JoeD

now we all know shorter final drive gearing (take the J's 4.44 gears for example) dramatically improve standing-start acceleration. but what about highway acceleration, like 60-120...or 80-150? i have heard different things from different people. some say shorter final drive gears will improve highway acceleration, some say it will not. are stock gears or 4.44 gears better for highway acceleration?

thanks.

sfphinkterMC

in gear acceleration is better everywhere.......acceleration at higher speed is always slower. in all cars...aero drag predominantly i believe. how many cars can spin the tires accelerating at 90mph??

i don't have higher gears. if u want buy some cheap kuhmo ecsta
205/215/225-40's....they are about $85 and will mount on stock rims, will lower car 1.5in, give 10% increased diff effective gearing
and look cooler with a teeny low profile appearance. i did it in past
and it was fun.....i'll try to post a pic later on this thread.

oh, your speedo will read high as well

Schatten

and don't forget... putting in the larger gear from the stock 4.1 to a 4.44 will also decrease that top end. so its doubtful that you'll see 150.

sfphinkterMC

not so, you will still "SEE" 150 on your speedo......u will just be going slower(vis a vee speedometer error w/o correction).
sorry, trying to be humorous.
its a disease.....REFLEX IRONY......i read it about it in the book "Generation X" and realized i got it.

SLD2000

How much top speed will be sacrifice with the J's 4.44??

JoeD

i used the top speed calculators, and with 4.44 gears in 6th at 9000 RPM, it will top out at around 155...if i remember correctly.

but that is beyond the point....

how will 4.44 gears effect highway acceleration?? take 60-120 for example. faster or slower with 4.44 gears compared to stock??

JoeD

?

dhess

I think that 4.44 would improve acceleration from a high speed roll as well.

I'm not sure if this is correct but here goes...

With 4.44 gears you are going to spend less time in each gear meaning that for a given period of time you are going to spend more time at peak power.

Also you will always be at higher RPM's at the same speed compared to the stock gears, and s2000 make asignificantly more power at higher RPM's.

wake88

This is my reply from a previous thread on the subject:


quote:
--------------------------------------------------------------------------------
Originally posted by PA S2000
I'll have to agree with you WAKE88 on not being a fan of hard launches but I suppose hard into second could hurt too. Also as far as loss of top-end I am not concerned myself but as far as I understand the stock ECU rev-limits 6th to top out at 145mph. This mean with gears (4.44) you would actually be doing 134. Aside from that as this is a GB thread. Any word on how many are in for the rear gears? Matt.
--------------------------------------------------------------------------------



Matt, there is no ecu speed limiter. Someone has hit 175mph before and it's proven on a video somewhere on this site. The true speed with speedo error corrected was probably about 170. So 6th gear tops out at 170 and therefore, with a gear change to 4.44, 6th would top out at about 157.

These calculations assume a true top speed of 170 stock at the rev limiter.

stock - 170
4.3 - 162
4.44 - 157
4.77 - 146



I've only ever been up to 148 (top down ) so I'm not concerned with dropping the top speed from 170 to 157.

wake88

Acceleration times would improve for any speed gap (40-80, 60-120) assuming the same amount of shifts would be required for the run. Remember, with higher gearing, there is more shifting involed period. You won't be able to get first gear to 40 mph anymore. The mph would be lower respective to the final gear ratio you get installed. So a run from 0-90 would then require you to shift into 4th whereas a stock S2K would be able to hit it in 3rd. To sum up, even if an extra shift is required, the acceleration should easily make up the time it takes you to put it in the extra gear. Only if you have decent shifts though These are all approximations and opinions btw, so take it with a grain of salt.

Steve