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Discussion Starter · #1 ·
every body knows that the new motor need more torque i have made a few adjudments like
knn air filter
the trotlle spacer
and the hyper tech programer

i still think we need more has anyone done andy cheap mods to their motor?
i know we can always trow a super charger but i think its to expensive--
 

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R E - G E A R !

:)
 

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gibson headers,gibson cat back,jet chip stage 2, cold air kit and 5.13 gears. I bought it with this already done. I did the gears also I found 2 bad plug wires so i put on some msd 8.5mm wires. I live in sac and allways going to the serras with the 5.13(im running a 6 spd and 35 km2) it pulls the hills good with cruz on. still I wish I could afford a s.c.
 

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R E - G E A R !

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This does not really solve any "hp/tq" problems. All this really does is correct for a tire diameter change to keep the Jeep in it's ideal power range.

The OP never stated he had a lift or larger tires, or even what gear ratios he has. So changing gears may do nothing or even hurt his power.

If you have larger tires, getting back to a ratio that puts the Jeep back into its power band is a great idea. But this still has NO effect on actually making the 3.8L any more powerful.
 

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This does not really solve any "hp/tq" problems. All this really does is correct for a tire diameter change to keep the Jeep in it's ideal power range.

The OP never stated he had a lift or larger tires, or even what gear ratios he has. So changing gears may do nothing or even hurt his power.

If you have larger tires, getting back to a ratio that puts the Jeep back into its power band is a great idea. But this still has NO effect on actually making the 3.8L any more powerful.
I simply would not recommend programmers or superchargers due to possible warranty complications. CAI's don't really add much either, so to me, re-gearing is the one recommendation that might help. I am not implying hp, but to the best of my knowledge there is nothing besides these things mentioned that will improve the (overall) acceleration issues that the 3.8 has.

I am curious as to how the re-gear may actually "hurt his power". That is new to me. Thanks for the input.
 

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Too steep of gears will make the engine spin too quickly through the power band causing the engine to spend too little time in the range where it actually makes power. This also narrows the effective power band.
 

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have you done anything with the exhaust? i had a local guy bend me a custom pipe for after the cat (cut stock pipe off) and moved the muffler to where the evap used to be , used a thrush muffler. with my CAI and the exhausti notced a difference around the 2.5 to 3.5k rpm ranges
 

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It gets your HP and torque to the rear wheels. Gears are the best way to achieve this.
Yes and no. Which was my whole point.

Gears only correct for tire size. They don't actually create any power. Hang with me a second and I will explain.

Adding an exhaust for example allows the engine to more spent gases out faster. Thus increasing its efficency and power no matter what tire/gear combo you have.

The best way to understand gears to to go ride a mountain bike around. Put the bike in the large ring on the front and small ring on the back. (this would be a 3:21 gear ratio for our conversation). The bike is VERY hard to get moving and get up to a certain speed. You must pedal very slow and hard to get moving, at some point you reach the effiency level, which in this gear is going to be a pretty fast speed. (very little power to the ground starting out, but lots at the top end)



Now change gears to the lowest gearing. (small front/large rear). Will call this the 6:41 ratio. The bike move forward very quickly, but only to a very low speed. You can pedal as fast as you can but only go so fast. This is much slower than the other gear ratio yet you are pumping as hard as you can. (lots of power to the ground up to 5mph, but nothing after that)

Most riders tend to settle somewhere in between. A gear that is easy enough to get moving, but achieve a decent speed, that is easy to maintain. In this case without a reference to what tire/gear combo the guy has. Telling him to change gears could make his Jeep worse.


Now, put Lance Armstrong on the bike instead of you.!!! He will be faster in ALL GEARS. That is the point of the thread, how to you make the engine better!!! (without changing the rider, that would include getting in better shape, etc)
 

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Yes, but gears allow what little HP we do have to actually get to the rear wheels. It won't create power but it will allow you to use what you have. Bolt ons (IE. catback, cai, throttle body spacer) are a total waste for a computer controlled fuel injected engine like ours. You have to modify the computer program for any of these to work. In the old days before computers, they would do a lot.
 

