Help spec out a Reenmachine track day car...

reenmachine

Dirt-Old 20+Year Member
Jun 27, 2004
1,256
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San Diego, CA
Sometime in the next year or so I want to build a dedicated track-day Mustang for HPDE events and the like. I've got a pretty good idea of what I want to do, but I thought it would be interesting to troll the forum for ideas and round out the build sheet.

The emphasis here is safety first, then reliability, followed by performance. The kind of car that someone without a ton of automotive knowledge can run and maintain. Budget is a big deal as well, and that's the fun part. Let's come up with a build that is as big as possible on "bang for the buck" versus something exotic.

This is a non-street legal car, for the track only (road course).

Here's the general framework, as I envision it so far. Everything is negotiable.

- '67-'68 coupe body (cheap and plentiful)
- totally gutted, everything delete (heater, radio, lights, wipers, etc.)
- sealed firewall
- full roll cage with NASCAR-style door bars
- racing seat and full harness
- fabricated dash panel with full instrumentation and fuse/switch panel
- Ford Racing GT40 302 (reliable, 345 hp is plenty for a car like this)
- Mass-Flo EFI (reliable, low-maint)
- Long tube headers, simple side exhaust
- G-force T-5 (lighter, more compact than TKO?)
- Fuel Safe fuel cell
- some kind of big brakes

So, there's safety (massive cage, seat/harness, fuel cell, brakes) and reliability (EFI, strong tranny, moderate engine), which leaves the fun part -- handling.

Shelby drop/boxed arms/roller perch/neg. wedge? TCP? Maier? Global West? Other? Let's find the best system for reasonable money.

5-leaf front-loaded rear springs w/Panhard bar? AirBar with coilovers? ?? 8" or 9"? Go for the Cobra IRS?

Think that late-model Cobra front brakes are up to the task of all-day repeated racing use, or is something more called for?

I'm picturing manual brakes with a good M/C, driver-adjustable prop valve, and braided flex lines.

Manual R&P steering using the Randall's Rack system.

Throw some ideas out there and let's come up with something!
 
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Here are a few lessons learned from open track days last year with my '65:

Use BIG brakes: 20-30 minute lapping sessions were enough to heat my SSBC Force10 (11" rotors F+R) brakes with DOT4 fluid enough to cause squishy-pedal syndrome on subsequent sessions

Find a balance between front and rear roll / spring stiffness. I've got GW fronts, 620lb/in coils, 1-1/8" sway and Maier racing leafs (165#/in I think?) on the rear with no sway. The car is a little too oversteer-happy, in my novice opinion, probably because of the super-stiff rear leafs, and their associated roll stiffness. A happier compromise might be less-stiff rear suspension and a tunable sway device on the rear so that you can tweak steering response to your liking. On the other hand guys like Historic seem to like some oversteer, so this might just be inexperience talking...

A couple of open track days did nasty things to my Goodyear F1-DS-G3 tires (4x 235/45R17). A track-only car opens your options up. Choose wisely!

fwiw... :D
 
That Ford "345hp" turns out to make NOWHERE NEAR that power...so it is NOT enough! STrongly recommend a different engine approach.

The key issue to me comes back to the issue of suspension...and that's why we are focusing more on my 'vert[as it will never be a handler...but having the shock towers gone sure makes turbocharging a lot easier;)]. My 2+2 will be built as a NICE, non-stripped road course/HPDE car that is also comfortable for daily driving [make the door bars removable as I want a full cage as well]. And nice sound system, but easily removable sub. Basically a semi-budget version of the Shelby GT350SR continuation car. Gotta be able to do it pretty nice for 1/2 of the 100k they are getting!
 
I just picked up an 86 gt for the same purpose. I'm not ready to start tracking the car but maybe next year I'll start going down this road. I plan on a windsor dart block as a base. Going stroker with a tremec gear box.

red65, I suggest calling Mike at Maier Racing to help with your suspension tune. On first glance the big sway bar up front and nothing in the rear is an imbalance. Shock selection will matter as well. You may want to level the car out a bit too either dropping the back or raising the front. Not sure how you're sitting. I too like a tiny bit of oversteer.
 
