jeeper52

Hey guys im looking to gain some extra power on my 2015jeep jk. I know a Hemi is the best way but $20k plus isn't going to happen right now and ive heard that swaping in a 5.7 hemi isnt worth the money. What about a supercharger or turbo? I live in colorado so im always driving up some sort of hill or mountian it seems. Im rolling 40's on tons with 5:38's and carry 200/300lbs of extra weight. Will either option help here in the high altitude? Is tuning a constant headache? Also is the power a supercharger or turbo predictable with slow rock crawling? Not looking for a rocket ship just a little more hp to help get me over the big hills and mountains here in Colorado. Let me know what you guys think. Thanks

robbins84

Ive heard good stuff about the prodigy turbo it gives low end power which is good for crawling. I dont have it so i cant really say much else it will give you more power then the supercharger I believe. Anyway both will give you better on road performance ive always leaned towards a supercharger maybe thats cause im a muscle car guy but thats my 0.02. Turbo is also slightly more expensive and tuning wise they are pretty equal although a turbo will give you a little more options when it comes to tuning.

Prodigy Performance

I think turbos are pretty awesome

Turbo will give you the most consistent power at different elevations because of how a wastegate works to target a fixed amount of pressure above ambient pressure. A supercharger multiplies pressure by a fixed amount no matter what the ambient pressure is.

Example: 8 psi turbo vs 8 psi supercharger (at sea level).

Atmospheric pressure at sea level: 14.7 psi
+ 8 psi = 22.7 psi absolute manifold pressure
/ 14.7 psi = 1.54 pressure multiplication


Atmospheric pressure in Denver at about 5000 ft elevation: 12.2 psi

Turbo: + 8 psi boost = 20.2 psi absolute manifold pressure

Supercharger: x 1.54 pressure multiplication = 18.8 psi absolute manifold pressure
- 12.2 psi atmospheric pressure = 6.6 psi boost

So at 5000 ft, the turbo gives the engine about (20.2 psi / 22.7 psi) = 89% of the amount of air as it does at sea level. There's a pretty tight correlation between amount of air and power output of the engine, so that's like a 11% loss of power due to elevation.

The supercharger comes out to about (18.8 psi / 22.7 psi) = 83% of the amount of air, or about a 17% loss due to elevation.

For comparison, the stock naturally aspirated engine would be about (12.2 / 14.7) = 83% of the amount of air, or about 17% loss due to elevation as well. Suspiciously just the same as the supercharger? It works out that way because the supercharger multiplies the pressure by a fixed multiple, no matter what the starting pressure is.

Some of the supercharger kits solve this problem by offering "high altitude" pulleys that are intended to be used in high elevations. It's a smaller pulley wheel that causes the supercharger to spin faster and multiply pressure more. But then if you drive down to lower elevations, you'll be making even more boost. I have not seen any clear statements about whether they officially support/recommend the higher boost of "high altitude" pulleys being driven at lower elevations.


It shouldn't be. All of the forced induction kits seemed to have some tuning issues early on. There's been lots of time for feedback from customers around the world to help make improvements to the early revisions of tunes. I can't speak for the supercharger tunes, but I can tell you that the tune for the Prodigy Turbo has really matured.

I personally experienced this because I installed the Stage 1 turbo kit on my Jeep soon after it became available. Myself an other early customers (I only joined Prodigy about 3 weeks ago; I was just a customer before then) provided feedback and data logs, then received new revisions of the tune. There have been some big improvements to the tune over the past 2 years, especially in the lower RPM range.

I won't lie to you and tell you the tune is 100% absolute perfection like a factory stock vehicle. The tune is very good, but I personally still occasionally encounter a split-second "glitch" in power delivery at certain combinations of speed, engine load, pedal motion, etc. It's nothing compared some of the complaints some people have had about driveability issues with some kits earlier on.

If you do experience any issues with a Prodigy Performance tune, you can contact us, send us a data log of the issue, explain the issue to us, and we will work to resolve the issue. Perfecting the tune is an on-going effort. We're not stopping at "good enough". Any future enhancements to the tune will be available to you at no charge.

