Drives like crap

rogerk93 · Aug 10, 2015

I have a 14 jku that drives pretty bad. It has superchip 93 tune, (I use 93 octane gas),sprint booster always in aggressive mode. 33x12.5 bfg km2 used mobile 1 extended performance since the first oil change. Added a transmission cooler but I'm still getting lack of power until 4,000 rpm then it picks up pretty good. Gear change is sluggish at times. I recently changed my gear oil. Gears are currently stock 3.21. I'm thinking about changing the spark plugs but not sure if that will help.

wayoflife · Aug 10, 2015

I hope you don't take this the wrong way but, had you just upgraded your gears to something like a set of 4.56 or even 4.88 instead of throwing a ton of money at your Jeep with useless gadgets, expensive gas and bolt do-dads, you wouldn't be complaining about your lack of power now.

rogerk93 · Aug 10, 2015

wayoflife said:
I hope you don't take this the wrong way but, had you just upgraded your gears to something like a set of 4.56 or even 4.88 instead of throwing a ton of money at your Jeep with useless gadgets, expensive gas and bolt do-dads, you wouldn't be complaining about your lack of power now.

Haha No worries glad you gave your opinion. I'm waiting to re-gear till around March that's when I'm going to lift my rig add 37's and adding a rear locker with 5:13. If the problem is coming from the gear configuration I guess I just have to wait. Thanks.

wayoflife · Aug 10, 2015

rogerk93 said:
Haha No worries glad you gave your opinion. I'm waiting to re-gear till around March that's when I'm going to lift my rig add 37's and adding a rear locker with 5:13. If the problem is coming from the gear configuration I guess I just have to wait. Thanks.

Okay, sounds like you've got a plan in mind for the future. Unfortunately, nothing is really going to help you for now and I would just sit tight until you make your upgrades.

jeeeep · Aug 10, 2015

rogerk93 said:
I have a 14 jku that drives pretty bad. It has superchip 93 tune, (I use 93 octane gas),sprint booster always in aggressive mode. 33x12.5 bfg km2 used mobile 1 extended performance since the first oil change. Added a transmission cooler but I'm still getting lack of power until 4,000 rpm then it picks up pretty good. Gear change is sluggish at times. I recently changed my gear oil. Gears are currently stock 3.21. I'm thinking about changing the spark plugs but not sure if that will help.

x2 on what Eddie said and I would recommend getting rid of the sprint booster and the 93 tune.

if you had performance coils and wires to allow for a better spark plug gap you would get better burn from using 93 octane - not more power, just better use of the 93 octane. As of now you're just putting money in the tank that you could be saving towards gears.

you may also be causing other issues to the ECU by using the 2 tuners together as they both try to do the same thing just different methods.

3.21 and anything bigger than the stock tire will not perform well until you change gears.

rogerk93 · Aug 10, 2015

jeeeep said:
x2 on what Eddie said and I would recommend getting rid of the sprint booster and the 93 tune.

if you had performance coils and wires to allow for a better spark plug gap you would get better burn from using 93 octane - not more power, just better use of the 93 octane. As of now you're just putting money in the tank that you could be saving towards gears.

you may also be causing other issues to the ECU by using the 2 tuners together as they both try to do the same thing just different methods.

3.21 and anything bigger than the stock tire will not perform well until you change gears.

That's what I thought regarding the 2 tuners I do notice a difference in performance that helps on the road and off road. But at times when I'm at 2500 rpm then gun it, it seems like it revs a little before it actually takes off. I thought I had gears slipping but I hooked up a camera to look at the speedometer as it happens and it is actually accelerating rapidly just sounds a little weird.

Clark Griswold · Aug 10, 2015

I have a 13 with 33's and 3.21 stock gears with no tune and it works great, downshifted a lot over 70mph but I started driving in manual shift mode and the downshifting pretty much went away and my mileage jumped 1 - 1.5mpg. You might want to consider shifting yourself for better performance until you get new gears. JMO.

JakeJK · Aug 10, 2015

jeeeep said:
x2 on what Eddie said and I would recommend getting rid of the sprint booster and the 93 tune.

if you had performance coils and wires to allow for a better spark plug gap you would get better burn from using 93 octane - not more power, just better use of the 93 octane. As of now you're just putting money in the tank that you could be saving towards gears.

you may also be causing other issues to the ECU by using the 2 tuners together as they both try to do the same thing just different methods.

3.21 and anything bigger than the stock tire will not perform well until you change gears.

I run 93 octane in my 2010 because otherwise it makes an awful knocking sound, I think it helps regardless of the performance wires and spark plug gap

A.J. · Aug 10, 2015

Higher octane fuel does not make more horsepower. It burns slower and and will not detonate as quickly allowing for more air fuel timing w/out detonation. The detonation or knocking is from the mixture detonating too soon and basically trying to drive the piston back down the cylinder before it gets to the top of the cycle.

A.J. · Aug 10, 2015

Stacking the tuners is probably a good portion of your drive ability problem. If you think about your jeeps ecu like a calculator solving a math problem over and over. It takes information from all the sensors and adjusts the air fuel spark to make it run. If one of these sensors is out of range a little it really messes up the math. So let's say your throttle position sensor is poorly grounded or just a bit off on voltage or you have 2 different tuners changing the math slightly. It is going to cause the math to break down. I take the TPS as an example because it is probably the most influential with acceleration downshifting etc etc. I have seen something as simple as adding an extra ground to a throttle body make a big difference in how it performs.

