Throttle Pedal Spring Mod

Like many people, I'm not thrilled with the throttle response of the Jeep. I'm used to a sensitive throttle with a light return spring force on my motorcycle, so the Jeep feels like it requires excessive force and motion to get any response.

One common solution is a SprintBooster, which increases the sensitivity of the throttle by reducing the physical range of motion that the pedal must travel through to get to 100% throttle. You get more throttle with less foot movement. The Diablosport Trinity and InTune tuners also have a "throttle boost" feature that does the same thing as the SprintBooster. I have mine maxed out to +20%, meaning that at 10% physical travel, the computer sees 12% throttle position. At 50% physical travel, the computer sees 60% throttle position, etc.

This helped, the throttle return spring still feels excessively strong to me. I've noticed that sometimes my Jeep feels sluggish because I go to press the throttle with a certain amount of force that I expect to get the response I need, but the pedal barely moves. The pedal feels like it's always fighting to prevent me from accelerating more. I've read some discussion/instructions on removing one of the two throttle return springs, but I haven't seen a detailed walk-through yet. So here's pictures of what I did...


This is on a 2013 Wrangler. These instructions should work for all 2012+ Wranglers. I haven't looked at a pre-2012 throttle pedal, so I don't know if it's the same. If the throttle pedal is the same, then all the pedal modding instructions are the same, but you're on your own for accessing the throttle pedal in 2007-2010 Wranglers (different interior).


First, move the tilt steering all the way up and move the driver seat back to give you room to work.

Remove the panel under the steering wheel. It just pulls out.

http://www.uselesspickles.com/files/...ng_panel_1.jpg

http://www.uselesspickles.com/files/...ng_panel_2.jpg

http://www.uselesspickles.com/files/...ng_panel_3.jpg

http://www.uselesspickles.com/files/...ng_panel_4.jpg


Remove 2 bolts to get the metal plate out of the way.

http://www.uselesspickles.com/files/...late_bolts.jpg

http://www.uselesspickles.com/files/...te_removed.jpg


I have a base-model Wrangler. If you have more electrical options, you may have some additional wire harnesses in the way here that need to be disconnected/moved. Now you should have a clear view of and access to the throttle pedal assembly. I found it easiest to access the pedal assembly by kneeling on the ground outside of the driver-side door.


Disconnect the electrical connector on top of the throttle pedal assembly.

These two nuts hold the throttle pedal assembly in place (and you can see where the electrical connector was plugged into the pedal assembly just to the right of the top nut).

http://www.uselesspickles.com/files/...l_mod/nuts.jpg


I used a 1/4" drive ratchet with a deep well socket (10mm, IIRC) and was able to reach both nuts with it. It's tight near the top nut, but it worked. Other people have reported using extensions and universal joints to attack the top nut from an angle. The bottom nut is easy.

http://www.uselesspickles.com/files/...ket_wrench.jpg

http://www.uselesspickles.com/files/...al_removed.jpg


The fun part is removing the cover off the throttle pedal assembly. It's snapped into place with a million plastic latches. Be careful. The plastic is brittle. Only flex it as little as necessary to unlatch the latches. I cracked mine in one place, but it's still plenty solid.

http://www.uselesspickles.com/files/...ng_cover_1.jpg

http://www.uselesspickles.com/files/...ng_cover_2.jpg

http://www.uselesspickles.com/files/...ng_cover_3.jpg

http://www.uselesspickles.com/files/...ng_cover_4.jpg

http://www.uselesspickles.com/files/...er_removed.jpg


There's 2 springs, one nested inside the other. Pry them out, but be careful not to lose any of the small plastic parts that may fly out at the same time. Once the springs are removed, the pedal will easily slide off the pivot point and out of the housing. If that happens, then the white plastic pieces will fall out too. All of this can be easily avoided by just keeping the entire pedal assembly on a flat surface with your hand over/guiding the spring as you pry it out.

http://www.uselesspickles.com/files/...ng_springs.jpg

http://www.uselesspickles.com/files/...gs_removed.jpg


Pull the inner spring out of the outer spring.

http://www.uselesspickles.com/files/..._separated.jpg


The smaller inner spring has a foam strip used to keep it from rubbing against the outer spring (probably to avoid metal-on-metal noise). Keep the spring and foam strip in a safe place in case you want to return to stock.

Put the larger outer spring back in.

http://www.uselesspickles.com/files/...einstalled.jpg


Snap the cover back on. Double check all the plastic latches. I had to press pretty hard to get them all latched.

Reverse the pedal assembly removal instructions. Don't forget to plug the wiring connector back in :)

Drive for a day or two and see how you like it. For me, it initially felt way too soft and touchy. I got used to it quickly, but I still didn't really like it. I needed something in between.

So I went to a hardware store and found a spring that was similar to the smaller spring, but softer.

http://www.uselesspickles.com/files/...ter_spring.jpg


Stock big spring on the left, softer small spring next to it, and stock small spring on the right. The spring I got was from a manufacturer called "Hillman", size 1-9/16" x 1/2" x .054 (the last number must be the spring constant; bigger = stiffer).

http://www.uselesspickles.com/files/..._installed.jpg


Now, with the softer smaller spring installed, the throttle pedal feels "just right" to me.

