Vorshlag 2011 Mustang 5.0 GT - track/autocross/street Project

[Norm Peterson]

Agree in principle. I'm not a cage designer either, but my background is structural.

However, the horizontal bar is only tacked in place and the down bar is only resting on it. There may be some gusseting planned that isn't in place. I know I'd want some, as solid as possible without running afoul of any "maximum number of attachment points" class regs that might be being accommodated.


That said, I don't like how the 1" square tube is landing on the main hoop at all. Local buckling of the round tube from punching = compromised buckling strength of the hoop. I really hope that some gusseting is intended here as well.


The guy whose opinion really matters is Alan Blaine of Blaine Fabrication. I know he posts over on Corner-Carvers.


Norm

 

[DILYSI Dave]

I am no cage designer but I would think terminating those down bars in the middle of the bar between the rear shock towers would be extremely weak and potentially result in bar failure in a roll over. IIRC those downbars are supposed to terminate at the shock towers for the most strength.

Agreed. Bad practice, and illegal for some sanctioning bodies.

 

[zquez]

I am no cage designer but I would think terminating those down bars in the middle of the bar between the rear shock towers would be extremely weak and potentially result in bar failure in a roll over. IIRC those downbars are supposed to terminate at the shock towers for the most strength.

agreed. Thats how I would do it if I was building one from scratch. I think they put it there to make it where you didn't have to hack up your interior or something.

 

[SoundGuyDave]

More disturbing to me, to be honest, is this:

Unsupported bends in the rear stays... A bent tube, unsupported, essentially sacrifices the bulk of it's rigidity along the longitudinal axis, which would let that main hoop pivot around the mounting points with sufficient load. To me, this is bling; no more than a glorified harness bar.

 

[zquez]

I would have never thought of that. Good catch.

 

[Vorshlag-Fair]

Terry - Unless you are typing 60+ WPM how do you find the time to post such extensive details of your events, link pictures, ECT, ECT.

Don’t get the wrong idea, I do enjoy your reads but & am having a hard time finding the time just to read the info you post. (Good reading by the way)

Writing these project thread posts takes more time than you can imagine, and there are many more ongoing project threads I'm writing than you see here on S197Forums - this is one of many projects we're building at once. I have a lot of help now with editing (Matt and Jason) and photos and video (Brandon), but it is still many hours of work, usually spread out over 3-4 days per big post. And the phone is ringing the whole time, and questions from my guys here at the shop, and emergencies and fires... I do my best writing at night and on the weekends, when the distractions are fewer.

I really enjoy sharing our track and autocross experiences, our testing and set-up tips, with others. Some of my racing competitors, friends and others in the industry think I'm crazy to give away so much ... but it is what I've always done, and customers appreciate it.

I’m glad you are doing so well. Mustangs have a horrible CD. - Add down force (More aero drag) -The HP per weight ratio goes to SHT. Higher CD cars are at a very large Disadvantage

Yes, the S197 Mustang definitely has more drag than say... a C5 or C6 Corvette (which can be in TT3 now) so I will keep the aero as clean as possible to keep up with similarly prepped Corvettes on the higher speed tracks (like TWS). The handling in a C5/C6 is also a damn sight better from the factory, but there are no modifiers for solid axle suspensions yet, so we just have to deal with that disadvantage. We've run against some Corvettes in TT, both this year and last, and it has been a close battle so far.

 

[ArizonaGT]

I am no cage designer but I would think terminating those down bars in the middle of the bar between the rear shock towers would be extremely weak and potentially result in bar failure in a roll over. IIRC those downbars are supposed to terminate at the shock towers for the most strength.

+100

 

[19COBRA93]

I'm anxiously waiting for the write up on the BFG Rivals.

 

[DILYSI Dave]

More disturbing to me, to be honest, is this:

Unsupported bends in the rear stays... A bent tube, unsupported, essentially sacrifices the bulk of it's rigidity along the longitudinal axis, which would let that main hoop pivot around the mounting points with sufficient load. To me, this is bling; no more than a glorified harness bar.

Agreed on that as well.

 

[SoundGuyDave]

Terry: The TT# classes are essentially unlimited classes... Wholesale suspension redesign, open aero, etc. Being so new, nobody has yet built to the limit of the rules for TT3/PT3, but (scratchpad thinking only) if I were to do that (not gonna happen!), it would probably be something like this:

Fabricated SLA up front, drop spindles, Moton triples. In back, another fabricated SLA with a lightweight diff, inboard brakes (Jag sourced diff?) and Moton triples. For aero, I would fabricate a venturi belly-tray, side-skirts, and rear diffuser, go to the airport and steal a wing off a 747, and then build a can-am style bullet-nose out of carbon. Inside, gut the living piss out of the entire body above the frame rails, then build in a 10/12/14 point cage, gusseted to what's left of the chassis, replace as much of the body with carbon as possible, then drop in a 4.6 3V with a straight-cut sequential, and restrict down to 280HP, and run a 9.95:1 ratio on a targeted 2800lb race weight, with 335mm DOT rubber on all four corners. THAT is what the ST/TT# classes are all about, if you're building to the rules. Yes, that'll be a $200K project when you're done, but I would bet it would set the bar for a loooonnnnggg time. This is also why there aren't (and most likely won't be) stick-axle modifiers, since you are allowed to change with no penalty, except in the wallet.

