The Engine Mod Thread

[YNOT]

can someone show me the way to finding out more about gears? i have no idea about that kind of thing

you mean what you have? or what you should get?

 

[danimalmax]

you mean what you have? or what you should get?

yeah, what to get, what to do? can you tell me more?

 

[YNOT]

check the glove box if you don't know what you have.

G80 = Locking rear differential
2.73 = GU2
3.08 = GU4
3.42 = GU6
3.73 = GT4, GQ1
4.10 = GT5

put some 4.10's of 4.56's in depending on what rpm you want to run on the highway. problem with gears is the labor is expensive.

 

[road1will]

check the glove box if you don't know what you have.

G80 = Locking rear differential
2.73 = GU2
3.08 = GU4
3.42 = GU6
3.73 = GT4, GQ1
4.10 = GT5

put some 4.10's of 4.56's in depending on what rpm you want to run on the highway. problem with gears is the labor is expensive.

Thats what i loved about the drop out 3rd member on my old land rover (similar to toyota)...remove the 3rd member, install new diff/gears, and then i'd take it to my local shop for them to adjust/check over. Never cost me more than $100 and a couple hours of my own labor to install gears or a locker.

 

[danimalmax]

Please forgive my stupidity, but why the rpm on the highway thing? And what gains will I see with 4.10 or 4.56?

 

[YNOT]

the lower the gear ratio, the more pull you have from a stop.
the lower the gear ratio, the lower your top speed is, because you hit redline at a lower mph.

---------- Post added at 09:35 PM ---------- Previous post was at 09:34 PM ----------

in 3rd gear with 4.10's is like 2800 rpms at 65mph.
in 3rd gear with 4.56's is like 3100 rpms at 65mph.

 

[danimalmax]

those rpms seem high, i know right now i get 2000 at 75 mph

---------- Post added at 06:33 AM ---------- Previous post was at 06:04 AM ----------

performance trucks has a good list of bolt ons that are proven to work:

http://performancetrucks.net/forums/showthread.php?t=395748&highlight=4.10+gears+tahoe

one of them was an exhaust cutout, that seems nuts, lol

 

[YNOT]

those rpms seem high, i know right now i get 2000 at 75 mph

i did the calculator in 3rd gear. 2000rpms is probably 3.42 in od

 

[blueflamed03]

but you have a servo?

but I don't have a tune. Servo was put in when tranny was being rebuilt anyway. Cheap $40 addition while it was out.

---------- Post added at 09:24 AM ---------- Previous post was at 09:21 AM ----------

Please forgive my stupidity, but why the rpm on the highway thing? And what gains will I see with 4.10 or 4.56?

low end grunt...it will 'feel' like you've added more HP and TQ, which in respects, you have. The 4.8 and 5.3 and revving motors, all yourr doing is getting the truck up and moving faster, with a deeper gear.
Example: 3.23 gear, eh around town, great on highway, keeps RPM's down
4.11 gear, great around town, good on highway, will use more gas, because motor is revving higher at highway speeds.

 

[danimalmax]

the fact that i do about half city half highway driving is kinda shying me away from the whole gear thing now...