Increase in mpg w/ 4.7L TB

TIJKK1220 · **Posted:** Sat Aug 23, 2014 1:27 pm

To answer your question Tom, it has a lot to do with how the computer manages the power. The ECS on our KK's is crazy and won't let us have any fun lol
All I have that is different is the 4.7 throttle. It would chirp the tires before but I'd never get both moving long enough to spin them for long

I'm also fully armored with full skids and steel bumpers front and rear. I'd expect it to be a dog but it's peppier than when it was just bone stock

Bmxer524 · **Posted:** Sat Aug 23, 2014 1:50 pm

I'm starting to really think about doing this. Any 11+ KK owners do it yet?

Gageraid · **Posted:** Sat Aug 23, 2014 1:58 pm

Bmxer524 wrote:

I'm starting to really think about doing this. Any 11+ KK owners do it yet?

Looks like everyone has been a 2008 so far. I don't see any reason why it wouldn't work on a "newer" KK. Same throttle body, just slightly different ECU/PCM (blah blah blah).

lfhoward · **Posted:** Sat Aug 23, 2014 3:02 pm

I'm interested but will hold off on doing any engine modification until after my 3 year, 100K mile warranty on my new engine is up. I'm sure the 4.7 TB would void my warranty. I'll definitely keep an eye on this thread, though. I am interested if the hp & mpg gains will be short lived until the computer re-learns, or if you'll begin to notice any other changes/problems down the line. I hope it's a permanent, safe, effective mod for you all!

Gageraid · **Posted:** Sat Aug 23, 2014 3:59 pm

lfhoward wrote:

I'm interested but will hold off on doing any engine modification until after my 3 year, 100K mile warranty on my new engine is up. I'm sure the 4.7 TB would void my warranty. I'll definitely keep an eye on this thread, though. I am interested if the hp & mpg gains will be short lived until the computer re-learns, or if you'll begin to notice any other changes/problems down the line. I hope it's a permanent, safe, effective mod for you all!

Just filled up for 19.2 m.p.g. a few minutes ago. 30 percent highway, and the rest city.
More than impressed.

TIJKK1220 · **Posted:** Sat Aug 23, 2014 5:21 pm

More than likely your dealer wouldnt be able to tell the difference. They look identical Ifhoward

Scar0 · **Posted:** Sun Aug 24, 2014 4:14 am

I did not make it to the parts store to get a new intake tube today. But I did drive it.
With only 1 day of driving 20 miles, the system is still learning.
Not real sure on power gains as my airflow is still restricted. But I did notice that I do not have to push as hard on the pedal to maintain speed. I also noticed that the compression braking is much better. Once I get the new intake tube I will fill up and report on mileage gains, if any.

12KK SFD · **Posted:** Mon Aug 25, 2014 8:03 am

I'm definitely keeping an eye on this thread. I'm hoping it'll work fine for us 11+ KKs. I'm saving pennies for my lift, first.

Scar0 · **Posted:** Wed Aug 27, 2014 8:15 am

Small update. I still do not have a larger intake tube.

Today I took a 116 mile trip. 65% freeway @ 72 MPH, 18% stop and go rush hour, 16% city, 1% idling in a parking lot, all with the A/C on.

Raw data. 116 miles, 7.395 gallons = 15.7 Mpg
Mpg calculated with compensation for my over sized tires. I think I did this right...
Revolution per mile; Stock 716.56/mi My tires 681.88/mi = difference of 34.68 Revolutions per mile.
Circumference of my tire = 95.83" X difference of 34.68" = 3323.3844"
3323.3844" / 692260" in a mile = .05 mile farther traveled per each mile on speedometer.
116 miles x .05 = 5.8 miles.
116 + 5.8= 121.8 miles total.
121.8 miles / 7.395 gallons = 16.47 MPG.
Not taking into account the fuel used when idling in traffic and in the parking lot.

On average, back when I was calculating my mileage, I was getting about 13-15 Mpg Raw. So this has already shown me a gain of .7 Mpg Raw data, with the intake tube still slightly restricted.

Not as good as I hoped for, also not the best conditions for a test, but at least I now have a starting point, and can go from there.
I did not calculate my mileage immediately prior to doing this Mod. So I have to start somewhere. I will continue to use Raw data as it is easier to calculate by hand.

There is still an RPM hang when revving the engine (while in gear) and putting in the clutch. If I shift it drops right down, if I just put in the clutch and are still rolling fast (over 30Mph) it will hang for about 1-2 seconds.

Gageraid · **Posted:** Wed Aug 27, 2014 11:57 am

Scar0 wrote:

Small update. I still do not have a larger intake tube.

Today I took a 116 mile trip. 65% freeway @ 72 MPH, 18% stop and go rush hour, 16% city, 1% idling in a parking lot, all with the A/C on.

Raw data. 116 miles, 7.395 gallons = 15.7 Mpg
Mpg calculated with compensation for my over sized tires. I think I did this right...
Revolution per mile; Stock 716.56/mi My tires 681.88/mi = difference of 34.68 Revolutions per mile.
Circumference of my tire = 95.83" X difference of 34.68" = 3323.3844"
3323.3844" / 692260" in a mile = .05 mile farther traveled per each mile on speedometer.
116 miles x .05 = 5.8 miles.
116 + 5.8= 121.8 miles total.
121.8 miles / 7.395 gallons = 16.47 MPG.
Not taking into account the fuel used when idling in traffic and in the parking lot.

On average, back when I was calculating my mileage, I was getting about 13-15 Mpg Raw. So this has already shown me a gain of .7 Mpg Raw data, with the intake tube still slightly restricted.

Not as good as I hoped for, also not the best conditions for a test, but at least I now have a starting point, and can go from there.
I did not calculate my mileage immediately prior to doing this Mod. So I have to start somewhere. I will continue to use Raw data as it is easier to calculate by hand.

