Prodigy Performance 3.6 Turbo DIY Install

[UselessPickles]

Keep it coming!

As you wish!

I got a nice clean data log of a 2nd gear full throttle pull. Here's my new boost curve:




And here it is compared to my boost curve with the exhaust leak:




Lesson: Make sure your exhaust system is leak free when you have a turbo, or else you'll be missing out on power and turbo response!


And for a fun comparison, I found this dyno chart of a RIPP supercharged 3.6 Wrangler, with a boost curve. Notice that the boost curve is not actually linear. It seems to be a shallow exponential curve. If it was linear, it would have 5 psi around 3250 rpm (half peak boost at half peak engine speed), but it doesn't actually reach 5 psi until 4600 rpm!

[Timmy]

[QUOTE=UselessPickles;3705]MOAR BOOST!

I now have seen boost peaking in the 8.0-8.3 psi range! Previously, I was only getting up to the 7.8-8.0 range. I seem to be on par with NOLA with boost numbers now. The highest I saw today was 8.58 psi in 4th gear."

Forgive me for asking, I'm only doing so for my own information, but it appears the boost numbers you are seeing are no better than what is seen for a supercharger with a standard pully, let alone the high elevation pully that seems to bring the boost up to 11 PSI. If I recall, the sales pitch on a turbo vs. SC was that it was suppose to spin up faster and provide more boost, but from your information here that doesn't appear to be the case? Am I missing something on this? Please know, this question is NOT a jab at anyone that has a chosen a turbo over an SC, I'm just trying to understand the differences for when it comes time for me to pick one.

BTW, JeepLab, you get that high elevation pully on yet? Any feedback? It appears you should have been seeing about a 30% increase in boost!

[JeepLab]

[QUOTE=Timmy;3727]

MOAR BOOST!

I now have seen boost peaking in the 8.0-8.3 psi range! Previously, I was only getting up to the 7.8-8.0 range. I seem to be on par with NOLA with boost numbers now. The highest I saw today was 8.58 psi in 4th gear."

Forgive me for asking, I'm only doing so for my own information, but it appears the boost numbers you are seeing are no better than what is seen for a supercharger with a standard pully, let alone the high elevation pully that seems to bring the boost up to 11 PSI. If I recall, the sales pitch on a turbo vs. SC was that it was suppose to spin up faster and provide more boost, but from your information here that doesn't appear to be the case? Am I missing something on this? Please know, this question is NOT a jab at anyone that has a chosen a turbo over an SC, I'm just trying to understand the differences for when it comes time for me to pick one.

BTW, JeepLab, you get that high elevation pully on yet? Any feedback? It appears you should have been seeing about a 30% increase in boost!

I had the SC out and separated, but I could not remove the pulley!

[UselessPickles]

it appears the boost numbers you are seeing are no better than what is seen for a supercharger with a standard pully, let alone the high elevation pully that seems to bring the boost up to 11 PSI. If I recall, the sales pitch on a turbo vs. SC was that it was suppose to spin up faster and provide more boost

I don't think anyone ever claimed that the turbo would produce more boost than the superchargers, but only that the turbo would produce more power. A turbo produces power more efficiently than a supercharger because it is using heat energy from the exhaust that would be otherwise thrown away out the tail pipe. The superchargers get their power directly from the crankshaft, so there is more parasitic power loss. Given a turbo and a supercharger that produce the same peak boost, the turbo will produce more net power to the drivetrain.

For the RIPP (and other centrifugal superchargers) specifically, even with the 11 psi high altitude pulley, you only get that 11 psi at 6500 rpm (and only if running down near sea level). The chart I posted with the RIPP boost curve appears to be with the high altitude pulley, because it gets up to just over 10 psi. Compare that boost curve to my boost curve. If the additional boost of the high altitude pulley being run at low elevations is enough to catch up with or surpass the power of the turbo, it will only beat the turbo near redline.

Somewhat unrelated, but speaking of high altitude pulleys...

The intent of the high altitude pulley is to compensate for thinner air at higher elevations, and produce the same amount of boost up there as the normal pulley would produce near sea level. With a given pulley, a supercharger will lose boost as go up into higher elevations.

The turbo, however, adjusts to changing elevations automatically. Its boost is controlled by a wastegate, which is calibrated to open up when boost pressure exceeds a fixed amount of pressure above ambient pressure. My turbo will produce about 8.2 psi peak boost at sea level, and up in the mountains, without making any adjustments.

[Pznivy]

The turbo, however, adjusts to changing elevations automatically. Its boost is controlled by a wastegate, which is calibrated to open up when boost pressure exceeds a fixed amount of pressure above ambient pressure. My turbo will produce about 8.2 psi peak boost at sea level, and up in the mountains, without making any adjustments.

This is why planes are turbo props. You couldn't use a supercharger on a plane. You'd crash.

[Timmy]

I don't think anyone ever claimed that the turbo would produce more boost than the superchargers, but only that the turbo would produce more power. A turbo produces power more efficiently than a supercharger because it is using heat energy from the exhaust that would be otherwise thrown away out the tail pipe. The superchargers get their power directly from the crankshaft, so there is more parasitic power loss. Given a turbo and a supercharger that produce the same peak boost, the turbo will produce more net power to the drivetrain.

For the RIPP (and other centrifugal superchargers) specifically, even with the 11 psi high altitude pulley, you only get that 11 psi at 6500 rpm (and only if running down near sea level). The chart I posted with the RIPP boost curve appears to be with the high altitude pulley, because it gets up to just over 10 psi. Compare that boost curve to my boost curve. If the additional boost of the high altitude pulley being run at low elevations is enough to catch up with or surpass the power of the turbo, it will only beat the turbo near redline.

Somewhat unrelated, but speaking of high altitude pulleys...

The intent of the high altitude pulley is to compensate for thinner air at higher elevations, and produce the same amount of boost up there as the normal pulley would produce near sea level. With a given pulley, a supercharger will lose boost as go up into higher elevations.

The turbo, however, adjusts to changing elevations automatically. Its boost is controlled by a wastegate, which is calibrated to open up when boost pressure exceeds a fixed amount of pressure above ambient pressure. My turbo will produce about 8.2 psi peak boost at sea level, and up in the mountains, without making any adjustments.

Thanks Pickles, food for thought when making a decision between the two.

[UselessPickles]

GRRR... my charts are getting shrunk because of ads to the point that they are difficult to read.

1) There needs to be a better way to allow ads to display in posts without making the entire right side of the screen unusable to post content. That's just a huge waste of space and leads to unnecessary shrinkage of images. Does the forum software or ad plugin have other options for how to display ads? Maybe display them between posts rather than inside posts? Or maybe have ads occupy a horizontal section of the post rather than an entire vertical section?

2) What happened to the feature that allowed us to click images to view them in full size?

[JeepLab]

GRRR... my charts are getting shrunk because of ads to the point that they are difficult to read.

1) There needs to be a better way to allow ads to display in posts without making the entire right side of the screen unusable to post content. That's just a huge waste of space and leads to unnecessary shrinkage of images. Does the forum software or ad plugin have other options for how to display ads? Maybe display them between posts rather than inside posts? Or maybe have ads occupy a horizontal section of the post rather than an entire vertical section?

2) What happened to the feature that allowed us to click images to view them in full size?

1. its vbulletins template, i cant alter it.

2. what kind of files are they. Upload as jpgs and it will think they are pics and make them full size when you click them.

[UselessPickles]

I'm hot-linking to images on my own web server ("From URL" option in the "Insert Image" dialog).

[FieryRobot]

But you can add a wastegate to a supercharger, no? Especially a centrifugal one.