Team NAXJA/Petty Cash Racing stock class KOH XJ build

[cal]

So.. We hitched a ride back to camp on the Crane of Shame.

 

[cal]

With a long night ahead, we started to look it over.

You can clearly see here, the knuckle was broken:

Time to throw up the DNO plaque and start tearing into it..

Our awesome crew had it apart in no time at all.

 

[cal]

Made a few quick phone calls to some friends and sponsors. It was determined that if we welded it back up, it would not hold, and that we had to have a new knuckle.

Blaine @ Black Magic Brakes had a new set of raw knuckles on the way to us within 15 minutes. Dallas from StinkyFabRacing and I took off to his shop where we met up with Kenyon and Erin and spent most of the night drinking his beer and watching Dallas fab stuff up.

First to measure every surface and determine what custom stuff Black Magic had done. I was surprised how detailed Dallas was in this stage.

Then off to the computer to draw some circles!

Load up a little material..

and press PRINT

Some test fitting and adjusting

 

[cal]

Dallas didnt have the thickness material we needed, so he combined pieces to get exactly what we needed.

So pretty

Once the spacing is done, a little drilling for the steering..

And lastly to the bridgeport to adjust the caliper mounts.

Oh wait, the bridgeport doesnt have the right tooling. Angle grinder for the win

 

[cal]

A quick nap on the couch, and back to the races!

GOOD TO GO!

 

[cal]

We still had to deal with the failing fan clutch. I didn't take any photos, but we drilled it out and thru-bolted it similar to what I did with our previous one last year. Re-assembled the car and while we missed qualifying, started the race at the back of the pack.

We were running fast and strong, and up to third place in class just a couple of laps in while fighting heavy traffic. Making a pass on the back strait away we revved the hell out of the motor (6000+) and then went into a hard corner. After the corner the car started to get warm fast, and then we lost power steering and charging.


Got out of the car and popped the hood. I dont have any photos (no camera in the fire suit) but our fan pulley was misaligned and the belt popped off of and was loose. With great difficulty we got it back on, fired the motor and but came right back off again. There was really nothing we could do with no tools or parts and only 45 minutes left in the race, so we sat back and enjoyed a great view of the race from mid field.

After the event was done got towed into camp. I didnt think to take any photos before the guys tore into the car, but here is what they eventually found:

On our high RPM runs down the back strait, the fan with no clutch had so much force that it pulled the bearings out of the housing. If the belt hadnt jumped, it probably would have put the fan into the radiator shortly.

 

[cal]

Today I'm back to the mechanical vs electric fan debate. I'm crunching numbers and still can't make it work.. if I get enough fan to cool the motor (3700 CFM or so) then we're pulling 60 amps of power, which I really am not comfortable with.

I'm going to put the car aside and work on my trail rig for a couple of weeks, so I have plenty of time to think on it.

 

[cal]

Some other great shots from the weekend; These shots by TBARS4.

You can just see our camp toward the right center.

Chatting with Randy Slawson, a former King of the Hammers

Drivers meeting

The shortcourse

Somethings missing here

More random

 

[yossarian19]

Ouch! Hard luck on the collision & fan clutch issues. Still looks like fun & cooling aside, the Jeep seems to have done darned well.
I'd thought the Taurus / Volvo fan put out 4500 cfm at 33 amps? Or was that the "low" speed draw?

 

[cal]

Everything I have seen for the Taurus fan is 2800 CFM.

But every site seems to list different numbers for it, too.

Whatever we do it probably won't be a single fan.

 

[RedHeep]

I was getting text messages with lap times, then I figured something happened.

There's a lot of room behind you. Do the rules say or is it feasible to rear mount a radiator with a big ass electric fan?

 

[cal]

Has to be within 3" of factory location.

 

[RedHeep]

Can you fit 3 12" fans in there? I know the dirtbound setup is for 3 10" fans. Spal has a few 12" fans in the 2200 cfm range at 13 amps. That would put you at 4400 for 2 and 6600 cfm for 3. You could turn them down with all 3 on and have an option to turn them up if you lose 1.

