Prodigy Performance 3.6 Turbo DIY Install

[Snarf77]

I'm very curious to hear if you end up with any MPG gains. I'm still dumb-founded when people say they get MPG gains after adding a turbo. Let's see, put in a device that pumps in more air, so you can dump in more gas to make a bigger explosion in the cylinder... Result... More fuel efficiency... Umm, something seems wrong with this equation. My only explanation is that Prodigy actually did a better job on the computer program than Chrysler did. Ohh, I guess it would help if the Cat converter and other EPA stuff was removed ;-)

Either way, Pickle, that awesome that you're getting 28 MPG (or say 25 MPG if you weren't driving like a grandma.) Right now, with 35" tires, top off and no doors, I'm getting around 15mpg average in city driving. If I go out on the highway, I bump allllll the way up to 16mpg.

I'm actually thinking I'm somewhere between 1 and 2 mpg better thus far. I'll have to finish the tank. Turbos are used throughout the world to make more efficient engines. Wasted energy converted into more air for an engine to combust. Doesn't surprise me a bit that there could be a fuel economy gain, especially on the highway. I'll have to stay off the pedal for a bit on a road trip tomorrow to see what happens.

[ljvsnyder]

So to sell this idea to my wife I need to tell her I am installing an "Ecoboost" kit.

[Snarf77]

So to sell this idea to my wife I need to tell her I am installing an "Ecoboost" kit.

I'm just over a 1.7 mpg increase over the previous tank at today's fill-up. 1.7 mpg isn't a huge boost until you look at it as a % increase, roughly 9% for me.

Let's hope the the wife doesn't do the math on how many miles it would take to break even on cost.

[JeepLab]

I'm just over a 1.7 mpg increase over the previous tank at today's fill-up. 1.7 mpg isn't a huge boost until you look at it as a % increase, roughly 9% for me.

Let's hope the the wife doesn't do the math on how many miles it would take to break even on cost.

Teach her to do a 37" KM2 Burn out, and all will be forgiven.

[ljvsnyder]

My little girls would go for the burn out, the wife not so much, but she is pretty bad at math.

[Timmy]

Teach her to do a 37" KM2 Burn out, and all will be forgiven.

If you find a women that is impressed by a 37" burn out, KEEP HER!!! They are very rare...

[UselessPickles]

I'm still dumb-founded when people say they get MPG gains after adding a turbo. Let's see, put in a device that pumps in more air, so you can dump in more gas to make a bigger explosion in the cylinder... Result... More fuel efficiency... Umm, something seems wrong with this equation.

You're only thinking of full-throttle when you actually make more power using the extra air and fuel. When driving "normally" and cruising steadily, you're not using more air+fuel with a turbo. You actually use less because now you have expanding hot exhaust energy spinning the turbo and helping push air into the intake (even if you're not making boost, the turbo is still helping some). Without the turbo, that exhaust energy is just dumped out the tail pipe and the engine has to work harder to suck air past the partially open throttle body, requiring more air+fuel to output the same net power to the wheels to maintain the same cruising speed.

Either way, Pickle, that awesome that you're getting 28 MPG (or say 25 MPG if you weren't driving like a grandma.)

I'm just over a 1.7 mpg increase over the previous tank at today's fill-up. 1.7 mpg isn't a huge boost until you look at it as a % increase, roughly 9% for me.

My completely unscientific observations based only on memory seem to indicate that I'm generally getting about 2 mpg better with the turbo for my usual daily driving to work. My dashboard average economy readout pre-turbo would always eventually settle into the 18-19 mpg range for me. With the turbo, now it seems to settle into the 20-21 mpg range after several days of just driving "normal" (with at least one full throttle blast through 1st and 2nd gear each day). This seems in agreement with Snarf's observations.

My 28 mpg trip was from abnormally gentle driving and not exceeding 70 mph on the freeway. It's nice to know that it's possible, but I'll probably not see such a high number again for a long time

I seem to be able to hit 25 mpg pretty easily when doing a lot of freeway and highway driving, as long as I stay around 70 mph or less. Bumping the speed up to 75 mph seems to drop fuel economy down to about 21 mpg.

Let's hope the the wife doesn't do the math on how many miles it would take to break even on cost.

The turbo will pay for itself much faster in fuel savings than big tires or a lift It's nice to have a fun mod that doesn't DECREASE fuel economy.

Remember to take into consideration the price difference between regular and premium fuel (turbo requires 91 octane). Here's the formula to calculate how many miles it will take to save a target $ amount:

[miles to save $] = [target $ to save] / ( ([regular fuel price] / [pre-turbo mpg]) - ([premium fuel price] / [post-turbo mpg]) )

If the result comes out negative, then it means you'll LOSE your target $ amount in that many miles!


And here's the formula to calculate how much $ you'll save after travelling a specific number of miles:

[$ saved] = [miles traveled] x ( ([regular fuel price] / [pre-turbo mpg]) - ([premium fuel price] / [post-turbo mpg]) )

If the result is negative, then of course that means you lost money.


Formula explanation: Dividing fuel price (in $/gal) by fuel economy (in mpg) gives you the cost to drive the vehicle in dollars per mile (henceforth, "DPM"). Multiply your DPM value by a number of miles to determine how much it costs to travel that many miles ($ = miles x DPM). Divide a dollar amount by your DPM value to figure out how many miles you can travel for that amount of money (miles = $ / DPM). The formulas above simply involve calculating a pre-mod DPM and post-mod DPM, then subtracting pre-mod-DPM from post-mod-DPM to get a "change in DPM caused by the mod" (henceforth, "delta-DPM"). Your delta-DPM then is used to calculate a change in cost to travel a specific number of miles (delta-$ = miles / delta-DPM), or a change in how many miles can be traveled by a specific dollar amount (delta-miles = $ / delta-DPM). The full formulas above are slightly rearranged and simplified to avoid some extra negatives and make more sense for the specific situations we're talking about. In pure form, savings would be be represented as a negative change.

[UselessPickles]

I discovered a stupid mistake I made while installing the turbo. I pushed the exhaust extension pipe too deep into the stock cat-back exhaust pipe. The whole stock cat-back system was pulled forward when I tightened the extension pipe to the down pipe, which caused this to happen:



The hump in the exhaust over the rear axle is out of alignment now, and the rear track bar crushed the exhaust a bit when my suspension bottomed out at some point (probably that day I spent off road soon after the install).

I wonder how much power I'm losing because of this exhaust constriction.

Anybody have ideas for the cheapest way to fix this? I've already posted in the "wanted" section of a few forums for stock exhaust take-offs.

[jeepsking]

I dont think its a defect . it came from the manufacturer like this. You can check with other JK if I am not mistaken.

[JeepLab]

I dont think its a defect . it came from the manufacturer like this. You can check with other JK if I am not mistaken.

x2 Jeepsking is dead on. My 12 also had the same exact dented pipe.

funny that they made such a big deal about the exhaust "loop". Super highly engineered exhaust.... then they bashed them all at the factory.