Brent94Z

Need some opinions please

If one has over 600 hp with a supercharged 396, are 4.10 gears beneficial over the stock 3.42 gears? There is going to be a killer amount of torque with either I would think.

The car will primarily be a daily driver car with not so much concern placed on racing it. However, it does seem that with 4.10 gears it would be necessary to shift out of 4th where as with 3.42 gears you could keep it in 4th for the entire 1/4 mile.

Anyway, just looking for some opinions. I know 4.10s are a "fun" gear and make good sense on a stock F-Body M6 or even one that is decently modded. But, what are the opinions if you go over 600 hp???

Thanks for opinions or suggestions!

shoebox

With that much HP, there won't be a lot of traction with the 4.10s and may be scary in the rain. Of course with the M6, you have plenty of overdrive for long hauls. I guess it just depends on how much "fun" you want to have with it.

Oh yeah, quit demoralizing the rest of us with posts like this.

EDS Z28

Hey Brent,
You are in the same predicament as me. I want to get a Moser 12-bolt and can't decide on the gear ratio, it is very confusing. Basically, the higher the ratio, the more torque is transmitted to the rear tires. So for big diameter racing tires (like 28") you need the 4.10's, no doubt about that. The 4.10's will be probably be too much for street tires though. I spin the heck out of my BFG's with just 3.42. The higher numeric ratio like a 4.10 will not add any power, just transmit more torque to the rear tires.
The 4.10's will put approx. 20% more torque to the rear wheels. If your tires can't handle it, they will just spin.
I guess the best solution is to just find a friend who has that ratio and drive it.
Ed

Brent94Z

Thanks, shoebox!

I demoralize myself by looking in my garage and seeing two killer engines doing NOTHING on engine stands. It depresses me everytime I go in the garage (daily). I really want to get something done this year and am trying to figure out my rear end situation ahead of time

Brent94Z

Hey Ed!

The only buddy who has anything close to what I have has between 450 and 500 hp (estimating) with 33" tall tires and 4.55 gears. His wouldn't be an accurate comparison. LOL!

I'm really leaning towards the 3.42 gears but definitely want other opinions. I also drive 30 miles one way on the highway (for the most part) so 3.42s would definitely help with the gas mileage. However, don't take that as me saying I'm justifying 3.42 gears because I'm going to save $5 a week in gas I'm probably one of the few morons who plans to use a car like this for a daily driver at 60+ miles a day. Saying I want to save a few bucks in gas while at the same time wearing out an engine which costs more than the car it is in just doesn't sound right. hahahaa

shoebox

Wait until you have had a car sitting in the garage for 25 years. Then you can talk to me. Some day, it will be back on the road.

I won't be worried about gas mileage either since it has 4.88s in it.

EDS Z28

Well, if you get the 12-bolt, there is also 3.55, 3.73, and 3.90's just to make it more confusing! At one time I was thinking about getting the 3.90's, then after driving my car changed my mind to 3.55's. It is just a change which affects the car so much. After driving around today, the 3.42's give it great power for most of the rpm range, except off the line it is lacking some torque.

magius231

I'm with Shoebox....your gonna have fun hooking up 600+HP with 4.10's...you'll be blowing the tires off in 4th

I would go with a more mild ratio, 3.42, 3.55 or 3.73, plus this gear will be more like what you will need on a dragstrip. 3.42's will be fun since very little out there can outrun 600hp on the low end, and with that gear you will have one HELLUVA top end

Camaro_SS/R

Hi Brent,

I would definitely recommend not doing the 4.10 even if you have the M6 and also especially if you have the SC.

I have the 3.73 and my car is dyno tune at 600rwhp. For the street, even with the Nitto drag there is basically no traction for first and second gear. I need this to get some traction for third gear. Finally first and second gear rev up so fast it is scary but still kinda fun. But with a 4.10 it will not be fun at all but plan scary. On the street with 3.73 I can play with 3 gear and start it at 3000rpm, but with a 4.10 and the same power level I don't even think 3 gear will hold and will just spin out even if you gas it at 3000rpm.

