June Fastrack Out
- Thread starter JeffYoung
- Start date
Andy Bettencourt
Super Moderator
EoB.
seckerich
New member
Same thing I thought when they came around to the line. Front tires they give us are good for at best 25 laps. Those had a lot more and they just gave up under the brakes. I was impressed I even had a car to load after I saw how close Sylvain came to the wall!! I will take a podium after the rotton luck of the past 2 races. 69 car was also very fast but broke a lower ball joint with no warning. On to Limerock.Steve, they can always adjust the weight.
What happened at Luguna!!!!!!!?????????? You had the car and the lead......WTF Happened?????????
I promised to behave on here about the RX8 so I will wait to see the numbers used. As I said in the past. EVERY rotary in IT was classed using known numbers at full prep--not the process because it fails on a rotary engine. The ITS rx7 was used as the "target" in ITS with its known numbers, not any percentage gain from stock. Same with the 12A, RX8 is a maxed version of a 13B from the factory and got classed with BS stock numbers, torque of a yugo, and a 15% adder. Only an idiot spends that kind of money to hope it gets fixed. Get used to seeing just BMW's Dan. I need to post the dyno plots form a E36 and an RX8 here and see how anyone can justify the weight difference.
Stepping away from the keyboard now.
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JoshS
New member
As an ITAC-member, I believe in using the stock horsepower. Especially as its already been through a major correction by the manufacturer, I find it believable -- Mazda would be in a world of hurt if it wasn't the actual output of that engine on an engine dyno, given what happened when the car was released.
But a chassis dyno is a different beast.
As a member (not as an ITAC member), I'm curious ... I would like to see a different dyno test than any that I've ever seen.
I'd like to see a dyno test that shows both raw (not SAE-corrected) *and* corrected numbers for a truly bone-stock RX8 and a bone-stock pick-your-piston-engine car on the same dyno on the same day. I have been led to believe by someone who knows these cars well that the correction factors tend to skew the results on a Renesis.
I also believe there is an abnormal amount of driveline loss on this car, but I have no idea why. Maybe Steve can explain it.
But in any case, the car got a 15% multiplier (the lowest used anywhere) and a break for being abnormally torqueless -- just like the S2000.
Now back with my ITAC hat on: as I mentioned in the other thread, although it doesn't specifically play into the result, we got just as many letters demanding weights above this number as we got demanding weights below this number. That we got letters demanding specific weights is odd, normally we just get requests to class ... shows a certain amount of passion for the results. Anyway, in the end, we tried to apply the process the best way we could. I'm sorry not everyone can be happy.
But a chassis dyno is a different beast.
As a member (not as an ITAC member), I'm curious ... I would like to see a different dyno test than any that I've ever seen.
I'd like to see a dyno test that shows both raw (not SAE-corrected) *and* corrected numbers for a truly bone-stock RX8 and a bone-stock pick-your-piston-engine car on the same dyno on the same day. I have been led to believe by someone who knows these cars well that the correction factors tend to skew the results on a Renesis.
I also believe there is an abnormal amount of driveline loss on this car, but I have no idea why. Maybe Steve can explain it.
But in any case, the car got a 15% multiplier (the lowest used anywhere) and a break for being abnormally torqueless -- just like the S2000.
Now back with my ITAC hat on: as I mentioned in the other thread, although it doesn't specifically play into the result, we got just as many letters demanding weights above this number as we got demanding weights below this number. That we got letters demanding specific weights is odd, normally we just get requests to class ... shows a certain amount of passion for the results. Anyway, in the end, we tried to apply the process the best way we could. I'm sorry not everyone can be happy.
JeffYoung
New member
Uh...Mazda was/is in a world of hurt over RX8 power figures. Still.
AGreed on your correction factor, I've heard that too although it doesn't seem to be a problem for the 12A or 13B.
I heard about the numbers at the higher weight. Like 3300. I hope those were immediately discounted as completely ridiculous and not considered in what was a fair weight for the car.
