ITB Review - Help Identify Potential Issues

Want to dispute the classification process or how things are or have been done? Don't like how on-track performance isn't being used more than indicator, or how the base multiplier for the class is off? Save it for another thread, maybe here.

The puropse of this thread is to help identify ITB cars in which people believe to be an issues. It's important that this is done according to how the current IT process is structored.

Ideally you'll post the HP rating and the weight it should be at using that and other attributes to the car per the classification process. Once compiled, we can submit it to the ITAC how they'd prefer us to. From the other post, here are a few copied.

Geo Storm: HP 130 x 1.25 x 17= 2762.5 - 55.3 = 2707.3, round to: 2705 GCR = 2380 or 325 pounds too light. Weight/HP = 15

Geo Prism: HP 130 x 1.25 x 17= 2762.5 - 55.3 = 2707.3, round to: 2705 GCR = 2455 or 250 pounds too light. Weight/HP = 15.4

Suzuki Swift: HP 100 x 1.25 x 17 = 2125 - 42.5 = 2082.5 round to: 2085 GCR = 1895 or 190 pounds light. Weight/HP = 15.5.

Needs more info:
Firearrow

Isuzu Stylus XS: 125 stock hp @ 2430 lbs.
Alfa Romeo GTV2000: 130 stock hp @ 2410 lbs

Due to the multivalve 30% default factor, I have to believe that there are ITB cars which need their weights adjusted. I can't think of any Hondas that are not multivalve, so those could be added to the list.

I think it's important to specify the trim levels of those cars, as both had lesser or different engined siblings. suzuki Swift Tsi/storm and prism GSi.

I'm suprised that the storm GSi and the Stylus XS use different factory HP numbers - they are 2 and 4 door versions of the same car, and both use the same engine (4XE1-W) which was rated at 130 hp @ 7000 RPM / 102 lb·ft @ 5800 RPM. the Stylus has 4 wheel discs and nifty Lotus stickers.

all of those listed above (excep the fire arrow and alfas) are DOHC / 4 valve per cylinder cars. we have to nip this 130% thing, because the numbers dave shows are big enough. I'd agree that both Geo GSi cars and the Isuzu are better suited for ITA, particularly at ~2300-2400# factory curb weights.

There was a thread about a year ago that hit on these same cars for this same reason, but my search-fu is weak.

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Originally Posted by gran racing

The puropse of this thread is to help identify ITB cars in which people believe to be an issues. It's important that this is done according to how the current IT process is structored.

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The Fire Arrow specs are hard to find. The best I could find with google is this and a couple of others. They all are in agreement - 137HP.

138 x 1.25 x 17 = 2935 GCR = 2360 or 575lbs too light.

I'll run through Kirk's sheet and get the correct GCR weights, update what I can.

Needs to be lighter with leaf springs in the rear and Mac(s) up front...and good luck hunting replacement parts.

The Volvo 240. The results of the re-Processing were supposed to get issued in last month's Fastrack, but it's being held up by the CRB. I may chime in again depending on the results.

Can someone email me a copy of the Process? I tried to get it awhile back, but it was a moral sin to release it at the time.

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Originally Posted by joeg

Needs to be lighter with leaf springs in the rear and Mac(s) up front...and good luck hunting replacement parts.

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ITAC manual V0.9 dated July 2010 doesn't allow for weight adjustments for leaf springs in the rear or struts on an ITB car.

Jeff, where is this updated version located?

[duplicate post]

It's on the SCCA website. Let me see if I can find the link.

CRB is I am sure working on the 240. We just sent the recommendation to them recently.

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Originally Posted by gran racing

Jeff, where is this updated version located?

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No changes from what was released a few months back.

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Originally Posted by JeffYoung

No changes from what was released a few months back.

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OK, that's the one I have. I read the header "Version 0.9, July 2010".

Still no allowance for struts in ITB or leaf springs.

No, there is not.

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Originally Posted by jjjanos

OK, that's the one I have. I read the header "Version 0.9, July 2010".

Still no allowance for struts in ITB or leaf springs.

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Quote:

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Originally Posted by Chip42

I think it's important to specify the trim levels of those cars, as both had lesser or different engined siblings. suzuki Swift Tsi/storm and prism GSi.

I'm suprised that the storm GSi and the Stylus XS use different factory HP numbers - they are 2 and 4 door versions of the same car, and both use the same engine (4XE1-W) which was rated at 130 hp @ 7000 RPM / 102 lb·ft @ 5800 RPM. the Stylus has 4 wheel discs and nifty Lotus stickers.

all of those listed above (excep the fire arrow and alfas) are DOHC / 4 valve per cylinder cars. we have to nip this 130% thing, because the numbers dave shows are big enough. I'd agree that both Geo GSi cars and the Isuzu are better suited for ITA, particularly at ~2300-2400# factory curb weights.

There was a thread about a year ago that hit on these same cars for this same reason, but my search-fu is weak.