 

[cal]

I just measured, and there's no way. We basically have 30"x11.5" to work with. I could cheat it a little bit on height by building a custom shroud and mount, but can't get any wider.


I looked up our trans fan, SPAL 30102029, which measures 12.625 wide and 13.125 tall. 2 of those wouldn't be enough air flow and I can't fit a 12 and 2 10's.

 

[RedHeep]

The dirtbound shroud is made for 3 10's, but the low pro spals only do 1100 cfm. That's not enough for what you need. I wouldn't run 3 fans that barely pull enough cfm to cool because when you lose one you're done.

What about pushers? Can you fit bigger fans on the front side?

Spal has medium profile 11's that do 1580 cfm at 8.6 amps. Can you find 1.5" on each side?

Edit: I'm an idiot. Those are metric numbers, not cfm. Those only do 960 cfm. I have no idea what cubic meters/hour are.

 

[David_Bricker]

Well, you know my luck with electric fans. You also know what I'm running today. Granted, I'm certainly not as severe as you are doing, but I do run in slightly toasty areas.

My vote (which has no bearing on anything) would be for the stock mechanical fan with as big a clutch as you could squeeze, given the giant radiator you have. I got lucky with my skinny radiator, and can run, barely, the ZJ extreme duty clutch. And of course, the stock late model electric aux fan.

David Bricker / SYR

 

[yossarian19]

Everything I have seen for the Taurus fan is 2800 CFM.

But every site seems to list different numbers for it, too.

Whatever we do it probably won't be a single fan.

Low speed, the taurus does 2500-2800, in there. Hi speed, 4500. This as per Gojeep. I am reading another link right now claiming the Taurus measured 2800 on low and 5600 on High using battery power, 6200 on high running off alternator. That's a lot higher than most of the numbers I see other places online, so, grain of salt.
I'll say, though, that people make a lot of power in Volvos (no, really. They do) without overheating, Volvos using the same fans as the Taurus. I'd think the stock AC fan + Taurus fan, like here, would do the job.

 

[jeeperjohn]

We still had to deal with the failing fan clutch. I didn't take any photos, but we drilled it out and thru-bolted it similar to what I did with our previous one last year. Re-assembled the car and while we missed qualifying, started the race at the back of the pack.

We were running fast and strong, and up to third place in class just a couple of laps in while fighting heavy traffic. Making a pass on the back strait away we revved the hell out of the motor (6000+) and then went into a hard corner. After the corner the car started to get warm fast, and then we lost power steering and charging.


Got out of the car and popped the hood. I dont have any photos (no camera in the fire suit) but our fan pulley was misaligned and the belt popped off of and was loose. With great difficulty we got it back on, fired the motor and but came right back off again. There was really nothing we could do with no tools or parts and only 45 minutes left in the race, so we sat back and enjoyed a great view of the race from mid field.

After the event was done got towed into camp. I didnt think to take any photos before the guys tore into the car, but here is what they eventually found:

On our high RPM runs down the back strait, the fan with no clutch had so much force that it pulled the bearings out of the housing. If the belt hadnt jumped, it probably would have put the fan into the radiator shortly.

You could stake/Loctite the bearing in or even break out an aluminum welder and weld on some bosses for screws and screw on a retaining plate.

 

[jeeperjohn]

Everything I have seen for the Taurus fan is 2800 CFM.

But every site seems to list different numbers for it, too.

Whatever we do it probably won't be a single fan.

I think it would be easier, cheaper and more reliable to stick with mechanical and mitigate the possible issues.
You could drill a hole perpendicular to the shaft and grind a small notch in the bearing shell and stick a roll pin in it to prevent the bearing from moving. This would also prevent any possibility of it spinning in the bracket.

 

[XJ_ranger]

or install a rev limiter less than 6grand... :smootch:

and change the gears in the axles to go faster if need be... :gag: