What kind of gears do i have? please help
09-27-2010, 03:58 PM
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What kind of gears do i have? please help Hey guys i bought this ls1 and noticed that my RPMS were a little high. Then i noticed that it seemed like i was driving a little slow, as soon as i was on the highway i definitely noticed i was driving slow. I'm not a big gear head but my suspicions were either it has the wrong size tires or it has gears. I looked at my tires and their the same size as the factory ones so that's not the problem. I think the previous owner put in some gears and didn't bother correcting the speedo. I got my gps and started driving around and the speedo is off. In 3rd gear at 2000 RPMs it says im doing 35 but im really doing 29-30. When im in 4th at 2000 rpms it says im doing about 45 but im really doing around 38. When i was on the highway in 6th i dont remember what rpm i was running at somewhere around 2000 but if i wanna cruise at 70 i have to do about 83 and to cruise at 75 i have to be doing 90. My questions are does anyone know what gear ratio i have? i know i wont know for sure unless i open it up but im sure its some kind of common gears. I had 3.42 stock so im thinking its 3.73's. And what can i do to fix the speedo? i think a SCT tuner or some kind of tuner will correct it but im not sure. The faster i go the bigger the difference is between my speedo and my actual speed, so i believe i have gears.... Any help is appreciated thanks 
09-27-2010, 04:11 PM
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It sounds like you have different gears in your rear and its most likely series 3 gears. I had 2.73's in mine and now 3.73's and my car is doing the same thing. A tune will correct this problem.
09-27-2010, 05:30 PM
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I just looked at a gear chart and i lined up my rpm speeds with my mph and i says i have 4.10s.
09-27-2010, 06:25 PM
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You most likely do then, I bet that thing will get up and go, like I said a tune will correct the speedo. Do you get good traction with the stock tires or alot of spinning?
09-27-2010, 08:29 PM
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Eh they are pretty good i cant complain, i can easily chirp 3rd gear but i dont race around a whole lot so they are fine for me lol. Do you mean a dyno tune? or will a tune programmer like a SCT hand held one do it also? Thanks for the help
09-27-2010, 10:38 PM
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Do 60mph (GPS reading) in 4th gear and look at your tach. The tach reading is around what gear size you have. ~3400 rpm = 3.42's.. ~3700 rpm = 3.73's etc etc.
09-28-2010, 03:31 PM
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Thanks ill give it a try just to confirm it. So i have to get a dyno tune to correct the speedo or will a hand held one do the trick? Thanks
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09-28-2010, 04:04 PM
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09-28-2010, 04:40 PM
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If you want to know for sure what you have jack the rear of the car up. Mark a spot on a rear tire and spin it one revolution around. Watch the driveshaft as you spin the wheel and count how many times it goes around, if it goes around a hair over 4 times then you have 4.10's. If it goes around 3 3/4 times you have 3.73's and so on. Its the only way to really know without opening the diff cover.
09-28-2010, 08:30 PM
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A tune from stock will net you a good 20hp. The lid is a nice gain as well and the tune will help your fuel mileage. Go with the mail order. The Hand held will do it, but there's not much you can do with it otherwise.
Go with the mail order. The Hand held will do it, but there's not much you can do with it otherwise.
09-29-2010, 05:05 PM
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Looks like ill be going with the mail order tune, Can you explain it a little better to me?
09-29-2010, 09:50 PM
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Explain the Mail order? or the Hand Held? The Hand held is usually only beneficial for stock-ish cars with a gear change, tire size change and MOSTLY an auto trans where you can change shift points. I wouldn't trust it to effectively change much else. You can alter timing with it, but you could run into a knock, then you have to go back and change it again anyway, bu. the hand-helds are mostly BASIC changes.. "Performance" selections. I haven't used them personally, but I have seen it enough to know what it does and doesn't.
The Mail order, just find out what gears you have, and tell them your mods, what year, transmission, engine and other items you have done to it and they can pretty much dial you in better than what you have now. basically leans the mixture out a little and advances your timing. Mail order is good for getting you in the ball-park, but once you start modding the car to the point of different engine, head and cam swaps, you REALLY need a dyno tune to log actual timing readings, exhaust O2 levels, stoich ratio, etc etc...
And I would ALWAYS trust an LS* Specific tuner (person) over someone who hasn't had much experience with them. That's why I spend the $450 for a dyno tune from a reputable shop because they KNOW what they are doing and they make a living doing it.
The Mail order, just find out what gears you have, and tell them your mods, what year, transmission, engine and other items you have done to it and they can pretty much dial you in better than what you have now. basically leans the mixture out a little and advances your timing. Mail order is good for getting you in the ball-park, but once you start modding the car to the point of different engine, head and cam swaps, you REALLY need a dyno tune to log actual timing readings, exhaust O2 levels, stoich ratio, etc etc...
And I would ALWAYS trust an LS* Specific tuner (person) over someone who hasn't had much experience with them. That's why I spend the $450 for a dyno tune from a reputable shop because they KNOW what they are doing and they make a living doing it.
10-01-2010, 03:33 PM
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Explain the Mail order? or the Hand Held? The Hand held is usually only beneficial for stock-ish cars with a gear change, tire size change and MOSTLY an auto trans where you can change shift points. I wouldn't trust it to effectively change much else. You can alter timing with it, but you could run into a knock, then you have to go back and change it again anyway, bu. the hand-helds are mostly BASIC changes.. "Performance" selections. I haven't used them personally, but I have seen it enough to know what it does and doesn't.
The Mail order, just find out what gears you have, and tell them your mods, what year, transmission, engine and other items you have done to it and they can pretty much dial you in better than what you have now. basically leans the mixture out a little and advances your timing. Mail order is good for getting you in the ball-park, but once you start modding the car to the point of different engine, head and cam swaps, you REALLY need a dyno tune to log actual timing readings, exhaust O2 levels, stoich ratio, etc etc...
And I would ALWAYS trust an LS* Specific tuner (person) over someone who hasn't had much experience with them. That's why I spend the $450 for a dyno tune from a reputable shop because they KNOW what they are doing and they make a living doing it.
The Mail order, just find out what gears you have, and tell them your mods, what year, transmission, engine and other items you have done to it and they can pretty much dial you in better than what you have now. basically leans the mixture out a little and advances your timing. Mail order is good for getting you in the ball-park, but once you start modding the car to the point of different engine, head and cam swaps, you REALLY need a dyno tune to log actual timing readings, exhaust O2 levels, stoich ratio, etc etc...
And I would ALWAYS trust an LS* Specific tuner (person) over someone who hasn't had much experience with them. That's why I spend the $450 for a dyno tune from a reputable shop because they KNOW what they are doing and they make a living doing it.
