I understand that the process for setting race weights for ECHC next year has probably been established but, for those with an interest in this question (anyone running SCCA IT), I have put together an fun experiment. Take a look at...

http://www.evaluand.com/it2/weightform.htm

and try inputting your car's specs, to see what it might be expected to weigh if the ITCS used physical attributes and a power/pounds index to set your minimum weight, rather than the "mystery formula" that looks at curb weight - theoretically.

You will find this interesting particularly if you are running a '92-95 DX in ITA

Let me know what you learn or think about this, either here or by email at kirk.knestis@evaluand.com.

Have fun!

Kirk

 

Couple questions, is Stock HP wheel, or flywheel, and Stock weight is full interrior from the factory?

 

To be consistent, I have been using manufacturer quoted HP and curb weight - like from NADA or the Kelly Blue Book. When it doubt, I go to http://www.cars.com for my numbers.

K

 

I now see why the SCCA has classed my 95 CIVIC EX in ITS! SCCA is using a method that is totally full of S@#T for their calculations. I am not afraid to tell anyone what my weights and wheel hp are. Here they are if anyone is interested and YES this is a car built to the extent of IT preparation (ie: minus sunroof, airbags, seats, carpet, sound deadening material, etc.)

WEIGHT: 2225 LBS WITHOUT DRIVER AND WITH 5 GALLONS OF GAS
HORSEPOWER: 123 hp at the wheels

According to the link on comparing the hondas the "race weight" of my car including a 200 lb driver should be 2184. HOW? THERE IS JUST NO WAY IN HELL!

No wonder,
13H4
Lyonel Kent

 

We're here for you Lyon. Calm down.
If it'll make you feel any better, we're going to leave you in H4 but make you add about 50lbs next year

As a very general overview, Karl and I plan to use power and weight in race trim as our starting point. We'll adjust from there if there are other items like a potential braking advantage.
This won't be all that hard since we only have to deal with Hondas. We also aren't saddled with club politics or a fear of single marque dominance.

As an example, we have already collected some weights and dyno sheets of various cars in the series. We also have SCCA and Grand Am minimum weights to reference (although SCCA appears to be too high nearly 100% of the time).

We will use this compilation of data to set the weights. It really won't be that hard, just tedious.

Great stuff Kirk.

 

My car...

1993 Honda Prelude 2200 cc - ITS
Race weight = 3215 pounds
Difference between stock and race weights = -465 pounds

My car with non vtec H23A motor...

1993 Honda Prelude 2300 cc - ITS
Race weight = 2633 pounds
Difference between stock and race weights = 117 pounds

582lb difference just because I have a VTEC motor with 30 more hp? Hum....

 

I like those numbers better. I'll have to compare other makes in ITA to see how it affects them. The current weight of 2330 for the DX in ITA is too heavy. I could shave a lot more weight, but currently the car is 2150 with 3/4 tank of gas. Add a 180 lb driver, and you have 2330. I'm stuck where it's at, but I don't know if I could get it down to 2056 with driver either.

 

Fun toy, and you can really get some wild results. Race weight for my Civic Si in ITC would be 4200lb . Yeah, I know they wouldn't let me run it there, but the mental picture is sorta silly.

 

Ironic that the Civic EX was actually the catalyst for all of my playing around with IT2 and weight formulas, huh Lyonel? Actually, it might make you feel better to know that data suggests that SCCA isn't doing any "calculations" at all!

What your figures tell you is that (a) SCCA doesn't use performance factors to classify cars in the first place, (b) if they did, to be aligned with the e30 325 (the coincidental index in ITS), you would have to reach an unrealistic minimum weight, and (c) your car fits nicely into IT2 - at an appropriate weight.

Similarly, JohnG has discovered that the DX probably won't meet the ITA formula minimum weight - that's because the numbers suggest that his car should really be in ITB (under this system) at a sensible 2222#.

I guess that I should have explained more clearly that this system doen't presume that cars are in a particular class, like the SCCA seems to. It defines a race weight, based on math, and then we have to judge whether or not it is reasonable. This might vary by car make or model, with some cars having more room to shed pounds.