Installing an update to the tune is pretty easy. You get a file emailed to you. Plug the handheld tuner into your computer via USB, and it will appear like a USB memory stick on your computer. Copy the file onto the handheld tuner. Then go plug the handheld tuner into your Jeep's OBDII port and navigate some menu options to choose the new tune and install it. There's some details in there about cycling the key off/on, waiting, etc., but it's all clearly explained with instructions on the handheld tuner.


Unfortunately, I do not have rock crawling experience. The closest to it is slow crawling up steep dirt hills with tight corners, washed out ruts, and small steps.

When using torque multiplication of gears properly (well-matched axle ratio for tire size, use 4LO, low transmission gear), my experience is that the engine does not work very hard to crawl up steep hills because of the massive torque multiplication of all the gear ratios involved. The turbo will only spool up and create boost if there is enough exhaust flow and engine load. My Turbo Jeep has performed flawlessly at low speeds off-road. I rarely cause the turbo to spool up in these conditions, and when it does, it is very smooth.

With the tire size and gear ratio combination you have, I would expect that you already have all the power you need for slow crawling in 4LO. If this is the case, then I would expect that you probably wouldn't even notice the turbo exists when off road at low speeds, especially if you generally stay in the lower half of the RPM range. I only notice the turbo off road in situations like a steep, long, smooth hill climb where I can be in a higher gear, mid-to-upper RPM range, giving it some throttle trying to accelerate quickly up the hill. Yes, there is turbo lag, so it's not snappy/instant big V8 throttle response in this situation. But it is smooth and predictable. It's very easy to feather the throttle and maintain control over the power. I like to think that the turbo lag is actually a benefit, because it reduces the chance of sudden shock load to the drivetrain from accidentally twitching the throttle . Turbo lag does not mean there is a complete delay in power delivery relative to the pedal motion that surprises you with a sudden onset of power. I think it's best described as "soft" or "dampened" throttle response. Special "crawl" tunes often include softening/dampening the throttle response more than stock to make it easier to control the power smoothly, so I'm not entirely insane in thinking that the turbo lag may actually be a benefit off road.

Again, YMMV, because I don't specifically have experience with technical rock crawling. But to summarize my experience, the turbo helps most on the street and in specific off-road situations that involve more engine load at higher ground speed (not low speed crawling). In low speed crawling situations, the turbo simply doesn't interfere, and stock-like power delivery is retained.


Our turbo kits can do both

And our kits are expandable.

You can start with a lower boost Stage 1 kit (no intercooler or blow-off valve) then upgrade to Stage 2 (intercooler, blow-off valve, higher boost) later on if you want. You can even make use of a boost controller (added separately) to customize your boost level.

For example, you could run the Stage 2 kit with the Stage 1 wastegate spring (for lower "base" boost), then use a boost controller to choose a boost level somewhere between Stage 1 and Stage 2 levels. You may want to run lower boost levels while crawling off-road for maximum control, but still benefit from the lower intake temps (and therefore lower under hood temps) that the Stage 2 intercooler gives you. Then turn the boost back up to become a rocket on the highway

Hope this helps. Please ask any questions you may have, and I'll do my best to answer.

~Jeff

Prodigy Performance

While the turbo does produce some decent gains in the lower RPMs, the big gains are in the mid-to-upper RPM range (HUGE gains starting around 3500 rpm, and carrying through to redline at 6400 rpm). The gains from the turbo are most useful for driving on the street (accelerating onto freeways/highways, passing on the highway quickly/safely, etc).

Proper axle gearing for your tire size and proper use of 4LO and low transmission gears is the best way to get good crawling performance from massive torque multiplication. If geared properly, and you don't insist on upshifting and lugging the engine at low RPM while crawling, then the stock engine should already have plenty of power for low speed crawling. As I explained above, the turbo does a good job of simply not interfering in situations like this, because there's not enough engine load to spool the turbo up.

An example of the decent low RPM gains is when cruising on the highway/freeway around 2200-2500 rpm. I can easily maintain speed up hills, gently accelerate to change lanes and move past slower traffic, etc. I was just watching my boost levels during situations like this on the freeway today and was seeing 4-5 psi boost during part-throttle acceleration around 70 mph, 2500 rpm.

