Cool Can?

[TiredBirds]

Would running a "cool can" be any benefit in Champcar? I have used them in the past for drag racing. They help keep your ETs consistent, especially on hot days. I'd run a large one and keep it away from heat. I'm guessing the ice would last at least an hour (we only get 1.5 a run). Then we'd drain/refill at the driver change. Pix just in case somebody doesn't know what I am talking about. 

[mgoblue06]

15 minutes ago, TiredBirds said:

Would running a "cool can" be any benefit in Champcar? I have used them in the past for drag racing. They help keep your ETs consistent, especially on hot days. I'd run a large one and keep it away from heat. I'm guessing the ice would last at least an hour (we only get 1.5 a run). Then we'd drain/refill at the driver change. Pix just in case somebody doesn't know what I am talking about. 

That’s 10 points probably

[TiredBirds]

37 minutes ago, mgoblue06 said:

That’s 10 points probably

probably... but we have around 100 to burn up. 

[smitham32803]

I think the cool cans are good when you don't have a return line and the fuel was deadheaded in the lines absorbing heat.  If you have a return you are moving the fuel through the line and back to the tank to help normalize the fuel temp.  

 

One think to consider would be one of the topics brought up in the fuel capacity threads which is the density of fuel in relation to temp.  I would say that if the cool can was really cool it would drop fuel temp and therefore use more fuel in your motor.  So what i am trying to say is you would use more fuel in a stent with this that without it.  You would also run a little richer unless you changed your tune  (or carb jet sizes).  

[enginerd]

1 hour ago, TiredBirds said:

Would running a "cool can" be any benefit in Champcar? I have used them in the past for drag racing. They help keep your ETs consistent, especially on hot days. I'd run a large one and keep it away from heat. I'm guessing the ice would last at least an hour (we only get 1.5 a run). Then we'd drain/refill at the driver change. Pix just in case somebody doesn't know what I am talking about. 

You'll burn through that ice in no time and be left hauling around 10 lbs of dead weight with additional fuel fitting failure points.

[petawawarace]

1 hour ago, smitham32803 said:

I think the cool cans are good when you don't have a return line and the fuel was deadheaded in the lines absorbing heat.  If you have a return you are moving the fuel through the line and back to the tank to help normalize the fuel temp.  

 

One think to consider would be one of the topics brought up in the fuel capacity threads which is the density of fuel in relation to temp.  I would say that if the cool can was really cool it would drop fuel temp and therefore use more fuel in your motor.  So what i am trying to say is you would use more fuel in a stent with this that without it.  You would also run a little richer unless you changed your tune  (or carb jet sizes).  

Recirculating fuel systems generate lots of heat actually. The pump running non stop heats all of the fuel up.

 

If you have a well tuned newer ECU, the short term fuel trim will pick up on this and reduce pulse width time if the fuel is colder.  So it will still run at the proper mixture, and you will actually use less fuel by volume, but the same amount of fuel by weight.

[TiredBirds]

4 minutes ago, petawawarace said:

Recirculating fuel systems generate lots of heat actually. The pump running non stop heats all of the fuel up.

 

If you have a well tuned newer ECU, the short term fuel trim will pick up on this and reduce pulse width time if the fuel is colder.  So it will still run at the proper mixture, and you will actually use less fuel by volume, but the same amount of fuel by weight.

we run a mechanical pump with a return and a carb.  

[enginerd]

4 minutes ago, petawawarace said:

If you have a well tuned newer ECU, the short term fuel trim will pick up on this and reduce pulse width time if the fuel is colder.  So it will still run at the proper mixture, and you will actually use less fuel by volume, but the same amount of fuel by weight.

Is it measuring fuel temp and correcting preemptively? Or is it that the O2 measurement will read a hair richer for cold fuel and will then adjust the injectors just like it would for any variation which results in a different O2 sensor reading?

[petawawarace]

13 minutes ago, TiredBirds said:

we run a mechanical pump with a return and a carb.  

Doubt you’ve got much heat in your fuel then. 

[petawawarace]

11 minutes ago, enginerd said:

Is it measuring fuel temp and correcting preemptively? Or is it that the O2 measurement will read a hair richer for cold fuel and will then adjust the injectors just like it would for any variation which results in a different O2 sensor reading?

Just adjusting based on O2 readings.  Colder fuel will be more dense, but has the same amount of energy.  Therefore to get the same mixture, it requires less pulse width time thus less volume of fuel.  

[TiredBirds]

16 minutes ago, petawawarace said:

Doubt you’ve got much heat in your fuel then. 

We have to move our fuel lines, they are along the rail near the exhaust and the factory line runs right up the front of the block. Not a fan of that.  It is more for a few extra ponies. The cooler charge makes more power. May not be worth the effort. I know it helps at the drag strip. 

[veris]

Better to use that pre-fill to get more energy density in the fuel tank. ie get fuel temperatures in your fuel jugs well below ambient. 

