JeepLab Prodigy Install LIVE

[jeepsking]

Hope you get a chance to compare with others legally in a track or down hills.

[JeepLab]

Jeff: to be honest I don't believe in dynos what I believe is personal experience so my question is what do you feel about the gain and did u got what expected from the kit. Same questions to others (impression). I already ordered the kit (still waiting) but once I installed I will try to compare it with other cars plus other upgraded JK if possible. Gears affect how quick is your car , but in major view it dosent affect the overall performance.

My butt dyno says Jesse's Girl is a rocket. But the 4.88s play into that. Did she feel fast? Yes. Was I going fast?... not as fast as it felt. I was merging onto a highway and I had the throttle nailed. It felt like I was on a roller coaster. But I was not blowing away traffic. Thats because the gearing was holding the overall speed back. (I think).

So is she fast? Yes, very fast.

Would she be faster with 4.10s? If we are talking about highway speeds, then yes. But the acceleration would suffer, and she might not feel as fast.

[JeepLab]

I think the 4.88 gears on Jesse's Girl could have significantly affected the dyno results, especially because it was run with stock 32" tires, and because of the nature of how a turbo works.

The overall gear ratio of 4th gear on that setup is close to 3rd gear with 3.73 gears, and is like something between 2nd and 3rd gear with 3.21 gears. This means that Jesse's Girl did not have as much load on the engine when run on the dyno as compared to Prodigy's dyno runs. This would lead to lower dyno numbers for 2 reasons:

1) The already-discussed issue of quicker acceleration on the dyno leading to lower dyno numbers because more torque is lost to accelerating the drive train more quickly.
2) Less load on the engine and quicker acceleration causes the turbo to spool up more slowly with respect to engine speed, so boost increases "later" in the rpm range, resulting in a lower peak torque that occurs higher up in the rpm range.

Additionally, common dyno practice is to use the transmission gear that is closest to a 1:1 ratio. 5th gear is a 1:1 ratio on the Wrangler, so it's possible that Prodigy's results are from a 5th gear dyno pull, meaning that Prodigy's dyno pull had even that much more load on the engine for slower acceleration, allowing the turbo to spool up at lower rpms, and giving up less torque to accelerating the drive train.

To get as close to Prodigy's conditions as possible, we need to find out what transmission gear they used for the dyno pull, then run Jesse's Girl one gear higher with stock tires. Even at one gear higher, Jesse's Girl will still be geared overall a little shorter (numerically higher), plus the driveshaft will be accelerating more quickly than the stock jeep (using up some of the torque), so I would still expect the numbers to be a bit lower than Prodigy's results.

I have never heard of a 5th gear dyno.

Ive also been told by separate people that the gearing doesnt matter with a tumbler style dyno machine.

Im not an expert, these points, I have heard from different people. The power comes thru the drive train, and the rear wheels roll the tumbler. The tumbler dosent know what the gearing is, and im not sure the number of teeth in the ring alters the power from the driveshaft thru the wheels.

Maybe I can get someone from dynojet to tell us exactly.

[UselessPickles]

Ive also been told by separate people that the gearing doesnt matter with a tumbler style dyno machine.

The math might work out so that it doesn't really matter for N/A or supercharged engines, where there is a direct relationship between engine speed and torque output. But we're talking about a turbocharged engine here. It takes engine load and time to spool up a turbo. Just compare a 3rd and 4th gear run from Jesse's girl and you'll see how much of a difference the overall gear ratio can make.

[boosted1]

If you are confident in the validity of the results, then let's see some stock vs RIPP vs Magnuson vs Prodigy charts!

This should be the story. Keep in mind all the results should be on the same dyno same configuration, same correction factor etc...
My thoughts are as follows.

1. Magnuson by design will deliver the highest off idle TQ gain
2. Magnuson will also have the lowest overall performance gain
3. Magnuson power will decline the longer it is ran due to heat soak and highest IAT

4. Ripp by design will have a linear power curve and will make peak HP only at max RPM
5. Ripp will make good power as the supercharger is large enough to move a high volume of air

7. Prodigy by design will deliver more power than ANY forced induction system on the market
8. Prodigy will make crazy power in the midrange where the Wrangler needs it the most Contrary to most dialogue
9. Prodigy will deliver sea level performance at higher elevation due to the use of a wastegate
10. Prodigy system can be upgraded giving it a win for HP per dollar

[boosted1]

Stage 1 is shipped with Red spring .4 bar
Stage 2 is White .5 bar

Read the bottom right of the image. I personally prefer the White and Green combination for Maximum fun.