I'd skip the MassFlo and use a 5.0 system...even more idiot-proof :D The FRPP crate motors use 2pc valves that WILL come apart at 6500rpm in a road-race situation. :o
8" with cobra brakes front & rear :D

Every opentracker mod, shelby drop, roller perches, adjustable strut rods, 4 torque boxes, roller idler bearing, panhard bar, boss302 crossmember, Maier engine bay brace, KONIs :D
 
mtbdoc said:
That Ford "345hp" turns out to make NOWHERE NEAR that power...so it is NOT enough! STrongly recommend a different engine approach.
I hear you, but I'm not sure that even 300 hp wouldn't be enough. There are a lot of 225 hp 5.0s out there in the FFR Cup and other series that run strong and are very reliable. Hell, the '83 RX-7 I used to race in the SCCA had about 110 hp at the wheels, but at 2300 lbs (wet, w/driver) with a proper suspension it would run circles around much more powerful cars. You don't need to be able to go insanely fast to have huge amounts of fun.
 
Fiberglass and aluminum where ever possible or cost effective to get the weight down. Subframe connectors (checkout Tinman http://www.tinmanfabrication.com/Products.aspx), or will the full roll cage be enough stiffness?
How does the bang for the buck enter the equation? If it's a priority then solid axle is the way to go, probably a 9" for reliability (and parts availability).
If you're building cars for customers, let them pick from a menu of crate engines. Their engine selection may be affected by local rules and class. Same for tires.
Fun post.
 
those tin man subs look good for conv.

John Z said:
Fiberglass and aluminum where ever possible or cost effective to get the weight down. Subframe connectors (checkout Tinman http://www.tinmanfabrication.com/Products.aspx

not to go :OT: but I just wanted to say that those Tin Man subs look like just the ticket for a convertible. I'm tired of subs that lose ground clearance by avoiding the "subfloor" there - I WANT to hack through that underseat subfloor but don't want a subframe intruding into the passenger rear floor area. I have an email in to them to see if they do just that.

It would seem that by welding that whole center section into the subframe it would help the subs a LOT. Plus not scraping over speed bumps, of which there are a lot in my area . . .

back On Topic . . . maybe I'll start another thread about these subs for convertibles.
 
John Z said:
Fiberglass and aluminum where ever possible or cost effective to get the weight down. Subframe connectors (checkout Tinman http://www.tinmanfabrication.com/Products.aspx), or will the full roll cage be enough stiffness?
How does the bang for the buck enter the equation? If it's a priority then solid axle is the way to go, probably a 9" for reliability (and parts availability).
If you're building cars for customers, let them pick from a menu of crate engines. Their engine selection may be affected by local rules and class. Same for tires.
Fun post.
I don't think subframe connectors will be necessary with a full cage. It'll be stiff as can be already.
 
5.0ina66 said:
I'd skip the MassFlo and use a 5.0 system...even more idiot-proof :D The FRPP crate motors use 2pc valves that WILL come apart at 6500rpm in a road-race situation. :o
Is that so? Any other opinions on this? Maybe the FRPP short block with AFR heads?
5.0ina66 said:
8" with cobra brakes front & rear :D
I'm inclined to agree that a good stout Currie 8" posi would be more than adequate for 350 hp in a road racer. We're not talking clutch drops here. I think there's a weight savings over a 9", no? Think it would still be durable?
5.0ina66 said:
Every opentracker mod, shelby drop, roller perches, adjustable strut rods, 4 torque boxes, roller idler bearing, panhard bar, boss302 crossmember, Maier engine bay brace, KONIs :D
Pretty much what I'm thinking, but I feel that manual R&P would be a great asset at speed. Opinions?
 
For ease of maintenance and reliability:

302/5.0 efi (or stroker) is a good choice, aim for around 300 whp.

Solid axle in the rear (8.8 is a good for durability and light weight).

Watts Link instead of panhard bar (EVM or Fays2)

2000 Cobra/Cobra R brakes up front. Better brakes will get you faster lap times than more power.

Jerico 4 speed in the tunnel.
 
A "Nascar" cage out to be stiff enough. Make sure to keep the uprights away from your head.

The Maier Racing shocktower brace is nice.

Front suspension, I'd go with TCP coilovers. By the time you pull together boxed upper and lower control arms, roller perches, and rod end strut rods, you're almost there price-wise anyway.

Second best, if you can weld, is to get some OE four-bolt UCA's and the Cobra Automotive brace plate and weld that on there. You need no ball joint pad realignment (Negative Wedge Kit) if you keep the Shelby drop to 1". But if you want to go to a 1.5" drop, you can cut the ball joint pad from the inboard side and bend it up ("up" meaning with reference to the ground), and weld a rectangle of sheet steel in the gap. Maier does this on its "realigned" UCA's, as you can kind of see in this pic:

1largems2102.jpg


You can also add the Maier bracing down the sides of the "A," as is seen in this pic.

