Poor Acceleration with a 5.9 vs 5.2
#11
04-22-2006, 03:16 AM
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#12
04-22-2006, 04:04 AM
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RE: Poor Acceleration with a 5.9 vs 5.2
Kayakman hit it on the head right off. Your tire size will made the most differance. What you need to do is both have the same size tires to do the test correctly.
I am assuming his 245's are stock size tire? So his gearing would truely be 3:55. Your truck should have came with the same size tire. But when you went to a taller tire(more rolling distance), you turned your gear ratio into a higher number, just a guess with out actually figuring it out, you are running closer to a 3:00 gear ratio now. So you will not have the same pull off the line and acceleration. You RPM's on the highway will be much less. You need to be running at least a 4:11 gear ratio to put you back to stock spec's.
Sadly that is where most people go wrong, they like the look of a taller tire, but if they dont change the gearing, they suffer performance and gas mileage. As it is making the motor work(lug) more to do what it originally was able to do with stock set up. I bet you will find nothing plugged up, try swaping his tires and wheels to you truck and do a test run, you will see your power came back.
I am assuming his 245's are stock size tire? So his gearing would truely be 3:55. Your truck should have came with the same size tire. But when you went to a taller tire(more rolling distance), you turned your gear ratio into a higher number, just a guess with out actually figuring it out, you are running closer to a 3:00 gear ratio now. So you will not have the same pull off the line and acceleration. You RPM's on the highway will be much less. You need to be running at least a 4:11 gear ratio to put you back to stock spec's.
Sadly that is where most people go wrong, they like the look of a taller tire, but if they dont change the gearing, they suffer performance and gas mileage. As it is making the motor work(lug) more to do what it originally was able to do with stock set up. I bet you will find nothing plugged up, try swaping his tires and wheels to you truck and do a test run, you will see your power came back.
#13
04-22-2006, 04:13 AM
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#14
04-22-2006, 07:47 AM
RE: Poor Acceleration with a 5.9 vs 5.2
Most all the trucks, 2WD and 4WD come with 3.55 gears and anywhere from 245 to 265 tires. Makes a difference but they aren't going to make but so many standard gear sets from the factory. The off road package with 275 tires jumps to 4.10 gears. If you plan on towing much a 4.10 is good to get from the factory.
It used to be if you got a tow package, trucks automatically came with 4.10-4.11 gears. That was before O/D transmissions. Most of you youngsters might not remember those days of .35 cents a gallon. Cigarettes were the same.
It used to be if you got a tow package, trucks automatically came with 4.10-4.11 gears. That was before O/D transmissions. Most of you youngsters might not remember those days of .35 cents a gallon. Cigarettes were the same.
#15
04-22-2006, 11:53 AM
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RE: Poor Acceleration with a 5.9 vs 5.2
ORIGINAL: livinginh
Kayakman hit it on the head right off. Your tire size will made the most differance. What you need to do is both have the same size tires to do the test correctly.
I am assuming his 245's are stock size tire? So his gearing would truely be 3:55. Your truck should have came with the same size tire. But when you went to a taller tire(more rolling distance), you turned your gear ratio into a higher number, just a guess with out actually figuring it out, you are running closer to a 3:00 gear ratio now. So you will not have the same pull off the line and acceleration. You RPM's on the highway will be much less. You need to be running at least a 4:11 gear ratio to put you back to stock spec's.
Sadly that is where most people go wrong, they like the look of a taller tire, but if they dont change the gearing, they suffer performance and gas mileage. As it is making the motor work(lug) more to do what it originally was able to do with stock set up. I bet you will find nothing plugged up, try swaping his tires and wheels to you truck and do a test run, you will see your power came back.
Kayakman hit it on the head right off. Your tire size will made the most differance. What you need to do is both have the same size tires to do the test correctly.
