Nov '12 Prelim Minutes & Tech Bulletin
- Thread starter erlrich
- Start date
Andy Bettencourt
Super Moderator
If the ITAC even believed that was the right way to go (it's almost a moot number) it might work on a new car but no way would you get a good number on a car that is almost 30 years old.
The number that matters is crank HP in IT trim so when there is dispute over the stock numbers validity, you need to go with a build example(s). If nobody is willing to do so, then they don't have much ground to stand on for a change.
Yeah, but with just a little bit of $ to prep it half-way into an IT car, you could show up at the ARRC and kick ITB-butt before the ITAC could fix it.
Ron Earp
Administrator
Agree.
the geo/isuzu twins and prism have been on my personal radar a LONG time, as have some of the old F2 3V/cyl mazdas (626, MX6, probe). if anyone sees these cars on track, let us know. they aren't processed correctly but haven't been a big issue because no one knows of any current examples. the GSi geos need lead if they are going to run ITB, plain and simple. Andy's right about them being more likely ITA cars. slowish ones, I'd bet, but ITA cars.
ron - MR2's are well dynoed and the issue has been put to bed (well, from the ITAC and CRB's perspective). unless someone finds more than 5whp over the best examples we've ever seen numbers on (~109whp), we're safe with the newly processed weight. I think you'll not be seeing changes there for a long time if ever.
ron - MR2's are well dynoed and the issue has been put to bed (well, from the ITAC and CRB's perspective). unless someone finds more than 5whp over the best examples we've ever seen numbers on (~109whp), we're safe with the newly processed weight. I think you'll not be seeing changes there for a long time if ever.
gran racing
Super Moderator
Time to be proactive on the Geo then. Get it classed right now before someone builds one, then gets bumped to an uncompetitive position in ITA.
Andy Bettencourt
Super Moderator
140hp FWD hatch? ITA.
erlrich
Super Moderator
Ok, so this bugs me just a little bit (not directed specifically at you Chip, but since you brought it up...). So what, we're going to wait until someone puts the time and effort into building one of these, then re-class/re-weight the car?
Rabbit05
New member
The HY and KV are European motors ..the KX and JT are the US motors. The KX is a lower HP because of a crappy 5-1 exhaust mani...the JT is the same motor, internal wise as the KX, except it was in the AWD 4000s and it had a "header" type Exhaust manifold...5-3-1 .
The very early Coupes came with a WE motor ..which is rated at 100 hp.
So if any member has a HP dispute ..they need to have a motor built by a Pro shop ? How does one quailify a pro motor ? This is getting a bit crazy....it went form ok go dyno your car ...to" nooo yours isnt built enough, it wont be good enough info"..to... I need a PRO MOTOR built and dyno'ed out of the car ???
Is there a certain $$$ amount I have to spend...?
You see where this is going ?
Andy Bettencourt
Super Moderator
John,
It's obviously not a great situation but the car we are talking about here is missing a critical piece of information used to classify cars. The suggestion that dynoing the Blethen cars for a data point is just silly. The information gained is 100% useless. Sorry to say, but it is.
So if you want a 'correction' you have to provide data that the ITAC can bite into and run with. Why would they reset your weight on non-developed power numbers when the power numbers are at the center of the weight number?
It doesn't have to be built by a pro shop, build it yourself. It just needs to demonstrate that the allowances are accounted for so that you can make a reasonable argument that it's representative of a 'best of breed' effort. There is no way around it.
I don't know what the weight is on that thing now but if it were me, I would set it using the 120hp @ 25% and make a change like to the MR2 once a handful of full builds are on dyno sheets or someone came up with the definitive stock hp number.
And what I mean by full build?
- compression bump
- IT legal head prep (lots to do there)
- overbore
- exhaust development
- intake development
- programmable ECU
These are just the core items. Like I said, does it suck Yes. But there is no way you can ask for a reset on weight when 'hp in IT trim' can not be estimated.
Crank HP in IT trim? Just how does one go about getting that number? Oh yeah, you have to back-calc it from WHP measured on a dyno. And that calculation will always be subject to a percentage error because drive line loss is different for each car. With the HP numbers we're talking about in A/B/C that drive line loss error can be the difference between a car appearing to make 30% vs 25% over stock.
sorry if you don't understand what Andy said...
but I agree 100% with it. He is absolutely right. I have always asked that dyno results not be considered. And It's only ONE reason why dyno results are useless in this context. Others are: how accurate the dyno and it's operator are,
what kind of tires are used (frictional//heat loss through tires is a BIG variable),
are correction factors for air density and temperature properly applied?
What are actual driveline losses for this specific car?
How well is the incoming air sequestered from contamination of exhausted air?
Has the car been mis-tuned to give a lower output and skew the result?
but I agree 100% with it. He is absolutely right. I have always asked that dyno results not be considered. And It's only ONE reason why dyno results are useless in this context. Others are: how accurate the dyno and it's operator are,
what kind of tires are used (frictional//heat loss through tires is a BIG variable),
are correction factors for air density and temperature properly applied?
What are actual driveline losses for this specific car?
How well is the incoming air sequestered from contamination of exhausted air?
Has the car been mis-tuned to give a lower output and skew the result?
Andy Bettencourt
Super Moderator
Well it's the actual result that is plugged in then to be multiplied by the target power to weight for each class. In most cases it's stock hp*1.25. In some the ITAC uses a dyno number they are confident is representative of attainable power and then ESTIMATES crank hp in IT trim using the OPS manual. 15% losses for FWD and 18% losses for RWD.