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I wasn't suggesting he use stock tires and go to a 5:13. Was assuming he would go to a 4:10 or 4:88 (if getting a little bigger wheel). The main reason for suggesting to re-gear was not to simply go out and instantly do it, rather that he might research what a different gear-set might help him achieve. :shaking:
 

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Bolt ons (IE. catback, cai, throttle body spacer) are a total waste for a computer controlled fuel injected engine like ours. You have to modify the computer program for any of these to work. In the old days before computers, they would do a lot.
That's why you need to incorporate a programmer into the mix so it can modify the computer program to make the changes for an aftermarket air intake/exhaust, larger tires, different gears....etc....etc.

What you have to remember is that manufacturers never program an engine to run at it's optimum performance. I'm not extremely knowledgeable in this area, but I'm sure other members can explain this in greater detail than I can, and can correct or expand on the information I provided.

An important point to remember is that any one product alone won't make much of a difference. An engine has 4 strokes: intake, compression, combustion and exhaust. Modifying only 1 phase (ie: adding an aftermarket air intake), only addresses 1/4 of the full equation and theirfore will only make a marginal increase in performance.

Like with any other area of Jeep performance you need to look at how products work as a whole to see the benefits your looking for.

Just as you can't just add 40" tires without first addressing a new lift kit, gears, axles etc....etc, the same holds true with making increases in horsepower and torque.
 

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I've been reading up a lot on the CAI topic and seems to get bashed a lot. I understand why a lot of folks would say there isn't a huge increase in performance, but I also notice most are "flat landers".

I can't help but think, based on fluid dynamics, that those of us at altitude (I'm at 6300') won't see a larger gain. The more volume helps with the less dense air. I could tell a slight improvement with the CAI and throttle body spacer (not just the noise volume).
 

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I've been reading up a lot on the CAI topic and seems to get bashed a lot. I understand why a lot of folks would say there isn't a huge increase in performance, but I also notice most are "flat landers".

I can't help but think, based on fluid dynamics, that those of us at altitude (I'm at 6300') won't see a larger gain. The more volume helps with the less dense air. I could tell a slight improvement with the CAI and throttle body spacer (not just the noise volume).
no gians here with the TB spacer (now a paper weight in the shop lol ) and minimal gains if any with the CAI the main reason i like the CAI is the reusable filter.
 

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I've been reading up a lot on the CAI topic and seems to get bashed a lot. I understand why a lot of folks would say there isn't a huge increase in performance, but I also notice most are "flat landers".
How many of those people have dyno'd thier rig afterwords? I think most peoples butt dyno hardly registers 5-10 hp increase. I bet most of those peolpe that bash just have not worked with building HP in vehicles to know what they are talking about..that is the problem with forums...So many people state their opinions as fact

now, the thing with a CAI intake is that by itself it really does nothing on a computer controlled fuel injected engine. The ECU will actually correct AFR's to compensate for the change in airflow negating the benifits. The only way to realize HP benifits from a CAI is by tunning the ECU for the new mod


I belive on a NA engine like ours that there may be slight HP increase. I am guessing 5-8 hp. I think the biggest performance increase would be better throttle response after tunning for it.
 

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no gians here with the TB spacer (now a paper weight in the shop lol ) .
yah, I think there aare better things to do with your money other then a TB spacer.

I do not belive they INCREASE power in any way. If anything, they may shift te power range down slightly making more power at a lower rpm. However, I belive it would only be a few rpm lower and only realy noticeable at the tourque peak. My point is, even though we want more low end power, I think it makes no difference at very low rpms where we need it offroad..just lowers the tourque peak.

With al that said, I do not belive it changes the power band as you are not changing the runner lengths. I think thy could even hurt throttle response as air would have even farther to travel.

As far as MPGs...it is possibe that fuel would have more time to atomize but again, you are not changing the injector distance.

In the end, Ibelive they have as much affect as magnets on the fuel line :lol:

Now, carburated engines, they would have an affect.


Until I see dyno results I put them in the myth file. You ma be able to see a light mpg increase and hp increase if you could tune for it but it would be so slight it still would not justify the cost. YOu coul get the same increase by buying a new clean airfilter and changing your driiving habits :D:beer:
 

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I gotta agree with Scott. Let's see some dyno graphs for this high $ junk. I want more low end torque not higher peak [email protected] RPM. I gotta rev the crap out of my Rubicon 2 door six speed to get it out of its own way and it has 4.10s. It's much more like driving my old Datsun 1600 Roadster than my 300-6cyl F-150. The cruise won't even hold going uphill in sixth. And don't get me started about towing. Sixth won't pull, double downshifts on mild hills, 8.5 mpg...
 
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