WTF is this guy runnin?

[ftpiercecracker1]

This is a video i have been wanting to put on here for the longest time, I have NEVER heard a 4.0 flogged so hard and he has video after video of the same thing.

What in the world do you guys think he has done to achieve such high RPM sustainablility?

[604rail_king]

Rediculously high gearing ...????

[yuppiexj]

Holy Hell

[ftpiercecracker1]

Rediculously high gearing ...????

you mean low? like a 5.56? Cause if it was "high" or some people call them tall gears like a 3.02 he wouldnt be able to turn the rubber he has.

But ya like i said, hes got about a dozen videos of different runs doing the same thing, I dont know for sure but it sounds to me like he is pushin 6500 rpm, maybe even more. Which is absolutely INSANE! He wont divulge any details, except that it is a jeep inline six, but i figured with our collective knowledge we might be able to uncover what this mad man has done under the hood.

[yuppiexj]

In one of his other videos he commented about leaving in 3rd gear around 3500 RPM, bouncing off the rev limiter at the end of the run.

I'd love to see that launch on pavement, if just to see what did break.

This tells me low range with stock 3.55 gears with lockers (or welded diffs)

I dig the in cab exhaust the dumps out where the hatch used to be.

[604rail_king]

Rediculously high gearing ...????

you mean low? like a 5.56? Cause if it was "high" or some people call them tall gears like a 3.02 he wouldnt be able to turn the rubber he has.

By hi gearing like 5.56 for rock crawling, that would give you only low speed abilities ... Which is what I was indicating. Itll allow the engine to rev up faster but speed is now reduced.
To me, tall gears means a low gear ratio such as 3.02 which would allow for higher speeds and make the engine less rev happy. Never seen many people referrence their gear swaps by how it changes their final speed ... Just the gear ratio.

I'd have a hard time believing this guy isn't melting his clutch if he is launching at 3500 roughly in 3rd with 3.55. That's a ton to load up on the clutch with that low of gearing, those tires, and sitting in mud

In any of his vids, is it confirmed how high his Rpms get?

[cruiser54]

He's just bouncing it off the rev limiter. Doesn't sound that wound up to me.

[SilverXJ]

In a comment or two he made it sound like he is running Mega Squirt and has the rev limiter set at 6000 rpm.

Also, I don't think the engine is under that much of a load as the tires aren't making much traction.

[ftpiercecracker1]

Load or not hes still holdin 6k for a freaking eternity, which has got to be absolute torture.

[SilverXJ]

I am not sure why it is so important to have a high RPM in your case. In his case he isn't making any extra power, he just needs the wheel spin. And judging from his setup it isn't exactly a daily driver or with longevity in mind.

The long stroke and cam harmonic do not make for a high reving engine. Even Chevy V8s don't rev that high stock. On the track sure, but they have a cam that won't idle at a decent speed and does crap below 3000 RPM.

[ftpiercecracker1]

He says in a description or comment he has been running the same motor going on 3 years, not sure when he posted that comment but its still three years.

[SilverXJ]

I doubt that and at some point he did say he replaced it.

[jsawduste]

Gerald Lee (Savvy) and John Currie (Currie :!: ). Winners on the KOH EMC 2012 and competing in many West Coast Ultra 4 and such events. Are spinning their Hesco built stroker with Diabolo controller to 7,000 rpm.

Gerald and John being the smart guys they are, tear the engine down after each event.

With a prepped aluminum head and enough cam. They are still making power way up on the rpm band. In this case they want a wide power spread and the ability to over run the powerband if need be.

[ftpiercecracker1]

Thats all fine and dandy, but those guys, savvy & currie, probably have gobbs of money to throw at their motor, so a complete teardown/rebuild + hesco stroker and custom aluminum head after every event means nothing to this thread. If i had all the money in the world i could probably build a motor to spin 10000 rpm, but hey i only have to rebuild the hole thing after every pull.

When i first saw this video, i was stunned, dumbfounded. I watched every video the guy has on youtube fearturing this particular XJ, he does the same thing over and over again, with presumably the same motor. I started this thread to see what it takes to build such machine, be it either how its geared, some kind of high quality bearings, or secret african voodoo.

lets see what we can come up with.

[SIXPAK]

Here is mine. At :39 seconds without N2O and spinning 5200-6000 and at 1:39 its turning 6000-7000 with N2O. Gotta love the sound of those inlines screaming. I could fall asleep listening to the Mud Bogger above!
http://youtu.be/dbHKyNPAWlg