"JBL HEAT" Build

[Machiavelli]

PREFACE
1. This thread will be dedicated to my trials and tribulations toward a successful JBL build. There's no substitute for good planning, so that's what I've been doing while Larry takes care of the chassis & body work.

2. I'm one fickle SOB who can't make his mind up when options present themselves, I also find ways to "think them up". Larry continues to exhibit the patience of Job with me, I've sent him down several dirt roads and never once a temper tantrum which would have been well deserved.

3. I have no 2nd thoughts about selecting JBL as my car builder, even after researching other builders for "trim" ideas, the photos on JBL's website continue to confirm I made the right decision.

4. Your comments are always welcome, my way is rarely the definitive right way, just one of the many "means" to get to an "end". I will always listen, the caveat - I have already justified in my own head that my way IS the right way.

On to the build ...


10/16/10

DRIVE TRAIN
Block: DART Aluminum, 4-Bolt Mains, 427 CID
Rotating Assy: Scat Super Light
Heads: Edelbrock Victor Jr. Aluminum
Valves: Ferrea
Pistons: Dish Type, 14-16cc
Transmission: Tremec TKO600
Rearend: 3.73
Drive Shaft: Custom ACPT Carbon Fiber

Comment: Still a work in progress. I'm going with George Anderson of Gessford Machine. Endorsed by Shelby and universally acclaimed for his engine building prowess. You get his individual attention when working through the motor details, he will build your motor to the budget and performance requirements you want, the man is a genuine pleasure to work with - enough said.

WHEELS
Mfg: Schott, 3-Piece Modular
Type: Sprocket
Front: 18x10, 4.75" Backspace
Rear: 18x12, 8" Backspace
Bolt Pattern: 5x108
Hub Centric/Lug Centric: TBD
Dish: Brushed Finish, Clear Ceramic Coated
Flange: Black w/Chrome Bolts, Ceramic Coated
Spokes: Polished, Clear Ceramic Coated

Comment: Not cheap! Yes, 18" diameter which is a departure from the standard JBL 17". Larry will work with you and aims to please! (although I think I am getting low on credits)

MISCELLANEOUS
Roll Bar: Full 1-Piece Unit, 2-point 3" Diameter
Mirrors: (2) Bullet Type Windshield Mount, 1 Rectangular Dashmount
Hood Scoop: JBL Small
Paint: Base Color Green, Stripes Cream (1 Wide, 2 Pin)
Upholstery: Cream/Tan Combination
Anti-Roll Bar Adjustment: Retro Knobs Activate Servo Control (not rocker switches)
Gauges -
100mm Counterclockwise Speedometer
100mm 8,000 RPM Tachometer
52mm Oil Temperature
52mm Water Temperature
52mm Oil Pressure
52mm Fuel Level
52mm Ammeter
52mm Voltmeter
52mm Clock
52mm Fuel Pressure
External Trim: Have some pretty trick ideas to iron out, more on that later.

Comment: Roll bar is not race legal, but I'm not going to race this car. Have touch-up paint from actual paint codes of cars I liked when cruising parking lots. Don't make the mistake of thinking your PC or Printer can render colors accurately, they cannot! I will paint up some samples and make my down select. Gauges will be more period correct like those from Smith, but not necessarily Smith. Yes, the dash will look like a Cessna intrument panel, oh well hehe.

[redd]

are you using the same offset as rhe 17"? Thanks

[Machiavelli]

redd,
Yes, but there are a lot of different offsets listed on the JBL website. Depending on the model and driving preference, each can be a little different. I decided my driving preference best fit the "Road use and mild competition" scenario, hence 4.75/8 front/rear. There are plenty of straights and nice twisties in my neck of the woods to put those porsche fanatics back in their place (reading my plate until the eye sight fails)

[David Biele]

What chassis did you order? comp or touring

David

[jmarsey]

Hey David,

Wondering also if Dave is making the comp chassis again?

Talk soon, John

[Machiavelli]

The competition Roadster (comp chassis), couldn't pass up the engineering.

[vector1]

congratulations on starting the build.

i was building a similiar kit and had an aluminum driveshaft made in place of the steel unit, and the wt. savings was little less then 1/2 lb. for a lot of money. your carbon fiber unit will of course be lighter but remember the tube is the only thing you are saving wt. on, the knuckles are pretty heavy. might be a place to save quite a bit of cash for something else. you could make the wt difference up with a lightweight flywheel/clutch which i would suggest also unless you like to do a lot of parading or driving in stop & go traffic.

i had looked at going to a different size rim and mr. hudgins advised me the chassis was setup for 17" wheels so that is what i went with and he explained it but i would have to find it somewhere. personally, after trying to change some stuff on the car and seeing some stuff incorrectly done i would stick to the way the car was designed, everything works together nicely.

i find the side mirrors useless. one mirror in the center is all i use and it is flat, but i am going to change it to a convex style first chance i get, like they use in boats.

with the aluminum block & liteweight rotating assy that car should rock and i like the sound of the color scheme.

keep us posted and use lots of pics.