If you are doing some very extreme/technical low speed rock crawling where you absolutely need more power at idle because you're going so slow that you're in 4LO, 1st gear, and still barely idling, then I'll be the first to tell you that a turbo won't help you here.

But if you feel like you need more low RPM power because you simply choose to stay in a higher transmission gear or 4HI instead of 4LO, lugging the engine at low RPM (or because you haven't re-geared for your big tires yet)... My suggestion is to embrace the torque multiplication of a lower gear and don't be afraid of using the mid RPM range while crawling. Re-gear your axle first if you haven't done so yet before seeking more power. Downshift more if you can. My Jeep very happily and smoothly crawls along slowly in 1st gear, 4LO, above 2000 rpm. The Pentastar engine makes all of its useful torque starting around 2000 RPM, so try to keep the RPM at least around 2000+, and don't be afraid to visit the 5000+ RPM range while climbing up something.


Yes! Our turbo kits produce substantially more torque and power than any other forced induction kit on the market for the Jeep Wrangler.

~Jeff

Prodigy Performance

A couple clarifications:

My initial response to this was supposed to be my attempt to put you at ease that myself and other early adopters have already gone through the hassle of reporting early issues with the tune, data logging, providing feedback, trying updates to tunes, etc. I think I was tired while writing my reply and never got around to making that point clearly. At this point, I have not touched the tune in months. If you were to purchase a new kit now, you should expect an overall excellent experience "out-of-the-box" with the provided tune.

Here's a video that walks you through how you install the custom tune from Prodigy Performance (if you pay a shop to install the kit, they would take care of this for you):

https://www.youtube.com/watch?v=BkJXXl5WDwU
I should have qualified this with "all else being equal". This is not a valid assumption when, for example, comparing different forced induction systems. Different types of superchargers/turbos all running the same level of boost can produce different amounts of torque/power gains due to various factors that affect the overall efficiency of the system. A turbo is inherently more efficient then all supercharger designs because a supercharger draws all of its power directly from the output of the engine (via the serpentine belt), whereas the turbo is driven mostly by the simple expansion of exhaust gasses. There is some indirect parasitic loss involved in a turbo system due to increased exhaust backpressure, but it is much less than the parasitic loss of directly driving a supercharger. A turbo produces more net torque/power to the wheels than a supercharger running at the same boost level.

~Jeff

jeeper52

Thank you for all the information. Sorry for the delayed response. What would you say the overall hp gain woukd be? Also do you have to run premium fuel? What exhaust mods are also required?

Prodigy Performance

Minimum 91 octane required. 93 recommended.

When driven "normal", depending on many things, there may be enough of a fuel economy improvement to offset the cost of higher octane fuel. It worked out that way for me a couple times on longer freeway trips, cruising at 65-70 mph. Other situations, mpg may be about the same as stock, or a couple mpg worse. All depends on how much stop & go driving, how heavy you are on the throttle, etc. Several back-to-back full boost runs will quickly drop your average mpg


No exhaust mods required. The turbo kit includes all new exhaust pipes for the front section of the exhaust system. The portion of the exhaust system that would traditionally be called the "cat-back" portion remains stock. Stock catalytic converters are removed, and a high-flow catalytic converter is included (approximately located under the driver seat).

A minimum 2" lift (specifically, minimum 2" bump stop extensions) is required to guarantee clearance between the front driveshaft and a portion of the turbo exhaust system. A 3/4" spacer lift has been sufficient for some people that never drive off road.


I wish I had some really solid stock vs turbo dyno chart comparisons to show you, but that's something we'll be working on soon. We're getting our own Dyno Dynamics dyno soon, and will work on getting dyno results for as many variations of the turbo install as we can, across the entire RPM range, as well as a stock baseline. Until then, I'll share the best info I have...

We do have an early stock baseline, but I personally don't trust it. Compared to other stock dyno results I've seen, the shape of the torque and power curves just didn't make sense. So I'll have to steal results from other sources of stock dyno results for now to show what the gains are.

Stock baseline: Both RIPP and JeepLab have reported about 190 hp and 175 ft-lbs at the wheels (about 33% drivetrain loss).

Our official claims (from a Dynojet dyno) for now from our website are...

