The Worlds Fastest Comanche

[Plechtan]

The worlds fastest Comanche is currently located at the Chrysler Museum in Auburn hills Mi. It was built to show the performance of the new 4.0L engine in 1987. It set a land speed record at Bonneville of 141mph and had a top speed of 146 MPH. GM did not take this lying down and hired Gale Banks to set a record with a S15 pickup in 1989. In the 240-261 cid class, the Banks truck went 183 MPH, totally blowing away the Jeep record. Banks continued to compain trucks and came back in 1990 with the Syclone, and set a record of 201 mph with a normally aspriated V6. I believe this was in the 261-305CId class.

So who cares? why is this important? Well I don' think it is right that a Chevy V6 holds a land speed record over a Jeep I6. This is one of those things that just puts the universe a little more out of wack. I think the situation needs to be rectified. To this end i have purchased a 1989 Comanche, LWB 2wd ( 4.0 of course) AX15 trans, and Dana 44 rear axle. I am collecting parts, and am looking to build the engine, It will not be easy to compete with the Banks organazation. The record is 20 years old, and technology has improved during that time. So i think a 4.0 can be competitive. I will be building it in my garage, with money out of my pocket, and help from anyone who wants to lend a hand.

Here is a some information on the engine restrictions.

The rules state that you can run a engine form the same engine family, but it must have the same deck height as the engine that came in the vehicle originally. The
E P/MP class is limited to about 261CID, so a 258 falls in good with the rules, but a 4.0 with a larger bore and a little stroke would probably out perform a 258. Some input from the group would be appriciated. You need a whole lot of HP to go 185 MPH

I want the worlds fastest Comanche to be parked in my driveway, and the second fastest Comanche to be in Auburn hills MI.

[amcinstaller]

best of luck, a little far to help or see it, but hopefully i see it on youtube someday. keep us posted!!

[gradon]

Here's what the 5.0 N/A Syclone did: http://www.highperformancetrucks.com/tr ... php?id=130.
You would need to stroke and turbo/sc to even get in the 400-500hp ballpark. Of course you're gonna want a strong roll-cage and some nice brakes. Overall you'd probably have to put $10-15K into it to make a serious attempt. My brother paced me at 136mph the other day on his YZF-600.

[Plechtan]

We are not going for a record in the 5.0 class, the maximum size engine we are allowed is 4.3 L The speed to beat is 183.942 The problem i have is that an internal combustion engine makes the most horsepower at high RPM. The Jeep motor does not like High RPM, so that is a problem i will probably have to solve if i want to be competitive. In the article it talks about the banks V6 reving to 8,000 rpm.

I have heard of rock crawlers reving to 7500, but that is the higest i have heard.

[Mgardiner1]

Didn't lexus put a 4.3 liter v-8 in there cars for a few years? maybe they still do. Either way, i'm sure you can find some import engine that will wind out to what you want!

[Plechtan]

In order to rin in the production class you have to run a version of the engine that came in the truck. If you swap engines, you then hav to run in a modified class. The modified M/MP class record is 187.7 vs the 183.9 record in the production class.

[Plechtan]

I came across the original press release for the 1986 Bonneville truck. Here is part of it:


"Southfield Mich. -- The Jeep Comanche pickup truck, only in its second year on the market, already has beaten the competition to the proverbial "Quick"
A specially -prepared 1987 2 wheel drive Comanche powered by a modified version of American Motors' new 4 liter, fuel-injected 6 cylinder engine set 9 US and 4 International records late in 1986 in the trials at the Bonneville Salt Flats.
The highlight was the the Comanche's record average speed of 141.381 mph in a two way dash over a 1 mile measured course at Bonneville. It's peak speed was 144.028 mph

Not only did the comanche set seven speed marks for trucks, it also established six national and international records for vehicles of any kind, including passenger cars."

The international records were set in the 3-5 liter class, this just goes to show how powerful the 4.0 was for the time. the 4.2l ( the old motor) was only rated at about 120hp, and the 4.0 was 175hp with the MPFI

The comanche was and is a great product, even today, it is hard to find a mini pickup with a 2200lb payload capacity.

[Plechtan]

I got some more info on the 1986 truck, I acually went and saw it and took some pictures at the Chrysler Archives. The drivers name was printed on the door, and i found out that he still works for Chrysler ( until Friday, then he retires)
He sent me a copy of a handout they use to give out at the auto shows, It claims that the engine in the Bonneville truck produced 284 hp @ 6000 rpm and 259 ft/lbs of torque at 4500 rpm. I wrote back and asked what modifications were made th the engine, I will keep you posted when i get a reply.

[seanyb505]

284 hp? I wonder if Chrysler was stroking engines back then?