Now I'm not saying that an essentially stock Mustang can't be competitive, but once one of the C5 guys slaps on a full WC suspension and aero package, they're going to be stiff competition!

 

[zquez]

Sounds like the perfect place for one of these tube frame bad boys

 

[SoundGuyDave]

There are only seven major rules that govern a TT# build (excepting, of course the power ratio):

7.A. Every vehicle must retain its unmodified:
1) OEM frame rails and/or Unibody, and Sub-frames
2) Strut towers
3) Inner/inboard side of the fender wells
4) Rocker panels
5) Transmission tunnel
6) Floor pan
7) Windshield frame location

So, no tube-frame happiness.. Of course, there are a host of allowances, exceptions, and clarifications of the above, but those are essentially the only major restrictions to a build. For example, while you have to retain the OE strut towers, there's nothing in the rules that say they have to be used for anything functional, and indeed, it is explicitly spelled out that you may reinforce them (bar from firewall to strut tower, 1/4" plate wrapping the tower, then another bar from the tower forward to the frame stub). Also, with a little creative rule-reading, you can pretty well swiss-cheese the things (brake ducting, damper canister lines, etc.).

I think it would be a lot of fun to do an unlimited-budget build on that rule set!

 

[zquez]

Ah, so no over the top craziness. I guess you could still do something like this, while retaining the stock strut tower. Maybe even a trans-axle independent rear too.
Sounds like fun. Wish I was rich.

 

[DTL]

Great write-ups! I'll be eagerly awaiting more info on your transmission mount as well!!

 

[19COBRA93]

Ah, so no over the top craziness. I guess you could still do something like this, while retaining the stock strut tower. Maybe even a trans-axle independent rear too.
Sounds like fun. Wish I was rich.

That looks like a very modified FR500GT.

 

[Roadracer350]

Ah, so no over the top craziness. I guess you could still do something like this, while retaining the stock strut tower. Maybe even a trans-axle independent rear too.
Sounds like fun. Wish I was rich.

I love the way that ram air is set up! I wonder how big of a pain it would be to tune? I guess you could set a cooling fan in front of the intake like we do with the bikes... Would be easy to make.... I will let you guys know how it goes!!

 

[zquez]

That looks like a very modified FR500GT.

Its oh so much more. That is the Brandon Davis ACS Express Mustang racing in the World Challenge GT class. Its been homologated to run in that class and very little is left of a stock mustang. Transaxle, motec engine management and abs, air jacks, tube frame, carbon fiber body, unequal length a-arms, irs with rising rocker suspension, ohlins dampers. Pretty much the epitome of insanity in a mustang.

 

[zquez]

I love the way that ram air is set up! I wonder how big of a pain it would be to tune? I guess you could set a cooling fan in front of the intake like we do with the bikes... Would be easy to make.... I will let you guys know how it goes!!

You like that better than the naca duct intake? It'll be a little harder to do if retaining the stock location of the radiator. Now, if you lay it down thats another thing.

 

[2008 V6]

TT was designed for the majority of low budget racers (99.9%.) Little if any sponsorship is available. (Just about Zero TV time if any) – What company wants to sink $50,000.00 – 1mil + into sponsorship for advertising if few will see it! You might be able to get a set of tires here, a free part or $500.00 there for a specific sized sticker space but Big $$$ Companies’ sponsor for a reason – to advertise TO MAKE MONEY.
Most Racer’s reimbursement is love, an adrenalin fix & a tax write-off. This is why NASA TT rules are so basic & can be interpreted with ones own interpretation (NO BIG MONEY INVOLVED.) This is also why SCCA is so stringent on rules. No major manufacturer wants to see an older model car beat their newest incarnation - Doesn’t sell new cars. (Solo racing being the exception in most cases)
Terry, Steve to name a few who input much appreciated data here are some of the few who are able to make money & finance their endeavors by selling / making parts for a specific market. My hat is off to all of you because I just about starved & had to quit to make money to eat & support my first what I thought was a better half wife years ago. I have a new, younger & improved version now.
(To draw this way too long personal statement to a conclusion - It is all business & bragging writes in the end.) Yes anyone can build a vehicle with in the rules to completely dominate a TT field but $$$$ investment, time and updated rules to single out your specific high $$$ vehicle will prevail in the END & FCK YOU.

 

[Vorshlag-Fair]

Yea, the budgets for Time Trial builds "letter classes" (TTB-TTF) tends to be much more restrained than in the "number classes" (TTU-TT1-TT3), at least from what I've seen. We used to run a TTU car (now TT1) that was a gutted E36 BMW, with a 490 whp 7 liter, weighed 2450 pounds, 315mm Hoosiers on 11" wheels, some aero, etc.

The E36 BMW "Alpha Car" at least had real safety gear, which I sorely miss when I'm on track in the Mustang - especially considering we're going faster now in the 2011 GT than we went in that E36 LS2 car...

At the Nov 2012 NASA event at ECR I was 1 second quicker in the street Mustang than in the 2450 lb E36 LS1 race car in 2008

These days a car prepped like that wouldn't even make the top 3 in TT1 locally, much less at the National level. They've stepped it up in TTU-1-2-3, and there are serious builds running those classes now. We have stepped into the deep end with our move to TT3 and it will likely be difficult to win events in a full weight, daily driven street car shaped like a brick.

Oh well, it will be fun trying.