Drag/Acceleration The Official 1/4 mile track thread.

[Matt77]

In order to calculate a true DA based off IAT you'd need to also account for the other properties of the air at that point (charge pipe). The elevation doesn't change, but the air pressure and the relative humidity will. The air pressure is obviously much higher thanks to the turbos, but the relative humidity I would think changes as well. Now you have me thinking...hmm. Time to read up on thermodynamics haha

DA is relative to atmospheric conditions, not conditions post compression from the turbo(s).

 

[Kato_the_kia_stinger]

Check this site to find the DA on any given day at the track you visited.
US Tracks « Air Density Online

 

[Hyperjetta]

DA is relative to atmospheric conditions, not conditions post compression from the turbo(s).

Agreed. It was just an interesting thought experiment to consider calculating DA based on post compression. Imagine running a naturally aspirated car in an environment that somehow had an ambient temperature of 140 F, atmospheric pressure of 28.5 psi and 80% relative humidity. The DA for those conditions is around -17000 ft if my math is right. Completely useless information other than to see how DA works.

 

[C Mandy]

You can take me off the list and let someone else move up. I got tired of all the problems with the car and traded it for a new F150. Ordering a whipple supercharger and going to run 10's.

 

[Terry@BMS]

You can take me off the list and let someone else move up. I got tired of all the problems with the car and traded it for a new F150. Ordering a whipple supercharger and going to run 10's.

Not an EcoBoost? We have JB4s for the F150 Eco and Raptors.

 

[C Mandy]

Not an EcoBoost? We have JB4s for the F150 Eco and Raptors.

No its a regular cab short box 4X4 5.0 coyote with a 10spd auto. Bone stock just picked up yesterday at 9am and at the track at 11am it went 13.83 at 100.18mph. Also can't get a 3.5 ecoboost in a reg cab shortbox.

 

[Terry@BMS]

Ah, I've got a 2018 RWD short cab 2.7L turbo. F150 are awesome trucks, congrats.

 

[nhcowboy28]

No its a regular cab short box 4X4 5.0 coyote with a 10spd auto. Bone stock just picked up yesterday at 9am and at the track at 11am it went 13.83 at 100.18mph. Also can't get a 3.5 ecoboost in a reg cab shortbox.

Wasn’t the tremor the 3.5 EB shortbed single can? I toyed with the idea of that... lowering it to make a street truck.

 

[C Mandy]

Wasn’t the tremor the 3.5 EB shortbed single can? I toyed with the idea of that... lowering it to make a street truck.

The Tremor was a limited run and only for 2013/14

 

[C Mandy]

Ah, I've got a 2018 RWD short cab 2.7L turbo. F150 are awesome trucks, congrats. With your business I can understand the turbo motors, but I like the rumble and was always planning on the supercharger.

 

[Hyperjetta]

My brother and I are going to have a friendly little rematch next week at the track and I'm wondering if I have any shot of hitting 11s...

My last run was a 12.3 a few months back on map 5 running race gas, but I didn't do any WOT pulls prior to my lap so I don't think my ecu had adjusted for it yet. I was dealing with some pretty awful heatsoak and the DA wasn't great. Other factors were Sport mode with lc and I let ecu/tcu handle the shifting.

This time around I should have a muuuch better DA, and I'm prepared to deal with heatsoak. Aaand I'll be sporting the BMS "oh shit" switch. I still have about 2.5 gallons of the sunoco 260GT plus gas I can run, or I was debating trying an e30 mix.

Any nuggets of wisdom (or realism) to be shared out there?

Fyi, my brother drives a 2018 mustang gt, with the 10spd auto, so I expect him to be super close to 11s.

Should I just disconnect his battery when he's not looking?

 

[Tonkabob]

12.3s seems about right for what mods you were running. The oh shit switch should knock off .2 or .3. Be sure to get out and test it before hitting the track. Race gas is probably safer than e30 as you will be running low on fuel pressure especially with the switch. Or do a race gas e20 blend and get some ethanol cooling but not too much where you risk low fuel pressure.
If the Mustang is on street tires you should take him. DRs probably not.

 

[Terry@BMS]

What was your 60' before? Every .1th reduction is worth around .15ths in 1/4 mile. So high 11s should be possible for you with the right launch.

