ITR Multiplier? ??

[StephenB]

Since ITR pretty much started during the most recent ITAC I was wondering if any of you may have the multipliers and formulas for ITR.

thanks,
Stephen

[Gary L]

See post #49 in the "....Chairman resigns" thread.

[erlrich]

IT-build HP (someone said that most ITR cars got 30% for expected gain) * 11.25

[StephenB]

IT-build HP (someone said that most ITR cars got 30% for expected gain) * 11.25

This is what I saw as a norm as well however I found something that implied the ITAC recommended the s2000 with only a 15% gain. So I will reword my question... what are the power gains that the ITAC used for each ITR car that they classified? This should be well documented based on recent posts about transparency...

Gary thanks for the link, that is part of what I need, I do understand the process and know I am looking for the rational and transparency part... I have a little homework to do: )

Stephen

[Ron Earp]

That are the power gains that the ITAC used for each ITR car that they classified?

Pretty easy to back calculate using the assigned weights. Slap'em in a spreadsheet and you can get all the power multipliers pretty easily.

[StephenB]

Pretty easy to back calculate using the assigned weights. Slap'em in a spreadsheet and you can get all the power multipliers pretty easily.

Ron... great idea, but that will only get me close to understanding the power gains I need to research the power gain goals...

So step 7 we get a 6% reduction for FWD
Does step 8 apply to ITR?
And step 9 seems like it could go all over the place... if any ITAC member (current or retired) is lurking feel free to share your knowledge!

I would love it if anyone on the ITAC could just share the spreadsheets... some cliff notes perhaps :)

Thanks again,
Stephen

[GKR_17]

The original proposal was in the July 2006 Fastrack. Here are the numbers as I know them, correct me if there are any errors:

15%:
Honda S2000
Porsche 968
Mazda Rx-8 (as originally classed, dropped 130lbs with no explaination in Dec 2009)

20%:
Acura Intergra Type-R
Ford Taurus SHO
Porsche 944S2

25%
Acura Legend, RSX-S
BMW E30 M3
Chevy Camero
Dodge Stealth
Ford Contour SVT, Mustang
Honda Prelude
Mitsubishi 3000GT
Nissan Maxima
Pontiac Firebird
Porsche Boxter, 911, 911S, 911SC
Toyota Celica GTS

30%:
BMW 6 cylinders (325, 328, 330, 635, Z3, Z4)
Lexus IS300, SC300
Nissan 300ZX
Toyota Supra

[Knestis]

The original proposal was in the July 2006 Fastrack. Here are the numbers as I know them, correct me if there are any errors:

15%:
Honda S2000
Porsche 968
Mazda Rx-8 (as originally classed, dropped 130lbs with no explaination in Dec 2009) ...

That's when the checks from Mazda cleared. ;)

The RX8 is something of a case study in both why the limited subjective decision-making of "version 2" of the Process is important, and how it was designed to work - at least as far as the ITAC's recommendation was concerned. We looked at a lot of information and were confident - collectively confident, by a documented individual roll-call system - in the multiplier used and the ultimate weight specification.

It's just a shame that there was no system in place to communicate to the membership how the checks and balances are intended to work. I'm *positive* that someone (read, "the competition") is always going want any car's given race weight higher than it is, but maybe if y'all had some confidence that I WAS joking about the fat check, you'd be able to accept that the ITAC was making recommendations equitably - and that the CRB was implementing them with the fidelity.

K

[Andy Bettencourt]

Stephen,

Anything specifically you would like to know? Maybe how a car that is not on the list might be classified?

[benspeed]

The RX8 has larger brakes than the S2000 and the 968 and now an even lower weight...course if it was my car getting a weight break I'd have no complaint :-) The weight break is sorta stacking the deck for Mazda on the short twisty courses...

Other than moaning over the weight on the RX8 - the multipliers are spot on - can't say I'd change any of 'em.

Hopefully we'll see some RX8s out there this season. There's an awesome Sahlen RX8 for sale on racing junk that would be a perfect STU car - grab that ride Flatout!!!

[Andy Bettencourt]

The RX8 has larger brakes than the S2000 and the 968 and now an even lower weight...course if it was my car getting a weight break I'd have no complaint :-) The weight break is sorta stacking the deck for Mazda on the short twisty courses...

Other than moaning over the weight on the RX8 - the multipliers are spot on - can't say I'd change any of 'em.

Hopefully we'll see some RX8s out there this season. There's an awesome Sahlen RX8 for sale on racing junk that would be a perfect STU car - grab that ride Flatout!!!

