4bangerjp.com
General Forums => The Mess Hall => Topic started by: noodlez914 on August 26, 2009, 08:13:35 PM
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How's it going everyone.
I am new to the world of Jeeps. I purchased a 97 TJ back in april. I was looking at 2 TJ's at the same time with the same mileage. The 0ne was the 4.0 and the other was a 2.5. The 4.0's body was not looking too healthy and I had concerns for the frame as well. the 2.5 had an excellent body (And 3" lift with 31" Tires) and excellent frame. No rust on floors or nothing. I bought the 2.5. I have no regrets I know I can make this to where I am happy but I wonder at what cost??? LOL. First off I have one stripped thread on the engine block where the exhaust manifold mounts which causes a nice leak up top. My mechanic is gonna fix that when he slows down after the summer. So that should be the first thing towards making me a little happier. I think. Will that give me a little more pep ya think? Also im hearing alot of changing of gear ratios in these forums.... Thats a pretty expensive venture isnt it? I mean are you really getting that much more out of the 2.5 with that investment? How about a new air intake system? Would that help. Im not trying to make this into a 4.0 because its not, and I am not a power nut, I just feel like this puppy takes forvever to build up to 55mph. And I love the look of it with the 31" tires and 3" lift, so I really don't wanna go back down to tiny tires. Any suggestions would be great. If i can get this thing on the highway and do a comfortable 65mph, i'll be all set. Thanks.
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you can stick 32s, even 33s on that 3 inch lift. i have a 2.5" lift and its rated for up to 33" tires and i must say my 31s look a bit small with that 2.5" gap. i feel like 31s seem small on a 3" lift. most of the people here have really good results when they re-gear esp when they fit larger tires. Intake wise, the selection is huge. i run AEM and im satisfied with the improvement. there's always headers and exhaust upgrades that will give ya a bit more go. TB upgrades work too as long as it's done right-follow the thread on the forum for that. another popular upgrade is the electric fan, also an abundant amount of info on this forum regarding that.
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Personally I think re-gearing is the way to go. When you put a larger tire on the gearing needs to be changed to get it back to where the Jeep "thinks" it still has the smaller tires. It is expensive but all the little power adders add up as far as costs. They do help out a little but nothing like changing the gears. A gear change your in the neighorhood of $1200 for parts and labor.
Is your tranny a auto or stick?
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There are some improvements you can do for little to a lot of money. The seat of the pants analysis will tell you that there were some gains, but really, without significant changes to the driveline or weight of your Jeep, your power to weight ratio is minimal and you may or may not like the results. My TJ weighs 3780#s with a 1/2 tank of gas. That is pretty heavy for a 120hp engine that could when it was new. Best thing to consider, figure the gear ratio to the tire size you will be running. Stock, depending on tire and trans, 27-28" tall tire with a 4.10 or 3.73 gear ratio. If you want a little more pep, get a gear ratio that is slightly deeper (higher numerically) to get you into the higher rpm range quicker. Your 4cyl like to rev and at highway speeds, it should be over 3000-3100rpms.
If you like being around people with the same interests, look for a local 4wd or Jeep club. Comraderie is fun, you gain knowledge of your Jeep, you'll learn offroading techniques, and you'll have a whole new set of friends. Some people are not into clubs and that just as fine. Some clubs, you don't have to participate in everything they do. The club usually functions for the majority of its members.
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Regear to 4.88. All that other stuff like efan and throttle body is good icing on the cake but the gears are going to make the biggest single difference by a mile. You could easily dump a thousand bucks into bolt-ons and they won't be nearly as effective as a $1200 regear.
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Regear to 4.88. All that other stuff like efan and throttle body is good icing on the cake but the gears are going to make the biggest single difference by a mile. You could easily dump a thousand bucks into bolt-ons and they won't be nearly as effective as a $1200 regear.
$1200? I thought you only need R&P, crush sleeve and shims (for pinion bearing and carrier bearing races) which should be around or little over $200 per axle - or did you add the labor as well?
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That includes labor. I went out on a limb here and guessed the OP isn't gonna tackle a regear in his driveway if he doesn't even want to take on a stripped exhaust manifold stud.
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That includes labor. I'm went out on a limb and guessed the OP isn't gonna tackle a regear in his driveway if he doesn't even want to take on a stripped exhaust manifold stud.
lol (sorry noodlez, nothing against you I just laugh at my previous post).
good point and my bad :stupid:, i should've paid attention to what he said in the top post - in that case you were generous with the estimate :)
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Not offended sharpxmen.
Well im certainly not a wrench head but i've been known to take on mechanical challenges sometimes and most of the time
Calculate my busy schedule added with my very slow work rate on something that is not my profession, and I end up bringing it to someone to have done. I actually was gonna tackle the stripped thread on the engine until i realized i would have to pull half the engine off to get to it. Now the gear thing....lol that sounds outta my league. I like the idea of finding a local club in my area might even be able to find someone in the club that would do the labor for a bit cheaper. Its sounding to me that the re-gearing is really helpful. I hear you guys saying 31's on a 3 inch lift is nothing but it feels like a moped pulling a travel trailer, but then again my main truck is a V8 Titan, so getting out of that then into the Jeep isnt helping my though process either.
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pull the 8cyl out of the titan and throw it in the jeep...that should help your thought process and take care of your power needs.
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If you plan on keeping the Jeep start with the gearing, go 4.88 and take everything else from there. All in all that seems to be about the best bang for the buck and will make you a heck of a lot happier. Unless of course you will never go past a 31" tire.
However with this Jeep disease thing, things tend to escalate rather rapidly.
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Regear to 4.88. All that other stuff like efan and throttle body is good icing on the cake but the gears are going to make the biggest single difference by a mile. You could easily dump a thousand bucks into bolt-ons and they won't be nearly as effective as a $1200 regear.
