4bangerjp.com
General Forums => The Mess Hall => Topic started by: grumpygy on June 02, 2011, 09:02:56 PM
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Its an Article in JP Magazine.
They talk of how to get more power out of the 2.5
1. Let the engine breath. Air intake system. 5HP
2. 4.0 Throttle Body 5-10HP
3. Header Breath in Breath out. 5HP
4. A High flow Cat and After Cat System. 5-10 HP
5. Electric Fan. No increase listed
6. Hotter Ignition 5-10 HP
7. Gearing 5-10 HP
So far I've seen these on this site
8. Roller rocker Kit with a 1.6:1 ratio Stock is 1.5:1 Said to be good for 10HP.
9. Adjustable MAP Sensor Also good for 10HP.
10. 505 Performance turbo Kit good for 40HP.
So anybody else read that and what do you think
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the 2.5L is what it is, I don't think its ever really gonna be a power house. However I have no problem keeping up with everybody on the trail. Mine only has a cold air intake, and I've got 4.88's now instead of the stock 4.10's. My jeep does good for what it is.
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Well I did a little checking and they are nuts. Roller rocker that they recommend if you can even find them run around $700. The turbo Kits when you get it with all you need right at $3,000 and it is hard to find.
That adjustable MAP Sensor I could only find it as a Discontinued Item. So that tells me it did not sell very well or broke easy.
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You might look into some of the build threads here, I know some guys here have done turbo's on their Jeeps heh
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Its an Article in JP Magazine.
They talk of how to get more power out of the 2.5
1. Let the engine breath. Air intake system. 5HP
2. 4.0 Throttle Body 5-10HP
3. Header Breath in Breath out. 5HP
4. A High flow Cat and After Cat System. 5-10 HP
5. Electric Fan. No increase listed
6. Hotter Ignition 5-10 HP
7. Gearing 5-10 HP
So far I've seen these on this site
8. Roller rocker Kit with a 1.6:1 ratio Stock is 1.5:1 Said to be good for 10HP.
9. Adjustable MAP Sensor Also good for 10HP.
10. 505 Performance turbo Kit good for 40HP.
So anybody else read that and what do you think
first off that ads to about 70 HP (keeping the turbo out), not going to happen just with those changes that's a 60% increase in power, that means you need 60% more fuel flow (pretty much that's how you make more power with more air and fuel unless you eliminate losses).
stock roller rockers are 1.6 but old ones due to age they deform and deflect and the real deal is 1.5x where x is 0 to 3 with 3 the best case scenario (check my roller rockers project, i measured the valve travel). you can probably get 10HP out of 1.7 rockers (given that you do add more fuel). I just don't see those other 60HP coming out of nowhere just with air filter, t/b, ignition (no way that gives you 10HP, maybe if the one that was there was busted then yes, but that's more on the lines of getting back the stock ponies) and so on.
it's simply not possible without some internal mods and extra fuel to get 190 HP out of the 2.5, getting back lost HP it's a different story (for example you replace a clogged air filter with a high flow CAI - and boom, 10HP - well, 5 or 6 of those were actually there if you'd just replace the stock filter with a new one).
but things do add up and it will improve but not to that level (just to manage your expectations).
probably the most realistic one is the turbo, you can make more than 40HP so that i would say it's on the conservative side
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So gearing increases engine output by 5-10HP? Funny, I always thought it just helped get the engine back into its correct power band.
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So gearing increases engine output by 5-10HP? Funny, I always thought it just helped get the engine back into its correct power band.
All magazines inflate their numbers to help support claims by the sponsors. Who's going to want to buy performance parts if all they're getting is 1-3hp for every $100 spent. Unless you spend big bucks for the forced induction people will realize it's not really worth it.
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So gearing increases engine output by 5-10HP? Funny, I always thought it just helped get the engine back into its correct power band.
it probably will show an increase if they did not update the parameters with the new gearing ratio,produced horsepower will remain the same, just the logged output will be different (and erroneous of course).
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Hence why I don't bother buying or reading magazines anymore... I realize aftermarket modification companies like to inflate their numbers to help their product sell, but to imply that regearing somehow magically makes the power output of the engine increase is ludicrous. It'd be the same as if I were to claim that removing 500 pounds of concrete that I had in the bed of my Jeep suddenly increased my engine output by 20HP; the engine itself is unchaged as is its output, it just doesn't have to work as hard.
