Dyno numbers to the Spec E30 Regional Directors

[TheRedBaron]

allenr wrote:

Where to get the exact amount of ballast and how to safely secure it

Spare tire FTW.

[jhall1957]

allenr wrote:

[quote]But heck since you bring it up, how would you feel if you invested a few K in a motor as a lot of guys have only to find that you just bought yourself a couple chunks of ballast to go with it?

Spec Miata, here we come! Who can win this arms race???

[Patton]

Thanks to Ed Davidson for the introduction of a wiggle-room variance.

SHOULD an over HP/Torque weight adder be introduced, one would have to assume that the weight added would be more than just a field equalizer, hence to discourage the full-tilt-boogie engine.

Good luck to those responsible for the rules.

Regards, Robert Patton

[Steve_D]

allenr wrote:

Although this could ruin someone’s weekend who happens to be reading one hp over the limit every time

If we are provided a simple cheap way of adjusting power (i.e. restrictor plate), this is no longer a concern. If you can show up at the track, do a cheap pull on the dyno and - if necessary - put in a restrictor plate to meet the rules-mandated maximums.

Dead horse, I know, but there is variation between dynos of the same manufacturer. So what you have is a weekend-by-weekend adjustment to be sure you are legal (if you want to push close to the limits).

If we have that trust-but-verify kind of tech available and someone is one HP over, tough luck. Bounce them.

Remember, under NASA rules, there is a built-in 1/2-of-the-next-digit wiggle room anyway. That’s 1/2 hp wiggle.

Steve D.

PS - Of course, if my restrictor plate suggestion is approved then we will have to modify the 2010 rules to state that it must be a 0.04" gauge flat metal plate to outlaw the illegal venturi “restrictor” plate custom designed to help in 5th gear at 110 mph, but designed to not add anything on a dyno sucking still air.:woohoo: :blink:

[Patton]

Restrictor plate=25 pound slug of weight…and that is only the start.

Good luck to those that make the rules.

Regards, Robert Patton

[FARTBREF]

JA, Skeen, and Carter all dyno within 1hp??? That would make me question the dyno or operator.

Al

[IndyJim]

No one has mentioned a claimer rule yet, just want to make sure we have all the crazy bases covered.

[Steve_D]

IndyJim wrote:

No one has mentioned a claimer rule yet, just want to make sure we have all the crazy bases covered.

:laugh: :laugh: :laugh:

That’s funny right there. I gotta meet this DTOM guy.

Steve D.

PS - Robert - Clearly restrictors & ballast are equal only in that they tend to slow the car. But they obviously do it in different ways. The ideal goal is to equalize the engines so why not use a mechanism that equalizes the cars right at the point we are trying to equalize them? After all, if we wanted to equalize our haircuts we wouldn’t start shaving our legs…

[Age]

Why would anyone want to mess with ballast or a restrictor plate at the track? Just assess a time penalty, make sure it is enough to bump the guilty off the podium, write it up in the log book and make the second offense a DQ for that weekend.

Perhaps there could be a log of dyno runs posted up on the web site. If one region is doing dynos on the top 4 that weekend, post them up for all to see.

[Steve_D]

Age wrote:

…make sure it is enough to bump the guilty off the podium…

Why would they want to mess with RP or ballast? Because nobody will know for certain they are legal until they check the dyno at the track.

With a good rule set, no one should be surprised of the results in post-race tech. Everything is verifiable beforehand.

If you want to turn post-race tech into a crapshoot, you will turn people off.

How do you write something up in the logbook? What is the true verification value of a run on another dyno that shows ‘legal’ power? What specifically needs to be fixed on the car?

Restrictor plates couldn’t be easier. Much easier than bolting in more ballast, for sure.

Steve D.

[allenr]

PS - Robert - Clearly restrictors & ballast are equal only in that they tend to slow the car. But they obviously do it in different ways. The ideal goal is to equalize the engines so why not use a mechanism that equalizes the cars right at the point we are trying to equalize them? After all, if we wanted to equalize our haircuts we wouldn’t start shaving our legs…

x2

Why would anyone want to mess with ballast or a restrictor plate at the track? Just assess a time penalty, make sure it is enough to bump the guilty off the podium, write it up in the log book and make the second offense a DQ for that weekend.

If they dont mess with a restrictor plate or something similar, how could anyone possibly avoid a second offense? Hope for warm weather? There has to be a quick and easy way to adjust power during the weekend.

[OriginalSterm]

Is this SAE corrected power? If so, temperature/altitude/humidity are all factored out.

Really, a CI on a large enough set of data would really only potentially screw a handfull of people across the series in a season. And they might be outliers who aren’t front runners or regulars anyways.