Big +1
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Anyone else see the article in JP about re-gearing Vs. bolt on power adders? I'd scan it but I don't have a scanner.
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Is that the one where they used one of those ricer drag computers to calculate an "artificial" HP/torque improvement of the gearing before and after? IMHO that was bad science.
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Is that the one where they used one of those ricer drag computers to calculate an "artificial" HP/torque improvement of the gearing before and after? IMHO that was bad science.
Sept 09 pages 40 and 42
They had a 95 2.5L YJ that they put a bunch of bolt on power adders. This was a while ago and spent $1520 in parts. E-fan,Banks header,Banks exhaust, high flow cat,4.0TB, AEM air intake. Results were 14HP and 7LBS of TQ.
Then they got a 89 2.5L YJ just added 4.88's with bearing kits and labor and spent $1090 in parts and labor.
They have a math formula that came up with all kinds of data. I am to much of a Tard to understand all their math speak.
But bottom line they put them on a 1/4 mile track results were.
4.10 geared with power adders 19.99 sec @ 63.8 MPH
4.88 geared otherwise stock 19.80 sec @ 70.9 MPH
Both had 31's
They did use a G-Tech Pro SS performance meter to get some data. (might be some bad science here) I don't know.
I know for myself I have only done the 62MM TB and I port matched the intake/TB opening. Othewise my motor is bone stock. Infact I took off the Rock-it city intake with K&N and replaced it with a OE 4.0 intake from a 4.0 TJ. While my Jeep is no rocketship it does pretty dang good on the FWY even loaded down with gear. (MY mileage sucks big time) but if I slowed to 60 it would improve a great deal. I choose the gearing route. VS. all the power adders. Now that I am done with building the axles and such I am going to start adding some of the power adders. I don't feel I need to but the Jeep bug bites pretty hard and it's hard to stop doing stuff.
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ive always wondered about gearing. im only running 31s but i too have been bitten by the bug and would love some more power. i have a few bolt ons..AEM, 62mmTB and spacer, and a junk "higher flowing exhaust" that im lookin to upgrade to a banks. if i were to regear, what do you guys think i should gear to? i dont really get all the ratios and stuff so im lookin to find out what it would do for me, ie: highway ride, off road, efficiency etc oh and of course, cost. i have an auto by the way.
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ive always wondered about gearing. im only running 31s but i too have been bitten by the bug and would love some more power. i have a few bolt ons..AEM, 62mmTB and spacer, and a junk "higher flowing exhaust" that im lookin to upgrade to a banks. if i were to regear, what do you guys think i should gear to? i dont really get all the ratios and stuff so im lookin to find out what it would do for me, ie: highway ride, off road, efficiency etc oh and of course, cost. i have an auto by the way.
With an auto I would think the 4.56 would be a good choice. But I am no expert when it comes to the auto stuff. With the sticks the 4.88's would be the ones to get.
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Folks may disagree but 4.88 will work great with 31" tires. Its simply not possible to overgear the 2.5L with the stock axle ratio options unless you are still running the 205's IMHO.
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Folks may disagree but 4.88 will work great with 31" tires. Its simply not possible to overgear the 2.5L with the stock axle ratio options unless you are still running the 205's IMHO.
The auto tranny does not have a OD. Their 1:1 in D. I do agree with running low gears. The mileage can suffer thou.
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I got the Banks header and stinger exhaust, AEM Brute Force CAI, 4.0 TB, ported intake, mustang injectors, brass contact dist. cap, hot coil (everything except the e-fan which I have sitting in box). The bottom line is that my 4 banger pulls harder than stock (verified by my bud who drives a bone stock '93 YJ), gets a slight increase in mileage, and with a slight increase in top end. These gains occur primarily at high RPMs, with a slight reduction in low RPM torque and a louder exhaust. The great thing about regearing (next on my list) is that you get both on-road and off-road performance improvements (with no increase in noise). Some folks get better mileage with the 4.88 ratio than the 4.10 because they have larger than stock tires and they're out of the powerband. Running a manual with 31s and 4.88 gears is the equivalent of having a tow package on a pickup. Better perrformance with minimal impact on mileage. My advice is to regear first, the add some engine mods over time, starting with the 4.0 TB. And if you get the itch to run 33s, you're all set as far as the gearing.
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why would providing more power by re-gearing hurt my mpgs?? does a regear require heavy tires in order not to hurt ur mpgs? are 31s too light? would regearing ever improve the mpgs?
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why would providing more power by re-gearing hurt my mpgs?? does a regear require heavy tires in order not to hurt ur mpgs? are 31s too light? would regearing ever improve the mpgs?
i think best mpg you get at stock ratio with stock tires - that's how it was calculated for 5th gear on the hwy and i think it's for 55mph/90kph if i'm not mistaking - so given you drive at that speed for a certain distance and compare the stock with a rig that has 33s the stock wins even though you have less rpms with the 33s. Dunno if that is the same for city driving. now if you have 31s, in that case I think (from what i recall) you're close to stock final ratio is with 4.56 - so that would give you closest to stock mpg - won't be identical, but the closest you could probably get. For city driving you could get better mileage with a lower ratio like 4.88s b/c your engine will need less torque/power to accelerate the vehicle, but that again depends on the style of driving, so the comparison only works if you are driving to achieve the same result (for example starting from a traffic light you will get to 35mph in the same amount of seconds) - but usually when you have a lower ratio you take advantage and accelerate faster and that results in a decrease in mpg (increase in fuel consumption) - and nothing really you can do about that other than putting a brick under the pedal. same with hwy driving, the faster you go the more power you need so the less mpg (and you would be able to go faster in the 5th with lower gears).