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Where are the Isuzu Stylus XS and the Storm GSi rated differently? I'll take a picture of my Isuzu FSM at home to show that the Stylus and Impulse XS are rated at 130 hp and 102 lb/ft.

I agree that both along with the Swift should be in ITA.

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Originally Posted by Robbie

Where are the Isuzu Stylus XS and the Storm GSi rated differently? I'll take a picture of my Isuzu FSM at home to show that the Stylus and Impulse XS are rated at 130 hp and 102 lb/ft.

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first post. listed weights are 50# different from each other as well.

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Originally Posted by Robbie

I agree that both along with the Swift should be in ITA.

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I disagree Re: the swift. It's a proper ITB car.

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Originally Posted by Chip42

first post. listed weights are 50# different from each other as well.


I disagree Re: the swift. It's a proper ITB car.

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I see that now. That was the rating for the 1.6L 1989 Isuzu I-Mark RS (which is actually a motor with higher potential than the Storm or Impulse/Stylus, it has much bigger cams), the Stylus/Impulse XS and Storm were all rated at 130/102 from the factory. I'll confirm that tonight.

Plymouth Fire Hawk: (138 x 1.25 x 17) = 2935 GCR = 2360
Geo Strom GSi: (130 x 1.3 x 17 x 0.98) = 2815 GCR = 2380
Alfa Spyder: (132 x 1.25 x 17) = 2805 GCR = 2805 (HP Sourced via google)
Isuzu Stylus: (130 x 1.3 x 17 x 0.98) = 2815 GCR = 2430
Geo Prism GSi: (130 x 1.3 x 17 x 0.98) = 2815 GCR = 2455
Fiat 124 1800: (118 x 1.25 x 17) = 2510 GCR = 2230
Suzuki Swift GT (100 x 1.3 x 17 x0.98) = 2165 GCR = 1895
Alfa Romeo Alfetta, GT, GTV, Sprint (128 x 1.25 x 17) = 2720 GCR = 2520

Based on what I could google on HP #s, there are something like twenty to thirty candidates for moving down to ITC. Not surprisingly, most of these cars have probably never been raced as ITB cars.

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Originally Posted by jjjanos

Plymouth Fire Hawk: (138 x 1.25 x 17) = 2935 GCR = 2360
Geo Strom GSi: (130 x 1.3 x 17 x 0.98) = 2815 GCR = 2380
Alfa Spyder: (132 x 1.25 x 17) = 2805 GCR = 2805 (HP Sourced via google)
Isuzu Stylus: (130 x 1.3 x 17 x 0.98) = 2815 GCR = 2430
Geo Prism GSi: (130 x 1.3 x 17 x 0.98) = 2815 GCR = 2455
Fiat 124 1800: (118 x 1.25 x 17) = 2510 GCR = 2230
Suzuki Swift GT (100 x 1.3 x 17 x0.98) = 2165 GCR = 1895
Alfa Romeo Alfetta, GT, GTV, Sprint (128 x 1.25 x 17) = 2720 GCR = 2520

Based on what I could google on HP #s, there are something like twenty to thirty candidates for moving down to ITC. Not surprisingly, most of these cars have probably never been raced as ITB cars.

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How is the Alfa a problem??? if the process and the GCR match? I suspect you typo-ed the GCR weight. (My GCR shows every single Alfa Spider at 2400) That car would need a TON of baggage to weigh that, I'd think.

Why are we burning up bandwidth on this...?

Find the appropriate documentation.

Submit a request that [Model X] be run through the Process.

Trust the ITAC to follow their internal rules.

Done.

K

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Originally Posted by Knestis

Why are we burning up bandwidth on this...?

Find the appropriate documentation.

Submit a request that [Model X] be run through the Process.

Trust the ITAC to follow their internal rules.

Done.

K

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I think Dave was going to submit one letter with all the cars in one letter. :)

Stephen

I think Pants was just listing cars that might be an issue.

Some of those early ones could be Net numbers too.

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Originally Posted by lateapex911

How is the Alfa a problem??? if the process and the GCR match? I suspect you typo-ed the GCR weight. (My GCR shows every single Alfa Spider at 2400) That car would need a TON of baggage to weigh that, I'd think.

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Quote:

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Originally Posted by lateapex911

How is the Alfa a problem??? if the process and the GCR match? I suspect you typo-ed the GCR weight. (My GCR shows every single Alfa Spider at 2400) That car would need a TON of baggage to weigh that, I'd think.

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Typo and an error on my part. HP number I had probably was gross, not net.

Car works out to: 17 x 1.25 x 115 = 2445 GCR = 2400 or just a little too low per the GCR.

Virtually all of the heavy lifting on this was done by Kirk (thanks Kirk!). I've added some data points and missing cars from the GCR. The inputs are rough and need refinement. A large number of cars are missing the important pieces. Feel free to correct and point towards good sources for data.

Pick a ITB orphan and send a letter Simple.