Maybe I could use their logic and add a couple to the list:
Drive downhill --> 5-15HP (depends on steepness of hill)
Smaller diameter tires --> 5-10HP
Replace steel wheels with alloys --> 5HP
Shift transfer case into 4LO --> 50HP
:koolaid:
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I was reading that someone posted over on cherokeeforum, it was a home brew mod where a guy took aluminum sheet and cut it up to place it in between the exhaust and intake manifold to help reduce the heat on the intake from the exhaust. His calculations before and after the shield showed a 10 degree drop when using it. Seems like a very inexpensive way if you have aluminum sittn around to gain a few hp and slightly better mpg from the cooler intake.....im sure exhaust wrap would do bout the same too though
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I was reading that someone posted over on cherokeeforum, it was a home brew mod where a guy took aluminum sheet and cut it up to place it in between the exhaust and intake manifold to help reduce the heat on the intake from the exhaust. His calculations before and after the shield showed a 10 degree drop when using it. Seems like a very inexpensive way if you have aluminum sittn around to gain a few hp and slightly better mpg from the cooler intake.....im sure exhaust wrap would do bout the same too though
You can buy reflective foil duct tape. It's used to wrap up HVAC duct work. I've used it on my air tube before. It's cheap to buy and does work but it's not going to make miracles. Makes a mess when it ages a bit and cracks then dust get inside it and collects.
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The reality of the 2.5L is that it works just fine offroad, but it suffers at highway speeds. You can improve HP, but typically, it is done by sacrificing low end torque (which is what you use when you wheel). Now, I have a ton of mods on my engine with more coming down the road, and what I can tell you is this:
1. All the small mods help a bit here and a bit there, and many of them work better together than by each own
2. Gearing will not increase HP, but WILL increase performance (you'll FEEL more power). I would say short of the turbo, it's the most felt mod, but it is also one of the more expensive ones.
3. If you want more power and do not want to use force induction, you can also try increasing the compression ratio. 10.1 to 10.5 seems to be a good range, but you will also need to run better fuel (91 octanes or more)
4. To have more power, like Sharp said, you need more air AND more fuel, and a way to ignite that mix; if you only increase one without the other, you will not get more power (the PCM will compensate as much as it can to be close to the 14.7 mixture, but it can only compensate so much).
Look online for what people have already done; there are a couple of turbo builds, I know Sharp was working on a supercharger (you ever finished that, Sharp?), and a someone increased compression ration not long ago. Everyone here will let you know the good, the bad and the ugly of what they did, and you can choose which is the better option for you.
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first off that ads to about 70 HP (keeping the turbo out), not going to happen just with those changes that's a 60% increase in power
Even with the low end numbers that's 50 hp. Ain't happening. Probably the most you'll see short of a turbo/compression/cam mods is 15 hp. To get more with those mods (in any 4-banger) will require spinning a higher rpm to see those bigger numbers, which isn't really the Jeep's ball of wax.
Ours holds speed on the highway a little better since I added an Airaid intake. I might do a Banks header and exhaust and high output ignition, but that'll be about all.
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Kind of wish they would have checked with folks who actually do work on 2.5's. The guys who wrote the Article even said they felt the best way to improve a jeep was with a bigger engine.
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I am happy with my 2.5 on the trails. The squirrels just aren't gonna break axles and driveshafts, etc. I have put a header and muffler on it, and use quality plugs, filters, etc. Runs great and is reliable. It is what it is on the highway, and I still love it... :beers:
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I am happy with my 2.5 on the trails. The squirrels just aren't gonna break axles and driveshafts, etc. I have put a header and muffler on it, and use quality plugs, filters, etc. Runs great and is reliable. It is what it is on the highway, and I still love it... :beers:
Im with ya, i for some reason have a passion for this lil 4banger and cant part ways with it, i can still run 75 down the hwy fine in mine
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Im with ya, i for some reason have a passion for this lil 4banger and cant part ways with it, i can still run 75 down the hwy fine in mine
I hear ya guys heh
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Just got 18.75 mpg on a 200 mile drive home from a local offroad park. This is with 36" TSL's :weee:
Of course I did drive a steady 60mph with lots of drafting :whistle:
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Just got 18.75 mpg on a 200 mile drive home from a local offroad park. This is with 36" TSL's :weee:
Of course I did drive a steady 60mph with lots of drafting :whistle:
I think its our wonderful So Il air cause thats about what i average,but im on 31 tsls lol
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I read that article and was on here researching the adjustable MAP.
I might do the DIY one, but ain't gonna buy one.
Interesting that their info is wrong on the rockers, I have found erroneous info in their articles before.
So, are you guys saying I could replace the rockers with new oem ones and see an improvement?
2001 TJ with 97500 miles.
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So, are you guys saying I could replace the rockers with new oem ones and see an improvement?
i don't know for sure, i'm just assuming the ones i measured travel for were coming at 1.52 due to age, but i doubt new ones will be at 1.6, if you want that ratio better go with roller rockers.
