[rgs]

I'm outfitting my TJ as a Crash Fire Rescue vehicle for our sports car club racing. It will carry a jaws of life, extrication equipment, a foam fire supression system, and various types of fire extinguishers. I'm working on sizing the water tank for the foam system and want to maximize it but am concerned with the overall weight I'm putting on it.

The Jeep is a 98 TJ but has many mods. For the suspension it has rebuilt Dana 44s front and rear out of a 2004 Rubicon, all 8 control arms are upgraded adjustable arms, it has Skyjacker 4" lift springs and shocks along with 1/2" poly spring isolators, and 33" tires. The driveline is a 60 over stroked 6 cylinder now at 4.7L, extensively ported head, stainless steel LS1 valves, beehive springs, roller rockers, Crane cam, etc. The transmission is a 42RE 4 speed automatic out of a Grand Cherokee but built up with extra clutched and 6 gear planetary, 231NP transfer case built up with wider chain, 6 gear planetary, and mega-short slip yolk eliminator. There's allot more but this covers the suspension and driveline.

It has been used on track for several years carrying equipment, fire extinguishers, recovery equipment, etc. The jaws with it's power unit and the entire foam system are new. I'd like to carry between 50 and 100 gallons but weight is the limiting factor.

Does anyone have a feel for how much weight I can safely put on? Anything else i should beef up on the suspension?

 

[Jonny Jeep]

Not sure how vehicles are rated over there, or if it will help, but Max Gross Vehicle weight over here means max load is (I think) somewhere in the region of 350-400 kg or 770-880 lb.

 

[PhulesAu]

It's still a1/4 ton truck. All of the lift and suspension are designed around that fact.

 

[Vinman]

Why not build a purpose built trailer for all the rescue gear? You could design it so each piece of gear is quickly accessible (no digging through other gear) as well as drastically increase the water carrying capacity. I would think that navagating a trailer shouldn't be a problem at a track.

Just a thought.

Vince

 

[rgs]

Why not build a purpose built trailer for all the rescue gear? You could design it so each piece of gear is quickly accessible (no digging through other gear) as well as drastically increase the water carrying capacity. I would think that navagating a trailer shouldn't be a problem at a track.

Just a thought.

Vince

The Jeep is my Quick Response Vehicle (QRV). We also have a firetruck on site with two fully equiped firemen. Unfortunately, they do not carry foam, just water. With ethanol becoming more prevelant in our racing, we want to be properly equiped, hence the foam. I currently carry two 1.6 gallon foam extinguishers, but feel we need to have more available.
The inspiration for going with an onboard tank came from a similarly equiped CJ sold on Ebay last month. It had a tank, gas powered pump, and some tools. It had been used by a fire dept for remote grass fires. I was interested in buying that one till the bidding passed $7000. I thought it had 100 gallons onboard but the ad is gone now. I figure if a CJ can handle 1000 lbs, my TJ should, but I am looking for feedback from anyone who has loaded down their TJ and any things to look out for.

 

[cheapjeep06]

Read here: http://www.cars.com/jeep/wrangler/1998/specifications/

Says payload is 800lbs.

 

[Netrix]

A CJ has leaf springs, just like a pickup truck. Your TJ does not.

 

[rgs]

Read here: http://www.cars.com/jeep/wrangler/1998/specifications/

Says payload is 800lbs.

800 lb with stock axles and suspension. How about with Dana 44's and the rest of the upgrades?

 

[rgs]

A CJ has leaf springs, just like a pickup truck. Your TJ does not.

My 1/2 ton pickup has coil springs

 

[cheapjeep06]

800 lb with stock axles and suspension. How about with Dana 44's and the rest of the upgrades?

About 3/4 of the way down: http://www.cars.com/jeep/wrangler/2006/specifications/?acode=USB60JDS011D0

Heavier rated springs do not change how much the vehicle/axles are rated for.

 

[Line58]

Why not build a purpose built trailer for all the rescue gear? You could design it so each piece of gear is quickly accessible (no digging through other gear) as well as drastically increase the water carrying capacity. I would think that navagating a trailer shouldn't be a problem at a track.

Just a thought.

Vince

That sounds like a good idea. I wouldn't imagine a trailer would slow the Jeep down much if at all and it would increase payload from 800 lbs to 2000 lbs.

 

[xtremzj]

800 lb with stock axles and suspension. How about with Dana 44's and the rest of the upgrades?

The axles won't do anything to hold more weight, and the suspension if anything won't hold as much (lift company's make em flexy and that is the opposite of carrying weight).

Get a pickup or trailer.

 

[Griff1918]

I work for a speedway for NASCAR as fire/safety. We use Toyota tundras. But we have all our crash stuff on one truck. And water skid unit in another truck. Each truck had fire ext on them. We also had just an extinguisher truck.
Anyways you are looking at just 400-800# of water. It's going to be way to much weight. I think the trailer idea is going to be your best option.

 

[chris142]

My 02 is sitting on the bumpstops with 400lbs of fat friends in the back.:hahaha:

 

[rgs]

That sounds like a good idea. I wouldn't imagine a trailer would slow the Jeep down much if at all and it would increase payload from 800 lbs to 2000 lbs.

Trailer is not an option.

I did some comparing on the Cars.com site.

A 1998 Grand Cherokee with similar type suspension is rated for 1150 lbs. load. Uses the same Dana 30/35 axles and coil spring suspension. Difference from the Wrangler is tires.

 

[Griff1918]

Then a tj is not the right vehicle for the job.

 

[RubiconRazorbac]

Then a tj is not the right vehicle for the job.

^x1000.

 

[Griff1918]

You know how much room you need for 50 gals of water.
Water=8.2lbs
7.3gals= per cubic foot
So you will need about 7 sqf and the back plate of a tj is only like 6sqf

 

[XXRider]

Most of the weights for payload etc are for safety on the road.

If you aren't using this jeep on the road, put some airbags in it to control the weight and load her up. The TJ has a pretty strong frame if it isn't rusted, axles are defiantly stronger than rated payload of the jeep. Just keep in mind that weight in the jeep is going to seriously effect handling at speed and braking.

Assuming that the jeep is only used on the track you could put a decent sided tank in front of the grill attached to the front bumper. But you may need to put in heavier springs or air bags in the front for the weight.

 

[jason m]

Just get a two wheel drive one ton truck that runs real well and even if its not the cleanest thing around its a track truck. It wont see the road, it can handle the weight you want to add and anyone can drive it. Plus being as its two wheel drive it will be cheaper.

TJ is not cut out for a trucks job, use the right tool dont risk a life on the wrong one.

Jason.