 

[Hyperjetta]

What was your 60' before? Every .1th reduction is worth around .15ths in 1/4 mile. So high 11s should be possible for you with the right launch.

60' was 1.953, trap was 115... the look on the guy's face in the Challenger next to me was 0.0. It honestly couldn't have been any more perfect. It was the "Angry Bee" Scat Pack model

12.3s seems about right for what mods you were running. The oh shit switch should knock off .2 or .3. Be sure to get out and test it before hitting the track. Race gas is probably safer than e30 as you will be running low on fuel pressure especially with the switch. Or do a race gas e20 blend and get some ethanol cooling but not too much where you risk low fuel pressure.
If the Mustang is on street tires you should take him. DRs probably not.

I'm pretty sure they're street tires on 20" wheels. The fastest slip he's ever shown me was also a 12.3, but I know stock Mustang GTs with that 10spd can hit 11s, or get damn close.

I hadn't thought of mixing ethanol with the race gas....hmm. I might give that a shot. Any idea which map I'd run that on, Terry?

 

[turboAWD]

My brother and I are going to have a friendly little rematch next week at the track and I'm wondering if I have any shot of hitting 11s...

...

Any nuggets of wisdom (or realism) to be shared out there?

Fyi, my brother drives a 2018 mustang gt, with the 10spd auto, so I expect him to be super close to 11s.

You're AWD - pick a rainy day :-D

 

[Terry@BMS]

I hadn't thought of mixing ethanol with the race gas....hmm. I might give that a shot. Any idea which map I'd run that on, Terry?

Race gas is better than E85. If you want the "best performance" just run straight unleaded race gas... As little gas as possible to keep weight down.

 

[Tonkabob]

Race gas is better than E85. If you want the "best performance" just run straight unleaded race gas... As little gas as possible to keep weight down.

Myself and others have found ethanol blends make better times and more hp on the dyno. Ethanol cools better, has its own oxygen and has a stoich in the 9s vs 14s. So blended you will be running leaner, closer to optimum. E20 drops gas stoich from 14.6 to 13.4.
At the track i switched from 95 octane E20 to 100 octane E0 and lost
.05 Not much but something.
Here is a good write up on why Alcohol makes more power and Nitro Methane even better.
Fuel Comparison, Gasoline, Methanol, Nitromethane - SMOKEmUP.com
Methanol is better than Ethanol and in small quantities only a few % power gain but may be enough for the win!

 

[Hyperjetta]

Myself and others have found ethanol blends make better times and more hp on the dyno. Ethanol cools better, has its own oxygen and has a stoich in the 9s vs 14s. So blended you will be running leaner, closer to optimum. E20 drops gas stoich from 14.6 to 13.4.
At the track i switched from 95 octane E20 to 100 octane E0 and lost
.05 Not much but something.
Here is a good write up on why Alcohol makes more power and Nitro Methane even better.
Fuel Comparison, Gasoline, Methanol, Nitromethane - SMOKEmUP.com
Methanol is better than Ethanol and in small quantities only a few % power gain but may be enough for the win!

Am I wrong in thinking that the benefits from running E85 would be somewhat dependent upon the tune? Since the stock ECU isn't set up to adjust for that much extra flow I would need the JB4 to adjust for it?

 

[Tonkabob]

Am I wrong in thinking that the benefits from running E85 would be somewhat dependent upon the tune? Since the stock ECU isn't set up to adjust for that much extra flow I would need the JB4 to adjust for it?

People have had good results running E20-E30. My tune is aggressive so I run out of fuel above E25.
Most tunes are targeting 11.5:1 to 12.0:1 so they are ok with lower Ethanol levels. Above E30 you probably have to start thinking about richening things up a little bit. The car doesn't know what you are running so just sends more fuel to hit the AFR target.

 

[Hyperjetta]

People have had good results running E20-E30. My tune is aggressive so I run out of fuel above E25.
Most tunes are targeting 11.5:1 to 12.0:1 so they are ok with lower Ethanol levels. Above E30 you probably have to start thinking about richening things up a little bit. The car doesn't know what you are running so just sends more fuel to hit the AFR target.

This is great info. Suppose the octane ratings are similar between a race gas and something like an E85 mix... Is there any timing being pulled/added just based on the fact that it is a different AFR?