The best ITB car nobody is racing?

[Ron Earp]

In all fairness, ITE is hardly 'regular' IT. As long as I've seen it, it's been pretty much ITEverthingelse.

Exactly.ITE rules are generally written to pretty much to allow anything built to IT specs with regards to safety. NCR Region also has an ITF this year for the 13 Hour that is the same at the ITE rules from 2009, which were the WDC-SCCA rules, which allowed all sorts of stuff due to the inclusion of NASA ST rules (ST1, ST2, STU, etc).

In other words, the region is trying to accommodate anything that meets safety specs so bring those odd ball race cars down. Years ago there was some really cool cars running the 13 hour; A Daytona Coupe replica, Turbo Hondas, FFR Cobra, and a few others. Most broke, but such as it goes, at least they were allowed to try. Heck, seems like in 04/05/06 the car counts were way up there too and teams were turned away.

[DoubleXL240Z]

I remember the Daytona Coupe, lasted about 3-4 hours if I remember correctly. Maybe 2005 or so? Also Synnergy had a 996 cup car there too. Didn't finish either!!!

[Ron Earp]

I remember the Daytona Coupe, lasted about 3-4 hours if I remember correctly. Maybe 2005 or so? Also Synnergy had a 996 cup car there too. Didn't finish either!!!

The Cup car didn't finish???

I knew the Daytona Coupe didn't finish because I was maybe 200-300 yards behind it entering Roller Coaster when the its motor let go. Fortunately no oil on track that I could detect but lots and lots of smoke. Shame. That was a pretty car but if I recall correctly it had too much hp to make a go of it for 13 hours. Needed to be fueled like every 30-40 mins or so, giving up a lot of the time it'd gained on the field each stop.

[Bill Miller]

I always wondered how the Storm GSi landed in ITB when things like the Golf / Scirocco 16v cars landed in ITA, even though they made less power than the Storm.

I always figured that the Fire Arrows would make killer ITB cars, but that they were enough of an odd duck that nobody would develop them, and that there was little to no aftermarket support. I raced against Scott and his car at Summit Point in my old Rabbit GTI, and I was honestly surprised that the car wasn't WAY quicker.


Ron,

I think it's great that the regions try to accomodate all those cars in the enduros, but it does present quite a challenge for guys w/ 'real' IT cars going for an O/A win. Me-otter reliability has certainly helped them. I agree w/ Kirk, get one that can run 3 hour stints and they should be able to do very well in a 12 hour race, w/ only 3 pit stops. You guys need any crew for that Lola?

[Ron Earp]

I think it's great that the regions try to accomodate all those cars in the enduros, but it does present quite a challenge for guys w/ 'real' IT cars going for an O/A win.

Hey Bill,

The 13 Hour race isn't an "IT-only" race. Six speed sequential paddle shifters, turbo cars, etc. are far and above most "IT" cars in performance, and well above our T70 for that matter, but legal in the 13 Hour with the varied ITE/ITF rules. Go for the win in your class is the way to go, let the rest fall where they may. We're signed up with an ITA Miata and would be happy for some help. Getting those pit stops down to nil would be key and I bet a fuel sipping ITA or ITB car with 25 gallon cell, as much usable as possible, would be key and a winner....

Now, those ITB Firearrows would be cool to see! 4.2L inline six? Seems that some local folks had quite a bit of success with one of those back in the day.

R

[ScotMac]

Hey Bill,

Now, those ITB Firearrows would be cool to see! 4.2L inline six? Seems that some local folks had quite a bit of success with one of those back in the day.

R

4.2? I thought they are 2.6? I raced against one at laguna in june. The guy that drives it had been doing rally racing. Sliding around the corners, i think he was about 2 secs faster than me, and once he cleaned it up a bit, he was down to 1:51 (about a second over the track record). He is trying to sell it, if anyone is interested.

