Sumbalt1

So how are the 3.90gears. i have 4.10s right now.


Posted from LS1Tech.com App for Android

HioSSilver

iTrader: (8)

3.90's are great. Gear of choice really and I've had them both. 4.10 is a bit much for these cars.

Sumbalt1

i was woundering because i do alot of freeway driven and this is my daily driver...



Posted from LS1Tech.com App for Android

LS1T56FTW

iTrader: (3)

Do you do digs fairly often? I am currently in process of installing 4.10s since my car with 3.42s cannot get out of the hole to save its life.

30th t/a

iTrader: (51)

Ive had 4.10 & 3.90s. They are so close but I prefer the 3.90s.

HioSSilver

iTrader: (8)

It's not a issue of rpm. It's that you just blow threw your tq and all you do is shift. The car accelerates better with the 3.90
I do digs. The 3.90 don't hurt that any, actually may stay hooked up a little better. I've had my best 60 with the 3.90's also. The 3.90 is also the stronger gear.

Sumbalt1

i done a couple digs and the 4.10s hook make who ever in the car head snapback...i would keep them but my rpm are high on the freeway


Posted from LS1Tech.com App for Android

LS1T56FTW

iTrader: (3)

I am not worried about strength by any means, I will end up running a strong rear eventually, it just the ratio I am unsure of. Once I run the 4.10s I will see if I like them or not from a shifting standpoint (car should be rolling tomorrow), but for the track 4.10s are matched perfectly with where my RPMs will be in 4th gear, so I am thinking that I will stay with them since I am personally having some serious issues cutting good 60s (and it is not due to traction - you can always fix that with tires/suspension, it is due to the car bogging very hard).

guppymech

iTrader: (7)

Quote:i done a couple digs and the 4.10s hook make who ever in the car head snapback...i would keep them but my rpm are high on the freeway

2k@70 is too high? 4.10 with .50 overdrive = 2.10 overall final drive ratio. Changing from 4.10s to 3.90 doesn't seem cost effective. Except for traction in first, 4.10s work great especially with a cam.

HioSSilver

iTrader: (8)

It's cost effective if you can't get threw the qtr w/o hitting the limiter in 4th. Also cost effective in the 3.90's hold up better and accelerate harder. I went from breaking ring gears with 4.10 to breaking axles with 3.90's.

guppymech

iTrader: (7)

Unless the OP can change the gears himself he needs to decide if he wants to spend $500 more on the 10 bolt for a .2 ratio change. Doesn't sound like he's going to the track or running out of gear.

LS1T56FTW

iTrader: (3)

What is your limiter at? At 6800 with a 26" tall tire you should be able to get 130 out of forth. If I hit the limiter at 7000 in forth I am going to be pissed.

HioSSilver

iTrader: (8)

Was @ 6800 and it would only go 122.xx with the 4.11's and a stock height tire beating off the limiter for a ways. Now it's @ 7000 and usually I trap 126+ with the 3.90's. I can still run it up to the limiter and have plenty of time to shut down. It might run 132-133 now@ 7000

I would think your gonna hit the limiter with that much power, or at least be past your power peak.

LS1T56FTW

iTrader: (3)

We will see. I definitely got right around 120 out of 4th gear last night before my shift light came on (have it set at 6400) so the gear calculators I have been using are correct. I think I will be OK with the 4.10 gears.

On another note, I am very happy with the gears. 3.42->4.10 is quite a jump. Car launches much better now.

HioSSilver

iTrader: (8)

Well good luck with them. I was all right for a while with them to. But as I refined my car it got faster and I maxed out the gear for my rpm. In the end if you keep you engine in it's sweet spot it will accelerate harder and longer. That's what 3.90's offered. I actually think 3.73's would not hurt my car much. If your trying to get threw the qtr and winding your motor to hang on to the gear then you have the wrong gear.

96lt4c4

iTrader: (5)

3.90 is the best gear for a street 6 speed car hands down. I have had 3.73, 3.70, 4.10, and 3.90.

3.90 is what I have now and love it.

LS1T56FTW

iTrader: (3)

http://www.richmondgear.com/101032.html

With my 4.10s, my 26" M/T's, I can get 130 out of 4th (6900RPM) before I would be getting out of my powerband at all. My car makes 470whp from 6000RPM to 6900RPM, so I don't think running out of RPM will be a problem any time soon. Not just that I will be adding a FAST to my setup eventually - should rev even higher theoretically. I will probably run 4.10s once I get a strong rear and just run a taller tire if I need "more gear."

With that said, if I am having trouble running out of gear (trapping 130+) I will have no problem switching to 3.90s, haha.

LS1T56FTW

iTrader: (3)

What's your problem with 4.10s? There are a lot of locals with 3.73s and they have some serious issues getting out of the hole, so I am leery of going to anything longer than a 4.10 personally.

96lt4c4

iTrader: (5)

Granted this is all with stock size street tires....

Too much shifting for me, 3.90 is pushing it, but I like it.
4.10 first gear is useless, unless you just like blowing the tires off all the time.

If you ever get a chance to drive a car with a 3.90 gear you will like it.

But you are right about 3.73, they were better than the 3.42 but still a little to tall. Some say you cant tell the difference blah blah...bull ****. I can tell the difference, 3.42 to 3.73, to 3.90, to 4.10...3.90 is the best.

Pluss the 3.90 Motive is a strong gear with a bigger pinion, than the 4.10.

LS1T56FTW

iTrader: (3)

Interesting. Yeah the 4.10s are a bit short and you do shift a lot even just driving around town. I have adopted the 1-3-5-6 shift pattern myself (unless I am accelerating hard). I was doing some practice digs last night and 315/35/17 Nitto NT555 (street tires, not the drag radial) were hooking up not too shabby. It would spin the top of first a bit and spin fairly hard on the 1-2 shift, but the car has always spun on the 1-2 shift so 3.90s would not change that. The car dead hooks from a 40 roll in second (and the RPMs are right at 4000 which is perfect for street racing). Also, I don't plan on getting any sort of longevity out of this rear though so I could care less about strength. My next rear will be strong enough that regardless of the ratio I won't have to worry about it.

Anyway I totally stole the OP's thread, but this definitely helped clarify some things.