In my view, with very limited technical knowledge, I would say 2980 is on the very extreme upward end of what is fair. It's probably high enough to scare off the top end builders, but probably not so high that someone won't try to privateer one to see how it does.
Maybe that is what you guys wanted, and maybe that is the correct result.
AGreed on your correction factor, I've heard that too although it doesn't seem to be a problem for the 12A or 13B.
I heard about the numbers at the higher weight. Like 3300. I hope those were immediately discounted as completely ridiculous and not considered in what was a fair weight for the car.
In my view, with very limited technical knowledge, I would say 2980 is on the very extreme upward end of what is fair. It's probably high enough to scare off the top end builders, but probably not so high that someone won't try to privateer one to see how it does.
Maybe that is what you guys wanted, and maybe that is the correct result.
WTF? Steve asks a direct question to see the numbers for how the car was weighted along with the sources used for data and this is the response? Are we playing Guess that Process? Sure seems like it. I hope a real answer is forthcoming.
David
lateapex911
Super Moderator
Well, I was hoping to see someone try, and I thought that might help illustrate the actual end result...
But Josh has let you in on the math above, so yes, you got the answer.
seckerich
New member
Lets see how close I can get to the mystical process.
Highest number for HP quoted by BMW guy=238 crank x 1.15 (stated it was like S2000) X 11.25 (ITR target power to weight) = 3079 (rounded up to 3080) and - 100# for gutless torque. Am I close?? That makes this a 274 HP crank motor (238 x 1.15 = 273.7) and somehow looses 60 or more HP to the rear wheels. It is not driveline loss guys.
High end rear wheel HP for this car full prep is 205 but lets just assume 215 for discussion.
Torque is at 141 rear wheel but lets use 160 again for discussion,
Now please justify this car at 2980 compared to a E36 BMW at 215 pounds lighter with 215 HP min rear wheel and 200 torque? I would like to see you back up the process. BMW BS'd low and Mazda got caught using high numbers and had to offer to buy back cars. You know the true story for both and still treated this car different. Sad.
Again, Please prove me wrong. Nothing personal guys, just the numbers and what you used and who to back them up. I was very open with the information provided to ask the car be classed. Please show me the same courtesy.
Highest number for HP quoted by BMW guy=238 crank x 1.15 (stated it was like S2000) X 11.25 (ITR target power to weight) = 3079 (rounded up to 3080) and - 100# for gutless torque. Am I close?? That makes this a 274 HP crank motor (238 x 1.15 = 273.7) and somehow looses 60 or more HP to the rear wheels. It is not driveline loss guys.
High end rear wheel HP for this car full prep is 205 but lets just assume 215 for discussion.
Torque is at 141 rear wheel but lets use 160 again for discussion,
Now please justify this car at 2980 compared to a E36 BMW at 215 pounds lighter with 215 HP min rear wheel and 200 torque? I would like to see you back up the process. BMW BS'd low and Mazda got caught using high numbers and had to offer to buy back cars. You know the true story for both and still treated this car different. Sad.
Again, Please prove me wrong. Nothing personal guys, just the numbers and what you used and who to back them up. I was very open with the information provided to ask the car be classed. Please show me the same courtesy.
JoshS
New member
I already gave you the numbers. The number is 238. Go ahead and ask Mazda what the real stock engine dyno horsepower is for this car. They'll tell you it's 238. It's 238. It all we can use.
15% is the lowest the process has ever gone for a gain multiplier. That's a gift.
And as for the torque, there is also a precedent for similarly-gutless cars, and that's what we used. It's simple, it's consistent. End of story!
Really, Steve, we can't just say, "We don't believe the manufacturer." That's a HUGE slippery slope. It's Mazda you have to blame, not us. If they've seriously overinflated their power numbers, then it is Mazda that screwed up this classification. It's just not right to blame us.
I'd still like to see what happens when you don't SAE-correct the dyno numbers. But it's only an interesting test if you do the same with another car at the same time on the same day in the same weather conditions.
