My little 2V is officially an LS1 eater.

Wild Horses

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I beat up on my first LS1 car tonight. Couldn't believe I took him. He was as shocked as I was. Looked like a 98 or so trans am 6 speed. We were neck and neck but third gear I started losing him real good. Next light I asked if he was getting on it and he laughed and just said "what do you have done to that thing? That's the 4.6 right?!"
My mods are in my sig. No heads yet. I was also on my 87 DAILY TUNE with a gallon of cam 2 that I had left over and 3 gal of 92. This guy said he had headers exhaust and he was definitely "getting on it". But still....
I Loved every second of that. Can't wait to get to the track next weekend.

Thoughts? Maybe his car was hurt? I mean it's not too far fetched with what I've got done. Especially with the 4:10s. I know I can put down a solid 13.5 now. It's gotta be there.
 
OP
OP
Wild Horses

Wild Horses

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It was a tight race either way. But yes since my bama tunes my car has been dead on every pull.
 

ReplicaR

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I going to say that the gearing is most like what you can attribute this to. T5 with 4.10 creates really aggressive gear ratios overall, and does wonders for acceleration.
 

the.greg

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Driver mod and gears maybe. Nice job regardless.

Typically your 4.10 gears would mostly help you off the line and the ls1 would have its biggest advantage as the speeds got higher. Anything can happen though.
 

ReplicaR

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4.10 don't just help off the line. They help all the way through. Gears work as torque multiplicators via mechanical advantage. If you want to calculate how much torque you are actually sending to the rear wheels, you take your dyno sheet, multiply that by gear ratio, and again by rear end ratio. This is why cars are always dynoed in a gear that's 1.00:1 ratio, and rear end ratio is dialed out through either computer or some other device. Let's say your car makes 300lbs of torque at the rear wheels on the dyno. Your true rear wheel torque is actually that, times gear ratio, times rear end gear. Therefore if you go from let's say 3.08 to 4.10, you will always make 33% more torque to the rear wheels, no matter which gear you are in.

So, you factor in the powerband, do the calculation on both sides, factoring in the speed, gear used, rear end gear and the engine output, and given that aerodynamically the cars are similar, the car making more rear wheel torque will always be faster, not just off the line. I used to always think that gears are all about getting you in the powerband sooner, but then before I upgraded my diff, I sat down and really did the research, asking why does it get there faster, or what is the driving mechanism behind it. I'd hate to be one of those guys who recites what everyone else is telling them, rather than actually knowing what really causes the faster acceleration.
 

ScottyDsntKnow

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Driver mod and gears there. 3.38 1st gear in the T-45 times 4.10 rear really surprises the shit out of a LOT of ppl. Its always hilarious to put a bus length on a stockish SRT8 car with a bolt on 2V, just as an example and its not hard at all. He was probably doing anywhere from 300-320 to the wheels and you are probably right around 275 with the higher compression NPI bottom end and a lighter car.

Ppl always underestimate these cars and I continually tell everyone that nothing is as big a sleeper as a SN95 with a "GT 4.6L" badge. With all this said, that TA would have probably gone by you eventually but at that point you would be going at a very high rate of speed which is never a good idea on a public road.
 

the.greg

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4.10 don't just help off the line. They help all the way through. Gears work as torque multiplicators via mechanical advantage. If you want to calculate how much torque you are actually sending to the rear wheels, you take your dyno sheet, multiply that by gear ratio, and again by rear end ratio. This is why cars are always dynoed in a gear that's 1.00:1 ratio, and rear end ratio is dialed out through either computer or some other device. Let's say your car makes 300lbs of torque at the rear wheels on the dyno. Your true rear wheel torque is actually that, times gear ratio, times rear end gear. Therefore if you go from let's say 3.08 to 4.10, you will always make 33% more torque to the rear wheels, no matter which gear you are in.

So, you factor in the powerband, do the calculation on both sides, factoring in the speed, gear used, rear end gear and the engine output, and given that aerodynamically the cars are similar, the car making more rear wheel torque will always be faster, not just off the line. I used to always think that gears are all about getting you in the powerband sooner, but then before I upgraded my diff, I sat down and really did the research, asking why does it get there faster, or what is the driving mechanism behind it. I'd hate to be one of those guys who recites what everyone else is telling them, rather than actually knowing what really causes the faster acceleration.

