The worlds Fastest Comanche

[troy6187]

i think one of the things you guys are overlooking is the gearing that is used in top speed cars versus street cars. cars built for top speed are geared super high... most of them need pushed by another vehicle to get moving. i'm pretty sure that there are 4 cylinder cars with less hp going 200mph or faster. what transmission was the banks truck using and what were the gears in the rear? also did they use a add-on overdrive of some kind maybe?

[Throttle_Jockey]

Yes I agree totally with the arodynamic factor's but on the same note gear ratio's from the trans. to the rear axle is going to play the major part of this project.

The ferrai enzo only claim's 660hp out of a 365 c.i. V12 6.0L and does'nt specify wether or not thats rear wheel HP or crank shaft,nor what the final drive ratio's are.

So with right suspension and gear combo and the max legal HP from the 4.5 I personally believe it can be done,IMO for all with the disbelief comment's should support this project instead of arguing that it's impossible stepping down.

 

Ferrari Enzo spec. sheet(well atleast the most detailed one I could find)

Brakes F/R: ABS, vented disc/vented disc

Tires F-R: 245/35 ZR19 - 345/35 ZR19

Driveline: Rear Wheel Drive

Engine

Type: V12

Displacement cu in (cc): 365 (5988)

Power bhp (kW) at RPM: 660(485) / 7800

Torque lb-ft (Nm) at RPM: 484(657) / 5500

Redline at RPM: 8200

Exterior

Length × Width × Height in: 185.1 × 80.1 × 45.2

Weight lb (kg): 3009 (1366)

Performance

Acceleration 0-62 mph s: 3.65

Top Speed mph (km/h): 225 (362)

Fuel Economy EPA city/highway mpg (l/100 km): n.a. (23)

[SoloCamo]

IMO for all with the disbelief comment's should support this project instead of arguing that it's impossible stepping down.

 

I 100% Fully Support this project, and to be honest if I lived closer I would lend a helping hand towards it. However, I'm hoping that my self being skeptical about the numbers needed to go those speeds is more of a educated criticism that is intended to help, not put down. I would love to see a Comanche go those speeds as it would be one hell of a site, however I just don't see it doing with 500whp. That's all. :cheers:

[Worlds Fastest Comanche]

The head has to be the same configuration as stock, I take same configuration to mean 2 valves per cylinder, no overhead cam, etc. Everybody ports and polishes the heads, so moving an intake port a little should not be a big deal.

 

My problem is that i will need to produce about twice as much airflow and fuel flow as a stock motor. The intake area will probably need a lot of work. I really question if the stock intake will flow enough air. We will probably have to use 60-75 lb/hr injectors

[Pete M]

So you can't use the 99 4.0 intake? :(

[carnuck]

A 6 speed with 2 overdrives is needed. I got clocked in my otherwise bone stock '87 MJ with 33" transport tires (no longer available) 3.08 gears and wound up to 3100 RPM in 5th gear at 140 mph (Old Airport runway)

I drove the truck this way to and from work for 8 months (S. Seattle to Poulsbo, WA) with an average of 22 mpg. '87 has a great bottom end cam to accomplish this.

It would take me about $3500 in parts to push my truck past 150 mph. (without stroking it even) I could have more fun if I took a 232 and 4.0L to build a different configuration.

[Worlds Fastest Comanche]

Ok here are some calculators to help out. The 1986 jeep did 16.986 in the quarter mile, at 80mph. If you run this through some of the calculators available on the internet it will say that you have about 140 rwhp. Which would make sense if the 1986 truck had a basicilly stock engine and about 20% in driveline and other loses. So the old truck set a record of 141 mph in the flying mile, and if we figure it took 140 hp to do it, you can run it through this calculator to figure the new hp required http://robrobinette.com/top_speed.htm I come up with about 316 rwhp, so again assume that is only 80% of the HP you need, it comes up to about 400hp at the flywheel.

 

Here is a calculator for calculating speed depending on engine rpm and gears

http://www.catherineandken.co.uk/sti/tyres.html

[Worlds Fastest Comanche]

Here is probably the best calculator page

 

http://www.wallaceracing.com/Calculators.htm

 

Just a note on all the corvette and other car top speeds, they are probably limited by their gears. A land speed record car usually has to be pushed off the line by another vehicle because it is geared so high. This would be unexceptable in a performance car, also rember if you are using all your hp to fight wind restisance, then you have no power to accelerate. Again for a sports car to accelerate at very high speeds, it need extra HP to do it.

