire diameter and max safe continuous revs
> generates the final drive ratios.
>
> So dude, what's tire diameter and max safe
> continuous rpms?
>
>
> John Vanlandingham
> Sleezattle, WA, USA
>
> Vive le Prole-le-ralliat
>
> www.jvab.f4.ca


did you click my link!!?? doooood, it asks for the tire size and max rpms!!

its a cool little calcumatator-simulator.....not like driving around, but will tell you max speed in each gear, and I just like the visualness of it, no guessing.

---

Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/

Jon Burke Wrote:
-------------------------------------------------------
> john vanlandingham Wrote:
> --------------------------------------------------
> -----
> > Jon Burke Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > what are your gear ratios?
> >
> > Hey those mean nuthin without knowing what
> the
> > normal tire diameter.
> > Box is box and the spread from peak torque to
> peak
> > HP generates the demands for the box ratios,
> but
> > tire diameter and max safe continuous revs
> > generates the final drive ratios.
> >
> > So dude, what's tire diameter and max safe
> > continuous rpms?
> >
> >
> > John Vanlandingham
> > Sleezattle, WA, USA
> >
> > Vive le Prole-le-ralliat
> >
> > www.jvab.f4.ca
>
>
> did you click my link!!?? doooood, it asks for
> the tire size and max rpms!!

I don't know his tire size of final drive or max safe rpm, he does.
I know gearing.
>
> its a cool little calcumatator-simulator.....not
> like driving around, but will tell you max speed
> in each gear, and I just like the visualness of
> it, no guessing.

except I can't guess those factors above.
>
>
>
>
> Jon Burke - KI6LSW
> Blog:
> 'Holy Shit!' @ 4:10

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

yeah i figure that would help in getting peoples help, giving all the info

3.369
2.035
1.36
1
0.856

i'm running a 215/75 15 it's 27.7" tall.

as for rpm redline is 6000, but i'm not always a fan of spinning that on every shift.

ok now discuss

also i'm not putting any kind of crazy power

the truck was rated at

116hp @ 5000rpm
136tq @ 3500rpm

now after talking to a couple owners of the truck through out the years they tell me of cam regrinds and head porting and milled heads. so power would be a little more, just not tons. and unlike most truck motors this one seems to like the upper rpms, which i'm figuring is the regrind helping that.

---

"Rally racing makes a heroin addiction look like a vague craving for something salty"



Edited 1 time(s). Last edit at 11/06/2008 09:18AM by mellow65.

Whoa what a BEEE-ZARRE graph.

Only been looking at speed vs rpm charts for oh lemme think, FORTYFIVE FUCKING YEARS! and never seen a chart without rpm on one scale.
Speed on one axis, and generally thats the Up/down axis and rpm on the horisontal axis.

The GEARS are obvious on any chart I've seen from Seattle to Chehgdu to Abisko:
the first trace nearest to the O starting point is probably a safe guess that it's first gear, the one next to it probably second gear etc.

Whew, it's bad enough that everybody under 40 says "Yeah I want to put in a 4.44 cause my 3.36 is too short and I want a higher gear"



Whew!!!

Anyway, I plugged in 4.88 and 5.3 and looks like realistically 4.88 might be as short as you'd want to go.

That "Mighty Max" is a Misterbitchy 2,6 iddnit? 91,1mm bore, 98mm stroke?
Fuel infected?

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Spend the time and money on a dyno pull. Once you have real peak power and torque values you can do the math accurately. The calculations will give you gear ratio spacing and over all final drive ratio (top speed).

Check out this site: http://www.wallaceracing.com/Calculators.htm

The dyno is the cheapest way to get the data you need to determine what gear rations and spacing you need. Be warned, competition gearing sucks for a daily driver!

Good luck, Robert.

---

Robert.

"You are way too normal to be on Rally Anarchy." Eddie Fiorelli.

so help me understand better how one would choose proper gearing based on your dyno...

so right now, on my street car, I have a long, flat torque/hp curve all the way from 3000rpms to 7000rpms (safe redline)...so my stock, long, WRX gearing and final drive is pretty good for that. If I wanted to get more agressive, I could go with a close-ratio gear set with slightly shorter gears, or keep the same gears and get a 4.44 (whatever) final drive...