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I was looking at the injector swap thread, the chart lists part numbers for the Ford injectors, but they don't work anywhere I've tried to look.
Anybody swapped injectors on a TJ?
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For a long time I was happy with the little 2.5L, but eventually with bigger tires and bigger obstacles it got cumbersome. Especially bad on greasy midwest hillclimbs. I had regeared, throttle body swap, injectors, elec. fan, etc. In the end it was either $$$ on a motor swap, supercharger, or a different Jeep. I went with a different Jeep. After wheeling with 4.0L+ power I'll never go back.
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For a long time I was happy with the little 2.5L, but eventually with bigger tires and bigger obstacles it got cumbersome. Especially bad on greasy midwest hillclimbs. I had regeared, throttle body swap, injectors, elec. fan, etc. In the end it was either $$$ on a motor swap, supercharger, or a different Jeep. I went with a different Jeep. After wheeling with 4.0L+ power I'll never go back.
I test drove a 03 rubicon today... the yj may be leaving the family soon :wall: :'(
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I test drove a 03 rubicon today... the yj may be leaving the family soon :wall: :'(
If I had a relatively stock YJ, I'd probably trade it for a Rubicon. The only problem with the 4.0L is the multi-pak ignition issues.
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If I had a relatively stock YJ, I'd probably trade it for a Rubicon. The only problem with the 4.0L is the multi-pak ignition issues.
I don't know is the rubi 44 just a beefed up 35 in the rear? and the front, doesn't it use D30 stuff?
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I don't know is the rubi 44 just a beefed up 35 in the rear? and the front, doesn't it use D30 stuff?
center is D44, tubes are D35, disk brakes, 30 spline axle shafts
same for front.
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I don't know is the rubi 44 just a beefed up 35 in the rear? and the front, doesn't it use D30 stuff?
The rear is a D44 with D35 axle tubes and bearings. The axles are 30 spline 1.30" and are the exact same shafts in the XJ D44. The front is a D44 with D30 inner knuckles (some people call them C's) and outers.
It's still an upgrade. Truss the rear axle and it will be fine. The Rubicon's did have issues with the front axle U-joints failing though. I forget if there was a recall on it or not. I know Chrysler tried to ignore the issue and for a time wouldn't do warranty work on them. The differentials are for higher ratios so the gears it uses are 'Thick'. This somewhat limits your choices on gears unless you either swap out the lockers or add a shim. Although I think you can get thick gears in 5.13's now. Not sure about 5.38's. Still not too many companies make gears for them.
If you're attached to your YJ then consider putting a 2-speed Atlas in it and swapping axles. Or at least swapping in a D44 or 8.8" in the rear.
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The rear is a D44 with D35 axle tubes and bearings. The axles are 30 spline 1.30" and are the exact same shafts in the XJ D44. The front is a D44 with D30 inner knuckles (some people call them C's) and outers.
It's still an upgrade. Truss the rear axle and it will be fine. The Rubicon's did have issues with the front axle U-joints failing though. I forget if there was a recall on it or not. I know Chrysler tried to ignore the issue and for a time wouldn't do warranty work on them. The differentials are for higher ratios so the gears it uses are 'Thick'. This somewhat limits your choices on gears unless you either swap out the lockers or add a shim. Although I think you can get thick gears in 5.13's now. Not sure about 5.38's. Still not too many companies make gears for them.
If you're attached to your YJ then consider putting a 2-speed Atlas in it and swapping axles. Or at least swapping in a D44 or 8.8" in the rear.
thats what puts in at a cross roads, I have a friend that has givin up on his scout project wants to practically give it to me which would be a source of d44s and a t18 trans (trans would go in a willys I think a 5 speed is better for the 2.5 with road use). but then its re gear lockers.... and the rust.. but the 2.5l has never let me down and surprised me... a 4:1 atlas would be nice. but then that gets low for the mud but rubi would be in same position. My indecisiveness is killing me right now. I know I have 1 more mod to do to the yj before it goes anywhere though :pot:....
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thats what puts in at a cross roads, I have a friend that has givin up on his scout project wants to practically give it to me which would be a source of d44s and a t18 trans (trans would go in a willys I think a 5 speed is better for the 2.5 with road use). but then its re gear lockers.... and the rust.. but the 2.5l has never let me down and surprised me... a 4:1 atlas would be nice. but then that gets low for the mud but rubi would be in same position. My indecisiveness is killing me right now. I know I have 1 more mod to do to the yj before it goes anywhere though :pot:....