There's also the Opentracker spring perch relocation idea, which gives your stock UCA some of the leverage advantage (i.e. that you can run softer springs) as a coil over:

adjuca05.jpg


Actually, what we all really need is for Opentracker to start selling his UCA with the bracing, the realigned ball joint pad, the multiple spring perch locations, the rollerized perch, correctly stiff springs, and correctly valved shocks.

Also if you're going homebrew don't forget to box the lower control arms, a la Maier Racing. But do not make the LCA's adjustable for length. Camber should only be adjusted with the eccentric. If you're worried that yours will slip, get the Eccentric Eliminator from Pro Motorsports.

The strut rods should be either the Street or Track units or the TCP.

Shocks should be Bilstein.

Regarding the trans, why go 5 speed? Is there something wrong with a toploader? Those G-force kits are about a thousand bucks, on top of the T5 core. But if you go T5, the MGW shifter with the gold handle is the one.

The rear axle, if you're sticking with a 5.0 and under 350 lb ft, an 8 inch with the Detroit Truetrac torsen diff is the way to go. The 8 inch is plenty strong, and weighs less and absorbs less power than the 9 inch. The torsen is also strong, will never wear out, and is smooth in engagement, unlike a locker.

Rear brakes, get the backing plates and drums, etc., from a late model Crown Victoria.

You must have Cal-Trac traction bars, to control wheel hop on both acceleration and braking. Slide-A-Links don't work on braking. And a set of 4.5 leaf springs did nothing to control wheel hop on my kids' '65 fb, so I went to Slide-A-Links. For springs, go to a local spring shop and get some fabbed, in about the 150# range. But get the shop to commit up front to working with you on ride height. Ride height with the leaf springs is a black art, and no one can predict how it will be affected by any given set of springs. If you're working direct with the spring builder, he can swap main leafs to get the ride height you want. Stay away from these bogus mid-eye and reverse-eye deals. Those are half-assed workarounds for builders too lazy to tune the spring pack properly.

You can always fine tune for a lower ride height with the "Opentracker" auxiliary spring -- i.e., you take the shortest leaf from a discarded spring pack and mount it upside down on your car's spring pack.

Get the Global West Del-Alum leaf spring bushing set.

For rear axle location go Watts link. I have a Fays2 on my kids' '65 fb, and it's a great product. These Evolution Motorsports guys have come out with a Watts link that will integrate with a proposed 3-link. I would pass on that, unless you want to wait till it's out before you even start this build. The problem with the 3-link is it junks your springs, shocks, traction bars.

The air bag option: no way. I thought this was going to be a price-conscious build.

Speaking of price conscious, I'd stick with a carb.

Also, you didn't mention an oil pan. You need one with the kickouts and the baffles. I have no brand name in mind, but there's Moroso for a start.

You should also use a sheet metal bell, for safety.
 

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John Z said:
I thought that might be the case. Your reply lead me to the need to state the obvious though. Stiffen the front end with a monte carlo bar and export brace. I think the one in this link looks cleaner and may be more effective than the typical seperate pieces.
http://www.mustangsplus.com/Merchan...MPFMP&Product_Code=05804&Category_Code=export
I guess Mustangs Plus charges you $45 to scrape the Maier Racing decal off the cross piece, because that's what this is, the Maier Racing underhood brace. $220 at Maier, $264 at M+. What freakin pirates they are.
 
reenmachine said:
Is that so? Any other opinions on this? Maybe the FRPP short block with AFR heads?

I would also skip the Mass-Flo approach and just go with a standard Ford EFI set-up. Parts are cheap and plentiful, they work, and that is basically all the Mass-Flo is with a GM MAF sensor and converter box in place of the stock Ford unit.
 
if this is a track only go for for a 3 link and PHB or watts in the back. no back seat means you can easily extend the 3rd link to hook up to the roll cage inside the car and run a sprung link. setup right it'll be exactly what you want, awesome grip and control.
 
John Z said:
Stiffen the front end with a monte carlo bar and export brace. I think the one in this link looks cleaner and may be more effective than the typical seperate pieces.
Absolutely. However, if I go with a traditional 5.0 intake system, will I be able to find a good brace that fits?
 
Bullitt said:
if this is a track only go for for a 3 link and PHB or watts in the back. no back seat means you can easily extend the 3rd link to hook up to the roll cage inside the car and run a sprung link. setup right it'll be exactly what you want, awesome grip and control.
I agree that this would be pretty close to ideal, but it may not fit into the "cost vs. return" box. Keep in mind that time to fab/install it counts as cost.
 
180 Out said:
A "Nascar" cage out to be stiff enough. Make sure to keep the uprights away from your head.
Yes. I have experience with this. I would lower the seat perches as well for both lower center of gravity and more helmet clearance.