JeffYoung
New member
Run the ITS RX7 using stock factory horsepower numbers.
Run my car using stock factory horsepower numbers.
Run the CRX using stock factory horsepower numbers.
In each of those cases, real world data showed us that we had to fix something that the process couldn't account for.
Let's ask the real question about the RX8 horsepower number.
1. Did you take the Mazda number as is because that is "class philosophy?"
or
2. Did you take the Mazda number as is because you did some research on the information that was given to you?
Run my car using stock factory horsepower numbers.
Run the CRX using stock factory horsepower numbers.
In each of those cases, real world data showed us that we had to fix something that the process couldn't account for.
Let's ask the real question about the RX8 horsepower number.
1. Did you take the Mazda number as is because that is "class philosophy?"
or
2. Did you take the Mazda number as is because you did some research on the information that was given to you?
seckerich
New member
Actually Josh it is the multiplier you used at the least. To state that 15% is a gift is a joke. It is much less and you know it. Find any tuner anywhere that claims more than 10%. With 25% less torque than anything else in the class 100# does not cut it.
You guys had no problem with my ITS 160 stock HP getting a huge correction factor. Whats the big problem when it goes the other way? Process only used when you get the numbers you want to get.
You stand by your process on this one. I will toss this out for discussion.
Look at these low torque cars with a power number like other race bodies do.
(HP + Torque) divided by 2
238 + 159 divided by 2 = 198.5
198.5 x 1.25 (standard gain, no "gift") X 11.25 = 2791 rounded to 2800
Compare that to cars with 210 200 and you might get the picture.
Far cry from 2980#
To answer 2 questions.
Josh I will be glad to show you any non SAE corrected data you want on the motors. This is the first a member of the ITAC has asked for. I offered a car and full access to all data--never got a call. And to be very clear Mazda did not class the car, the ITAC did so take some responsibility. I understand what you did and why. You guys had no problem going way high on the correction for other cars but have this lower ceiling of 15% even when data proves otherwise? You have had over 6 months to do your homework on this car and this is the best answer you have is you used stock published numbers? All the time you spent on the E36 with the restrictors and the SIR BS and none of you would take us up on the offer of a dyno session all at our expense. I have the original proposal to support these facts. Really says volumes.
Jeff The stock published numbers were used because it "preserves the process" even when people know it is wrong. But is thrown out when the numbers are known too high.
You guys had no problem with my ITS 160 stock HP getting a huge correction factor. Whats the big problem when it goes the other way? Process only used when you get the numbers you want to get.
You stand by your process on this one. I will toss this out for discussion.
Look at these low torque cars with a power number like other race bodies do.
(HP + Torque) divided by 2
238 + 159 divided by 2 = 198.5
198.5 x 1.25 (standard gain, no "gift") X 11.25 = 2791 rounded to 2800
Compare that to cars with 210 200 and you might get the picture.
Far cry from 2980#
To answer 2 questions.
Josh I will be glad to show you any non SAE corrected data you want on the motors. This is the first a member of the ITAC has asked for. I offered a car and full access to all data--never got a call. And to be very clear Mazda did not class the car, the ITAC did so take some responsibility. I understand what you did and why. You guys had no problem going way high on the correction for other cars but have this lower ceiling of 15% even when data proves otherwise? You have had over 6 months to do your homework on this car and this is the best answer you have is you used stock published numbers? All the time you spent on the E36 with the restrictors and the SIR BS and none of you would take us up on the offer of a dyno session all at our expense. I have the original proposal to support these facts. Really says volumes.
Jeff The stock published numbers were used because it "preserves the process" even when people know it is wrong. But is thrown out when the numbers are known too high.
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seckerich
New member
Here is the link to Mazda Ad touting 232 HP in 08 after some upgrades. That drops the weight 50# with just that difference.
http://www.mazdausa.com/MusaWeb/displayPage.action?pageParameter=modelsMain&vehicleCode=RX8&bhcp=1
Josh please answer the question about the RX8 to E36 BMW weight. You should be very up to date on their numbers.
http://www.mazdausa.com/MusaWeb/displayPage.action?pageParameter=modelsMain&vehicleCode=RX8&bhcp=1
Josh please answer the question about the RX8 to E36 BMW weight. You should be very up to date on their numbers.