BUT, with a restrictor, HP will drop off severely after 5200 rpms....power range from 3000 to 5200 rpms...(blah, blah, we all know that)

so for that, I would want the 4.44 final drive AND shorter gears, yes? but how short? What top speed should I be at in 1st, 2nd, 3rd, etc at 5200 rpms? (optimally...or at this point is it simply driver preference and style?)


nothing I'm worrying about at all, just wanted to see for discussion sake.

---

Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/

john vanlandingham Wrote:
-------------------------------------------------------

> Anyway, I plugged in 4.88 and 5.3 and looks like
> realistically 4.88 might be as short as you'd want
> to go.
>
> That "Mighty Max" is a Misterbitchy 2,6 iddnit?
> 91,1mm bore, 98mm stroke?
> Fuel infected?
>
> John Vanlandingham
> Sleezattle, WA, USA
>
> Vive le Prole-le-ralliat
>
> www.jvab.f4.ca

86.5 mm bore and 100 mm stroke 2.4 fuel infected

and the 4.88s was what i was thinking of putting in, but that's why i was asking about just going balls out and going even lower.

---

"Rally racing makes a heroin addiction look like a vague craving for something salty"

Hey there, I am by no means the expert, but...

when deciding how low is too low, figure out what your top speed will be at redline in top gear, but also figure out something reasonable for transits. You don't want to end up turning over 4000 rpm just to do a little highway driving. maybe plan on not using 5th on stage and go for a slightly higher ring and pinion. Then you don't have to shift as much. I dunno...


-Al

4.88 gives you a setup a tad shorter than mine and I'm clocking around 4k to keep with freeway traffic. Shifts drop between 1k and 1.5k between gears.

Out of curiosity, you running a Starion gear box?

-Eric

---

KK6EAR



Edited 1 time(s). Last edit at 11/06/2008 09:29PM by RallySol.

nope running the stock truck tranny, which from what i have found is the same gearing as the starion.

---

"Rally racing makes a heroin addiction look like a vague craving for something salty"

Jon Burke Wrote:
-------------------------------------------------------
> so help me understand better how one would choose
> proper gearing based on your dyno...
>
> so right now, on my street car, I have a long,
> flat torque/hp curve all the way from 3000rpms to
> 7000rpms (safe redline)...so my stock, long, WRX
> gearing and final drive is pretty good for that.
> If I wanted to get more agressive, I could go with
> a close-ratio gear set with slightly shorter
> gears, or keep the same gears and get a 4.44
> (whatever) final drive...
>
> BUT, with a restrictor, HP will drop off severely
> after 5200 rpms....power range from 3000 to 5200
> rpms...(blah, blah, we all know that)
>
> so for that, I would want the 4.44 final drive AND
> shorter gears, yes? but how short? What top speed
> should I be at in 1st, 2nd, 3rd, etc at 5200 rpms?
> (optimally...or at this point is it simply driver
> preference and style?)
>
>
> nothing I'm worrying about at all, just wanted to
> see for discussion sake.
>
> Jon Burke - KI6LSW
> Blog:
> 'Holy Shit!' @ 4:10



Well since I have the 4.44 FD and short gears (well RA short gears which arent THAT short) I can tell you. I'm making alot of power so first is a bit of a PITA. I can't grab second before the revs are screaming to redline. I'm getting power WELL before 3k rpm (with properly sized turbo) and with head work I KNOW I'm making power signifigantly beyond 5200 rpm.


Edit: I know I'm making enough power that I don't NEED short gears but I don't NEED alot of things I have but I can still WANT them.

---

Gone fishing



Edited 1 time(s). Last edit at 11/07/2008 12:35AM by david amor.

alkun Wrote:
-------------------------------------------------------
> Hey there, I am by no means the expert, but...

Wells I's an Ex-spurt!
And my car takes 4333 rpm for 65mph.
105mph top speed at 7100.
>
> when deciding how low is too low, figure out what
> your top speed will be at redline in top gear, but
> also figure out something reasonable for transits.
> You don't want to end up turning over 4000 rpm
> just to do a little highway driving. maybe plan on
> not using 5th on stage and go for a slightly
> higher ring and pinion. Then you don't have to
> shift as much. I dunno...
>
>
> -Al
>

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.