OMG...Prodigy...TURBO!

[UselessPickles]

There's some people poo-pooing all over my thread about the turbo over on the wranglerforum, with comments such as, "When are you ever going to get the RPMs high enough to even get the turbo spooling off road?"

I decided to actually do some basic math and answer that question, and I think the results are interesting enough to share over here. The following is a copy/paste of my reply...



Since we don't have details on the 3.6 turbo kit, let's talk in terms of the existing 3.8 turbo kit, 12 psi. Here's the torque gains at a few rpms (refer to the dyno chart I posted earlier if you want to confirm the numbers):

2000 rpm: 25 ft-lb, 16% gain
2500 rpm: 55 ft-lb, 33% gain
3000 rpm: 105 ft-lb, 68% gain
3500 rpm: 185 ft-lb, 116% gain

Now let's look at the speeds attained at the same rpms.

First, let's assume my plain old stock Wrangler Sport with 29" tires and 3.21 gears, in 1st gear, 4LO.

2000 rpm: 5.3 mph (25 ft-lb, 16% gain)
2500 rpm: 6.6 mph (55 ft-lb, 33% gain)
3000 rpm: 7.9 mph (105 ft-lb, 68% gain)
3500 rpm: 9.3 mph (185 ft-lb, 116% gain)

So there you have it. Significant gains in the 5-10 mph range. That is a very common speed range for me on the off-road trails that I drive on. If you are not focused on extremely slow rock crawling, then this is usable torque for you.

But that's pretty tall gearing for off-roading. How about a Rubicon with the 4:1 transfer case, 33" tires and 4.10 gears?

(EDIT: corrected a miscalculation of speeds)
2000 rpm: 2.7 mph (25 ft-lb, 16% gain)
2500 rpm: 3.4 mph (55 ft-lb, 33% gain)
3000 rpm: 4.0 mph (105 ft-lb, 68% gain)
3500 rpm: 4.7 mph (185 ft-lb, 116% gain)

I'd say that looks pretty damn usable for low-speed off-roading. Maybe still not extreme rock-crawling usable, but I'm not a rock crawler, so I don't know.

The kinds of trails I drive on, I'm often in the 5-10 mph range in 4LO and 1st gear. Yes, I actually keep it in 1st gear so I can make use of the mid/high rpm range and the power that comes with it!

I hope this answers your question.

[JeepLab]

There's some people poo-pooing all over my thread about the turbo over on the wranglerforum, with comments such as, "When are you ever going to get the RPMs high enough to even get the turbo spooling off road?".

I've gotten the same note in each supercharger thread.

Its a short sighted opinion that is easy to throw out with little knowledge of superchargers and their uses offroad.

The answer to this question, is when your offroad, you can crawl in lower gear, at higher rpm WHEN you need more power. RATHER than goose the throttle.

I did a video on this technique. Its a very simple concept, and I dont understand why some people cant grasp it.

The extra power is useful when your slow offroad and fast on the highway, You just need to manipulate the RPM to use it... when its called for.