4.10 gear question...

[Darrin]

Ok....brother is putting in 4.10 gears. It's a '88 lx 5.0 with 225, 60-15 tires and an AOD trans. He want's to know if anyone has this setup because he wants to know when he crosses the 1/4 mile mark if it will still be in 3rd or is he gonna have to go to OD. Thanx

 

[Darkwriter77]

NEVER shift into OD when you're jamming it on down the 1/4-mile. Good way to destroy the OD band, even in a beefed-up AOD. Keep it in OD-lockout no matter what - if you run outta gear before the end of the 1320, try running a taller set of tires in the rear.

He should be fine with 4.10's in an AOD if he's running a stock H/C/I car. It's not likely at all that he'll top out 3rd gear before the end with full weight and stock power in an AOD Fox. If he's stripped the thing down to the bare nubbins and thrown every bolt-on possible on there, again, you might want to look at taller tires first (maybe DR's, coupled with a higher-stall converter) before stepping down to something like 3.73's, but otherwise 4.10's are plenty fun n' good for an AOD.

 

[talladam]

In my car I'm in 4th gear around 4500rpm with a 4.10 245/50/16's and a t5.

246rwhp and 276rwtq

 

[cenok is family]

In my car I'm in 4th gear around 4500rpm with a 4.10 245/50/16's and a t5.

246rwhp and 276rwtq

man, you've got a really similar setup to mine. i put down 229rwhp and 278rwtq with a 10.0:1 a/f. i just changed my injectors back down to 19#er's so hopefully that fixed my a/f and freed up some power.

 

[SVT32VDOHC]

It will go into OD, but not on its own...you will have to back of the gas. My 91 AOD car would NOT shift into OD under WOT...pist me off!!

 

[dls322]

In my car I'm in 4th gear around 4500rpm with a 4.10 245/50/16's and a t5.

246rwhp and 276rwtq

Hmmmm, in the 1/4 i'm at like the point where i basically have to shift to 5th....It's either ride the gear out past the point where it's amking power or take the shift to 5th.....wish mine was at 4500.

 

[PJB]

In my car I'm in 4th gear around 4500rpm with a 4.10 245/50/16's and a t5.

246rwhp and 276rwtq

How is driving your car on the street with a 5 speed and 4.10's?

Ive currently got 4.10's and an AOD but Im swapping to a T5 soon.

 

[Fox8950]

It will go into OD, but not on its own...you will have to back of the gas. My 91 AOD car would NOT shift into OD under WOT...pist me off!!

Heh well you can make em shift into OD at WOT with most shift kits but you'll only do it a couple times before it smokes the OD band .. OD is for cruising ONLY and most people that build performance AODs tell you to not even shift it into the OD slot until your at cruise speeds. Currently running 4.10s in my AOD here and its a bit much for me but I do alot more interstate driving than racing, am also running a st of 17s w/ z rated tires as well so that don't help either.

 

[RYC CUKR]

my 93 AOD car runs 12.72@109 with a 255/50/16 tire and it is getting close to being out of gear but its not quite there yet. He should be fine with the 4.10s.

 

[talladam]

yeah the power i made was prior to the 65mm tb and tweecer, 65 tb broke a bolt for the tps so i put an 80mm bbk race one on. hell the air filter was dirty on that dyno pass, never though to check it.

4.10's on the street are badass. 1st gear is about useless, i shift before getting through most intersections. kinda cool to roll really slow about 5mph and stab on it, cooks tires then! i think 65mph equals about 2350rpm in 5th. the car is a killer on the freeway, drop into 3rd at 65, stab, grab 4th. the nicest thing is that the car doesn't lug like it used to when it had 3.08 gears.

i had some 24v taurus asking for it a few weeks ago, dude was on my ass in and out of the other lane. he got on my ass and we both punched it from 60mph. i walked away hard until i let up at 120. probably had him by 4 or 5 car lengths if i had to guess. i know i know, no street racing. that mf'r had it coming though. you dont' roll up to taunt me. hell i passed a cop on the way to work last week, guess he shouldn't of been goin 10mph under the limit.

adam

 

[TRWXXA]

my 93 AOD car runs 12.72@109 with a 255/50/16 tire and it is getting close to being out of gear but its not quite there yet. He should be fine with the 4.10s.

I'd say you're pretty close to topping out 3rd. 110 mph is about all you'll get with 4.10s and those tires. With the 225/60/15s, it's about 107 mph.

 

[RYC CUKR]

Yeah its close I might have just a bit more in it.

My window switch shuts the nitrous off at 5800 and it pretty much falls on its face just after I cross the traps so I know I am at least turning 5800 rpm.

A little bit taller tire would probably help out some with keeping it in the powerband a little longer.

 

[talladam]

and to think i almost put a 3.73 in my car until my brother talked me into a 4.10. i generally try to reason with him, seeing how he built a 13.5 to 1 302 a few years back.

 

[ninety15.0]

In my car I'm in 4th gear around 4500rpm with a 4.10 245/50/16's and a t5.

246rwhp and 276rwtq

This information is not correct by my calculations. If you use a gear ratio or rpm calculator it will show you your exact rpm for a given speed.

In 4th gear your tranny is at 1:1 with a T-5 or an AOD...and the stock tire size is 25.744". Adam you tire size is slightly SMALLER at 25.645".

I dont know what your trap speed is but based on your HP and TQ numbers you should be running at least 100mph.

At 100 mph with 4.10's and your tire size you ARE turning 5370 rpm. This is math and must be correct. Your tach is probably off...the stock tach's are horrible to say the least. What does the tweecer tell you your rpm is going through the traps?

 

[Fox8950]

Why the heck would a 5 speed go 1:1 in 4th gear?

 

[ninety15.0]

well because thats what the 4th gear tranny ratio IS in a t-5! just the facts bro...

The 1:1 gear in an AOD is 3rd gear. This is why you do all your dyno pulls in 4th gear in a stick car...b/c there are no torque multiplication factors...engine speed equals output shaft speed.

 

[Fox8950]

Ah sorry for the confusion, I wasn't saying you were wrong or anything but when you said "In 4th gear your tranny is at 1:1 with a T-5 OR an AOD" it threw me off.

 

[DREAMZOFHIRPM]

do not,,do not go into od while ripping down the 1/4.. like dark.. said its a great way to blow your o/d band... even my lentech,,, good for 1000 horse states.."od must be locked out when full racing"..... you wanna keep it locked out ...usually it wont go into o/d when under full throttle... but forget about od and the 1/4 in the same sentence

 

[talladam]

I don't recall for sure what the tach on my shift light read and the tweecer wasn't in the car at the time.

I've had the car 115 in fourth and shifted into 5th soon after that. If my brain can recall correctly, I shift into 5th at 5700 when the shift light comes on and speedo reads 119-120mph. The speedo is 1mph too fast according to the tweecer. I know the calculations are a ballpark and can vary in the real world based on revs per mile on the tire, speedo drive gear wear, etc.

Adam

 

[lang williams]

this has me thinkin of getting 390's instead of 410's.....the car currently has 456's in it an 28" 275/60/15 dr's