We had a chance to build whatever we wanted for ITR this winter...and the RX-8 didn't make the cut. Don't think it can make the power and the transmissions are total crap. Still nothing better on paper than an E36.

[benspeed]

Thankfully we are keeping ITR from becoming 'Spec E36"...

That S2000 is going to be a great addition - Steve will be in contention, no doubt

After looking over that list again - I'd change the multiplier on the Boxster to 15%. Nobody seems to be able to make any extra power out of that motor.

[seckerich]

We had a chance to build whatever we wanted for ITR this winter...and the RX-8 didn't make the cut. Don't think it can make the power and the transmissions are total crap. Still nothing better on paper than an E36.

We will see if we can change that opinion this year. :D Totally agree on the trans but we found most of the fixes. Definitely not for the ham fisted driver.

[robits325is]

The RX-8 looked fast in the Rolex 24!

[StephenB]

I would really like to join ITR with whatever my new build is, however in realty i cant spend 40k on a car. I am trying to think about the best option for me to have fun and be in the top half of the field. I dont have an unlimited budget, i dont have a huge shop with all the best equipment, i know nothing about ecu mods. So i am thinking a car I love like the Lexus is a much more expensive build with 30% gains than with an RX-8 at 15% as a goal. Granted that extra 15% is expensive but so will that last 15% on a car with a 30% goal. I am thinking that If I took a car that only has 15% as a target then I am at an advantage with the limited buget over building a car with a 30% multiplier. Compairinfg the rx8 and the is300 I am thinking the rx8 would be faster if I didn't do engine modifications on either car....

These are my dilemmas!
Stephen

[Ron Earp]

V6 Camaro.

If you can't build a pretty basic, but decent one, for around $8k then you're not trying hard enough. Plentiful parts, high quality ones too, at low prices. Good weight distribution, good brakes, and they did AutoX well back in the day.

Competitive? Not sure, but I think the power is going to be there for you. Live rear axles are not as henious as people make them out to be in IT (ask Jeff Young), and you'll have fun I bet!

You can then join the ITR Domestic Brigade, spoiling the look of IT.

[benspeed]

Ron - the Camaro was a top pick for me. That V6 can make some power on the cheap and a good cage will stiffen up that chassis right. I liked the V6 Mustang too!
Both are the econo competitors...

Stephen - grow a mullet dude - race domestic! That Lexus will be an excercise in pain

[erlrich]

Stephen - grow a mullet dude - race domestic!

Hey, hey...watch it! :D

Ron, you gonna take that?





- Earl, who doesn't have enough hair to grow a mullet...

[dj10]

Definitely not for the ham fisted driver.

Oooo........ Nick Ham maybe offended.:rolleyes:

[Ron Earp]

Hey, hey...watch it! :D
Ron, you gonna take that?
- Earl, who doesn't have enough hair to grow a mullet...


Ron "Growing Mullet Now for My 2010 Domestic ITR Debut" Earp

[lateapex911]

The RX-8 looked fast in the Rolex 24!

All three rotors of it's tube framed self!

Steve, go count your wheels and tires, and the "Stuff" that makes your current effort tick.
Now go replicate that for a Lexus (you're nuts) or an RX-8. Do the math.
Now, remember the rule, "buy, don't build",
Then apply the corollary, "If you must build, don't be the inventor".

I see you breaking every one of those. Do you really want to go backwards competitively, while spending double and triple what you're used to??

[seckerich]

All three rotors of it's tube framed self!

Steve, go count your wheels and tires, and the "Stuff" that makes your current effort tick.
Now go replicate that for a Lexus (you're nuts) or an RX-8. Do the math.
Now, remember the rule, "buy, don't build",
Then apply the corollary, "If you must build, don't be the inventor".

I see you breaking every one of those. Do you really want to go backwards competitively, while spending double and triple what you're used to??
If we could have kept all 3 rotors happy on both cars we would have been 1-2. That was a heart breaker for us on the 69 car. Just a freak failure.

Most of the work has been done on the RX8 with our Grand Am cars. Most of the suspension parts Speedsource made are available from Mazdaspeed. The wheels for the 8 are not much worse than the Volks on the ITS car because there are actually cheaper, lighter options available. Most tuners just piss the motor off and loose power because short of a good exhaust and intake there is not much to do. All things compared it is a pretty reasonable car to build for ITR. Just be aware it is going to be expensive to buy those big tires. Not so easy to cage because it has no B pillar and you really need to understand FEA to get a strong, legal design. In GA we could seam weld and unlimited attachment points, not ITR. Good luck with your decision.

[benspeed]

LOL Ron! Can't wait to see that spoiled class look. I will bring you a wifebeater T shirt when I get down for some SARRC events :-)