Stage 1: 330 hp and 342 ft-lbs at the wheels at about 6.8 psi boost
That's 140 hp (74%) and 167 ft-lbs (95%) gain.

Stage 2: 359 hp and 373 ft-lbs at the wheels at about 8.2 psi boost
That's 169 hp (89%) and 198 ft-lbs (113%) gain.

Those were both obtained with the Garrett turbo on wastegate spring pressure only (no boost controller; as shipped), and they were using early revisions of the tune. We've seen improvements with newer revisions of the tune, such as Stage 2 results up in the 370-380 range for both hp and torque.

Our best results so far are with a Stage 2 kit with the Precision turbo, a boost controller, and Magnaflow performance exhaust:
427 hp and 418 ft-lbs at the wheels at about 9.1 psi boost
That's 237 hp (124%) and 243 ft-lbs (139%) gain.

https://www.youtube.com/watch?v=7KA0PTvaR6Y
That setup ran 12.76s @ 106.5 mph in the 1/4 mile:

https://www.youtube.com/watch?v=hDF8HPEkjQI
Again, remember that the stock baseline I'm using is from a different source (but two different sources that agree with each other). Once we get our own dyno, we'll create some solid comparisons to produce offical claims of gains. Also remember that the videos above featire an automatic transmission, so the dyno chart is not a valid representation of actual lower RPM performance.

Low RPM performance gains with the turbo is a complex topic worthy of its own post. I won't get into that now because dinner is almost ready, and I'm hungry. For now, I'll just say that the huge gains of the turbo start around 3500 rpm and carry through strong to redline. There are gains in the lower RPM range, but not huge gains. The gains really start to ramp up around 2500.

~Jeff

jeeper52

Im definitely interested in this setup. However i do worry a little bit about heat that is generated from the hot exhaust gases that are piped around the motor. I go to moab a couple times a year and as we all know its freakin hot there in the summer. Will this be an issue? Also i saw on your site that you offer an additional part to the stage 2 kit that allows the turbo to spool up at a lower rpm instead of 2500 tlms its now around 2000 rpm. Is this correct?

Prodigy Performance

The heat from the extra exhaust pipes and turbo is partially balanced out by removing two major heat sources: the stock catalytic converters, which are directly on each side of the engine. The turbo kit's exhaust has its own high-flow catalytic converter, which is located about under the driver seat (not in the engine compartment).

The turbo itself only generates substantial extra heat when there's significant engine load causing it to spool up and generate boost. When driving around slowly off-road with light engine load, at lower RPM, the turbo isn't doing much. A turbo blanket on the turbine side also helps contain heat.

We have customers running turbos over in the middle east, on the sand dunes, in 120*F heat. For hot climates, we offer a 180*F thermostat and accompanying changes in the tune to the cooling fan behavior to reduce engine temps by about 25*F. If you have an automatic transmission and plan to run your turbo hard (racing, blasting around sand dunes) in a hot climate, then we also recommend an aftermarket transmission cooler with its own cooling fan.

Multiple techniques are used in the tune to keep combustion temps in check and avoid pre-ignition, such as rich fuel mixture at high boost, and adjustments to ignition timing based on intake air temps.

We have the biggest intercooler of all forced induction options for the Wrangler. This keeps intake temps low, which in turn keeps combustion and exhaust temps low, which keeps engine coolant and under-hood heat in check, which helps keep intake temps low.

I personally have not had any issues with the Stage 2 kit out on the sand dunes on sunny summer days (mid 80's). The engine coolant temp gauge would budge past the center after a couple hard runs up sand dunes (high speed, high RPM, high boost), but would return to center after a few minutes of gentle driving or sitting still idling. I've never seen the gauge budge from center on the street/freeway, even on 90+*F high humidity days. I did have some excessively high intake temps in a similar situation on the sand dunes with the Stage 1 kit (no intercooler), so I would definitely recommend Stage 2 for hot off-road driving where you may run the turbo hard.

If you are concerned about under-hood heat, you may consider getting the exhaust pipes ceramic coated. I would not recommend the cloth-like exhaust wraps if you're driving off-road in dirt/mud/water. My pipes are not coated or wrapped.

