Help spec out a Reenmachine track day car...

[68rustang]

Absolutely. However, if I go with a traditional 5.0 intake system, will I be able to find a good brace that fits?

I have seen your fab skills, they are better than mine, and I didn't have any trouble making this little piece.

Total cost was $10.00 and an evening's worth of time. These are available as well:

EDIT: I didn't see that John Z had already linked to the M+ brace.

M+

Maier

LMM has the same thing for I think $100.00 but I couldn't find it on their site.

 

[John Z]

Absolutely. However, if I go with a traditional 5.0 intake system, will I be able to find a good brace that fits?

It is described as a brace for EFI cars. The tubular braces going to the firewall are much thiner than the traditional expport braces. I did not mean to imply that I was recommending purchasing from M+; I was just using their site to show the concept.

68rustang was and I were posting at the same time. \

 

[1970fastback]

I've never posted here before, but I felt compelled to chime in, as I've read almost every Reenmachine post that have been posted, and I've come to admire his approach quite a bit.

A very good friend of mine and I have done quite a lot of field research on getting together a fun and optimal vintage mustang race car together. He did about 8 years of SCCA autocrossing and 4 years of Open track at Sebring, etc. in Central Florida. Recently, we spent a year getting a plan together to heavily modify and set up a 69 fastback for use as a more serious car that could be used in the same events you guys are talking about here.

The result: we scrapped the idea in favor of a 2004 body in white.
The reasons were many, but I'll list a few of the most important here:
1. No need to do body / rust repair mods just to get the body to the point where it's a good candidate.
2. Cheaper mods available, overall.
3. FAR better aerodynamics.
4. Far better steering geometry built right in.
5. Not that it's a huge concern for Reen, but IRS is made for these, and hence a bolt in affair.

The list goes on and on.. I mean, making a classic Mustang into a racecar has the advantage of being unique, certainly.. I've gone out to Autocrossing and had a blast in my 70 'back.. But for some serious racing, I don't see where it's any cheaper / better / more reliable doing it with a 60s car over the newer ones..

Just my 2 cents.

 

[reenmachine]

I've never posted here before, but I felt compelled to chime in, as I've read almost every Reenmachine post that have been posted, and I've come to admire his approach quite a bit.

A very good friend of mine and I have done quite a lot of field research on getting together a fun and optimal vintage mustang race car together. He did about 8 years of SCCA autocrossing and 4 years of Open track at Sebring, etc. in Central Florida. Recently, we spent a year getting a plan together to heavily modify and set up a 69 fastback for use as a more serious car that could be used in the same events you guys are talking about here.

The result: we scrapped the idea in favor of a 2004 body in white.
The reasons were many, but I'll list a few of the most important here:
1. No need to do body / rust repair mods just to get the body to the point where it's a good candidate.
2. Cheaper mods available, overall.
3. FAR better aerodynamics.
4. Far better steering geometry built right in.
5. Not that it's a huge concern for Reen, but IRS is made for these, and hence a bolt in affair.

The list goes on and on.. I mean, making a classic Mustang into a racecar has the advantage of being unique, certainly.. I've gone out to Autocrossing and had a blast in my 70 'back.. But for some serious racing, I don't see where it's any cheaper / better / more reliable doing it with a 60s car over the newer ones..

Just my 2 cents.

I absolutely agree, and a '67-'68 isn't cheaper, better, or more reliable. But it is a vintage Mustang, and that's what I like. I'm not building it to be the fastest or most optimal car on the track, but to be a kick-ass track car with the character only an early model can provide (IMHO).

Tell me this doesn't get your blood pumping:

 

[mdjay]

The M+ version is from Maier! It's posted like they're different

I like the early cars too, but I'm going this way.

 

[68rustang]

The M+ version is from Maier! It's posted like they're different

No, it's posted like there are a couple of different places to get the same thing.

 

[mdjay]

my bad...

i didn't see where is was clarified earlier...

 

[66Runt]

Pick up a used '91-'93 GT 5 speed car and use it's drive train

I'm seeing late model Fox body GT cars going for around $2,000.00 to $2,500 around here.
Send the motor out and for about $3K you've got a beautiful 331. Send the T5 out and for $1K you've got a strong enough box with a 0.80:1 O.D.
Cut off the brackets, weld on some spring perches (about 3 hours work and $20.00), and you've got a nice little 8.8" differential with limited slip. Add gears and a Truetrac, for another $600.00. Add a set of 5 lug axles and whatever flavor of brake you like ($500-$2K depending on how you go).
Use the GT's drive shaft, P. brake handle assembly, and brake lines (fittings).
Add whatever flavor front brakes you want. The '04 Cobra brakes are a good "bang for the buck" and you can get all kinds of different pads for them, on the cheap. Remember big brakes mean big wheels.
Now you've got all the EFI stuff, including the harness, and fuel line plumbing. Add $300.00 for some higher flow injectors, and take it to the local dyno shop for some tuning.

You get a lot of "bang for the buck" out of that drivetrain. All for about 3 hours worth of looking, and 8 hours labor to strip the GT.
Then send the shell to the scrap steel place to buy enough beer for the "bench racing sessions that are sure to follow.

Just my two cents worth.
Scott

 

[reenmachine]

Yeah, that's pretty much the Factory Five roadster approach. I do like the idea of the 8.8 rear end -- it may be a good middle ground between the 8" and 9". I know DVS is working on a kit to put the 8.8 in early Mustangs much like their IRS kit. That could be an option.

 

[Jimmys66]

Not to overstate the obvious, we all know that mustangs are notorious for being front heavy.