The one place where I am guessing is still the variable valve timing multiplier. I really appreciate Lyonel's data and am guessing that the engine wasn't dyno'd out of the car? If it was, I would be interested to find out what kind of HP gain was achieved - or if someone knows what WHP for a stock EX/Si might be - I could check my 1.2 multiplier. My assumption at this point is that VVT systems gain more than engines without, under IT-type preparation rules - that may not be accurate, however.

Kirk

 

For what its worth...
Through our data collection and talking with Honda IT racers and engine builders we have developed a rule of thumb that seems fairly accurate.
Many of the IT/HC prepped VTEC cars we've looked into are coming up with WHP numbers very similar to their stock CHP numbers. Plus or minus about 5 hp. The non VTEC cars are coming up with about 5 to 10 WHP more than stock CHP.

examples (names/cars omitted) with stock CHP listed first and prepped WHP 2nd...

Type R - 195/188
GSR - 172/171
Civic (SOHC VTEC) - 125/125
88-91 Civic/CRX Si - 110/120 (pretty typical for a 1.6 ITA car)

Since dynoing every single car isn't really an option, this looks like a good "rule of thumb" to me.
And I agree that the SCCA doesn't really have a formula beyond "We're scared of Hondas." I realize that sounds alot like a Honda guy just whining, but it appears to be true when you compile the evidence.
Think about this, Chris Brinson would have to add nearly 200lbs of lead to make his car ITS legal. 200 friggin' lbs. I weigh 225 and my car isn't lightened to the extent of IT rules and I would still have to add 65lbs of lead to be ITS legal.
Unreal.

 

under this formula i get.... Getting the car down to 2066 lbs with driver and the saftey get is... well... impossible under IT rules. James Walker, of team scR finally got his car 'underweight' for ITA last year but dicking around with every little peice he could find to remove weight, and his pimpy volk wheels finally got the weight down. ITB for the car? probably not... finished 4th in ITA at AARC last year.

RJ

 

The saturn SC is not a bad A car at all. It's very good I think. You just can't go wrong with a 2170 lbs car and 151 hp, 136 torque out of that 1.9L (according to team scR's website). Another ITA saturn is (was) driven by Gary Lippert. I don't know whether he is still racing his car, but when he did in '00, at road atlanta at least he was always a tad faster than Walker, and Walker is by no means slow at all with a 4th place finish last year. Those saturns can definitely move in the right hands.

 

Remember that, under a system like this, ITB wouldn't be ITB as we know it (exactly) and all of the other classes would be shuffled around some. This is why a proposal like this will probably never fly - it respresents a complete rethink of the process. Any comparisons between specs from this hypothetical process and what is currently going on will be difficult at best.

You also mention one of the great myths of IT classification, by the way - that the ARRC is somehow a statistically significant indicator of how accurately cars are classed. It just isn't but its high profile makes it attractive to use it as such, under the current "system".

Thanks, everyone, for the ongoing info and discussion. The real world stats are great indicators of where I might have to tweak the formula...

K

 

Yeah, but it's the best we have at this point. And I'm all for reclassifying the Hondas (but not in the direction ya'll want ) Send the CRXs to ITS where they belong

BTW, my RX-7 would need to weigh 2110 to compete (not the current 2300). No wonder the CRXs are kicking Wankel ***.


[Modified by Crack Monkey, 11:04 AM 10/7/2002]

 

How am I supposed to make my min weight in ITS. ITA looks like it "might" be possible. Looks like I too will have to go H-C racing.

1990 Honda Accord 2197 cc - ITS
Race weight = 2253 pounds
Difference between stock and race weights = 497 pounds

Car 2

1990 Average IT2 Car 2197 cc - ITA
Race weight = 2656 pounds
Difference between stock and race weights = 94 pounds

 

The 1990 Accord is not - as far as I know - actually listed in SCCA's IT category at this point, although the '92 Prelude S (with the 2.2) is listed in A at 2680#. Remember that the IT2 online weight calculator doesn't have anything to do with SCCA's actual specs.

I would think that the Accord would slot nicely into IT2 - understanding that it is as hypothetical at this point as the process that we are playing with!

Kirk

 

Judging by this calculator, a 1998 Subaru Impreza RS should be perfect for ITS

1998 Subaru Impreza 2500 cc - ITS
Race weight = 2709 pounds
Difference between stock and race weights = 91 pounds

competitive? only in the rain.



[Modified by elgorey, 11:25 PM 10/7/2002]

 

corey could drop that engine in and win h3 next year