That's what makes the Atlas 4 speed or a Klune so important to the 2.5 (small motor) crowd. Plenty of gear choices for whatever terrain you encounter.
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If you're attached to your YJ then consider putting a 2-speed Atlas in it and swapping axles. Or at least swapping in a D44 or 8.8" in the rear.
(http://i196.photobucket.com/albums/aa185/95yjman/HPIM2952.jpg)
Done :biggrin:
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Done :biggrin:
you might wanna cut them u-bolts flush with the nuts, gain another 1 or 2 inches of clearance
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thats what puts in at a cross roads, I have a friend that has givin up on his scout project wants to practically give it to me which would be a source of d44s and a t18 trans (trans would go in a willys I think a 5 speed is better for the 2.5 with road use). but then its re gear lockers.... and the rust.. but the 2.5l has never let me down and surprised me... a 4:1 atlas would be nice. but then that gets low for the mud but rubi would be in same position. My indecisiveness is killing me right now. I know I have 1 more mod to do to the yj before it goes anywhere though :pot:....
Here are ratios with the NP231 (2.72) and with an Atlas (4.3), assuming 4.56 axle gears:
in 1st
48.74 77.06
in 2nd
28.90 45.69
in 3rd
17.98 28.43
in 4th
12.40 19.61
in 5th
10.54 16.67
Unless you are running in mud in 3rd (you might as well be in 4hi, first gear) or 4th, the Atlas 4.3 will provide a similar ratio. Also, the Atlas can be run in any gear but the 4:1 Rubi transfer case, due to the 4:1 planetary assembly, probably gets abused in the higher gears (like the Tera 4:1).
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you might wanna cut them u-bolts flush with the nuts, gain another 1 or 2 inches of clearance
Already done, just a picture right after the swap happened heh
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Already done, just a picture right after the swap happened heh
:thumb:
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Here are ratios with the NP231 (2.72) and with an Atlas (4.3), assuming 4.56 axle gears:
in 1st
48.74 77.06
in 2nd
28.90 45.69
in 3rd
17.98 28.43
in 4th
12.40 19.61
in 5th
10.54 16.67
Unless you are running in mud in 3rd (you might as well be in 4hi, first gear) or 4th, the Atlas 4.3 will provide a similar ratio. Also, the Atlas can be run in any gear but the 4:1 Rubi transfer case, due to the 4:1 planetary assembly, probably gets abused in the higher gears (like the Tera 4:1).
I doubt anyone runs much in 3rd in the mud; I do cruise in 3rd between mud pits, though (sometimes even 4th). But when I reach the mud, it's 1st (2nd if I'm lucky to get it up to speed to shift, but most often than not, it's 1st).
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usually use 2nd gear for deep mud, with the synchronized 1st downshifting into first is a possibility if you start to run out of power (unlike the willys). first gear low is abit low to get momentum built up. gaining speed to shift to second. in low range starting in 2nd is easy enough... the rubi would be nice but there is something to being different and surprising people.
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usually use 2nd gear for deep mud, with the synchronized 1st downshifting into first is a possibility if you start to run out of power (unlike the willys). first gear low is abit low to get momentum built up. gaining speed to shift to second. in low range starting in 2nd is easy enough... the rubi would be nice but there is something to being different and surprising people.
It sounds like an Atlas 4.3 would work great for you. You would still have that second gear ratio, only now in third.
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:thumb:
But now I'm wanting to throw the thing on tons :brick: the D44 will last while I compile parts heh
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4:1 is too low for trail riding in the Midwest from what I've seen. The Rubi's are always struggling with the hill climbs. 2.72 is pretty good if the axles are geared properly.
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4:1 is too low for trail riding in the Midwest from what I've seen. The Rubi's are always struggling with the hill climbs. 2.72 is pretty good if the axles are geared properly.
If there is a problem with running the manual tranny Rubis in 3rd and 4th in low range (and there very likely is, just like with the Tera 4:1), I can see how they would struggle. But the 2.72 gearing is actually still there in 2nd, 3rd, and 4th. If these Rubis have automatic transmissions, then maybe there is no easy workaround and it is just too low.
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I just hate fallowing the rubis with their 4:1. :guns: will idle in first gear the hole day so you have to stop wait pull forward and stop again... definitely the most anything part of the bighorns jeep jamboree since 98% of the jeeps where rubis. :rant:
as it is for hills i usually run 2nd gear low range maybe third. first is too low for hills (as mentioned above). actually when snow wheeling I had to go 1st gear high range to maker it up a few hills.