JakeJK · Aug 10, 2015

A.J. said:
Higher octane fuel does not make more horsepower. It burns slower and and will not detonate as quickly allowing for more air fuel timing w/out detonation. The detonation or knocking is from the mixture detonating too soon and basically trying to drive the piston back down the cylinder before it gets to the top of the cycle.

I'm confused as to how a cylinder would detonate too early in a gas burning engine? What you said makes sense when referring to a Diesel engine but am I wrong when I believe that the spark plugs determine when the compressed mixture explodes?

A.J. · Aug 10, 2015

JakeJK said:
I'm confused as to how a cylinder would detonate too early in a gas burning engine? What you said makes sense when referring to a Diesel engine but am I wrong when I believe that the spark plugs determine when the compressed mixture explodes?

If the air/ fuel mixture explodes in the cylinder too soon it tries to drive the piston at the wrong time. Timing and spark also play a huge roll in this. Having higher octane fuel allows for a little longer window to get air and fuel into the cylinder. This is why when using power adders like superchargers, turbos and nitrous oxide you have to retard timing use higher octane fuel and lower compression so it doesn't get lit too soon. The more air and fuel you get in the more power you can make, but any pre detonation is even more severe and can cause big time damage. In theory the lower the octane fuel you can put in and not detonate would make more horsepower, but the tuning window would be very very small.

JakeJK · Aug 11, 2015

A.J. said:
If the air/ fuel mixture explodes in the cylinder too soon it tries to drive the piston at the wrong time. Timing and spark also play a huge roll in this. Having higher octane fuel allows for a little longer window to get air and fuel into the cylinder. This is why when using power adders like superchargers, turbos and nitrous oxide you have to retard timing use higher octane fuel and lower compression so it doesn't get lit too soon. The more air and fuel you get in the more power you can make, but any pre detonation is even more severe and can cause big time damage. In theory the lower the octane fuel you can put in and not detonate would make more horsepower, but the tuning window would be very very small.

Okay makes sense now, because the previous cylinder allows the next cylinder more time to pump gas and air into the next cylinder before the previous cylinder finished combusting correct? Now it makes sense

A.J. · Aug 11, 2015

JakeJK said:
Okay makes sense now, because the previous cylinder allows the next cylinder more time to pump gas and air into the next cylinder before the previous cylinder finished combusting correct? Now it makes sense

It is all about the timing of the explosion when the piston gets to the top of the cylinder. If it compresses and ignites too soon it will rattle, too late loss of power. Doesn't matter if it is 1 cylinder or 12.

rsmwrangler · Aug 11, 2015

Remove the spring booster while leaving the superchips tune, the condition should improve, also the superchip tunes are way too aggressive on engine timing, at least in other platforms where V8's are involved, I know people that run their 91 tune with 93 octane to avoid engine ping. You migth want to try how she feels with the stock tune, all you need to do is adjust the tire size worst case and that's about it.

I run 91 myself, don't really care about the 87 octane piss we get around here, and not only I can see timing advance, knock retard, fuel trims, mass aircharge, torque management etc, etc, I can change and improve what the factory did, I don't use the kiddy type superchip stuff, I use a pro Tuning software to get the job done.

I run 33's with the factory 3.21's and my own tune, no complaints about power so far, and I'll venture to say if you were staying with 33's, you didn't need to regear, I love how the new engine/trans feel like compared to the old 3.8 or 3.7 engines/trans setup.

mo0s3 · Aug 11, 2015

I ran the 3:21 for about a week, went to 4:88 and I have to say Eddie is correct. Night and day. Seems to be a better crawl ratio as well. And correct me if I'm wrong but if you have a Dana 30 it would not be wise to go more then 4:88 right ?

Edit: 2015 JKU sport
35" Toyo M/T
2 1/2 lift
4:88 gears

JakeJK · Aug 11, 2015

mo0s3 said:
I ran the 3:21 for about a week, went to 4:88 and I have to say Eddie is correct. Night and day. Seems to be a better crawl ratio as well. And correct me if I'm wrong but if you have a Dana 30 it would not be wise to go more then 4:88 right ?

Edit: 2015 JKU sport
35" Toyo M/T
2 1/2 lift
4:88 gears

I know jeep people don't care about this but, did going from 3.21s to 4.88s decrease your gas mileage any? If so how much

NFRs2000NYC · Aug 11, 2015

rogerk93 said:
I have a 14 jku that drives pretty bad. It has superchip 93 tune, (I use 93 octane gas),sprint booster always in aggressive mode. 33x12.5 bfg km2 used mobile 1 extended performance since the first oil change. Added a transmission cooler but I'm still getting lack of power until 4,000 rpm then it picks up pretty good. Gear change is sluggish at times. I recently changed my gear oil. Gears are currently stock 3.21. I'm thinking about changing the spark plugs but not sure if that will help.

You bought a jeep, not a mustang. Also, the bolded comment tells me that you don't seem to know much about modern engines. The only thing that will help you is changing out your gear ratio.

NFRs2000NYC · Aug 11, 2015

JakeJK said:
I know jeep people don't care about this but, did going from 3.21s to 4.88s decrease your gas mileage any? If so how much

Depending on how you drive, you may not lose any, and actually increase MPG because you have less throttle input for certain situations. My 4.10s and 35" tires get better gas mileage than my 3.21s did with 33s.

JakeJK · Aug 11, 2015

[QUrOTE=NFRs2000NYC;564395]Depending on how you drive, you may not lose any, and actually increase MPG because you have less throttle input for certain situations. My 4.10s and 35" tires get better gas mileage than my 3.21s did with 33s.[/QUOTE]
i tried to tell me dad that haha he didn't believe me

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