[Yoinkers]

This should be the story. Keep in mind all the results should be on the same dyno same configuration, same correction factor etc...
My thoughts are as follows.

1. Magnuson by design will deliver the highest off idle HP gain
2. Magnuson will also have the lowest overall performance gain
3. Magnuson power will decline the longer it is ran due to heat soak and highest IAT

4. Ripp by design will have a linear power curve and will make peak HP only at max RPM
5. Ripp will make good power as the supercharger is large enough to move a high volume of air

7. Prodigy by design will deliver more power than ANY forced induction system on the market
8. Prodigy will make crazy power in the midrange where the Wrangler needs it the most Contrary to most dialogue
9. Prodigy will deliver sea level performance at higher elevation due to the use of a wastegate
10. Prodigy system can be upgraded giving it a win for HP per dollar

Wes, why does your dyno chart show a loss of power, I understand the goal of midrange power, but I cannot understand why the prodigy power line dips under the stock line.

Also, can you give your position on axle gearing with dynos?

What tranny gear was prodigy's dyno done in?

[boosted1]

Wes, why does your dyno chart show a loss of power, I understand the goal of midrange power, but I cannot understand why the prodigy power line dips under the stock line.


Also, can you give your position on axle gearing with dynos?


What tranny gear was prodigy's dyno done in?

When the vehicle is turbocharged, load is a huge factor. Graphing the lower RPM band is the most difficult. We ran the vehicle in 4th gear and slowed to the lowest point we could maintain a wide open throttle pull. So picture yourself in 4th gear and slowing down to like 2k and then give it wide open throttle. Not really ideal...
We use the dyno as a tuning device to hold the vehicle stationary. We then make adjustments while recording data from the vehicle and the dyno. This helps determine what adjustments are needed next. When its all done the street is where the fine tuning comes into play.

We used 4th gear for our pulls and also tested with 3rd gear. They were close enough where it didn't matter.

As for axle gearing on dynos, I personally have not seen this as a real issue. When I am taking the time to dyno a car I would start with a baseline, make the modification and retest to see the results of the modifications. If you are looking to compare something then the variables need to remain the same all the way down to how they are tested. What gear they are driven in, tire size, weather etc..

Gear ratio just changes how quickly the engine pulls through the RPM band. A gear change can deliver faster acceleration but will also get less fuel economy as it cruises at a higher rpm on the hwy. Turbochargers like load and I find ratios closer to stock work best. Over gearing may deliver adverse affects like poor fuel economy and surging on the highway.

Typically over gearing is done just to make up for the overall lack of power. If the Jeep performed great stock and you changed the tire size why wouldn't you just install the gear that puts you closest to stock? Choosing a different gear than this could give improved acceleration but would also change the rpm at cruise. The reason the performance went away is due to the weight of the tire and wheel combination. To get the performance back you will need more power.

[Snarf77]

Gear ratio just changes how quickly the engine pulls through the RPM band....

Typically over gearing is done just to make up for the overall lack of power. Choosing a different gear than this could give improved acceleration but would also change the rpm at cruise. The reason the performance went away is due to the weight of the tire and wheel combination. To get the performance back you will need more power.

Moving through the RPM band faster has an effect on power at the wheels; the significance of the loss is to be debated and could be a non-issue with regards to this level of power.

Higher numerical gear ratios are also used to increase crawl ratio off-road. That was one of my goals, especially with my manual trans. The higher the rpms when crawling..the smaller the the movements for a given throttle input. This also helps me into that midrange power band where my turbo shines.

Luckily I've had no highway surging of any kind; the highway driveability has been massively improved over stock.

Do you envision separate tunes for Stage 1, Stage 2, and eventually Stage 3 systems?

[UselessPickles]

When the vehicle is turbocharged, load is a huge factor.

We used 4th gear for our pulls and also tested with 3rd gear. They were close enough where it didn't matter.

These two statements seem contradictory to me, when talking about a dyno pulls on a simple inertia dyno. Jesse's Girl definitely produced very different results in 3rd gear vs 4th gear.

Wes - are you using one of the much nicer dynos that can dynamically change its load to maintain a controlled/constant rate of acceleration during your dyno pulls? If yes, then we'll never reproduce those results on a simple inertia dyno.