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I just hate fallowing the rubis with their 4:1. :guns: will idle in first gear the hole day so you have to stop wait pull forward and stop again... definitely the most anything part of the bighorns jeep jamboree since 98% of the jeeps where rubis. :rant:
as it is for hills i usually run 2nd gear low range maybe third. first is too low for hills (as mentioned above). actually when snow wheeling I had to go 1st gear high range to maker it up a few hills.
1st high range is almost identical to 3rd low range in a 2.5 YJ with the NP231 (within 0.35%) but using 1st in high range will protect the planetaries and would probably have less parasitic drivetrain loss. I wonder how much loss there is? It seems to be noticeable.
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I love the Atlas 2 speed, I can tach it out in low range in any gear, 5th in low range gives it a bit more oomp than 1st in high range so in essence I have a 10 speed tranny, The big beast definitely climbs long sand hills better than my little Jeep.
Where the little one chokes and digs in on ling hill climbs in 3th low the big one just keeps screaming and climbing in 4th low and has enough momentum left at the top of the hill to make a turn and climb another one
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Most of my wheeling I use the Klune (4:1) But I know how to use the tranny. 1st is pretty low for just a bumpy dirt road. I try and not go to slow if the trail is easy. I agree with others in just because you can go slow does not mean you need to. But with the auto crowd they don't have much of a choice unless they take it out of low.
I still say 2 boxes are better than one. 20 forward gears VS. 10. :thumbsup:
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I love the Atlas 2 speed, I can tach it out in low range in any gear, 5th in low range gives it a bit more oomp than 1st in high range so in essence I have a 10 speed tranny, The big beast definitely climbs long sand hills better than my little Jeep.
Where the little one chokes and digs in on ling hill climbs in 3th low the big one just keeps screaming and climbing in 4th low and has enough momentum left at the top of the hill to make a turn and climb another one
Doing the math (have a spreadsheet already set up), 4th in your big Jeep is 33.6:1. Adjusted from 39.5s to 33s this would be 28:1. 3rd in your small Jeep is 33.6:1. Adjusted from 35s to 33s this is 31.7:1, about 13% lower. I´ve also found a gear around 28 or 29:1 with my 33s to be ideal for hills and wet ledges, almost like magic. It's amazing how seemingly small differences in gearing can make such a difference.
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Doing the math (have a spreadsheet already set up), 4th in your big Jeep is 33.6:1. Adjusted from 39.5s to 33s this would be 28:1. 3rd in your small Jeep is 33.6:1. Adjusted from 35s to 33s this is 31.7:1, about 13% lower. I´ve also found a gear around 28 or 29:1 with my 33s to be ideal for hills and wet ledges, almost like magic. It's amazing how seemingly small differences in gearing can make such a difference.
it's the other way around, the smaller the tire the lower the ratio (if i understand correctly what you meant by "adjusted from 39.5 to 33")
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It's ok, the smaller tire would need the numerically lower gear ratio to move the vehicle at the same speed.
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It's ok, the smaller tire would need the numerically lower gear ratio to move the vehicle at the same speed.
i see what you mean now.
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Looking at the calculator again something does not jive, my speed and rpm at 65 is way off. in 6th at 65 the Jeep turns about 26-2700 rpm and not 2172 as the calculator shows. As far as rubicons go they could simply shift to high range or rev them up some more. The terra lo has the rpm restriction on it never hears of that on a 231 transfer case it has a different planetary setup than the stepped gears in a terra lo. Seems to me it's more a problem of in experienced drivers to lazy or afraid to shift to high range. Also truth be told for mud wheelin a 4 to 1 transfercase is not the way to go
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Looking at the calculator again something does not jive, my speed and rpm at 65 is way off. in 6th at 65 the Jeep turns about 26-2700 rpm and not 2172 as the calculator shows. As far as rubicons go they could simply shift to high range or rev them up some more. The terra lo has the rpm restriction on it never hears of that on a 231 transfer case it has a different planetary setup than the stepped gears in a terra lo. Seems to me it's more a problem of in experienced drivers to lazy or afraid to shift to high range. Also truth be told for mud wheelin a 4 to 1 transfercase is not the way to go
what gear and ratio (for transmission) and what ratio do you have in your axle?
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Also truth be told for mud wheelin a 4 to 1 transfercase is not the way to go
Especially if you need to use reverse in the mud!
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As far as rubicons go they could simply shift to high range or rev them up some more.
And lose the use of the lockers, unless they're one of the rare few to mod the switches to work in 4hi.
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One of the best mods for a Rubicon is to ditch the stock locker switch and install 2 switches for the lockers Either the style arb uses or whatever tickles one fancy. The wiring is fairly simple and easy to do that way you can use either locker when ever you want too