[jmarsey]

You may have problems getting the car to ride low enough while maintaining the static settings for the suspension geometry to work properly and at its optimum. In my layman experience setting up the comp chassis, ride height and suspension settings are fairly critical. As Vector said, the chassis is designed for 17" wheels, or, a specific tire height.

John

[Machiavelli]

vector1/jmarsey,
I appreciate your comments, YES, tinkering with design parameters is a risky business, sort of like fooling with mother nature - the ramifications could be catastrophic. But understand, I am not working alone in a vacuum on this stuff -

Wheels: Everything wheel related has already been discussed with Larry & Richard. An 18" rim is transparent to the car, you can buy tires for the 18" that keep the overall diameter within 99% of the 17" configuration. As stated earlier, the backspaces remain unchanged from the 17" spec. In fact, when talking to Larry about this, he actually said the 18" rims would look pretty nice.

Carbon Fiber Drive Shaft: Here, I was not looking for the "weight savings" so much as the efficient transfer of power to the wheels. Have you checked out the ACPT website? Dan Gurney gave them a try back in 1987, says the ACPT carbon fiber drive shaft was a big part of him winning the IMSA championship that year. Always looking to save weight and I'm not done there, but the drive shaft idea wasn't one of them.

Mirrors: The windshield mounted side mirrors was Larry's idea, he said the chassis mount configuration was pretty much useless, the windshield mount was the way to go. That was fine with me, I kind of like the look anyway, and definitely a function over form decision.

In general, I think this build will turn out ok and with some scoot. Somewhat of a departure from the traditional cobra mold, but I knew that going in. As for JBL, since when did they subscribed to conventional cobra thinking when a better snake trap could be built

[jmarsey]

Should look cool with 30 series. Sounds like you have it all figured out. Have fun and best of luck, John

[Richard Hudgins]

Machiavelli,

I strongly suggest that you allow the roll Bar to be a proper functional piece.

The four point unit as designed works well and is an integral part of the rear cross-member design as well as the mounting point for the shoulder belts.

The only problem with the 18 inch wheels is the change in actual chassis wheel rate.

The spring rates may have to be lowered by the percentage of the increase in tyre sidewall stiffness.

As well a damper valving.

But this also depends on the tyre construction.

You are just going to have to get the sidewall design details from the tyre manufacturer once you pick what you are going to use in order to calculate the required spring and damping rates.

May not be an issue at all.

[GMS]

Ahhh..... plenty of patience credits left, Brett. The fun is just starting!!

Larry

[David Biele]

Good luck with the build, you picked a great chassis with the comp.

David

[vector1]

my car with the windshield has the bullet mirrors mounted to the uprights, these i find useless, fender mount would be somewhere in left field.

i have found setting up the jbl using race specs and ride height with driver wt. alone is fine for street use except for the moderate dips and bumps re: rear tires into the fender lips. what i do is after setup is put about 3 more turns in the rear passenger side shock for street use, especially if carrying a passenger, this keeps the tires out of the fenders, then when going back to the track take the 3 turns out. i believe larry has modified these on the newer bodies though.

[Machiavelli]

Richard/Larry,
Wow! Time to reel in Machiavelli (Brett) before he gets too far outside the box! Ok, I'll stop screwing with mother nature ... RESET!

Roll Bar: Four point unit as designed
Wheels: 17" with Competition offsets
Rim: Schott Sprocket, good freak'in luck talking me out of that one!

Thanks for the course correction, it ain't easy being me.

[Richard Hudgins]

Machiavelli,

I am not in any way suggesting that you do not use the 18 inch wheels.

There is a much better selection of tyres available in 18 inch.

I just need to know the sidewall construction in order to give Larry the spring rates and damper curves.

But this as I stated may be of very little import as the 17>18 inch tyre spring rate may be so close that nothing needs to be done. (If it does need to changed it is not at all a big deal, I just spec the bits to Larry and he puts them on the chassis.)

Stick with the 18's.

[redd]

i sent you a pm with question on the jbl comp model. Thanks:

[Machiavelli]

Richard,
I'm on it and will let you know, much thanks!

[Machiavelli]

redd,
I never got your PM, give it anothet shot.

[vector1]

how about pics of the retro knobs to activate the adjusters.