 

You could get between 1/2 to 1 gallon (10 to 20 gallon tank) more in your tank with a 40 degree change in temperature. Basically enough to off set the 2022 fuel change rule. 

 

 

Edited October 19, 2021 by veris

[Todd K]

I have thought about this for our situation but with FI and returning fuel through the whole system along with short loop for a swirl pot there's a lot of work going into moving the fuel (adds heat) plus the heat soak from engine components in the engine bay + ambient temperature / heat transfer through remaining parts of the car.  If you had a fully insulated fuel system it might be worth trying.  HOWEVER - we did try this with kart racing and cooling the fuel down significantly before going on track.  What we found, especially in Florida, was the humidity caused condensation inside the fuel jugs and tank which resulted in water in the fuel negating any of the hopeful power increase.  As a matter of fact it was more detrimental to the performance.

 

With a carb and mech fuel pump it could work out OK but you might need an insulator gasket to keep the heat soak on the carb under control.  For the cost it could be worth trying.

 

I've used one for drag racing which is OK when you're heads up and trying to get every HP out of the engine but it also caused inconsistent results and thus caused problems when bracket racing / dial-in predictions.  So we got rid of it to remove the variable.  

Edited October 19, 2021 by Todd K
additional comments

[Team Infiniti]

6 hours ago, petawawarace said:

Just adjusting based on O2 readings.  Colder fuel will be more dense, but has the same amount of energy.  Therefore to get the same mixture, it requires less pulse width time thus less volume of fuel.  

How many cars are trimming fuel mixture @ WOT? 

[TiredBirds]

3 hours ago, veris said:

Better to use that pre-fill to get more energy density in the fuel tank. ie get fuel temperatures in your fuel jugs well below ambient. 

 

You could get between 1/2 to 1 gallon (10 to 20 gallon tank) more in your tank with a 40 degree change in temperature. Basically enough to off set the 2022 fuel change rule. 

 

 

so a keg fridge is the way to go? What is the 2022 fuel change rule? 

[Ian]

7 hours ago, TiredBirds said:

It is more for a few extra ponies. The cooler charge makes more power. May not be worth the effort. I know it helps at the drag strip. 

 

Since the ice won't last the full driver stint, you'd still need to tune the carb to run safely with a hot fuel load, which would likely negate any benefits when it's cold.  Unless you can adjust the carb on the fly.  Not to mention the added weight likely offsets any power gains.

 

I also think your estimate of 1 hour run time on a load of ice is quite rosy.  I'd bet it's warm water a lot quicker than you think.

[karman1970]

47 minutes ago, TiredBirds said:

so a keg fridge is the way to go? What is the 2022 fuel change rule? 

Put a big Yeti cooler in the trunk. Call it a cool suit system.  Run your fuel lines through that.

[MR2 Biohazard]

My understanding is that it works for drag cars because most that use it are carbed. With FI and if it has a wideband with closed loop it will compensate for fuel density and keep the APR constant. I wonder how much of a benefit on a FI non boosted car the lower temp fuel would have to lower in the intake charge and get denser air in. I doubt it is much of a gain for our cars in our situations. Though I am exploring the idea to cool fuel down to help, though logistics of such are complicated. How do you cool down 120 gallons of fuel for a weekend and keep it cool until it gets in the car. hmm.

 

Maybe you could freeze a sold block of ice and each pit stop change it out like you do cool suit water. That would be interesting.

 

If you did the AC condenser as a cooler and ran it through there it might cool it down enough, but the weight of that would vastly outweigh the benefits. Every 10-20 lbs is like .05-.1 of a second on lap times.

[TiredBirds]

2 hours ago, MR2 Biohazard said:

My understanding is that it works for drag cars because most that use it are carbed. With FI and if it has a wideband with closed loop it will compensate for fuel density and keep the APR constant. I wonder how much of a benefit on a FI non boosted car the lower temp fuel would have to lower in the intake charge and get denser air in. I doubt it is much of a gain for our cars in our situations. Though I am exploring the idea to cool fuel down to help, though logistics of such are complicated. How do you cool down 120 gallons of fuel for a weekend and keep it cool until it gets in the car. hmm.

 

Maybe you could freeze a sold block of ice and each pit stop change it out like you do cool suit water. That would be interesting.

 

If you did the AC condenser as a cooler and ran it through there it might cool it down enough, but the weight of that would vastly outweigh the benefits. Every 10-20 lbs is like .05-.1 of a second on lap times.

yes but an ac condenser would add 2 extra gallons of fuel easy...lol I did think about using an finned PS cooler. I think if the cool can was in the right spot it might make it almost 1.5 hours, I wouldn't use ice cubes, I'd use a solid chunk of it. These cool cans don't weigh much. I mean we are in a 88 Firebird what's and extra 2-3lbs? 

[ross2004]

Sounds like a lot of squeeze for not much (if any) juice.