Also consider painting the intercooler with special black radiator paint. I used Eastwood Radiator Black (satin finish):




This black paint helps the intercooler emit heat more efficiently when there's no airflow (slow driving/crawling, sitting idling). When applied properly (not excessively thick; not clogging the fins), it has negligible impact on the efficiency of the intercooler at speed when air is flowing through it.


You must be referring to the Precision turbo option. It's not an additional part, but a different turbo unit altogether. The standard turbo is a Garrett turbo. This is not exclusive to Stage 2. You can opt for the Precision turbo with a Stage 1 kit as well. I have had both on my Jeep: first the Garrett, now the Precision.

The Precision spools more quickly in general. This makes lower RPM part-throttle driving (daily driving) more enjoyable by being generally more responsive. I also feel that the power ramps up more smoothly/controllably during part throttle acceleration up into the RPM range where the turbo is capable of making more boost. When stomping on the throttle at high RPM, the Precision responds a bit more immediately (full boost within 1/4 second for Precision vs 1/3 second for Garrett according to my data logs around 4000 RPM).

But the Precision makes a bit less boost than the Garrett when running the same wastegate spring. For example, I would see a max of about 8.4 psi boost in 2nd gear with the Garrett, but only about 7.5 psi with the Precision. We don't have any Garrett vs Precision dyno charts yet, but I predict that the Precision makes a bit less torque/power as well. The Precision has a smaller A/R turbine housing than the Garrett, which helps it spool more quickly, but has the trade-off of being a bit more restrictive to exhaust flow, and causing lower boost when running on wastegate spring pressure only. It is possible that the nicer CNC machined compressor wheel of the Precision is more efficient and makes up for some of the boost reduction.

Between the two, I like the Precision better. It's generally more enjoyable to drive. And I made up for the reduction in boost by adding Grimmspeed MBC (manual boost controller). It's easy to add more boost to the Precision, but you can't make the Garrett spool faster.

(boost controller is an at-your-own-risk modification; with great power comes great responsibility)

The Precision also makes more noise. Sounds like this: https://www.jk-forum.com/forums/jk-s...-video-331448/


For reference, here's the quote from the website about the Precision vs Garrett spooling:
When a turbo "spools" is a pretty ambiguous and potentially subjective topic.

One possible meaning: at what RPM does the turbo reach "full boost" during a full throttle acceleration?

This all depends on how much engine load there is, or what transmission gear you are in. It takes time for a turbo to spool up. (With the Precision) In 2nd gear, I see full boost starting around 3750 RPM. In 4th gear, I've seen full boost around 3000 RPM (I personally don't recommend doing that; boost at lower RPM is more strenuous on the engine. Downshift if you really want to accelerate fast with a manual transmission; auto trans just won't allow this anyway). According to my data logs of a 2nd gear full throttle acceleration, the Precision hits full boost about 250 RPM sooner than the Garrett. Not a lot sooner, but every little bit helps In higher gears with more engine load, the quicker spooling of the Precision may allow it to hit full boost even earlier than the Garrett, but I have only data logged 2nd gear full throttle pulls from low RPM, so I don't know.

Another meaning of "when a turbo spools" I have seen is: At what RPM does the turbo start making substantial/noticeable boost. This is where it can be very subjective (how much boost is "substantial"?), and this what I think the quote from the website is talking about. During part throttle acceleration around town, the Precision will start to easily make *some* decent boost (1-2 psi) just above 2000 RPM. The Garrett would not behave similarly until closer to 3000 RPM. Another observation is that if I lift of the throttle during part throttle acceleration in 2nd/3rd gear around 2000 RPM with the Precision, I'll hear the BOV release some pressure. With the Garrett, I wouldn't hear a similar release of pressure until somewhere between 2500-3000 rpm.

Hope that helps. Basically, don't expect huge boost/acceleration as low as 2000 RPM with the Precision. The huge gains kick in starting around 3500 RPM. But part throttle acceleration/responsiveness of the Precision is a worthy improvement over the Garrett. The Precision's faster spooling is probably also what allows it to make decent boost at part throttle on the freeway around 2500 RPM, but I can't recall how the Garrett behaved in that situation for comparison.

~Jeff

richlortz

Are your kits CARB approved. I live in California and have to do biannual smog checks. Also are the aftermarket cats CARB approved.