 

The choice that the car builders make is to gear a car somewhat low so it has power off the line. Putting a 6 speed trans in helps with top speed.

[dakineJ]

What are the rules concerning tires and wheels?

[Worlds Fastest Comanche]

the tires have to be rated for the spped you atee running, you can use V or Y rated tires up to 200 mph. Over 200mph you need to run a special tire for land speed racing, or get permission to run a specific tire. Goodyear makes an Eagle tire for land speed racing rated for 300 MPH.

 

You can run steel or Alloy wheels, Steel is prefered, and over 16" the center has to be welded to the wheel both front and back.

[Redramman]

So does this mean the twin under bed Turbos and Supercharger are against the rules??? :yes: Anyway I like the Idea of capitalizing on the super low end torque of an I-6 with super overdrive gears! :thumbsup:

[Worlds Fastest Comanche]

Here's the problem, torque comes from your stroke times the power pushng down on the piston. If you go with a long stroke to make more torque, then you piston becomes smaller ( to keep the same cid), Smaller piston, then smaller cylinder, then smaller valves, so less airflow. Since HP is torque over time, then the more explosions per second you can have, the more power you can make. Until you start running out of air ( turbos would help)

The bonneville engine will probably peak around 7,500 rpm and over 400hp. The block and pistons will be similar to stock ( better quality) but the power will be made with the intake, head and cam.

[Sugarfoot]

I did ask about any other arvchive information, and he said that the archives at the jeep headquarters were in the basemant and that alot of the material was water damaged, and had to be thrown out.

 

My hope is that i will be able travel over to Detroit to actually look at the truck and take some pictures of it.

 

I guess I will have to wait for the powers that be at Chrysler to make a decision.

 

So did you ever get in to see the original truck? The way things are going with the Big 3 you just might want to do that soon and make them an offer to buy it on the spot. I have great fear for Chrysler's future. Have you approached the AMC clubs with your project?

 

I think the water damaged files could be true due to the early July storms that I worked up there. But throwing them out would be a great surprise to me as freeze drying has gotten really cheap over the last few years. Their insurance should have covered that. But then again that's flood damage and it appeared Flood coverage from FEMA does not exist in that area. But they should have had data insurance anyway. Hard to believe they were still strictly paper archives from 1986-88???.

 

If Chrysler were to go under, hopefully they will donate all their archives to a museum such as what Chris Craft Boats did with the Mariners Museum.

 

I support your project however you eventually get there. Let me know when you plan to go the Salt Flats. I drove through there this summer and it is a way cool place. I'll gladly make a trip back to see a Comanche do 185 mph. Especially a red one.

 

GO HORNS !!! LOOK OUT ROLL TIDE we figure you as next. We will crush you!

[jtdesigns]

I did ask about any other arvchive information, and he said that the archives at the jeep headquarters were in the basemant and that alot of the material was water damaged, and had to be thrown out.

 

My hope is that i will be able travel over to Detroit to actually look at the truck and take some pictures of it.

 

I guess I will have to wait for the powers that be at Chrysler to make a decision.

 

So did you ever get in to see the original truck?

 

 

http://www.comancheclub.com/forums/viewtopic.php?f=3&t=13074

[Worlds Fastest Comanche]

Yes, thats the thread about the trip to the Archives.

 

Let me give you a little update on what's going on. I picked up a 2000 xj motor at a junkyard, $200.00. Looks like the guy never changed his oil. #1 main bearing was spun. It came with a HO head that was in great shape, although we will be using a Hesco aluminum head. The engine is at the machine shop, they have to measure the deck height, and see how thick the cylinder walls are. based on that information, we will figure out bore and stroke. Looks like custom pistons and custom rods. The crank will be from a 232 and it will be offset ground to get the correct stroke. The engine will have to turn about 7,500 rpm and produce in excess of 400hp.