I know how gears work. I had 4.10s on my combo. However, his biggest advantage with his setup vs a ls1 6spd car would be off the line, and at lower speeds- this is what I meant if I was unclear to you. A ls1 fbody was rated at 305crank hp, OP's combo may be good for 250 crank hp if he is lucky. A ls1 is pretty smooth throughout the whole rev band, whereas a 4.10 geared 2v will be anemic at the higher revs.

Fbody cars totally stock with a great driver have gone high 12s in the 1/4 with the 6spd fyi, they are more of a match for a bolt on mach 1 than a na bolt on 2v.
 

the.greg

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And if the ls1 car did have headers and exhaust as the op said, it should have been absolutely no contest. They respond well to those
 

ReplicaR

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I know exactly what LS* cars are capable of, a lot of my friends have them. LS* cars have incredibly flat torque as well, so they are pretty potent off the line too. I guess my point was that unlike most of what people believe, gears don't just help off the line only, but all the way across the range, no matter what rpm range, how much throttle you give it.
 

RICE ETR

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Nice kill and props, calling your car a ls1 eater might be a stretch though. There could of been driver failure on his part for sure. Now if you took a few of them, then ya I agree with the title.

My friend has a '01 GT (stock) 5 spd and he wanted to have a friendly go with my auto 5.0, theoretically he should have walked me, easily. I ended up taking him by nearly a car length by 70mph. I would definitely not call my self a '99+ eater.
 

redriderjf87

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4.10 don't just help off the line. They help all the way through. Gears work as torque multiplicators via mechanical advantage. If you want to calculate how much torque you are actually sending to the rear wheels, you take your dyno sheet, multiply that by gear ratio, and again by rear end ratio. This is why cars are always dynoed in a gear that's 1.00:1 ratio, and rear end ratio is dialed out through either computer or some other device. Let's say your car makes 300lbs of torque at the rear wheels on the dyno. Your true rear wheel torque is actually that, times gear ratio, times rear end gear. Therefore if you go from let's say 3.08 to 4.10, you will always make 33% more torque to the rear wheels, no matter which gear you are in.

So, you factor in the powerband, do the calculation on both sides, factoring in the speed, gear used, rear end gear and the engine output, and given that aerodynamically the cars are similar, the car making more rear wheel torque will always be faster, not just off the line. I used to always think that gears are all about getting you in the powerband sooner, but then before I upgraded my diff, I sat down and really did the research, asking why does it get there faster, or what is the driving mechanism behind it. I'd hate to be one of those guys who recites what everyone else is telling them, rather than actually knowing what really causes the faster acceleration.

Not disagreeing, but the 33% figure only applies if you're in the same gear, which is only going to be some of the time if you're upshifting sooner. I think he emphasized off the line because that really is that much more torque, 1st to 1st. Not arguing how helpful the gears are at all, I just wanted to make that distinction for anybody else.

Nice kill btw OP
 

Sinned83

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Nice kill bro. I'm gonna make it my mission to smash as many LS1's as possible soon.
 

ReplicaR

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Not disagreeing, but the 33% figure only applies if you're in the same gear, which is only going to be some of the time if you're upshifting sooner. I think he emphasized off the line because that really is that much more torque, 1st to 1st. Not arguing how helpful the gears are at all, I just wanted to make that distinction for anybody else.

Nice kill btw OP

While you are upshifting sooner, you are also accelerating faster. So, hypothetically speaking by the time that you've shifted into 2nd on the car with the more aggressive rear end gear, you are already ahead in the total speed, and are climbing well into the powerband again, this time working with the second gear. In reality, the less aggressive geared car will only have a slightest advantage, while the more aggressive gearing will actually provide more power over the longer period in the gear. Your arguement would be valid, if the cars were moving at the same speed, but they are not since the more aggressive gearing does give you higher ground torque.
 

MaxxRPM

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Nice kill OP!..........Now go race another one because that's not the norm........

