Just Finished My 410 Gear Install

rockyracoon

10 Year Member
Nov 23, 2005
874
27
49
margate NJ
Well like the sub line says I just got done installing my 410 gears and trac loc rebuild and quite frankly im a little let down, I mean the install is fine no whine whatsoever but the car doesn't seem to be a lot different in terms of performance. It does sound a lot meaner but it just seems like it makes a lot of noise but doesn't really go anywhere. I dunno I haven't really layed into it in leiu of proper break in although I can kinda tell its not a major difference from the 327s that were it there. could it be that the trac loc is a little too tight ? I went with the 0.45 shim figuring the tighter the better. Or do I at this point just need a tune ?
 
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Remember, you're not making any more power to the rear wheels with this mod.

As well, you're going to be spinning 25% higher on the tach now. It will take some getting used to but I suspect you'll end up digging those gears. You'll probably also come to think of 1st gear as optional...
 
Yeah that kind of mod is referred to as a SOTP (seat of the pants mod). Like Trinity said,
you're not gaining horse power. Its just a mod you'll feel a bit in the seat. I had 4.10s in
my automatic 98 GT and I felt a bigger difference when I installed 3.73's in my manual
2002 GT. So not sure if you're trans has anything to do with it.

Congrats on the mod install though. Its good that you don't have any gear whine. Its a pain
to deal with fixing that issue if the install goes poorly. I think you'll end up liking your mod!
 
It's hard to feel improvements sometimes. Sometimes if you do a mod, go for a drive but its 100 degree and humid out and the last time you drove it it was 60 you might not feel a lot of difference. Engines make a range of power that is depended on many things. You are overall faster, just might not have noticed yet.
 
I also picked up around .1 in worse weather. Correcting for weather, it picked up around .25 seconds.

Of course, this will vary for any given setup. But gears make you faster/quicker for 2 reasons:
1) You can get into your powerband more quickly. On my car, an automatic, I don't have the ability to slip the clutch and start out in that nice powerband like manuals do. I launch at 1500 rpm, and then have to lug through the low RPM until 3000ish where the car really starts making power. Gears get through this range more quickly, maybe half a second faster, which REALLY makes a big difference.

2) It actually makes more average torque on the wheels down the 1/4 mile. See below (this is my car, red is 3.73s, blue is 3.27s)

gearsmycar.jpg

It's not as much as it feels like because you don't really feel those ranges where it's making less torque. But when you integrate over the entire range until 120 mph, the 3.73s put around 6% more torque on the tires over the entire pass.