[JoshS]

4.2? I thought they are 2.6? I raced against one at laguna in june. The guy that drives it had been doing rally racing. Sliding around the corners, i think he was about 2 secs faster than me, and once he cleaned it up a bit, he was down to 1:51 (about a second over the track record). He is trying to sell it, if anyone is interested.

Yeah, it's a 2.6. Maybe he's confusing it with the 4.2L AMC Spirit in ITA. When was the last time someone saw one of those show up?

I was there at Laguna that weekend but left Friday afternoon after my head gasket blew on lap 2 of practice ... I never noticed the Fire Arrow, oh well, would have liked to look that car over.

[Ron Earp]

Yeah, it's a 2.6. Maybe he's confusing it with the 4.2L AMC Spirit in ITA. When was the last time someone saw one of those show up?

Yep, I was, sorry. Those AMC/Pymouth sorts of cars run together for me a bit. I'm told there was a AMC 4.2L six somewhere in the SE but I'm not sure I've ever seen it.

[Tristan Smith]

Yeah, it's a 2.6. Maybe he's confusing it with the 4.2L AMC Spirit in ITA. When was the last time someone saw one of those show up?

I was there at Laguna that weekend but left Friday afternoon after my head gasket blew on lap 2 of practice ... I never noticed the Fire Arrow, oh well, would have liked to look that car over.

Ed Forrest drives one here in the Atlanta Region. Has been for years. It's always fun to see what falls off/out of the the motor each race.

[924Guy]

For reference...

[Bill Miller]

Ron,

I know it's not IT-only, was just commenting on the chances for a 'real' IT car to vie for the O/A win against the likes of some pro endurance cars.

You guys aren't running the Lola at VIR? I'll check my calendar and let you know.

[Z3_GoCar]

Ok, so I'm sitting here playing those mind games you play when you need a break from the daily grind, and was thinking about what my next IT project might be. Since a real, competitive ITR car isn't going to fit the budget I've been thinking about looking for an ITB car. The fact that it is probably the most competitive class in IT right now makes it really attractive, and it doesn't hurt that there are probably more different cars that can win in this class than all the others put together. So I was just perusing the GCR and wondering if there is maybe a car in there that nobody has built yet (or at least not seriously) that could keep up with the Golfs, Preludes, CRXs, etc. Something like the Excort EXP, Fiero, or one of the later year Celicas...

So I figured I would ask the pros - if you could build any car for ITB, outside of the current favorites, what would it be?

Oh BTW,

What happened to the camero? I figured it'd be a very affordable route into ITR.

[erlrich]

Oh BTW,

What happened to the camero? I figured it'd be a very affordable route into ITR.

I'm sure it would be one of the least expensive cars to build for ITR, but I'm 98% convinced that it has a 0% chance of being competitive with the top dogs in ITR. I still plan to do some testing with it in limited IT trim, but unless it suprises the hell out of me it will probably be relegated to becoming a project car/track day toy.

I mean hell, if I just wanted to race an also-ran, I already have one...

[rsportvolvo]

For reference...

A 0.36 Cd isn't that good these days. A Volvo 240 wagon had a 0.39 Cd and many new cars are sub 0.30. (sleek shapes don't always tell the story) The Cd is only part of the equation. Frontal area is another big factor. I pulled this from the Bosch Automotive Handbook, 5th ed.

FL = 0.5 * ρ * Cd * A * V^2

PL = FL * V = 0.5 * ρ * Cd * A * V^3


PL = aerodynamic drag, in Kilowatts
FL = aerodynamic drag, in Newtons
ρ = air density
Cd = drag coeffecient
A = frontal area
V = velocity

There is a complete overview of how to run a coast down test to accurately calculate a cars aerodynamic drag and actual Cd in the Bosch Automotive Handbook. I highly recommend this book to anyone developing a car or wanting to learn more of the theory side of automotive design.

