I think if you use the flex 4136 cooler in a box with forced air thru a hose/tube into the front of it and allow the air to escape out the rear thru vent holes, you'd get the same effect as having it up front. My fabbing skills kinda suck so I never did it. one other option might be to put it in the frame and force air down the frame thru the cooler. I MAY attempt something on the CTD for the fuel out of the tank. with gelling being an issue I'll have to find out how it reacts when it's chilled, under pressure and flowing.

 

This is one mod I'm really skeptical about. First, if air cooled, no matter how much air flow you have, it won't get the fuel below ambient temp. If the air is 90* the fuel won't get below 90*. The Cool Can with ice/water would be much more effective at lowering fuel temp.
But, how much is this going to help? With fuel injection, the cooler fuel won't affect the air entering the T/B and intake manifold.

Has anyone done this, with proven results? I read one post here where someone claimed it added power, but he did TWO mods at once, so he can't say if it really helped or not. If it works, I'd do it myself. I do believe it's been somewhat effective with carbs.

It's cool to experiment and learn, though. I'll be watching to see where this goes.

 

Well the problem is, FI has a return line, so hot fuel is being returned to the tank. Also remember, at speed ambient temperature will cool things off through convection, think of putting a fan on you on a hot summer day, the fan is technically blowing 90* air, but because of the action is cooling you off.

 

Moving air will cool things faster but it won't cool it below ambient temp.

I was thinking that one would be able to put the cooler on the return line and thus cool the fuel returning to the tank. Then wrap all the fuel supply/rail lines really well so they don't pick up any heat and it should produce close to the same results. You could have the cooler somewhere else but up front . As Mike said without some external cooling like the Cool Can with ice/water I don't see how your going to get anything lower than ambient temp. Don't get me wrong ambient temp is cooler than what the fuel temp going in now. Anyway it was just a thought.

 

Yeah, I did it 3 times on 3 different cars/trucks. 2 bmw's and my 2000 ram. EACH time my low end and midrange torque increased. more noticeablly on the bmw's since they are significantly lighter. when I did it on my ram it happend to be in the middle of a 1800 mile trip. I saw a 6% increase in mpg with it on the hiway.

You are right, the fuel will only get as cold as the ambient air temp - the wind chill of whatever speed your doing. Flex-a-lite claims up to 80 deg can be pulled out of the fuel. I find that kinda hard to believe but it definately pulls heat out of the fuel.

when I sold my M3 to another motorhead (he had several m3 buddies in the crowd he hung with) I had to pull it all off prior to the sale, I instrucked him on how to re-install it when he was ready. about 3 weeks after the sale I got a call from him and he mentioned that he re-installed it along with all the other mods I sent him with that were on the car to begin with when he test drove it. He mentioned that he found that one of his friends with an m3 had a similar setup with the execption of the fuel cooler and insulated fuel lines, he and his friend had a few runs and my old m3 came out on top every time. in his (buyers) terms, he "walked away from him every time".

but, the bottom line here is that when you cool the fuel, insulate the metal lines and fuel rails so they cannot be heat soaked, you will be squirting cold fuel into each combustion cycle. this WILL cool your incoming airflow into the cylinder. No one ever claimed it cooled the air in the intake or the air passing thru the throttle body... thats the CAI's job. and your only going to be able to cool it enough to offset some of the heat soak the intake manifold is going to get sitting on top of the engine.

the fuel can & ice works great on the track but is not practical for every day driving. my original problem was trying to get the pinging to stop on my bmw 325is while using 91 gas with a chip installed that required 93 octane to run right. insulating the fuel lines/rails and adding the cooler helped to eliminate the pinging. on one trip in 108 deg ambient temps and a carload of stuff/people, I stomped on it pretty good to see if I could hear it ping and not once did it ever ping that i could hear.

One last thing to add... when i thought of using the fuel cooler on the 325is, I discovered that in the heat of the summer, my 3 would ping more than in the winter (mild winters, hot summers here in CA), so i added the insulation to the fuel rail and it helped out quite a bit. didnt do much for power but it helped with the pinging. Thats when I did some more research and decided to give the cooler a try. Once I had it installed, the benifits were clear.

sorry for the long post guys but it's better to hear the whole story...

 

From the link for the cool can Chopper1 posted:
NOTE: Not recommended for high-pressure fuel injection systems

Whatever you get, make sure it's designed for FI.

 

there is no return line on the rams... only the jeep grand cherokee, '93 and maybe '94 had a return line. I have one sitting in my garage (fuel rail).

I never was able to measure the temps, I let my butt dyno do the analysis for me. As for the ambient temp comments, in my previous post I mentioned the hot summer days here in CA... well, how it really went was, on a low tank of fuel, my bmw 325 would ping like crazy, then one day I noticed after filling it up at lunch time that the ping was gone. thats when I realized the cool fuel would stop the pinging. once that full tank became heat soaked, it would ping again. so the solution was to find a way to keep the fuel as cool as possible and have it so I dont have to think about it... the cooler was the best solution.

 

BTW, this is by no means a cheep mod... the fuel injection line itself ran me about $80 bux. add the cooler at $40 and the fittings to get you to & from the lines & cooler and thats another $25~30. it adds up but it's worth it.

 

Well that's the question, it's not really somthing to dynoable but i'm just trying to decide if airflow along the fram rails would be as good as up front, or if there's a way of mounting it up front without it being a complete fire hazard.

 

I wasn't sure whether or not the Ram's had a return line as I hadn't noticed one. I was just figuring if it did the cooler could be put in the return line, but since there isn't one that's not an option. I was trying to think of other places to put a cooler besides the front of the vehicle.

I'm guessing in CA your pretty much picking heat up from just about everywhere in the summer (sun heats up the old black top pretty good). Here in northern BC the heat doesn't become that big of a concern.