[Steve_D]

OriginalSterm wrote:

[quote]Is this SAE corrected power? If so, temperature/altitude/humidity are all factored out.

Really, a CI on a large enough set of data would really only potentially screw a handfull of people across the series in a season. And they might be outliers who aren’t front runners or regulars anyways.[/quote]

Yes, the dynos all adjust for temp/alt/hum. But that adjustment is imperfect at best.

THAT STILL DOES NOT SOLVE THE PROBLEM that there is variation between readings from different brand dynos.

A dyno is NOT and ABSOLUTE measuring device - it is a RELATIVE measuring device. You gauge changes in power by making different runs on the same machine.

Data collected from a bunch of different cars on different dynos will not yield a close enough grouping to solve the issue of power disparities. A good, tight set of specs for engine components and rebuild methods will solve it.

For tech to be respectable, you MUST have measuring tools and methods that are repeatable - any day, any car, any conditions. IMO dyno readings do not fall into that category.

Steve D.

PS - I am no statistician, but doesn’t a 95% CI mean that 5% of the legal cars would land outside the Interval? Or 2.5% on the high end of the CI range, so one out of 40 legal cars would get bounced?

[OriginalSterm]

Steve D wrote:Yes, the dynos all adjust for temp/alt/hum. But that adjustment is imperfect at best.

THAT STILL DOES NOT SOLVE THE PROBLEM that there is variation between readings from different brand dynos.

A dyno is NOT and ABSOLUTE measuring device - it is a RELATIVE measuring device. You gauge changes in power by making different runs on the same machine.
[/quote]

All of this is true, a dyno brand or style must be chosen for the region/national standard and calibration documentation must be up to date. This will eliminate SOME of the variation.

And I agree, it’s still not perfect.

[OriginalSterm]

Steve D wrote:

PS - I am no statistician, but doesn’t a 95% CI mean that 5% of the legal cars would land outside the Interval? Or 2.5% on the high end of the CI range, so one out of 40 legal cars would get bounced?

I am also not a statistician, but I believe that means that 5% of the cars tested will be outside a certain range. Not that they are legal or not. You get a mean, determine the CI, then that tells you what range you might expect the cars to fall in. From there, you could pick acceptable numbers.

[grydemon]

I am in a Stats class right now and making a Confidence Interval (CI), based on t-distributions would be the best method. Using t-distribution is better since our group will be relatively small.

[MikeD]

This is a great discussion but it’s getting a little silly.

This is simple!

If your car dyno’s above %95 of the other cars you get a weight penalty. The weight penalty should be a deterrent and not an opportunity for new strategies.

If you come out and dyno 170hp and the nearest competitor’s HP is 154hp then just take your sorry ass home because you built a cheater motor.

.com brought up a great point as well with looking at the hp as well as torque at pre-determined rpm.

[allenr]

If your car dyno’s above %95 of the other cars you get a weight penalty.

I might not be understanding this right but doesnt this mean that the guy with the most hp, no matter how much hp or how little hp, is garunteed to get a penalty? If so thats not a good way of doing it. Once the rules are established, the competitors should be able to push them as far as they want regardless of what other drivers choose to do… or not to do.

If you come out and dyno 170hp and the nearest competitor’s HP is 154hp then just take your sorry ass home because you built a cheater motor.

I’ve been told by some engine builders who are familiar with the se30 rules that they could build a legal motor with 170+hp, so dont be too quick to accuse someone of cheating.

This is a good discussion as you say but I have a feeling that all of this has already been decided .

[MikeD]

allenr wrote:

[quote]

I’ve been told by some engine builders who are familiar with the se30 rules that they could build a legal motor with 170+hp, so dont be too quick to accuse someone of cheating.
( .[/quote]

There’s no way. It’s not possible.

[Steve_D]

MikeD wrote:

[quote]If your car dyno’s above %95 of the other cars you get a weight penalty. The weight penalty should be a deterrent and not an opportunity for new strategies.

If you come out and dyno 170hp and the nearest competitor’s HP is 154hp then just take your sorry ass home because you built a cheater motor.
[/quote]

Just to play devil’s advocate…

95% of the cars at that race? Nationally? In Carter’s database so far?

If you pull a 159 and your competitors pull 158, 157, 157, 156, 156, 156, 155, 155 and 154, you should be DQ’d? You’re above 100% of them.

I am absolutely in favor of a hard-and-fast series of HP/TQ numbers at various RPM. Without a tight limit you don’t have the equalizing rule everyone is cheering for.

But without an effective way to detune the engine at the track, that limit could be an onerous penalty.

I’m not concerned about the 170 vs 154. I’m concerned about 161 when the limit is mandated as 155+/-5.

Steve D. <<happily representing the 151hp posse in Carter’s data set.