The Porsche 924 has a good chassis, decent suspension, ok engine and good aero (for the '70's), but is a great package with proven speed. As with any Porsche the factory has done alot to help you out and the HUGE aftermarket makes the development cycle fairly short. The main drawback is the P-tax paid on parts.

[924Guy]

The Porsche 924 has an excellent chassis, great suspension, weak engine and great aero (for the '70's), but is a great package with proven speed. As with any Porsche the factory has done jack squat to help you out ...and the modest aftermarket made the development cycle very long. Thankfully, with 90% VW parts, you're saved the P-tax paid on parts.

Fixed that for ya.

[JeffYoung]

Good point on "vintage" aero. TR7s look aerodynamic. They are not -- I bet a Mark III Golf has a better CD.

A 0.36 Cd isn't that good these days. A Volvo 240 wagon had a 0.39 Cd and many new cars are sub 0.30. (sleek shapes don't always tell the story) The Cd is only part of the equation. Frontal area is another big factor. I pulled this from the Bosch Automotive Handbook, 5th ed.

FL = 0.5 * ρ * Cd * A * V^2

PL = FL * V = 0.5 * ρ * Cd * A * V^3


PL = aerodynamic drag, in Kilowatts
FL = aerodynamic drag, in Newtons
ρ = air density
Cd = drag coeffecient
A = frontal area
V = velocity

There is a complete overview of how to run a coast down test to accurately calculate a cars aerodynamic drag and actual Cd in the Bosch Automotive Handbook. I highly recommend this book to anyone developing a car or wanting to learn more of the theory side of automotive design.

The Porsche 924 has a good chassis, decent suspension, ok engine and good aero (for the '70's), but is a great package with proven speed. As with any Porsche the factory has done alot to help you out and the HUGE aftermarket makes the development cycle fairly short. The main drawback is the P-tax paid on parts.

[Knestis]

But again, Cd is different than total aero drag in "negative power." Frontal area of the Golf III is probably 1.5 924s.

K

[Greg Amy]

TR7s look aerodynamic. They are not...

Wha, wha, WHAT? "The Shape of Things to Come" is not aerodynamically efficient....????

Confused in CT...

P.S., Nebber, nebber, NEBBER use Cd as a comparison number; it's meaningless to anything but the egghead engineers. Doing so is truly ignorant (in the truest sense of of the word). This is why Miatas are truly NOT "not aerodynamic" and why my NX2000 truly does NOT have the aerodynamics of a McLaren F1...despite the Cd numbers to the contrary.

[Z3_GoCar]

Wha, wha, WHAT? "The Shape of Things to Come" is not aerodynamically efficient....????

Confused in CT...

P.S., Nebber, nebber, NEBBER use Cd as a comparison number; it's meaningless to anything but the egghead engineers. Doing so is truly ignorant (in the truest sense of of the word). This is why Miatas are truly NOT "not aerodynamic" and why my NX2000 truly does NOT have the aerodynamics of a McLaren F1...despite the Cd numbers to the contrary.

Greg, you egg-head

To truely compare aero (for low-speed, low-reynolds numbers conditions) you need both Cd and cross-section area, one without the other is pointless.

[JeffYoung]

No, the TR7/8 are not aerodynamically efficient.

Sure, you need cD and frontal area. But I bet the frontal area of a TR7 or a 924 is not 1.5 times a Golf.

Look at the edges, transitions and gaps in a car from the 70s vis a vis a car from the 90s. No blended edges and all sorts of gaps and "dirty" devices on the older car.

We really see this in the TR8 and the 260z versus newer cars, and in particular the RX7 and the Integra in ITS. All with similar horsepower, but the newer cars really make ground at 120 mph+ while the Z and the 8 hit an aero wall.

The cars are balanced -- don't get me wrong I don't think we need to do anything about it -- because the Z and the 8 are so much better in the midrange.

But anyway, my point was it is just as ignorant to look at a "shape" and say "good aero!" without looking at cD (and frontal area).