 

For the rear axle we picked up a 9" ford. we will change the rear suspension to be like the mid 60's chevy pickups. this is also the same style suspension that Nascar uses. It's 2 arms that run from the axle to a crossmenber at the front of the bed. Chevy used coil springs, we will use airbags. For the front suspension (2wd) we will use a axle out of a later model cherokee with WJ brakes. We will relocate the attachment points for the arms 3-4" lower. this will keep the front end geometry the same, but get the truck down. The tires we will be running will be about 25" in daimeter , the stock tires are 28 or 29" so 2 inches lower because of the tires, 3 inches due to suspension drop, so 5 inches total, maybe more with the front airbags. this should get the truck slammed.

 

Work is also progressing on the timing belt setup. A custom intake manifold will be used with 2 throttle bodies. The trans will be a Tremic, we will probably use a T5 for testing, then get a TKO for the Bonneville run. I n currently funding this out of my pocket, so some things have to wait until i get the money.

[Hawk]

Everything sounds cool to me except the 9" rear. Are you sure you'll need a rear that strong and heavy for this? I think you could get by with something lighter since you won't be doing hard launches with the truck.

Unless you plan to drop the diff out of it to put in more streetable gears during the 'off-seasom'.

 

Thought about using a Toyota rear axle?

[Worlds Fastest Comanche]

I have a D44, but it will be eaiser to change ratios on the 9". It is eaiser to find a disc brake setup to work on the 9" as well. As fpr the weight, i will prpbably have to put some ballast in the back for traction.

[Redramman]

A Firebird used an ice filled cooling air intake system kind of an intercooler concept,claimed it was a big differance. What about a fuel cooler as well? Just more crazy ideas thought I'd run by you. :popcorn:

[possum]

Yeah our Trans Am at the shop I used to work at used an icewater intercooler. It does make a big difference but it usually is used with some kind of forced air induction. I believe forced induction is against the rules of what he is shooting for.

[jtdesigns]

Peter, any updates?

[james750]

Yeah our Trans Am at the shop I used to work at used an icewater intercooler. It does make a big difference but it usually is used with some kind of forced air induction. I believe forced induction is against the rules of what he is shooting for.

Does that mean that there cannot be any superchargers or turbos?

[Worlds Fastest Comanche]

Correct no supercharges or turbos.

 

As for an update, The engine is at the machine shop, we were able to get a 4" bore out of it. The head will come from Hesco, it will be one of thir aluminum ones. 2.02 intake and 1.060 exhust. Work is progressing on the timing belt drive and the aftermarket ECU. We got the tires in 215/60-15 boy are they small 25" diameter. When the wheather gets better we will start working lowering the suspension.

[Worlds Fastest Comanche]

I finally got the head going, originally Heasco did not want to put larger valves into their head. Business must have slowed down, because they finally aggreed to do it. Cost is $2,900.00 and delivery should be around the end of january. When i get it, it will be shipped to Harland sharp for the shaft roller rocker setup to be installed.

 

The ATI Danper arrived, the hub is a little strange, It is too long and sticks out the front of the damper. I think it was originally designed to run a external oil pump via a belt drive. I will post some pictures when i get a chance.

 

The engine ended up with a 4" bore and a 4" Stroke giving about a 302 cid displacment. I amlooking for about 1.5 hp per cubic inch. The engine will have a 12.6:1 CR and will require 118 octane fuel.

[Darren]

 

The engine ended up with a 4" bore and a 4" Stroke giving about a 302 cid displacment. I amlooking for about 1.5 hp per cubic inch. The engine will have a 12.6:1 CR and will require 118 octane fuel.

 

Wow. :eek:

[1974CJ5]

I can tell I am not near as knowledgeable as any other person posting on this thread but...

 

Wouldn't a heavy flywheel help with the low end torque to race on up in ridiculously high gears?

 

Do you have plans to add down force to the rear end? Since you have no weight back there.

 

Are you going to be higher in the back than in the front, or have some sort of front lip to help keep drag off of your undercarriage?

 

I think this record is attainable for this truck. The doubters; using the corvette as an example is valid, but those cars are more interested in 0-60 times than top end. German spec VW's that everyday people are driving on the autobahn are turning ridiculously high top speeds for the hp ratings they have.

 

More knowledgeable posters feel free to tear this a new one, Just if/when this truck makes history I wanted to make sure I got a post in here! :D