this sunday i plan to get in maybe 2 runs at the import v. domestic event @ MIR. i've never dragged on a dragstrip before, but i have launched successfully on more than one occasion.

i just got a cryoed 4.77 put in my diff last friday, but i am the 3rd owner of the gear. i'm sure the gear has been broken in.

my questions are:

1) would launching with the 4.77 in my stock, NOT reinforced AP1 diff pose a threat to the diff or anything else?

and

2) should i wait 1,000 miles then change out the diff fluid, even though the gear is not brand new?


side note: i have bridgestone potenza RE-01Rs. would i be more likely to break the diff with these tires because they're supposed to have mad grip? i haven't launched on these tires yet, but they are broken in. i have maybe 800 miles on them.


thank you!

 

first

 

pwned!

 

first bamma to post nothing

 

Nightcrawler, you probably know as well as anyone that it's mostly just a matter of how (and where) you launch the car. You have to evaluate the available grip and take that into consideration when you decide how you're going to launch, and if you get it wrong, you can break things. Some drag strips deliver a heck of a lot of grip even with S02's, so if you're going to try to break the tires loose, be careful. DO NOT go through the burnout box, and give the differential time to cool down between lanuches. Our diffs get very hot, very quickly, and repeatedly launching the car without letting the diff cool is asking for trouble.

If it were me, I'd want to get some miles on the new gears just to be sure everything was up to snuff before taking the car to the strip, but that's just me being paranoid.

Do be careful. I don't want to see you brandishing a Pawned Diff badge.

 

thanks Red, for some useful tips

i shouldn't go through the 'burnout box' because then i'll have more off the line traction, where i would REALLY want to break the tires loose, correct?

also i'd do one, MAYBE two runs. the gear whines a bit, but other than that everything feels solid, and after almost a week i've run in to no problems driving it in the cold, hot, (it changes VERY QUICK around here) traffic, highway, and twisty backroads.

i was just wondering if having a 4.77, or any other upgraded gear for that matter, would increase the risk of damaging something.


thanks again, Red!

 

Kinda off the subject a bit but how much for just some 4.77 gears not installed. (Just gears.)

 

^^300-400, add $100 for cryo treating and $100 for yellow box from rick's. most places charge ~$500 for the install but i found a place that installs it AND drops/reinstalls diff all for $285

 

Yea, avoid the burnout box, because you can pick up stuff on your tires that will give you way more grip than you'd normally get, so just avoid it altogether. The lower gearing (higher numerically) will deliver more torque to the rear CV joints, but the diff is sill going to be the weakest link. Even with the Comptech reinforcement the diff can still take a dump (just ask CKit), so it's best not to launch hard unless you're willing to buy a new diff if things go badly. LOL, I don't want to discourage you, because to get a decent time you have to launch hard, but you do need to take the risks seriously, especially if the cost of a new diff would be a burden. Better safe than sorry.

 

THANKS--i might just not do it...

but when i launched on the street i held it at about 6500 then popped the clutch and it smoothly but very swiftly lunged forward. the tires chirped but there was no slide at all (and this was on my Potenza RE960AS Pole Position all seasons). man i'm getting scared now...