Contest time! Guess the ET and MPH to win!

-
Bill, what do you attribute the performance loss to, primarily? The added weight, or the induction mods? Or, just the combo of mods.. And were these passes on drag radials? If so, faster or slower than slicks?
 
33IMP said:
Bill, what do you attribute the performance loss to, primarily? The added weight, or the induction mods? Or, just the combo of mods.. And were these passes on drag radials? If so, faster or slower than slicks?
Click to expand...
On slicks. Same setup at previous race. Only changes was the hood and air cleaner. I absolutely believe the biggest factor to be weight however I could tell the car was down on power as well. I didn’t want to risk running without the air cleaner because of how close the carb is to the hood and despite the fact that I tried to clean it out as much as possible, what sentiments could be trapped in the 55 year old hood that could fall out and get ingested.
 
Last edited:
The bigger question is why is the car picking up so much? You started day at 10.68 and ended at 10.50. That's almost 2 tenths. Did the weather/wind change that much, traction issue?
 
How did I miss this? 10.50 @ 127 is my guess
( From a vision)
 
moparstud440 said:
The bigger question is why is the car picking up so much? You started day at 10.68 and ended at 10.50. That's almost 2 tenths. Did the weather/wind change that much, traction issue?
Click to expand...
Weather changed tremendously between the first round of qualifying and the 10.50 pass. You can see the changes in the weather data that is posted along with those timeslips. Also the fact that I started the day with a full tank of fuel and never added any played a part, albeit not a huge amount.
 
-Boosted- said:
Weather changed tremendously between the first round of qualifying and the 10.50 pass. You can see the changes in the weather data that is posted along with those timeslips. Also the fact that I started the day with a full tank of fuel and never added any played a part, albeit not a huge amount.
Click to expand...

Did I miss something on those slips and weather data. Looked to me like the weather only changed 500 foot DA during the course of the day. From around 2200 to 1700. That is typically 2-4 numbers, maybe 5. Moving almost two tenths is a head scratcher. Never seen anything like that before.


Regards gas, even if you went through 5 gallons, that’s only 30 pounds or a hair more and because of where that weight is, that might not even show up on a slip. If I splash in a couple gallons at the track I don’t generally even account for it dialing the car. It’s a non factor to the ET.
I made 6 passes my previous outing one day,
weather stayed roughly the same, car went back and forth one number all day, with less gas each round obviously, and I never topped it up. 1/2 a dozen passes is maybe 4 gallons of fuel for me.
 
B3422w5 said:
Did I miss something on those slips and weather data. Looked to me like the weather only changed 500 foot DA during the course of the day. From around 2200 to 1700. That is typically 2-4 numbers, maybe 5. Moving almost two tenths is a head scratcher. Never seen anything like that before.


Regards gas, even if you went through 5 gallons, that’s only 30 pounds or a hair more and because of where that weight is, that might not even show up on a slip. If I splash in a couple gallons at the track I don’t generally even account for it dialing the car. It’s a non factor to the ET.
I made 6 passes my previous outing one day,
weather stayed roughly the same, car went back and forth one number all day, with less gas each round obviously, and I never topped it up. 1/2 a dozen passes is maybe 4 gallons of fuel for me.
Click to expand...
Temps, DA and water grains dropped quite a bit. With my car, water grains makes a big difference in how it runs.

Other than that, I have no explanation. The car always goes quicker later into the afternoon and night.
 
-Boosted- said:
Temps, DA and water grains dropped quite a bit. With my car, water grains makes a big difference in how it runs.

Other than that, I have no explanation. The car always goes quicker later into the afternoon and night.
Click to expand...
That's how you dial yourself out lol
 
-Boosted- said:
Temps, DA and water grains dropped quite a bit. With my car, water grains makes a big difference in how it runs.

Other than that, I have no explanation. The car always goes quicker later into the afternoon and night.
Click to expand...

DA is only moderately related to temperature.
I have slowed down at night when it’s 70 out, compared to when it was 85 out in the middle of the day, just because of humidity and or dew point coming in.
Actually your DA didn’t drop much. Going from 2200 + DA to 1700 plus is only a very few numbers. That is actually a very stable race day.
I raced between 1500 and 2300 feet my first weekend out. Both days were actually completely different. Warm and clear. Dreary, cloudy and humid.
Car was between 6.56-6.60.
This weekend just finished I just got back from racing in Ohio. The heat was stifling. Car ran 6.66-6.68, but that was at 3600-4000 foot DA all weekend.
So basically probably a tenth and a half quarter mile but my DA went up 2500 feet, not 500 feet. I had a 10.48 1/4 mile hit, about 1.5 tenths off from good , not mineshaft air( under 1000 foot)
Think that is probably pretty typical. I don’t lean the car out for heat, or fatten it up( usually) for cool weather.
 
I never had a “Thumper Carb” but both of my APD carbs needed leaned out right out of the box. This is how I look at it. Lean I will feel or hear. Rich I will pick up like crazy when it cools down and I can finally use all that extra fuel.
 
I like the new look but, of course it's going to hurt performance. It's probably frustrating to slow down but again I like to factor-in 'points for style'...Not sure it was considered a factor but if you're on the edge for timing then drawing underhood heat is going to hurt that's not quantified in the weather data.
 
