101 replies to this topic

[Jim Drago]

Pat
That is not accurate..
Once a 99/00 is tuned with Fp regulator and timing wheel and a 1.6 is tuned the best of it's ability.. An illegal ECU should gain both about the same, VERY LITTLE.

[Bench Racer]

Parity 2011 Runoffs is the title of this post, correct.

I would be quite sure most of you have read posts on this site of the "power number" as being one of the factors used to show parity of the different Spec Lines. I question where this power number came from & what engineering value of this number can be certified. As individual words we understand the engineering definition of horsepower, torque, car weight.


horsepower + torque/2 = average number

weight of car/average number = power number

Or for a 1.6 the numbers are, if you believe the SCCA numbers.

123 hp + 105 torque/2 = 114 average number

weight of car 2275/average number 114 = power number 19.96

The 1999 power number is 20.00. WOW, that's four one hundredths of a pound difference, that must be parity.

That should be enough for now to get some conversation started.

[dmathias]

What attracted me to the class were regional events of 30 cars and national events with 60...everyone should be asking why that is changing...

Quote of the week!

[Blake Thompson]

Parity 2011 Runoffs is the title of this post, correct.

I would be quite sure most of you have read posts on this site of the "power number" as being one of the factors used to show parity of the different Spec Lines. I question where this power number came from & what engineering value of this number can be certified. As individual words we understand the engineering definition of horsepower, torque, car weight.


horsepower + torque/2 = average number

weight of car/average number = power number

Or for a 1.6 the numbers are, if you believe the SCCA numbers.

123 hp + 105 torque/2 = 114 average number

weight of car 2275/average number 114 = power number 19.96

The 1999 power number is 20.00. WOW, that's four one hundredths of a pound difference, that must be parity.

That should be enough for now to get some conversation started.

Why do I feel like I'm watching a electorial debate. #fuzzylogic

Though I like your numbers

[Andy Finke]

My view from the sidelines...

I'm just a guy that is HEAVY into karting, and loves the SM class. I'm kicking around jumping in, and would likely do it 12-24 months from now.

I fully understand that there will never be full parity at the front, and that's where I'd intend to aim for. I also understand the level of driver and car development it takes to run up front. I've done it for myself and several others in karts, and know I'm not ready for any car faster than a Miata to learn it all in at SCCA.

The #1 biggest thing to help attract me and others like me is rule stability. No changes for 3 years would be AWESOME! Then I could buy a 'favorite' car to attempt to run up front, or save some cash and buy a '2nd tier' car. Either way it's up to me, and I know what I'm in for when I sign up.

I know that you have to write the rules to satisfy the group that shows up, but don't forget the group of us looking in. Karting has been down for the last couple years, and is coming back. Especially in the less expensive classes with bigger groups and a couple measures of parity!

You guys are in great shape to attract the next wave of fanatics. It seems you are doing a great job so far, even with the personal chaos that comes with any competitive class. Thanks.


Andy

[Tom Hampton]

Parity 2011 Runoffs is the title of this post, correct.

I would be quite sure most of you have read posts on this site of the "power number" as being one of the factors used to show parity of the different Spec Lines. I question where this power number came from & what engineering value of this number can be certified. As individual words we understand the engineering definition of horsepower, torque, car weight.


horsepower + torque/2 = average number

From a purely physical point of view, it is meaningless. As an engineer, I wouldn't use mixed up units like that for any serious work.

On the other hand, as a quick&dirty approximation to what really matters, it might work pretty well. I don't know about trying to compare to 3 digits of precision though. That's probably asking a bit much. Once I get down to worrying about 1% or less...that's when I get serious. At that point, I make sure that everything is measured carefully, all the formulas are correct, I've taken into accound numerical and statistical issues, conduct an error analysis, etc.

But, we all know that its the area under the HP curve that matters. Ok, even that is arguable...because you can argue about which end of the curve matters more..which is track dependant.

At the bottom end of the power-band, the TQ number is very close to HP at that RPM (TQ * RPM/5252) = TQ * 5000/5252 = TQ * 0.95....give or take. The 5000 is obviously just an approximation of the max TQ RPM...but, the point is there is only a few percentage points difference between TQ and HP in that part of the band.

Given that, the formula is using a straight-line approximation for computing the average HP in the power-band....not unreasonable for a well-tuned engine....that's kinda the whole point---a FLAT TQ curve across the power band -> linear HP vs RPM curve. So, given these assumptions: the formula is approximating area under the horsepower-to-weight curve. That should be a very good predictor of STRAIGHT-LINE performance (drag race down the straight).

As I started with, if you are trying to compare to the sub-1% level...then this approximation isn't really good enough for engineering. The exact RPM of the TQ number makes a few percentage point difference. The exact shape of the HP-RPM curve matters, too. Straight line approximation won't get you to 0.5%. However, its a good first check before moving on to a more precise calculation.

