gearing
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gearing
Hi i have a 1999 f-250 7.3 6-speed with 3.73 gear ratio. I am wondering what gear ratio you would recomend for more acceleration and not running to many rpm's on the highway. The truck just cant pull out in traffic or get out of its way. It has a 4'' exhaust a free flow air filter and a Hypertech power programer. thanks for the help.
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From: Taxachewsetts
Something is wrong if your truck can't get out of its way with a stick and mods you have listed.
I have 4:88's in my F550 and can't cruise much over 70mph without sucking down the fuel.Turning over 2k rpms by 60.
Even at 12.5K lbs empty,my F550 6x6(SCT,air filter,exhaust mods)merges just fine with traffic and even outpulls the fartcan drivers.
I have 4:88's in my F550 and can't cruise much over 70mph without sucking down the fuel.Turning over 2k rpms by 60.
Even at 12.5K lbs empty,my F550 6x6(SCT,air filter,exhaust mods)merges just fine with traffic and even outpulls the fartcan drivers.
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Thanks for the help. My truck does run good but if you have ever driven a stick version of these trucks you would know how slow they are to accelerate with the time it takes to actually make the shift. I am wondering if 4.10 gears will be enough of an acceleration difference to be worth the change.
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From: Taxachewsetts
I know what you are saying about the trans shifting slow.It's not a Mustang for sure!I'd trade my 4r100 in a second for a stick though.
You running stock height tires?You could go to a 245/75/16" for better snap off the line.I did that with my 01 f250 for towing and it really helped.
You running stock height tires?You could go to a 245/75/16" for better snap off the line.I did that with my 01 f250 for towing and it really helped.
Post Fiend
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From: Millbrook Alabama
Originally Posted by scottty
Has anyone changed there gears without changing there tire size. thanks
285s and 305s are 33" tires 315s are 35" tires
33" tires + 3.73 rear end= 3.55 final ratio.
33" tires + 4.10 rear end= 3.73 final
35" tires + 4.30 rear end = 3.73 final
the above are estimates, but pretty close to real world figures.
remeber if its 4 wheel drive then you have to change gears in both diffs
If you are running stock 31" tires then you should be able to get out of your own way, have you checked for boost leaks?
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Cargo Master
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From: Vilonia Arkansas
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From: Twin Falls Idaho
Again what size tire are you running? My F550 with 4.88'sand 33 in tires will run out of RPM quicker than I can shift it. but it will out accelerate most of the fartcan cars. Barney
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I have a 2001 F-250 2wd crew cab stock except for a hypertech power programmer. Do you tow heavy loads? The most I tow is a 21 foot boat that weighs maybe 5000 lbs. My truck came with 3.73's but I changed it to 3.55 and I love it. I chose 3.55 because I had a 1992 F250 7.3 with a 3.55. I can't imagine that a lower gear and more RPM's is the answer with an empty truck. It certainly shouldn't be lacking power unless something is seriously wrong. However, I have never driven one with a stick. I wouldn't have switched gears if I intended to tow anything heavy like a big fifth wheel. I tow the boat in OD and the faster I go the better it runs!
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Thanks I have the stock size tires 285 75 16. I do tow an off roas jeep wrangler with big tires and a v-8 but i cant imagine running 3.55 gears. I am sorry if this post is missleading because the truck does run good. I am just looking for a little better acceleration. Before i put in the hypertech programer it was really dangerous to accelerate into traffic but now it is better and is now safe. Thanks again for the help.
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From: Millbrook Alabama
Originally Posted by scottty
Thanks I have the stock size tires 285 75 16. I do tow an off roas jeep wrangler with big tires and a v-8 but i cant imagine running 3.55 gears. I am sorry if this post is missleading because the truck does run good. I am just looking for a little better acceleration. Before i put in the hypertech programer it was really dangerous to accelerate into traffic but now it is better and is now safe. Thanks again for the help.
have you checked for boost leaks(major power killer), check that all boot clamps are tight, there are 6 boots, one on each end of the two CAC(intercooler) tubes, then also 2 going from the spider to the intake plenums. after all those have been tightened, check your up-pipes (going to the back of the turbo from the manifolds) WITH A COLD ENGINE , run your fingers around the up-pipes where they connect to the turbo and check for soot(you should not have any). If you do find soot back there, then the donut between the up pipes and the turbo has probably eroded, you can replace the donut, but a better solution would be bellowed up pipes from International as well as many of or fine sponsors here.
Hope this helps. Merry Christmas.
Tuned
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From: Holden,La.
Scottty...I would not change gears unless You want to use a lot of fuel. I would do as bdrummonds said and look for leaks in exhaust and boost tubs. If You are not getting the right amount of boost it will be slow getting up and going.
Cargo Master
Joined: Apr 2004
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From: Vilonia Arkansas
My old 96 F250 with 3:55 and a tired auto would run just fine in stop and go traffic with 5000 or 6000 lbs behind it . It only had a superchips tuner, a 10K mod , straight exhaust ,and a 6637. I have 4:10 s in my dually and I wish I had a gear venders overdrive to get the r's down get over 60 mph and you getting over 2 grand. On vacation towing nothing with just the family in the truck I only averaged 16 mph and I was trying to keep the speed down to at the most 72 mph. I don't believe that you are going to see the increase in performance that you want with a gear change with the jeep being the heaviest thing that you tow on a regular basis.
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i have a 6speed with ts chip and the thing screems. gears is not the answer, try ditching the hypertech for something that can change on the fly like a ts or dp. If you need the power just turn the dial to the 100 setting.