I am assuming his 245's are stock size tire? So his gearing would truely be 3:55. Your truck should have came with the same size tire. But when you went to a taller tire(more rolling distance), you turned your gear ratio into a higher number, just a guess with out actually figuring it out, you are running closer to a 3:00 gear ratio now. So you will not have the same pull off the line and acceleration. You RPM's on the highway will be much less. You need to be running at least a 4:11 gear ratio to put you back to stock spec's.
Sadly that is where most people go wrong, they like the look of a taller tire, but if they dont change the gearing, they suffer performance and gas mileage. As it is making the motor work(lug) more to do what it originally was able to do with stock set up. I bet you will find nothing plugged up, try swaping his tires and wheels to you truck and do a test run, you will see your power came back.
#16
04-22-2006, 02:25 PM
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RE: Poor Acceleration with a 5.9 vs 5.2
ORIGINAL: livinginh
Your truck should have came with the same size tire. But when you went to a taller tire(more rolling distance), you turned your gear ratio into a higher number
Your truck should have came with the same size tire. But when you went to a taller tire(more rolling distance), you turned your gear ratio into a higher number
#17
04-22-2006, 05:06 PM
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RE: Poor Acceleration with a 5.9 vs 5.2
Bigger tirers are more resistance, but your truck should be a bit higher...wierd though.
My truck seems slower then it should be too, I want to get it on a Dyno just to see if I'm where I should be or if something is really wrong with my truck and I only have like 195 hp or something.
So far I've done exhaust, t-chain, and a tune up, nothing big but I hardly saw a diffrence.
My truck seems slower then it should be too, I want to get it on a Dyno just to see if I'm where I should be or if something is really wrong with my truck and I only have like 195 hp or something.
So far I've done exhaust, t-chain, and a tune up, nothing big but I hardly saw a diffrence.
#18
04-22-2006, 07:01 PM
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RE: Poor Acceleration with a 5.9 vs 5.2
ORIGINAL: livinginh
So you will not have the same pull off the line and acceleration. You RPM's on the highway will be much less. You need to be running at least a 4:11 gear ratio to put you back to stock spec's.
So you will not have the same pull off the line and acceleration. You RPM's on the highway will be much less. You need to be running at least a 4:11 gear ratio to put you back to stock spec's.
Also, whats the probability that if I changed tires from 275 -> 245 it would solve my problem?
Should a 5.9 have better acceleration and top speed over a 5.2?
Another thing, how much does the air filter affect this problem?
#19
04-23-2006, 12:30 AM
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RE: Poor Acceleration with a 5.9 vs 5.2
your tires will definately kill peformance, as well as gas milage. re-gear it and it'll be good as new. One thing I couldnt find was what years you were talking about. In 2000 they had 3 cats on some trucks, mine is setup that way and so is the wifes '02 dakota. 3 cats can hurt performance . In 1999, I believe they still had only 1 cat in front of the muffler.
Also as suggested, check your cat. Look at the FAQ at the top of the forum for how to test it.
Also as suggested, check your cat. Look at the FAQ at the top of the forum for how to test it.
#20
04-23-2006, 01:53 AM
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RE: Poor Acceleration with a 5.9 vs 5.2
ORIGINAL: steve00ram360
your tires will definately kill peformance, as well as gas milage. re-gear it and it'll be good as new. One thing I couldnt find was what years you were talking about. In 2000 they had 3 cats on some trucks, mine is setup that way and so is the wifes '02 dakota. 3 cats can hurt performance . In 1999, I believe they still had only 1 cat in front of the muffler.
Also as suggested, check your cat. Look at the FAQ at the top of the forum for how to test it.
your tires will definately kill peformance, as well as gas milage. re-gear it and it'll be good as new. One thing I couldnt find was what years you were talking about. In 2000 they had 3 cats on some trucks, mine is setup that way and so is the wifes '02 dakota. 3 cats can hurt performance . In 1999, I believe they still had only 1 cat in front of the muffler.
Also as suggested, check your cat. Look at the FAQ at the top of the forum for how to test it.