Nevertheless, a rule-of-thumb like this can be quite useful even in an engineering sense...as long you understand the limitations of it.

[Strongbad]

From a purely physical point of view, it is meaningless. As an engineer, I wouldn't use mixed up units like that for any serious work.

On the other hand, as a quick&dirty approximation to what really matters, it might work pretty well. I don't know about trying to compare to 3 digits of precision though. That's probably asking a bit much. Once I get down to worrying about 1% or less...that's when I get serious. At that point, I make sure that everything is measured carefully, all the formulas are correct, I've taken into accound numerical and statistical issues, conduct an error analysis, etc.

But, we all know that its the area under the HP curve that matters. Ok, even that is arguable...because you can argue about which end of the curve matters more..which is track dependant.

At the bottom end of the power-band, the TQ number is very close to HP at that RPM (TQ * RPM/5252) = TQ * 5000/5252 = TQ * 0.95....give or take. The 5000 is obviously just an approximation of the max TQ RPM...but, the point is there is only a few percentage points difference between TQ and HP in that part of the band.

Given that, the formula is using a straight-line approximation for computing the average HP in the power-band....not unreasonable for a well-tuned engine....that's kinda the whole point---a FLAT TQ curve across the power band -> linear HP vs RPM curve. So, given these assumptions: the formula is approximating area under the horsepower-to-weight curve. That should be a very good predictor of STRAIGHT-LINE performance (drag race down the straight).

As I started with, if you are trying to compare to the sub-1% level...then this approximation isn't really good enough for engineering. The exact RPM of the TQ number makes a few percentage point difference. The exact shape of the HP-RPM curve matters, too. Straight line approximation won't get you to 0.5%. However, its a good first check before moving on to a more precise calculation.

Nevertheless, a rule-of-thumb like this can be quite useful even in an engineering sense...as long you understand the limitations of it.

Does this mean my 1.6 is fast enough now?

[Blake Thompson]

Does this mean my 1.6 is fast enough now?

There is no such thing as fast enough.

I am reminded of an awful country song.

[James York]

James, I have asked, JD for that matter, and he advised me that it can't be done on a 1.6 atleast not any significant gains. It is a OBD0/1 and it can't be flashed. Are you telling me your 99 can't be flashed? Right now we have no ECU rule, period. They can't be teched, they pretty much admitted that in the Town Hall Meeting. So if a 99 can be tampered with and the 1.6 can't than who has the car that can gain the most thru the ECU?

If you can't tech it than lets open it to all cars to use whatever.

I agree, the early cars can't be flashed (that I know of); however, the ECUs can be modified.

I am not telling you that a 99 can't be flashed. I am saying it is not legal to do so. Just like it would also be so to modify a 1.6 ECU.

There is an ECU rule, like many other rules we have. I can't speak to whether they can be reasonably teched or not. Last year the SCCA ran my car on the dyno at the Runoffs to check for an illegal ECU. Probably not as easy to pop the cover and look at the 1.6 ECU board.

So you want to allow MOTECs, etc, and spend $$ more trying to get an optimized program for each track, weather, etc. because someone out there maybe getting a wee more hp more from an ECU cheat compared to the FP and timing allowances? Wouldn't that just add more ground between the have and have nots?

Personally I am ok with getting 95% or so of the gain legally. Nobody is beating me with 1/2 hp from an illegal ECU. (Lots of other reasons, but not 1/2 hp)

[Alex Bolanos]

Pat
That is not accurate..
Once a 99/00 is tuned with Fp regulator and timing wheel and a 1.6 is tuned the best of it's ability.. An illegal ECU should gain both about the same, VERY LITTLE.

Just want to quote this for emphasis...

Fuel, Air, Timing. It's pretty simple stuff guys, all 3 are legal to modify now in the rules. If you want to modify it with a $1000 cheated up computer instead of a $100 regulator and a timing plate that's your prerogative but there isn't any real difference.

[FTodaro]

Just want to quote this for emphasis...

Fuel, Air, Timing. It's pretty simple stuff guys, all 3 are legal to modify now in the rules. If you want to modify it with a $1000 cheated up computer instead of a $100 regulator and a timing plate that's your prerogative but there isn't any real difference.

There is a difference just not a big difference and not a big enough one to cheat over. I have the Manual system the pressure regulator and the timing wheel. when I dyno'ed the car I could lean it out to 13.5 until the car gets to about 6,000 RPM and then it starts to go rich. so there is a little of a compromise at the end of the RPM curve. if you lean it out enough to catch that last 1000 rpm you are running to lean and hot in the lower RPMs.. At least that is what my results showed.