There is still an RPM hang when revving the engine (while in gear) and putting in the clutch. If I shift it drops right down, if I just put in the clutch and are still rolling fast (over 30Mph) it will hang for about 1-2 seconds.

You definitely have a gain. If you do another run like that, try to keep the A/C off. :twisted:

I hope once you get the intake tube the mileage goes up a little, too.
My coasting ability under 35mph is one of the things that has increased. Keep that in mind and try to coast farther at those speeds.
Took a little less than 2 (two) weeks for the revs to calm down. Now when I start it up, the revs are pretty normal. It also took me a while to get used to 1st gear. Barely any effort at all is needed to get to 30mph.
My last tank was 19.2mpg mixed driving, and I'm hoping for the same or slightly better. I'm at a half tank right now and the numbers look extremely well right now. At ~185 miles on ~half tank right now.

Scar0 · **Posted:** Wed Aug 27, 2014 6:40 pm

I'm sure the A/C had a lot to do with it. It is very seldom I use the A/C here at all. Maybe 20 times a year. Yesterday was one of the hottest days of the year here.

With my manual trany, I could do a lot of things to increase my MPG. But I am driving the same as I always do. Otherwise the MPG #s I post would not be an accurate depiction of the true gains from this Mod.

I'm sure the power gains would be more noticeable if I didn't already have a CAI and muffler prior to doing this. Back when I did the CAI, with the muffler, the power gains were very noticeable.
An example is a hill I used to have to downshift on to maintain hwy speed. After the CAI and Muffler, I can leave it in 6th gear with the cruise set to 70 and up she goes no problems.
On the same hill this last trip I can't say for sure if it was any easier or not...

Gageraid · **Posted:** Wed Aug 27, 2014 11:45 pm

Scar0 wrote:

I'm sure the A/C had a lot to do with it. It is very seldom I use the A/C here at all. Maybe 20 times a year. Yesterday was one of the hottest days of the year here.

With my manual trany, I could do a lot of things to increase my MPG. But I am driving the same as I always do. Otherwise the MPG #s I post would not be an accurate depiction of the true gains from this Mod.

I'm sure the power gains would be more noticeable if I didn't already have a CAI and muffler prior to doing this. Back when I did the CAI, with the muffler, the power gains were very noticeable.
An example is a hill I used to have to downshift on to maintain hwy speed. After the CAI and Muffler, I can leave it in 6th gear with the cruise set to 70 and up she goes no problems.
On the same hill this last trip I can't say for sure if it was any easier or not...

Sounds like you're like me. I don't use the A/C. Only use it on long highway trips when my lady says it's too hot. She knows I won't use it putting around town.
Do you notice yourself driving any faster now? Definitely the first week I noticed I was driving about 5 mph faster without intentionally doing it.

Scar0 · **Posted:** Thu Aug 28, 2014 1:24 am

A little. The first time I drove it I noticed I did not have to push as far down on the throttle to go the same speed as before. Now after the long trip I am pretty used to it. I tend to drive according to the hum/pitch of my tires on the road. But I still have to watch myself when accelerating up to speed.

Gageraid · **Posted:** Tue Sep 02, 2014 11:45 pm

Just thought I'd bump this thread.
All is still well with this mod.
Mileage has still been better. Latest fill up was 19.2mpg (hand calculated).
I've had a handful of better than 19mpg fillups and one that was less.
Most of you that know me can verify that I always track my mileage.
My data has shown a little less than a 2mpg INCREASE at the pump.
I will continue to post my mileage in the what did you do to your KK thread...

12KK SFD · **Posted:** Wed Sep 03, 2014 7:43 am

How have the RPMs been? Still hanging at start up? No CELs to date?

Gageraid · **Posted:** Wed Sep 03, 2014 9:44 am

12KK SFD wrote:

How have the RPMs been? Still hanging at start up? No CELs to date?

Starts up and shuts off normally. Took a little over a week for the rpms to calm down at startup.
No CEL's to date.

Dewphy · **Posted:** Wed Sep 03, 2014 12:20 pm

Thanks to everyone who discovered this and have tested it with reports. I have a new air intake ordered and as soon as I can find a 4.7L throttle body at a decent price, i will be pulling the trigger!

Gageraid · **Posted:** Wed Sep 03, 2014 12:28 pm

Dewphy wrote:

Thanks to everyone who discovered this and have tested it with reports. I have a new air intake ordered and as soon as I can find a 4.7L throttle body at a decent price, i will be pulling the trigger!

Nice! Get a Hypertech, too if you can find one reasonably priced.

MGRead · **Joined:** Mon Feb 18, 2013 1:17 pm **Posts:** 12

Gageraid wrote:

Dewphy wrote:

Thanks to everyone who discovered this and have tested it with reports. I have a new air intake ordered and as soon as I can find a 4.7L throttle body at a decent price, i will be pulling the trigger!

Nice! Get a Hypertech, too if you can find one reasonably priced.

What hypertech are you using. I have a 08 nitro and trying to find one for it.

Sent from my iPad using Tapatalk

Gageraid · **Posted:** Wed Sep 03, 2014 11:32 pm

MGRead wrote:

Gageraid wrote:

Dewphy wrote:

Thanks to everyone who discovered this and have tested it with reports. I have a new air intake ordered and as soon as I can find a 4.7L throttle body at a decent price, i will be pulling the trigger!

Nice! Get a Hypertech, too if you can find one reasonably priced.

What hypertech are you using. I have a 08 nitro and trying to find one for it.

Sent from my iPad using Tapatalk

http://www.hypertech.com/products-results.aspx

Increase in mpg w/ 4.7L TB

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