JoshS
New member
I can't share the details because I promised not to, but we didn't just "preserve the process." I personally spoke to some people at Mazda who know this car very well, and was told very clearly that the 238hp is a real number on an engine dyno.
I know you don't believe it. And I'm sorry I can't give more details, but the reason is because the people in question don't want to be questioned on internet message boards. Imagine yourself in their shoes.
238 is the number. I think arguing the 15% multiplier, or the (lack of) torque adjustment, is totally reasonable. We went with those for consistency with the process. The S2000 is very similar in those regards, and although owners grumble about the weight, people ARE building them.
As far as arguing the veracity of the stock 238hp number, I'm not going to engage that discussion any further.
I know you don't believe it. And I'm sorry I can't give more details, but the reason is because the people in question don't want to be questioned on internet message boards. Imagine yourself in their shoes.
238 is the number. I think arguing the 15% multiplier, or the (lack of) torque adjustment, is totally reasonable. We went with those for consistency with the process. The S2000 is very similar in those regards, and although owners grumble about the weight, people ARE building them.
As far as arguing the veracity of the stock 238hp number, I'm not going to engage that discussion any further.
its66
New member
WOW, I didn't see that coming. 2980 lbs.?? Yes, I'm biased, but I don't understand that. ..And the e36 is listed at 2800lbs.???
If we assume the factory HP rating is wrong, must we continue to compound the error, by deriving a weight as a percentage increase over a potentially flawed number? Is it possible that some engines respond very well to IT tuning, and some don't respond much at all? I would think so.
If we assume the factory HP rating is wrong, must we continue to compound the error, by deriving a weight as a percentage increase over a potentially flawed number? Is it possible that some engines respond very well to IT tuning, and some don't respond much at all? I would think so.
isn't the E36 ~65hp shy of the RX8 in stock form?
i'm trusting that they have good information that the 238hp is accurate.
as different as the RX8 is from the S2000, they couldn't be anymore the same from my perspective. both of them make pretty big hp from the factory (for the performance target of the class), both double a-arm, both gutless on the bottom and run well up top, both probably won't gain much from IT modifications, and both are classed at a weight that make me not particularly interested in one.
RSTPerformance
New member
Anyone notice how the Fuel Cell rule is being relaxed? I am guessing this is in an effort to allow easier integration of your IT car into the Production classes???
IMO this is THE BEST thing that SCCA has aproved since ITR...
Next big moment will be to allow the FIA 8856/1986 driver suites!!! Send your letter of support to [email protected] and get this approved!!!
Thumbs up to the CRB and BOD for making some great improvements!!!
Raymond
IMO this is THE BEST thing that SCCA has aproved since ITR...
Next big moment will be to allow the FIA 8856/1986 driver suites!!! Send your letter of support to [email protected] and get this approved!!!
Thumbs up to the CRB and BOD for making some great improvements!!!
Raymond
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Ron Earp
Administrator
With these comments you are certainly giving those that don't agree with the weight plenty of room to be concerned.
Did palms, tea leaves, and chicken entrails come into the discussion too?
I think you'll get less heat saying you picked it with the rotating dart board method.
Ron
seckerich
New member
Look closely Raymond. It is only for cars with the fuel tank inside the axles. Rear mounted still require a cell.
seckerich
New member
Fair enough. Care to tell the rear wheel numbers these experts at Mazda were willing to share with you. You already admitted the RX8 seems to show very big driveline losses. Where do you think all this HP goes? Even given the 238 number as fact in full prep form it will not have anywhere near a 15% rear wheel gain and you know it. 205 -210 is not a 2980 # car. I might have to rethink my earlier statement to Kirk about the HP and classing. It seems more true than ever now. Your failure to answer the BMW question tells me all I need to know.