So the Reflash maybe would flatten that out but As it has been said, its not legal and not worth it to me anyway.

[Bench Racer]

Why do I feel like I'm watching a electorial debate. #fuzzylogic
Though I like your numbers

Blake, first things first. Your fiance Steph is a strikening pretty young lady.

Now on to the "#fuzzylogic". That would be SCCA board member #fuzzylogic and as one poster within this thread stated in terms of engineering it is "meaningless". That was my point in posting the information. But, we have way to many amongst the good buddies for anyone to pay attemtion. No one said a word about the #fuzzylogic when it was originally posted untill I re-posted it's meaningless numbers. I can hardley wait for the pi$$ing & moaning after the new Spec Miata rules are proposed/implemented.

1.6 Miata options:

1.6 Spec Miata = new rule pounds

ITA = 2255 pounds

F production = 2127 pounds

[Andrew Charbonneau]

gotcha

[Andrew Charbonneau]

YOU asses stop the parity shit lets get it on with the beat good looking guy award http://www.funnyordi...friend-is-fabio

[Blake Thompson]

Blake, first things first. Your fiance Steph is a strikening pretty young lady.

Now on to the "#fuzzylogic". That would be SCCA board member #fuzzylogic and as one poster within this thread stated in terms of engineering it is "meaningless". That was my point in posting the information. But, we have way to many amongst the good buddies for anyone to pay attemtion. No one said a word about the #fuzzylogic when it was originally posted untill I re-posted it's meaningless numbers. I can hardley wait for the pi$$ing & moaning after the new Spec Miata rules are proposed/implemented.

1.6 Miata options:

1.6 Spec Miata = new rule pounds

ITA = 2255 pounds

F production = 2127 pounds

so you're saying I don't need to lose 35lbs this winter? That won't make stephie happy.

[Bench Racer]

so you're saying I don't need to lose 35lbs this winter? That won't make stephie happy.

You know what they say, it's way easier to keep a customer than it is to find a new customer. Same, same with a lady. If it were me I would loose the 35#, move it to the right & improve my side balance. Please note I didn't same cross weight.

[William Keeling]

Ok, and the 1.6L computer can't be flashed to rev to 8000rpm? Would it not breathe better than the 99 up there because there is no restrictor plate?

not flashed the crystal is changed the raises the rev limit and leans the mix but does not flaten the curve like you can with the flash on later ECUs. flashing the later ECU allows you to flaten the mix as the restrictor plate limits air up top. The 1.6 does have a restrictor plate it is called AFM; without removing the AFM more revs don't help the 1.6

[High Chair]

not flashed the crystal is changed the raises the rev limit and leans the mix but does not flaten the curve like you can with the flash on later ECUs. flashing the later ECU allows you to flaten the mix as the restrictor plate limits air up top. The 1.6 does have a restrictor plate it is called AFM; without removing the AFM more revs don't help the 1.6

There are now and have been for at least 4 years that I know of 1.6 ECUs that hold a perfectly flat AF curve and have a higher rev limit. There are also MAF for 1.6s that will also hold a flat A/F curve but they are easier to detect has they make the car sound way different on the grid. Secondly a higher rev limit does help a 1.6 a great deal; it is simple math to figure out how much. The ECU's on the later cars do not hold a flat curve like many people think but instead only step up the fuel/air ratio just as if you leaned it out with fuel pressure. We can now get the exact same power with mechanical adjustments making the ECUs no better or worse than other adjustments.

[Danny Steyn]

A cheated ECU with a raised rev limiter is very easy to detect on the track. For every track there are well established shift points, and I think we all possess video of some of our competirors shifting way beyond these established shift points.

There are tracks where a couple of hundred extra RPM's will move a shift point to a more desirable spot - crest of a hill, beyond the apex of a turn etc.

Some time back we asked one of our competitors to swich back his ECU as we were all aware of what was going on and he complied immediately. I think we can do a lot of the policing of this in our own class without teching and protesting.

However if we are not going to self-police, tech or protest ECU's, expect to see the established shift points at your local tracks start to creep. Just sayin!

[pat slattery]

There are now and have been for at least 4 years that I know of 1.6 ECUs that hold a perfectly flat AF curve and have a higher rev limit. There are also MAF for 1.6s that will also hold a flat A/F curve but they are easier to detect has they make the car sound way different on the grid. Secondly a higher rev limit does help a 1.6 a great deal; it is simple math to figure out how much. The ECU's on the later cars do not hold a flat curve like many people think but instead only step up the fuel/air ratio just as if you leaned it out with fuel pressure. We can now get the exact same power with mechanical adjustments making the ECUs no better or worse than other adjustments.

So do you agree with these 1.6 ECU's that are being used Jamie?