It takes a max effort 2V (NA) to beat even a stock LS1 F body.
 

redriderjf87

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While you are upshifting sooner, you are also accelerating faster. So, hypothetically speaking by the time that you've shifted into 2nd on the car with the more aggressive rear end gear, you are already ahead in the total speed, and are climbing well into the powerband again, this time working with the second gear. In reality, the less aggressive geared car will only have a slightest advantage, while the more aggressive gearing will actually provide more power over the longer period in the gear. Your arguement would be valid, if the cars were moving at the same speed, but they are not since the more aggressive gearing does give you higher ground torque.

Sure, but my argument still is valid, for that portion of the speed range where you might be in a taller 2nd, or shortened 3rd gear for example. There will be some speeds, where your taller rear keeps you in a lower gear, and vice versa (but more often should favor the shorter rear). The overall ratio is what really matters. But from a stop, it's comparing short 1st to tall 1st, and of course short 1st is better in that situation. Which is what I think people were getting at originally, it would've been a more clear cut advantage from a stop.
 

ScottyDsntKnow

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Taller gears are great for a NA 2V but can hurt in other situations. Example, there are a lot of auto Coyote guys who buy into the whole "auto needs 4.10s" thing and find out the hard way that their cars are at a completely incorrect point in the powerband at the 1/4 track. Also the auto 1st gear is so steep it makes having the 4.10s completely useless. 3.31 is the optimal gear for the auto Coyotes. It is all about the overall combo. Good rule of thumb for something that makes a decent amount of torque like a 2V with a KB on it or a Terminator or whatever is a 10 multiplier for 1st gear traction. 1st gear in the trans times rear gear ratio=10. So for example a car with a T-5/T-45/3650 that all have the similar 3.3x first gear... you are looking at 3.08s or 3.15s really. Go with that or whatever rear gear puts you at the top of your powerband in 4th gear going past the 1/4 pole for a stick.
 

sneaky98gt

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While you are upshifting sooner, you are also accelerating faster. So, hypothetically speaking by the time that you've shifted into 2nd on the car with the more aggressive rear end gear, you are already ahead in the total speed, and are climbing well into the powerband again, this time working with the second gear. In reality, the less aggressive geared car will only have a slightest advantage, while the more aggressive gearing will actually provide more power over the longer period in the gear. Your arguement would be valid, if the cars were moving at the same speed, but they are not since the more aggressive gearing does give you higher ground torque.

You are ahead in total speed, but when you shift sooner than the other car because you're more aggressively geared, the other car will catch up somewhat because it's now got the advantage of more gearing (his 1st gear vs. your 2nd, or his 2nd vs your 3rd, etc.).

If you actually map out a graph of total toque on the wheels vs. speed, you'll see that there's actually not much of an advantage after 1st gear, because of this give-and-take. If I think of it after work, I'll post up a couple of graphs from a racing calculator I built in Excel. IIRC, there was less than a tenth difference in the 1/4 mile between a 3.27 geared car and a 4.10 gear car (stock 2-valve PI) if the 60' was the same. Of course, with proper traction, a better 60' is attainable with a steeper gear.

Always speaking, the ideal gear is the one that places you nearest the highest average horsepower throughout. Regardless of anything else, the car that puts the highest average horsepower to the ground (per given weight) will win. Always. Typically speaking, this is the one that is geared such that the rpm are at redline when in the tallest transmission gear needed to get to the desired speed at the end of the race.

Also, an inertia dyno measures horsepower, and back-calculates engine torque. It does not know or care what the transmission or rear gearing is, and reads almost the exact same thing regardless.


Lastly, to the OP: nice kill, enjoy every win, but don't fool yourself into thinking that you have an "LS1 eater". A full bolt-on NPI head, PI intake/cams car will run in the mid/high 13s at around 101-102 at absolute best with a fantastic driver. A bone stock LS1 Camaro will run high 12s/low 13s at 106-107 all day long. That difference is easily made up with a good driver/bad driver combo, but equal driver for equal driver, the Camaro is significantly faster, especially up top when you lose the gearing advantage.
 

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