This doesn't seem like a bad place to overbuild and to rebalance some front to back weight.

 

[Bullitt]

Not to overstate the obvious, we all know that mustangs are notorious for being front heavy.

This doesn't seem like a bad place to overbuild and to rebalance some front to back weight.

not necessarily true... my '67 fastback is 53/47 (with driver). full interior with aluminum heads, radiator, AC, aluminum driveshaft, battery in the trunk, and versailles 9".

they're balanced a lot better than the newer fox-style cars (a fox coupe is 60/40 stock with driver).

Reenmachine - i saw your post earlier about the 3-link being time consuming... not really, you can buy all the brackets, upper link and so forth from a number of circle track places. only "tough" part is deciding where to put your front mount and then making a sheetmetal cover or whatever you want inside to cover the assembly. super simple and VERY effective.

 

[reenmachine]

not necessarily true... my '67 fastback is 53/47 (with driver). full interior with aluminum heads, radiator, AC, aluminum driveshaft, battery in the trunk, and versailles 9".

they're balanced a lot better than the newer fox-style cars (a fox coupe is 60/40 stock with driver).

Reenmachine - i saw your post earlier about the 3-link being time consuming... not really, you can buy all the brackets, upper link and so forth from a number of circle track places. only "tough" part is deciding where to put your front mount and then making a sheetmetal cover or whatever you want inside to cover the assembly. super simple and VERY effective.

So, with no A/C compressor, lights, P/S pump, bumper, battery, etc. up front and a heavy cage which is by nature biased rearward I bet we could get a good balance.

I'm interested in learning more about the 3-link setup. Have any good references on the subject?

 

[66Runt]

Yeah, that's pretty much the Factory Five roadster approach. I do like the idea of the 8.8 rear end -- it may be a good middle ground between the 8" and 9". I know DVS is working on a kit to put the 8.8 in early Mustangs much like their IRS kit. That could be an option.

FWIW,
Really isn't much to putting an 8.8 into the 67-68. I just finished building one for my '66. It's the perfect width for a 67-68 stock out of the Fox body. Seriously, 3 hours with an axle swap, if you keep the drums (and that includes two diaper changes ).
If you go to North Racecar's web site, they've got the complete setup for doing the Cobra brakes, including proper axles to make the rotors Hub-centric. Probably the easiest thing you'll do in the whole project.
Run a rearend girdle, and that rear will handle anything you'll throw at it, in a roadracer.
Figure an additional 4 hours to do the complete North Racecar setup, you'll need to weld up a couple of brackets to the tubes to secure the brake hoses from each caliper and tweeking of the brake hose bracket that goes to the body.

Scott

 

[reenmachine]

FWIW,
Really isn't much to putting an 8.8 into the 67-68. I just finished building one for my '66. It's the perfect width for a 67-68 stock out of the Fox body. Seriously, 3 hours with an axle swap, if you keep the drums (and that includes two diaper changes ).
If you go to North Racecar's web site, they've got the complete setup for doing the Cobra brakes, including proper axles to make the rotors Hub-centric. Probably the easiest thing you'll do in the whole project.
Run a rearend girdle, and that rear will handle anything you'll throw at it, in a roadracer.
Figure an additional 4 hours to do the complete North Racecar setup, you'll need to weld up a couple of brackets to the tubes to secure the brake hoses from each caliper and tweeking of the brake hose bracket that goes to the body.

Scott

I was talking about swapping in the 8.8 including the multi-link suspension as well. Regardless, if leaf springs turn out to be the way to go, the 8.8 is probably the right choice anyway.

What's the URL for North Racecar?

EDIT: NM -- found the URL and the kit you mentioned

 

[Bullitt]

So, with no A/C compressor, lights, P/S pump, bumper, battery, etc. up front and a heavy cage which is by nature biased rearward I bet we could get a good balance.

I'm interested in learning more about the 3-link setup. Have any good references on the subject?

pick up Herb Adam's book "Chassis Engineering" (or just get it from the library). there's some good info in there on the benefits of a 3-link and what sort of geometry you're looking for. basically a 3-link allows for anti-squat which greatly enhances traction under power. the "sprung" 3rd link is sorta like a shock with springs on both sides of the "piston". so under acceleration you can't shock the tires as much because some of the initial hit is taken up by the spring and the car won't have torque-arm axle tramp problems because the link is spring in that direction as well. very very very slick!

 

[Jimmys66]

not necessarily true... my '67 fastback is 53/47 (with driver). full interior with aluminum heads, radiator, AC, aluminum driveshaft, battery in the trunk, and versailles 9".

they're balanced a lot better than the newer fox-style cars (a fox coupe is 60/40 stock with driver).




Is it better to have the car lighter or better balanced? A couple hundred pounds would be detrimental. But say adding 75 for a heavier rear or is it just better to have less unsprung weight?

 

[Bullitt]

it's better for the car to be lighter. move weight, but don't add it.

there's a lot you can do with suspension tuning to make the car "neutral". just takes more work.

 

[bnickel]

personally i would skip out completely on the 8.8" rear, i HATE c-clip axles. if you really want an an efficient rear go for a 9" with curries 9+ carrier that uses 12 bolt chevy ctyle pinion placement. it puts the pinion gear riding further up on the ring gear as opposed to the very bottom of the ring gear like a stock 9". if you use the aluminum carrier the weight difference between the 9" and the 8.8" actually comes out in the 9"s favor.

i would do as many Opentracker style mods as possible. another option would be to use a coilover shock assembly in place of the stock shock/spring/spring perch assembly and completely eliminate the spring perch altogether.