NOBODY EVER SAID this was spot-on accurate. It's a framework we live by and try to be consistent with. Does it fail some cars? Sure. Is there a desire to micromanage the classifications? NO.
JeffYoung
New member
I do not agree. If the Blethen's car makes less than 120 whp, then we know the 120 stock crank number is wrong.
It's not definitive in anyway, but it's a piece of a multi-faceted puzzle that needs to be considered. It's no different than what you, Kirk, Jake and Josh did with using builds "similar" to IT prep levels with the Neon, the RX8 and others.
preparedcivic
New member
FYI; there is one of them 4AGE powered ITB Geo Prizms in our Hooptie movie from this year's IT Fest linked a page or two back. It looked a little awkward on track and didn't have the straight line one would expect.
For full disclosure, our camera car is a 1G CRX Si. Very well driven and gets around turns well despite a seriously underdeveloped chassis, and being sad-motored as well. Compared to my 103 whp autocross 3G Civic EW4, the ITB car seat of pants feels like about 85 tops. These motors make 91hp crank BTW. These are the Hondas that lost 160 lbs last year, and are still at a 30%+ multiplier given the accepted 100 +/- whp for these motors in full-build IT trim. Doing the math on the previous 2130lb weight, that factor was at something over 40%. A totally arbitrary number that a previous ITAC and CRB pulled out of ass or thin air.
Having been on SCCA advisory committees and program boards for years, I wholeheartedly respect the effort the current ITAC and CRB put in, however I will offer, from that 10 years of previous experience, it is not in the best interests of a category to be too "activist". Turbos in IT? Why? The Audi Coupe STILL being discussed? It's been 3 or 4 years already. The A2 VW? These cars have been running in IT for almost 20 years. No data anywhere on what a legal build in these cars makes power-wise?
For full disclosure, our camera car is a 1G CRX Si. Very well driven and gets around turns well despite a seriously underdeveloped chassis, and being sad-motored as well. Compared to my 103 whp autocross 3G Civic EW4, the ITB car seat of pants feels like about 85 tops. These motors make 91hp crank BTW. These are the Hondas that lost 160 lbs last year, and are still at a 30%+ multiplier given the accepted 100 +/- whp for these motors in full-build IT trim. Doing the math on the previous 2130lb weight, that factor was at something over 40%. A totally arbitrary number that a previous ITAC and CRB pulled out of ass or thin air.
Having been on SCCA advisory committees and program boards for years, I wholeheartedly respect the effort the current ITAC and CRB put in, however I will offer, from that 10 years of previous experience, it is not in the best interests of a category to be too "activist". Turbos in IT? Why? The Audi Coupe STILL being discussed? It's been 3 or 4 years already. The A2 VW? These cars have been running in IT for almost 20 years. No data anywhere on what a legal build in these cars makes power-wise?
Except I don't believe anyone is disputing the IT-multiplier on the car. It's the number that goes into it. Putting anything other than a stock car on the dyno is going to get "well. it's not fully prepped" because certain people "know" the car makes 120 stock.
Andy Bettencourt
Super Moderator
Help me understand this line of thinking. I can't figure out any foundation for a theory like this. If Blethen's car make 117whp, how is it possible to understand what stock crank number was accurate?
The issue at hand is this theoretical 117whp is of totally unknown origin. Is it 15% lower than it's capable of or is he within 1% of the 'max' by shit luck?
Disagree 100%. The Neon numbers were taken from a factory IT kit from MOPAR and the RX-8 numbers were taken from full-tilt GAC Speedsource builds, which given the allowances for a rotard, was EXACTLY an IT build. Those numbers were then backed up by Pro Formula Mazda sealed engines with Motec.
Any attempt to get data like that was only considered if it was maximizing allowances from IT. If say a stock ECU was used, it would have been useless data.
I am just not getting it. How does a data point from a 5 year old motor with no compression bump, off the shelf intake and header, stock ECU and NO tuning of timing or fuel help?
What if it was a 120hp (crank) that made 117whp? That's a 15% gain. Reasonable given the development. But that 117whp on 110 crank would be 25%.
A Miata like mine - in similar prep as these cars - would make about 120whp. On a stock number of 128hp. Trying to draw a line to stock HP with an unknown subject is impossible to me.
Help a dummy understand! I have to be missing something.
I think we have to agree that we don't know the real stock HP and unless you find one in a museum somewhere, you never will. So you have to use dyno data to 'correct' the listing. And the only data that would be worth the paper it came on was a proper effort.
Andy Bettencourt
Super Moderator
I disagree here too. Nobody has gotten to the multiplier because nobody can agree on the starting point. If that dust were to settle, then the debate starts on if the cars can get to the estimated power.
Maybe Audi owners would be happy with 25% if it were applied to 110 but furious if it were applied to 120...why? Because all that matters if the calculated number. The crank-in-IT number. 137.5 vs 150. Or 212.5lbs in ITB.
Right now - at 2500, they are classed at 120 / 25%. I don't see any way to move off of this unless real dyno data or a magic paper appeared with the 110 on it.
We "know" the multiplier for the car is 1.25 because the imposed stock HP is 120. The powers-that-be have declared that this car can make 149HP in ITB trim. Dyno any IT-prep car and any result less than 149 will be deemed "not 100% prepared" by those powers. Anything over 149 will result in the multiplier increased. If someone admits the car makes 120 stock and gets a dyno pull of 144 (implying a 1.20 multiplier), the result will be deemed not applicable as the car is not 100% built.