180 Out said:
The Maier Racing shocktower brace is nice.

Front suspension, I'd go with TCP coilovers. By the time you pull together boxed upper and lower control arms, roller perches, and rod end strut rods, you're almost there price-wise anyway.
I may be inclined to agree with you. What do you think about RRS for that matter?
180 Out said:
Second best, if you can weld, is to get some OE four-bolt UCA's and the Cobra Automotive brace plate and weld that on there. You need no ball joint pad realignment (Negative Wedge Kit) if you keep the Shelby drop to 1". But if you want to go to a 1.5" drop, you can cut the ball joint pad from the inboard side and bend it up ("up" meaning with reference to the ground), and weld a rectangle of sheet steel in the gap. Maier does this on its "realigned" UCA's, as you can kind of see in this pic:

You can also add the Maier bracing down the sides of the "A," as is seen in this pic.

There's also the Opentracker spring perch relocation idea, which gives your stock UCA some of the leverage advantage (i.e. that you can run softer springs) as a coil over:

Also if you're going homebrew don't forget to box the lower control arms, a la Maier Racing. But do not make the LCA's adjustable for length. Camber should only be adjusted with the eccentric. If you're worried that yours will slip, get the Eccentric Eliminator from Pro Motorsports.
I do have the equipment and ability to do this, but it falls under the "time is money" category. Not that I'm building this car to sell, but building it will take me away from working on cars that I am.
180 Out said:
Regarding the trans, why go 5 speed? Is there something wrong with a toploader? Those G-force kits are about a thousand bucks, on top of the T5 core. But if you go T5, the MGW shifter with the gold handle is the one.
I totally agree. A properly-geared toploader should be perfect.
180 Out said:
The rear axle, if you're sticking with a 5.0 and under 350 lb ft, an 8 inch with the Detroit Truetrac torsen diff is the way to go. The 8 inch is plenty strong, and weighs less and absorbs less power than the 9 inch. The torsen is also strong, will never wear out, and is smooth in engagement, unlike a locker.
This is what I was thinking I would hear. Lighter weight and less parasitic loss, with fine durability at this power/torque level.
180 Out said:
Rear brakes, get the backing plates and drums, etc., from a late model Crown Victoria.

You must have Cal-Trac traction bars, to control wheel hop on both acceleration and braking. Slide-A-Links don't work on braking. And a set of 4.5 leaf springs did nothing to control wheel hop on my kids' '65 fb, so I went to Slide-A-Links. For springs, go to a local spring shop and get some fabbed, in about the 150# range. But get the shop to commit up front to working with you on ride height. Ride height with the leaf springs is a black art, and no one can predict how it will be affected by any given set of springs. If you're working direct with the spring builder, he can swap main leafs to get the ride height you want. Stay away from these bogus mid-eye and reverse-eye deals. Those are half-assed workarounds for builders too lazy to tune the spring pack properly.

You can always fine tune for a lower ride height with the "Opentracker" auxiliary spring -- i.e., you take the shortest leaf from a discarded spring pack and mount it upside down on your car's spring pack.

Get the Global West Del-Alum leaf spring bushing set.

For rear axle location go Watts link. I have a Fays2 on my kids' '65 fb, and it's a great product. These Evolution Motorsports guys have come out with a Watts link that will integrate with a proposed 3-link. I would pass on that, unless you want to wait till it's out before you even start this build. The problem with the 3-link is it junks your springs, shocks, traction bars.
I like what you're saying about the springs and need to research this a bit more. I was figuring we'd end up with good leaf springs, a Watt's link, Cal-Tracs, and good shocks.
180 Out said:
The air bag option: no way. I thought this was going to be a price-conscious build.
I wasn't saying use the airbags, just get the AirRide triangulated 4-link and run it with coilovers instead of the bags.
180 Out said:
Speaking of price conscious, I'd stick with a carb.
This is one of the areas where the cost comes second to reliability and ease of use. Even though this is a car for me, I want to build it as though it's for a customer down the road. The typical disposable-income type wanting a track-day car doesn't want to be fooling with tuning a carb at various tracks and conditions.
180 Out said:
Also, you didn't mention an oil pan. You need one with the kickouts and the baffles. I have no brand name in mind, but there's Moroso for a start.

You should also use a sheet metal bell, for safety.
Yeah, I'll worry about the details after the big stuff is figured out. The oil system will certainly consist of a road-race pan, remote filter, and oil cooler up front.

Thanks for the massive input -- very helpful. There's going to have to be a big-ass StangNet sticker on this thing! :SNSign: