Reducing Heat Soak At The Track

[KevinMar]

I'm not happy with how my engine performance degrades throughout a track day. My engine oil temps have always remained within the normal range, however as I progress through each track day the reduction in engine performance is noticeable, especially around the uphill sections of Big Willow.

The reduced price and engine temperatures that a switch to E85 should bring are very attractive. I'm not looking for maximum horsepower gains, I know that isn't the limiting factor in my lap times. What are your thoughts on how a switch to E85 and a better cold air intake would affect my engine's performance on a hot track day?

I'm currently leaning towards Lund's E85 tune, however I am open to other suggestions including the Flex Commander. Lund explicitly recommended the PMAS Fenderwell Intake, however I am not convinced that is the best intake for my needs.

Looking for any and all thoughts on this prospective upgrade.

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[Dana Pants]

Rumor has it holes in the hood are your best bet to get heat out.

 

[KevinMar]

Rumor has it holes in the hood are your best bet to get heat out.

I don't disagree, but I'd prefer to not mutilate my hood.

 

[ihasnostang]

not sure how long there is between sessions but my events are about 40 minutes apart, and i usually let the car idle for 10-20 minutes with the heat turned all the way up. the heater core will suck heat out of the coolant and thus the oil as well. My oil temp was at 190 while heading out for the start of the second session.

Unless someone has a theory otherwise, i think running E85 at at the same power level you are currently at would reduce engine temps.

 

[ZXMustang]

I just run e20 on my 93 wengerd tune. It adds a bit of octane and holds down any weather or temp related knock. No need to do anything to the tune. The car runs in closed loop at all times and the widebands will add fuel via the fuel trims as needed. My car was perfectly happy on e20 with LOADS of headroom for a bit more if I wanted.

Wengerd looked at my logs and said I was only adding like 6-10% at any given time through the fuel trims to offset the extra ethanol. But the car was rock solid, seeing no knock. Being a car with factory widebands, you could theoretically do this on a stock car and gain a bit of octane. I basically do 2 gallons of E and then top off the tank with 93. Car is very happy on that.

 

[KevinMar]

not sure how long there is between sessions but my events are about 40 minutes apart, and i usually let the car idle for 10-20 minutes with the heat turned all the way up. the heater core will suck heat out of the coolant and thus the oil as well. My oil temp was at 190 while heading out for the start of the second session.

Unless someone has a theory otherwise, i think running E85 at at the same power level you are currently at would reduce engine temps.

I usually let the car idle for about 5 minutes, but had never thought to turn the heat on. Plus in the hot SoCal sun I sometimes have the AC run between engine start and track entry. Somebody else recommended I bring a blower fan, I might give that a try too.

I just run e20 on my 93 wengerd tune. It adds a bit of octane and holds down any weather or temp related knock. No need to do anything to the tune. The car runs in closed loop at all times and the widebands will add fuel via the fuel trims as needed. My car was perfectly happy on e20 with LOADS of headroom for a bit more if I wanted.

That's why an ethanol or flex tune is so attractive. The same hardware as the Flexfuel F-150's and Explorers is in the 350 so no extra hardware is required to detect the (approximate) ethanol content.

 

[RagmopInKona]

I don't disagree, but I'd prefer to not mutilate my hood.

Junk yard crawl, hood, vent away.

 

[Hack]

Junk yard crawl, hood, vent away.

GT350 hoods might be a little tougher to find compared to a regular GT, and I totally get not wanting to destroy the value of a GT350R.

I like the idea of the ethanol tune. Flex would be the best, because there are a lot of places around here where there's no E85. Definitely ethanol will cool a lot more than regular gasoline since a much larger volume of fuel is being used.

 

[ChipG]

I have a ProFlex Commander I'm not using if you're interested in it. Worked well on E85. Not a power adder but if you want to run E85 to run cooler could be just what you need.

 

[JAJ]

I'm not happy with how my engine performance degrades throughout a track day. My engine oil temps have always remained within the normal range, however as I progress through each track day the reduction in engine performance is noticeable, especially around the uphill sections of Big Willow.

The reduced price and engine temperatures that a switch to E85 should bring are very attractive. I'm not looking for maximum horsepower gains, I know that isn't the limiting factor in my lap times. What are your thoughts on how a switch to E85 and a better cold air intake would affect my engine's performance on a hot track day?

I'm currently leaning towards Lund's E85 tune, however I am open to other suggestions including the Flex Commander. Lund explicitly recommended the PMAS Fenderwell Intake, however I am not convinced that is the best intake for my needs.

Looking for any and all thoughts on this prospective upgrade.

I see three different, and only a bit related things going on here:

First, air temperature in the intake. The intake manifold volume is about 12.55 liters in a Voodoo. With full throttle airflow, the entire volume of air in the manifold changes 10 to 20 times a minute. There's really not much time for heat to soak the air. My point is that a CAI probably won't help much. The factory intake is actually a CAI to begin with and the rapid change of air in the manifold keeps intake air temperatures close to ambient.

Second, switching to E85 without a tune (like a Flex Commander) won't make a lot of difference either. Engine will probably run cooler, but other than that, power will be more or less the same as gasoline.

Third, with an E85 tune, you'll have more spark advance and more power. It'll still fade as the air above the track heats up, but at least you'll start the day with more power.

 

[KevinMar]

I like the idea of the ethanol tune. Flex would be the best, because there are a lot of places around here where there's no E85. Definitely ethanol will cool a lot more than regular gasoline since a much larger volume of fuel is being used.

Luckily I can count on having access to E85 where I live, and have 2x 5 gallon tanks I can keep filled as well.

I have a ProFlex Commander I'm not using if you're interested in it. Worked well on E85. Not a power adder but if you want to run E85 to run cooler could be just what you need.

Why aren't you using it? It should add power, but I understand that it's not an ECU tune so it isn't making the most of the increased octane or changing power curves significantly.

First, air temperature in the intake. The intake manifold volume is about 12.55 liters in a Voodoo. With full throttle airflow, the entire volume of air in the manifold changes 10 to 20 times a minute. There's really not much time for heat to soak the air. My point is that a CAI probably won't help much. The factory intake is actually a CAI to begin with and the rapid change of air in the manifold keeps intake air temperatures close to ambient.

Second, switching to E85 without a tune (like a Flex Commander) won't make a lot of difference either. Engine will probably run cooler, but other than that, power will be more or less the same as gasoline.

Third, with an E85 tune, you'll have more spark advance and more power. It'll still fade as the air above the track heats up, but at least you'll start the day with more power.

Great points. My main gripe with the stock intake is the seal it makes with the hood. The rubber/foam is already deteriorating and I'm not convinced it's making any kind of seal with the hood. The corrugation in the tube also isn't great, but not the biggest issue...

I agree that using the Flex Commander is not the right option if power gain is my goal, however the increased fuel volume flowing through the engine is a factor that should yield some small decreases in cylinder temp. There will be some power increase by virtue of the increased octane in the high compression engine, however, as I stated above, the effect won't be nearly as great as if an ECU tune is applied.

This was my initial thought as well. If I increase the maximum power potential for the engine, as well as flow more fuel through it, in general temps should remain lower as long as I'm not pushing the engine to its limits.

If I know I can always run E85 then the only advantage of the Flex Commander is not touching the ECU tune. I've already replaced my original short block under warranty, and the car is now 5 years old, so I'm not that adverse to tuning the ECU.


Thanks for all of the inputs, guys!

 

[5.0_Lojos]

I just run e20 on my 93 wengerd tune. It adds a bit of octane and holds down any weather or temp related knock. No need to do anything to the tune. The car runs in closed loop at all times and the widebands will add fuel via the fuel trims as needed. My car was perfectly happy on e20 with LOADS of headroom for a bit more if I wanted.

Wengerd looked at my logs and said I was only adding like 6-10% at any given time through the fuel trims to offset the extra ethanol. But the car was rock solid, seeing no knock. Being a car with factory widebands, you could theoretically do this on a stock car and gain a bit of octane. I basically do 2 gallons of E and then top off the tank with 93. Car is very happy on that.

What is E20? Im also wengered Tuned on pump 93 with a stage 2 prochrger.

Is it mixing 2 gallons of E along with 93? My car sits most of the time.

 

[ZXMustang]

What is E20? Im also wengered Tuned on pump 93 with a stage 2 prochrger.

Is it mixing 2 gallons of E along with 93? My car sits most of the time.

Yes that’s E20.

 

[5.0_Lojos]

So find a gas station that has both E85 and Pump 93 and pump 2 gall of E85 and the rest 93? Would this be considered a "flex fuel" set up or requiring an updated Tune? I did read all looked good on the logs.

 

[ZXMustang]

So find a gas station that has both E85 and Pump 93 and pump 2 gall of E85 and the rest 93? Would this be considered a "flex fuel" set up or requiring an updated Tune? I did read all looked good on the logs.

Yes that’s exactly right. And no tune update needed. Your car will adjust the fuel trims accordingly to account for the added ethanol as observed by the widebands. The added octane will have a mild cooling effect as well as adding octane to fight spark knock. It’s like running 94/95 octane. And it’s mild enough to where the car has the ability to correct for it. I’ve discussed this at length with Wengerd and he’s all for it. You might see your trims +10-15% but the car is more than capable of handling it. It should run a bit smoother and with no knock.

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