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LSD and Gearing
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10-17-2007, 10:35 PM | #1 |
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LSD and Gearing
I am planning to get an LSD with 3.46 gearing. I never had a chance with owning one. Can anyone tell me the benefits and features of having this through there experience....
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10-18-2007, 02:31 AM | #2 |
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pm kaji335 he has lsd!
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10-18-2007, 03:28 AM | #3 |
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do you have an AT or MT?
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10-18-2007, 07:52 AM | #5 |
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Don't go with a numerically higher rear-end gear. You will just turn first gear useless. There is a lot of torque in these cars that there is no need for a shorter gear. If you add a piggyback, a shorter final-drive will exacerbate traction problems.
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10-18-2007, 12:49 PM | #6 |
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OK it's not like this car makes 1000HP... A shorter final drive would be awesome in these cars especially with 6th gear available. Tons of high HP cars are running 3.73s and 4.10s. A good driver can control launches. I'd get shorter gears if somebody made them.
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10-18-2007, 01:16 PM | #7 |
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i was asking because of the difference in gearing between the two, but i see his is 3.06.
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10-18-2007, 01:20 PM | #8 |
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It's not the 1000 HP, it's the amount of torque available at low revs. As it stands, I don't really need to ever down shift from 6th to pass on the highway now (PROceed equipped). Acceleration isn't too much of a problem with plenty of torque available at cruising RPM. If you plan on adding more torque, you will find 1st gear useless and 6th gear turning into the 5th gear of an effectively 5-speed transmission.
If you had a car that rev'd to 9000 RPM with the power band coming on after 4k, then shorter gearing is fine. The goal there is to get past the low-end as quickly as possible, or to avoid it entirely by launching from a high RPM. The nice thing about these cars is the amount of torque available from a wide range that precludes any need to wind the engine out to get performance. A shorter ratio will mean launching at a lower RPM or starting off in second gear, which effectively increases your final drive ratio. |
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10-18-2007, 03:24 PM | #9 |
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Maybe it's just me but I find the car far from being some sort of torque monster... Coming from some LSx based cars I find the 335 pretty anemic honestly. 300-350ft/lbs of torque isn't bad, but it's a far cry from 550+ft/lbs of torque from 2kRPM to redline while on 3.73s.
Cruising around you might not "need" more torque or a shorter geared rearend. But then again you don't "need" to go past 70MPH either. But if you want some real acceleration figures then the stock gearing is pretty pathetic. Unless you are spinning the tires off idle on sticky tires, there's plenty of room to get more power and lower gearing.
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10-18-2007, 06:00 PM | #10 |
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With an LSD and stock tires I can still break the tires loose with my PROceed equipped car if I wanted to in first. If you just wanted better acceleration in gear, shorter gearing may work, but it's easier to just down shift and keep the tractability of a rear-end suited to this car's suspension and narrow tires. If you had gobs of fender well to fill with sticky tires, have fun with the 3.73, but our cars can't fit really large tires.
I just don't see the benefit of shorter gearing to simply get better in-gear acceleration numbers when I still have the choice to down shift. I personally would like to get a taller gear to maximize my low-end torque when coming off the line and to give more time before the next shift and its reduction in acceleration. I also think it would be cool to reach 60 MPH in first gear. ![]() |
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10-18-2007, 06:19 PM | #11 |
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Limited slip differentials work to maintain traction. To explain the LSD, we first need to understand how wheel speed works while a car is taking a corner.
As a car is going around a corner, the inside tires move slower than the outside tires. The outside tires have a larger circumference to traverse, and so have to spin faster than the inside tires for the car to move smoothly around the circle. If the inside driven wheel and the outside driven wheel were completely locked together, the inside tire would have to slide or hop along the ground as it took the corner, in order to try to keep up with the outside tire. This leads to poor handling characteristics and bad traction. The differential is designed to allow the inside and outside driven tires to turn at different speeds, improving cornering ability and accelerative traction. An open diff allows for infinite variability of wheel speed, meaning one wheel could be dead stopped, and the other spinning at 200mph. This is the worst kind of differential for good handling. The open diff creates problems in a high powered car because one wheel can be completely spinning while one wheel can be completely gripping. This creates a situation where the car does not smoothly transition to and from oversteer, but instead snaps to and from an oversteer condition. The car is hard to control as a result. Limited slip diffs have various mechanisms to prevent this infinite speed variability. They do allow the two wheels to turn at different speeds, but up to some limit. This means that even though the inner and outer wheel can spin at different speeds, past some pre-designed point of excessive speed differential, the two wheels will begin to lock together. This ensures that even when going around a corner, both wheels will be driving the car. A limited slip diff will typically make for an easier to control car, due to it's smoother transition into and out of oversteer. I hope that made some sense and answered your question! ![]() |
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10-18-2007, 06:31 PM | #12 |
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At the track you don't have the option to downshift when you're starting from 1st. On the street I can spin the tires in first gear as well and I'm bone stock. But on a VHT prepared track with sticky tires the car is just going to bog like crazy. And 1st gear isn't even that short in this car, I see it as being plenty useful even if I got shorter gears.
There's definitely a ton of experience from all sorts of users that a shorter final drive will lower your acceleration times, I don't think you can really argue against that. And with a tall 6th gear for cruising, I just see no reason to NOT do it if you're going to install an LSD anyway.
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10-18-2007, 11:19 PM | #13 |
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True, you don't down shift at a 1/4 mile track, but you will at a road event. For a MT, there is also time wasted shifting, these trannies really don't like power shifting. As long as you have traction, a shorter final drive will help, but the roads I travel aren't prepped the same way a track is prepped.
All well, I will eventually go taller gear, but not before I play with the engine a bit more in a year or so. |
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10-19-2007, 12:25 AM | #14 |
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Thanks for all the comments, I'm need all the help I can get to make my decision. I dont track the car or any...just looking to have more fun with speed and handling when my V2 comes in.......
any advice will be greatly appreciated... thanks guys Jason |
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10-19-2007, 07:55 AM | #15 |
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As for the LSD, I bought my clutch-type LSD from Koala Motorsport.
http://www.koalamotorsport.com/ I live about an hour away from KMS and I have used a clutch-type LSD in one of my previous cars and I like the way they work, plus the pre-load will help me more in the winter. |
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10-22-2007, 03:18 PM | #16 |
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jtecnik, if you have the $ then a LSD is a key mod. With V2 I think that you don't need to go with a shorter final drive ratio.
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10-23-2007, 06:12 PM | #17 |
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Lets be honest here. Just about everyone including me wants a LSD so we can leave 2 long even black marks on the ground,PERIOD!
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10-23-2007, 11:30 PM | #19 |
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10-24-2007, 12:19 AM | #20 | |
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![]() If I were you I would go with an after-market LSD like..... Dinan, (TMS) Tuner Motorsport, Hartage But, they are pricey. I dont know the price for Dinan. But, (TMS) Differentials start off at 4,000$ without install, and Hatage LSD starts off at 4,500$ without install. But its worth it to some people.
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10-24-2007, 02:04 PM | #22 |
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Let us know how the custom LSD goes. It's still such a green market right now that I'm sure many people are interested.
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