B3422w5 said:
DA is only moderately related to temperature.
I have slowed down at night when it’s 70 out, compared to when it was 85 out in the middle of the day, just because of humidity and or dew point coming in.
Actually your DA didn’t drop much. Going from 2200 + DA to 1700 plus is only a very few numbers. That is actually a very stable race day.
I raced between 1500 and 2300 feet my first weekend out. Both days were actually completely different. Warm and clear. Dreary, cloudy and humid.
Car was between 6.56-6.60.
This weekend just finished I just got back from racing in Ohio. The heat was stifling. Car ran 6.66-6.68, but that was at 3600-4000 foot DA all weekend.
So basically probably a tenth and a half quarter mile but my DA went up 2500 feet, not 500 feet. I had a 10.48 1/4 mile hit, about 1.5 tenths off from good , not mineshaft air( under 1000 foot)
Think that is probably pretty typical. I don’t lean the car out for heat, or fatten it up( usually) for cool weather.
Click to expand...
Keep in mind, I’ve made 75+ passes with an aero scoop fiberglass hood and 6” tall velocity stack style air cleaner. This was the first time running a flat steel hood with 3” drop base air cleaner so I have zero data to work with. It was an experiment that showed .15-.20 slower 1/4 mile times and if that’s not enough, it totally changed the way the car leaves. I finally got a handle on the car with the original setup and will be going back to it next time out. Flat hood will be put away for now.
 
-Boosted- said:
Keep in mind, I’ve made 75+ passes with an aero scoop fiberglass hood and 6” tall velocity stack style air cleaner. This was the first time running a flat steel hood with 3” drop base air cleaner so I have zero data to work with. It was an experiment that showed .15-.20 slower 1/4 mile times and if that’s not enough, it totally changed the way the car leaves. I finally got a handle on the car with the original setup and will be going back to it next time out. Flat hood will be put away for now.
Click to expand...
I am extremely curious to see what the scoop was worth...
I would think the change in leaving the line would be more of a weight distribution thing, especially with a car as dialed in as that, but I really don't know.
 
ValiantS said:
I like the new look but, of course it's going to hurt performance. It's probably frustrating to slow down but again I like to factor-in 'points for style'...Not sure it was considered a factor but if you're on the edge for timing then drawing underhood heat is going to hurt that's not quantified in the weather data.
Click to expand...
I love the look for sure but the car is much happier with the scoop so it will be going back on.
 
jos51700 said:
I am extremely curious to see what the scoop was worth...
I would think the change in leaving the line would be more of a weight distribution thing, especially with a car as dialed in as that, but I really don't know.
Click to expand...
Absolutely weight changed the way the car leaves. I think the scoop attributed to a little more power and mph but more importantly, consistency. With the scoop, I saw a maximum of .10 swing with extreme weather change but in only 3 passes, I saw .18 with the flat hood.
 
-Boosted- said:
Absolutely weight changed the way the car leaves. I think the scoop attributed to a little more power and mph but more importantly, consistency. With the scoop, I saw a maximum of .10 swing with extreme weather change but in only 3 passes, I saw .18 with the flat hood.
Click to expand...
Really? I figured you'd see wider variations with the scoop. That's nuts. I figured the scoop would add variables of wind speed, cross winds, external temperature fluctuations etc.

Some things, I never would have guessed.
 
jos51700 said:
Really? I figured you'd see wider variations with the scoop. That's nuts. I figured the scoop would add variables of wind speed, cross winds, external temperature fluctuations etc.

Some things, I never would have guessed.
Click to expand...
I think underhood temps played a big part in it. Car definitely got hotter with the flat hood.
 
jos51700 said:
Really? I figured you'd see wider variations with the scoop. That's nuts. I figured the scoop would add variables of wind speed, cross winds, external temperature fluctuations etc.

Some things, I never would have guessed.
Click to expand...

I agree. I have a flat hood and see virtually no changes worth mentioning during the course of a racing day.
Big thing is trying to get the car to the same temp entering the water box each pass. I just open my hood and leave it open till I get ready to strap in. Electric paup and fan make a huge difference. Huge.
That can get difficult in later rounds though. I was at 180 the other night going rounds, sucked. Hot lapping us from round two on.
 
-Boosted- said:
Keep in mind, I’ve made 75+ passes with an aero scoop fiberglass hood and 6” tall velocity stack style air cleaner. This was the first time running a flat steel hood with 3” drop base air cleaner so I have zero data to work with. It was an experiment that showed .15-.20 slower 1/4 mile times and if that’s not enough, it totally changed the way the car leaves. I finally got a handle on the car with the original setup and will be going back to it next time out. Flat hood will be put away for now.
Click to expand...

I hear ya. I had a bolt on hemi Dart spare hood for my car when I bought it. Sold it 4 or 5 years back. Couldn’t bring myself to further molest my sleeper look.
In hindsight, would have been fun to try it.lol
 
B3422w5 said:
I hear ya. I had a bolt on hemi Dart spare hood for my car when I bought it. Sold it 4 or 5 years back. Couldn’t bring myself to further molest my sleeper look.
In hindsight, would have been fun to try it.lol
Click to expand...
I prefer the flat hood look for sure. Think I might get a flat fiberglass hood and try it without the air cleaner. Just need to play with it for a while and figure out what the car likes.
 
You must log in or register to reply here.
-

Back
Top