April Mid-Ohio Dyno runs

[bedmonds]

[quote=“epalacio19” post=76729]I’ll continue to run under 155 and not worry about weight.
It’s saving me $$ from needing to refresh the head to chase that 162.8.[/quote]

A common plan but what happens when the dyno at the track reads 160 on race day for some reason?

[epalacio19]

I add the extra weight I bring with me to the track every weekend.

At Road Atlanta I dynoed on Friday. Probably won’t dyno again until Nationals.

[bedmonds]

I don’t fully understand this. How is weighing after a race not equal? I guess someone could gamble on Yellow flags but that is a gamble. We add fuel by weight. As an example we know at Mid-Ohio we burn 0.9 lbs of fuel per lap. We figure how many laps we expect to run based on the race time and fill up to that. There are the occasions when the scales seem off so if we get a strange number during our weighing before a race we go across again. All this checking is free unlike the Dyno.

Look at it this way. Currently, i run an extra 15-25 lbs just to ensure that i am over 2700 at the end of the race. Yes i could cut it close but i would be gambling and it’s not worth it.

Now imagine the rule is this (and remember this is all off the cuff numbers):
Minimum weight 2750 FULL. If the car weighs less than 2700 (read again: 27zerozero)follwing a race, you have the opportunity to fill it up at impound and reweigh. Less than 2750 after reweigh, fail & DQ. That’s 50lbs of gas (approx 7.5-8 gallons).

For guys like me who don’t weigh fuel and do “math” (whatever that is), that is an easy way to stay legal. Fill it up, put it on the scales, get it to minimum weight and you’re done. No matter how long the race is you will always make weight because if you have to fill up at impound you will hit 2750.

For the math guys, you can still play the numbers but it takes out some of the range at which you can, ahem, work the weights. For example, if you gamble and figure out that you can weigh 2725 full and burn 24 lbs of fuel and avoid having to reweigh, then good for you. But if you actually burn 26 lbs of fuel, you will have to fill up at impound, reweigh, and you will only get to 2724 and get DQ’d.

As a comparison, NASCARs must weigh 3400 ready to race (meaning full). They don’t even have a tolerance like i am proposing, just a flat out minimum. They fill everybody up that they tech and weigh them. Under 3400, fail. I’m not saying we go to the trouble of requiring a fill up to weigh, only if it falls out of the bottom range (which would imply possible “math” and be against the spirit of all being the same weight when we start).

Clear as mud now?

[Patton]

[quote=“ilateapex” post=76720]I don’t fully understand this. How is weighing after a race not equal? I guess someone could gamble on Yellow flags but that is a gamble. We add fuel by weight. As an example we know at Mid-Ohio we burn 0.9 lbs of fuel per lap. We figure how many laps we expect to run based on the race time and fill up to that. There are the occasions when the scales seem off so if we get a strange number during our weighing before a race we go across again. All this checking is free unlike the Dyno.

Look at it this way. Currently, i run an extra 15-25 lbs just to ensure that i am over 2700 at the end of the race. Yes i could cut it close but i would be gambling and it’s not worth it.

Now imagine the rule is this (and remember this is all off the cuff numbers):
Minimum weight 2750 FULL. If the car weighs less than 2700 (read again: 27zerozero)follwing a race, you have the opportunity to fill it up at impound and reweigh. Less than 2750, fail & DQ. That’s 50lbs of gas (approx 7.5-8 gallons).

For guys like me who don’t weigh fuel and do “math” (whatever that is), that is an easy way to stay legal. Fill it up, put it on the scales, get it to minimum weight and you’re done. No matter how long the race is you will always make weight because if you have to fill up at impound you will hit 2750.

For the math guys, you can still play the numbers but it takes out some of the range at which you can, ahem, work the weights. For example, if you gamble and figure out that you can weigh 2725 full and burn 24 lbs of fuel and avoid having to reweigh, then good for you. But if you actually burn 26 lbs of fuel, you will have to fill up at impound, reweigh, and you will only get to 2724 and get DQ’d.

As a comparison, NASCARs must weigh 3400 ready to race (meaning full). They don’t even have a tolerance like i am proposing, just a flat out minimum. They fill everybody up that they tech and weigh them. Under 3400, fail. I’m not saying we go to the trouble of requiring a fill up to weigh, only if it falls out of the bottom range (which would imply possible “math” and be against the spirit of all being the same weight when we start).

Clear as mud now? :P[/quote]

NO it is not clear.

This is clear: Fill car to brim, the weight is at rear where you want it. Weigh car. Write it down on your mirror. Double check the weight at other tracks/scales. But always weigh it full of fuel.

You will use 1 pound of fuel per minute of race(not quite 1 pound but this will keep it safe when you go to the scales).

Make weight allowances for weather/cool suit.(Or, extra pizza/beer the night or weeks before.)

Fill up for next race.

Repeat for the next 10 years or so.

RP

[harper]

for the engine ignorant…how the hell are people “tuning” their cars down based on dyno runs…besides adding the power steering back, what are they doing to take away power?

signed…confused in Richmond

[barkerdm]

for the engine ignorant…how the hell are people “tuning” their cars down based on dyno runs…besides adding the power steering back, what are they doing to take away power?

Good question. Rules don’t explicitly state what’s a legal way to de-tune the engine. Power steering & thick oil only go so far, so does that make all de-tuned engines illegal?

[RGrace]

[quote=“barkerdm” post=76705]Any thoughts on just a horsepower cap?

+1 for only a hp cap[/quote]

^I’m with stupid…I mean Rob. The power to weight idea is good in theory but the brackets are far too small and it is going to make things extremely complicated. People are going to lose/win races based on DQs for 1 hp this way or that way.

I support ditching the power/weight rule but retaining a hp cap.

[Buzzbomb]

The 944spec class uses the total of HP and TQ and divides by two to create your final number. They then allow +- 2HP for dyno variation with a minimum weight of 2600lbs.

I saw variations of 6 hp at the last Nationals in Utah. Spent lots of time and money chasing the rabbit. This is on the same dyno over 4 days.

[Foglght]

I (car 21) dyno’d 10 days earlier at a local dynojet with my best pull being 142hp 142tq. There where no changes to the car from then to Mid-Ohio and I gained 8hp and 4tq.

What’s interesting is you could consistently out drag me last year, even on starts. Very interesting to see the hp/tq of my old car above anything I ever saw on a dyno.