If you replace either of the stock springs, make sure the replacement spring doesn't prematurely fully compress and bind up, preventing full travel of the throttle pedal.

I might have to check into this. I have an 2007 model so I will be able to compare to the newer JKs. When I get the chance I will post my findings.

Pickles is on FIRE!

but overall. does the throttle response feel different? or just a smooshier pedal?

I ask because since i geared BB, I have had to use more leg to hold the pedal down to maintain higher speeds. This may be the solution to turn her back in to the long distance cruiser that she used to be. (she still cruises pretty damn good)

I see a benefit of having a "stiffer" pedal while off road. While bumping and jarring around as jeeps do, the extra pedal tension would prevent accidental heavy acceleration. In other words, a lighter pedal, with increased throttle response is more sensitive to the small movements.

Now that you mention it, I notice the pedal's requirement for some force. That being said its not an issue for me (maybe my big feet help). I'll be interested to see how this work for you in the real world. '

Also..not sure the spring rate..the more open factory smaller spring could be stiffer than the smaller, more tightly coiled spring. I"m sure a simple device could be used to measure the force to compress both to compare. Too many variables for me to wrap my mind around. Seems like trial/error would be the best way.

I'll wait for pickles results then copy cat!

Im copy catting everyone on this forum.

Im about to try to tackle TIMMY's electric running boards.

The spring I used is definitely softer that the stock spring I removed. I took the stock spring with me to the hardware store for comparison to find one of roughly the size, and also squeezed all the springs to compare to the stock spring, looking for one that seemed about half as stiff. You can't make any assumptions about coil tightness and diameter, because springs can be made of different alloys or wire thickness. Also notice that my new spring is a bit shorter than the original. This causes it to be less pre-loaded than the stock spring, so that the initial effort to get the pedal moving is decreased as well. It seems to get rid of the feeling of the initial pedal movement having no effect.

I've been driving with this softer spring for a few days now, and I really like it for daily driving. It definitely improves *perceived* throttle response, just because it takes less effort to make things happen. You could get the same exact acceleration response out of the vehicle just by moving your foot with more force, but it's the increased ease of using the pedal that makes it feel more responsive. It doesn't feel "smooshy". It just feels normal to me. With the inner spring completely removed, it did feel too weak/smooshy/sensitive to me.

I'm not sure when I'll get off road again to test it on the trails, but I have the ability to easily adjust the throttle boost setting with my InTune if the throttle turns out to be too sensitive. If the softer spring without throttle boost is still a bit too touchy on the trails, then I'll probably just adapt to it.

It's a pretty low risk mod, as long as you are careful while prying the cover off the pedal assembly. It only took about 15 minutes to do the mod the second time to add the softer inner spring. It can be easily returned to stock if you don't like it.

It might be worth mentioning that if you put a new spring in there, make sure the new spring doesn't fully compress and bind up before the pedal reaches the end of its travel.

Quote:

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Originally Posted by UselessPickles

It might be worth mentioning that if you put a new spring in there, make sure the new spring doesn't fully compress and bind up before the pedal reaches the end of its travel.

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yikes, imagine the springs bind up an the pedal stays down? that is scary.

You guys are brave, screwing with the gas pedal

I think you'd have to really mess something up to get into a situation where the springs could prevent the pedal from returning.

Oh great... And now there is another "issue" that I didn't know I would question until someone pointed it out. Now I'm going to be driving around questioning if I like the weight of the throttle pedal and wondering if I need to do this mod!!!

I was just thinking to myself how well my Jeep was driving, now I'm questioning it because of this... Thanks Pickle.

I guess this is retribution for me pointing out to you how dumb it is that the speedo is on the left of the dash vs. the right and pondering that every time you drive (grin.) And let's not forget the volume control swap that I'm also considering. I didn't have an issue with the location of the volume control buttons until I learned how easy it was to swap them with the radio controls. Now when I pull up to a stop light from 60mph, EVERY TIME, I sit there and think "why haven't I swapped the volume control on the steering wheel so I can turn down the volume with my left hand while I down shift through the gears with my right!" (obviously both of these issues are only problems for us "real" drivers that have manual transmissions... oooohhhh, them's is fighten words, right!?! [ducking] :p)

Long-term follow up: I'm still happy with my modded pedal. Both for street driving and off road. I have not had any issues with the pedal being too sensitive. But I also only do moderate trails; no rock crawling, etc, so YMMV.

Also, the replacement spring has never bound up, caused my pedal to "stick", and it hasn't even made my balls fall off yet!

Quote:

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Originally Posted by UselessPickles

The spring I got was from a manufacturer called "Hillman", size 1-9/16" x 1/2" x .054 (the last number must be the spring constant; bigger = stiffer).

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BTW - I found out that the last number in the spring size (.054) is the diameter of the wire in inches that was used to make the spring. So while it's not directly the spring constant, a larger number here should generally make for a stiffer spring.

This has become one of my favorite mods. The lighter feel makes traffic a breeze. I was scared to screw with the gas pedal.