For a mostly street car like mine, I wouldn't go more than 3.73 and wouldn't consider the 4.10 at all, this is for a 396 supercharged to 600rwhp setup.

cheers

CamaroRob97

600 hp!! Well i dunno i mean i've heard alot of people with those kinda steep gears just breakin them like only after a year or so of having them, just seems kinda risky with like 4.10s. Now granted im chickensh*t compared to all u guys, with more experience and all out knowledge! So i mean u've built this 600 HP beast so im gunna say u've accomplished this much im sure u'll make the right descision in the end, the REAR end!
just my $.02

mycarisfasterthanyours

I would say the only reason to go with the lower gear i.e. 4.10s would be if your setup does not do very well at low rpms. I suspect however that with a blower and a 396 you are not killing very much drivability with a big cam. I have a pretty lumpy cam that really likes the 4.10s. Anything lower, and I would hardly use sixth and slow traffic would be a bitch. With a supercharger cam though you should still have a very good idle. I say 3.42, maybe 3.73.

jimlab

Brent, I went with 3.55s in my '03 Cobra 8.8" IRS for a number of reasons.

First, I'm using an M29 (long story) T56 (2.97, 2.07, 1.43, 1.00, 0.80, 0.62), so I already have more gear to start with. With 3.55s, my final drive in 1st gear is 10.54:1, just a bit shy of a 2.66:1 T56's final drive of 10.91 with 4.10s. So in other words, I've got enough gear in first to help smooth out my big solid roller cam at low speeds as Jordon recommended.

Here's the overall comparison with my 3.55s on the left and a standard T56 with 4.10s on the right...

1st - 2.97:1 (10.54:1) vs. 2.66:1 (10.91:1)
2nd - 2.07:1 (7.35:1) vs. 1.78:1 (7.30:1)
3rd - 1.43:1 (5.08:1) vs. 1.30:1 (5.33:1)
4th - 1.00:1 (3.55:1) vs. 1.00:1 (4.10:1)
5th - 0.80:1 (2.84:1) vs. 0.74:1 (3.03:1)
6th - 0.62:1 (2.20:1) vs. 0.50:1 (2.05:1)

Second, the Z06 has the same 1st through 4th ratios with a 3.42 diff, so 3.55s gave me a slight advantage (not to mention the 400 lb., 1,000 rpm, and 250+ horsepower advantages) over that configuration, so I felt I couldn't go far wrong closely duplicating it. The 3.55s were the best compromise between acceleration and traction. 3.73s would have been too much gear and 3.27s would probably have been too little.

Third, the 3.55s put my cruise rpm right about 2,000 rpm @ 70 mph in 6th gear, which was just about perfect. They also mean I don't have to shift as often while building a lot of wheel speed, which gives me another slight advantage, I think. With a 7,600 rpm arbitrary redline, I can top out at well over 150 mph in 4th gear alone, and 5th will take me to nearly 200.

Fourth, 3.55s gave me the highest trap speeds in simulations. I won't be drag racing much, and won't be running slicks, but a high trap speed tells me a lot about the car's acceleration minus the launch, and 3.55s gave me 138-139 mph traps in Car Test 2000, for whatever it's worth.

I also invested in a RaceLogic traction control system to help out with traction. I knew that MTI Z07 conversions had traction problems in lower gears with the stock 3.42s in the Corvette, so I knew I had to take the extra step to help get the power to the ground.

So would I run 4.10s on the street with a 2.66:1 T56? Jordon did, and highly recommended them. However, without a more sophisticated traction control system, your right foot will be the limiting factor in lower gears, and you really won't be able to hook well until 60-70+ mph, probably. With 3.42s, you'll have a bit better chance, or at least more "granularity" in your throttle input between gears, and with a forced induction engine, you don't really need more gear to improve streetability.

So with a big solid roller, I'd recommend 4.10s, but with a supercharger, I'd recommend 3.42s. Unless you intend to drag race often, I'd stick with the stock gears for street use, or 3.73s at the most, the same as mycarisfaster recommended. Hope that helps.

xxsaint69x

i would go with 3.73s
Marcin

IDOXLR8

In all honesty I would stick with a 3.42. You will be much happier. A 4.10 and 3.73 are just way too low of a gear for your setup. It makes 1st gear pretty much usless. I currently have a 3.50 gear in my 9-in.

Derrick Redd

I'd stick with the 3.42's.