3.73 gears are now in

[mrr23]

the black formula. i was asked if i wanted to do some more testing for the company i did the 4.10 tests for through vinci high performance. well, i couldn't pass up the opportunity to try a different ratio. i'll be dynoing and swapping out about 6 sets of 3.73 gears. all from different manufacturers. the company that wants the wear testing done, does a special processing to the gears. that's why they want dyno and wear testing done. they want about 500 miles on them. and try to do the swap at the rate of once a week. 6 gear sets in 6 weeks. and 3000 miles in total. here's some pics i took while doing the swap today.
http://www.stealthram.com/gearswap.htm

[BlackHawk T/A]

Are they paying for all your gas? Wow...

And how are gears going to show much wear after only 500 miles? You better put them through hell...ask them for some sticky tires too...

[mrr23]

yes. paying for gas and time driving. i get to keep the last set of gears.

[mrr23]

update. on the 4th gear set. got to finish up by nov 30th. gears will be on display at PRI on dec 1-3.

[artchvz]

what should i go with on my 99 camaro 3.73 or 4.10. I really don't want to change my 17" SS Rims on stock tires.

[mrr23]

auto = 3.73
manual = 4.10

[artchvz]

Thanks mrr23? are motive gears a good brand to go with?

[mrr23]

they are a good brand. i have AAM in both cars now.

[artchvz]

thanks

[hammertime]

mrr23,

Having done dyno tests on the gears, is there a difference in rwhp between two different ratios? I thought the dyno operator was supposed to key in the correct ratio to get the number calculated right.

I've seen people say that higher numeric gears will make your car gain/lose power. I understand the difference in the amount of power it takes to turn a 9" or 12-bolt.

Just curious, if thats something that they let you know about...

Thanks!

[mrr23]

you do not input gear ratio on a dynojet. it calulates that via rpm/mph. you'll notice on a dynojet dyno sheet in the comments section rpm/mph = xxxx on a mustang dyno, you input gear ratio.

here's my post i did about power loss/gains from swapping gears
http://www.ls1.com/forums/showthread.php?p=6281#post6281

[hammertime]

That link kept taking me back to this thread...

I think I found what you were refering to though:
http://www.ls1.com/forums/showpost.php?p=6281&postcount=1

Good info!

[mrr23]

fixed.

now, i'll add the last syno where i went from 4.10 to 3.73
http://www.stealthram.com/familypics/formula00/dynosheet/373gearprocessed.jpg

[artchvz]

So if im reading this right you got more power and torque from the 3.73 vs the 4.10

[mrr23]

yep. but, will it get me quicker down the track???? haven't taken the black car out since the 3.73 swap due to trans issues still. that's coming real soon. on the bottle, i had to go into 4th gear to finish the run about 60 ft before the end. which, i think, is why my mph is so much lower compared to the wife's car. 117.67 vs 120.96. usually, the black car is 2 mph less given the same et.

[hammertime]

:lol: I can see it now. People will be rushing to get 2.73's in their car so they can claim to have a factory freak.:slap:

Good info though, interesting to see the relationship between measured HP and gearing.