The Reenmachine DOHC '67 Shelby Clone Convertible Progress

reenmachine said:
I'll check that out. I used to have an '03 350Z that had a CF driveshaft, and they're not actually that much more expensive than a good aluminum one if I recall correctly.
OK, I was wrong. From Inland Empire at least (one of the huge driveshaft manufacturers) carbon shafts are about 3x the price as aluminum. Looks like it'll be aluminum!
 
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samwe said:
Looking at those last pics it is clear where a a fox body windsor pan would be interferring with the rack if the engine were mounted like that.
I have a '67 fastback with a 289 that I put the same front end in. It has the rear sump/dual sump pan you speak of and it works. The engine's higher up, but it's still basically at the stock height. The rear sump pan on the 4.6 allowed me to get the engine really low and far back.
 
Heidt's and Handling

Hey Reen,
I have a few questions about the Heidt's. It looks like an attractive package, and you get rear discs in the process so it looks at first glance to be a little cheaper than a TCP or Unique non-IRS package.

Got a few Q's:

-What options did you spring for (lousy pun intended) on the heidt's? (I am assuming from the look of yours that you declined chroming/polishing on everything)

-Any advantages/disadvantages to the center-mounted brakes?

-I know it hasn't been driven, but what do you think the Heidt's will handle like? I know you planned to compare it with the Cobra IRS. From the looks of it and from the street rod background, it looks like it can handle more HP than the Cobra.

-NOW I see how that front connector ties in to the sub frame connectors, very cool.

-Is there anything else "one-off" that you did to it? Any ideas if you'll offer it as a kit?

thanks,
Joe
 
Yeh the carbon shaft is mighty expensive. It can be very light, but mainly I like it's unique properties, like the fibres actually twist and tighten as torque is applied, giving a little springs to the drivetrain, like I guess a belt final drive on a Harley does as opposed to chains. Also, they are said to have inherent safety in that once they break they unwind and brush themselves to death, they polish the underside of your car, unlike metal which turns into a flailing stick of doom. I have heard however that if scored they will weaken substantially, and there's a more chance of running over something (a speedbump even) on the road than a race track.

Anyway, I thought you'd laugh at the idea, but am glad you gave it some thought.

70vert, two benefits of central discs I can think of are mass centralisation and reduction in unsprung. It would look wierd though with open wheels - nothing there behind them. Putting new rotors on looks like it would be a pita to do.
 
I got mine turned around in two days from streetortrack.com. $300.. without the yoke, which I already had.

reenmachine said:
OK, I was wrong. From Inland Empire at least (one of the huge driveshaft manufacturers) carbon shafts are about 3x the price as aluminum. Looks like it'll be aluminum!
 
yeah, reduction in unsprung is a biggie

Route666 said:
Yeh the carbon shaft is mighty expensive. It can be very light, but mainly I like it's unique properties, like the fibres actually twist and tighten as torque is applied, giving a little springs to the drivetrain, like I guess a belt final drive on a Harley does as opposed to chains. Also, they are said to have inherent safety in that once they break they unwind and brush themselves to death, they polish the underside of your car, unlike metal which turns into a flailing stick of doom. I have heard however that if scored they will weaken substantially, and there's a more chance of running over something (a speedbump even) on the road than a race track.

Anyway, I thought you'd laugh at the idea, but am glad you gave it some thought.

70vert, two benefits of central discs I can think of are mass centralisation and reduction in unsprung. It would look wierd though with open wheels - nothing there behind them. Putting new rotors on looks like it would be a pita to do.

I figured the reduction in unsprung would be a benefit, it's sitting at the center rather than flailing around out at the ends. I wonder if there is more or less airflow down there for the brakes. Prolly more since it's not surrounded by a wheel. But depending on exhaust routing that could heat things up down there. I wonder what provisions they have for brake work - do you just unbolt the u-joint when you want to slide a rotor off?
that would cause a few double-takes, no brakes visible in the rear, granted.
I imagine the reason you don't see this setup on production cars and race cars is the difficulty of replacing a disc, but if anyone else has an opinion I'd love to hear it. Plus a u-joint breaking under hard braking
:) would be a PITA.

Joe
 
You do see inboard disc brakes on Jaguars from about 60s on. Popular with hot rodders and Cobra replica builders.

Unsprung weight is the advantage as well as eliminating leaf springs means lots of room for w i d e rear tyres. Rotor replacement is not difficult and one hardly needs to for years and years.

Here is a pic of my 66 with Jaguar IRS.
Marshall View attachment 514456
 
Yes, reduced unsprung weight is an advantage, and, like anything, there are trades. The half shafts have to be beefier because they act as upper control arms and thus have to take a compressive load in addition to the torsional load. They must also transmit braking torque. Also, if a shaft fails your rear suspension collapses on one side, but you simply engineer enough margin into the design to make this extremely unlikely.

70vert: The options I ordered from Heidt's were Ford 4.5" bolt pattern for the wheels ($120), positraction ($400), and the dual parking brake kit ($250).

It was not really a straightforward install, and some of the components had to be modified to fit. The kit is really made for a '32 Ford-type chassis and it took some creativity to get it to work in a unibody car.

I think it will ride and handle wonderfully, probably with the emphasis on ride. The Cobra IRS may handle a bit better due to more modern geometry, with respect to anti-squat for example. We'll see. There's a new 2000 Cobra R IRS setup on a truck headed my way right now!
 
looks MUCH better w/o the chrome and polish

reenmachine said:
70vert: The options I ordered from Heidt's were Ford 4.5" bolt pattern for the wheels ($120), positraction ($400), and the dual parking brake kit ($250).

forgot to mention that it looks much better than the all-chrome IMO. Maybe the kit you were looking at developing with the necessary custom bits will be available from Reenmachine/K.A.R. by the time I get around to the rear sometime in this decade. Looking forward to hearing how the Cobra IRS compares. I assume Heidt's would handle more HP, and have a little better ride due to less unsprung weight, the Cobra maybe good up to 500hp and have better handling? Oversimplified I'm sure, but for us n00bs it helps to have that kind of distinction.
Glad I'm not posting this on Corner-Carvers.com. :stupid: I tried to find info about heidt's on there but couldn't find anything and didn't dare to ask for fear of the fiery :flame: . thanks, guys.
 
Things are coming along nicely in the engine compartment. I'll be able to use a lot of the original peripherals to maintain that OEM look. The Painless chassis harness has been straightforward so far.

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I received the 2000 Cobra R IRS yesterday for the other car...it's totally sweet looking. There's some surface rust on the bare metal parts just from sitting for 5 years, but it's brand new, 0 miles, etc. I'm going to disassemble most of it to "restore" it, and I have to make some simple mods to the aluminum uprights for the 13" Wilwood brake kit while it's apart. I'll post pics later on today.
 
I really like following this thread. It's nice to see a new angle on modifying these old mustangs. Reen, are you planning on installing a cold air intake? I just thought it would look better than the stock black intake tube. Regardless, its a great looking project.
 
bgs66 said:
I really like following this thread. It's nice to see a new angle on modifying these old mustangs. Reen, are you planning on installing a cold air intake? I just thought it would look better than the stock black intake tube. Regardless, its a great looking project.
I'm trying to keep things as stock looking as possible under the hood, hence the OEM black air intake. I'm going to use the original snorkle as well and route it through the core support where it'll get a direct supply of fresh air. The assembly fit nicely into the old battery location.