I have the radium hanger with twin Walbro 450 pumps, 1 lift and 1 feed. It’s super hot where I am, and I’m on the side of the road after sitting in traffic with a low / fluctuating fuel pressure situation.

seeing as its hot today (like 95f) and the regulator feels insanely hot to the touch, I’m guessing it’s just “too hot to handle”.

So where have you guys stuck fuel coolers? This is modified street car, so no hacking up the trunk or hanging a cooler off the exterior. PWM pump is another solution, if there’s a nice one that fits the Radium hanger I will definitely consider it. Cooler will probably be cheaper and solve the issue.

Please show me your solutions. Not driving the car on a hot day is not a solution. Tucking a small cooler with a fan is.

 

This is not a direct answer to your question, but...

In cars with fuel injection, fuel cooling usually only helps keep fuel flowing (minimizing vapor lock) when the fuel is not at the higher pressure (usually 30 psi or more) present after the main pump. There, IMO, is no good way to cool fuel on the inlet (suction side) of the pump (i.e., in the tank) where vapor lock can be an issue. The best solution is a low-pressure, cool running, pre-pump feeding the high-pressure (30-psi or more) pump. This can reduce the possibility of vapor lock that can occur at the too-warm main pump inlet.

OTOH, if the main pump idle FP is too low (less than 15 psi), vapor lock can occur anywhere, even after the main pump, especially with higher vapor pressure winter gas.

Less likely, if the fuel cap is too restrictive, the tank "could" develop a vacuum, but that is not as probable in hot weather.

 

Fuel cap is an easy button, I’ll try a new one.

A cooler on the return would be fine. Anything to cut down on heat building up in the tank. This is all about cutting into the heat soak and less about squeezing power, I can just turn up the boost a bit. The pump cover was quite warm to the touch

 

That makes sense, as long as you can find a cool place with good air-flow to place the cooler.

I assume you don't have this issue while stuff is still cool just after you start driving. So, another thought - cover front and bottom surfaces of the tank with heat-insulating foil to minimize the heating effect of engine and exhaust-heated air passing under the tank. Or add some baffles to deflect the hot air and air scoops to direct cool air to the tank surfaces.

 

I have 3 fuel pumps on the radium( + the lift pump) and i do not have this issue and where my car is much warmer than 95F, your problem is elsewhere

 

Yup, problem only appears when the car is heat soaked

I live in Thailand, the ambient air temp is 95f (35c). My water and oil are fine, between 185f-205f (87-95c) when cruising. What is your ambient air temp?

While my problems might lie elsewhere, letting the car cool down solved the issue until I sat in traffic again for an extended period. Good thing my A/C is icy cold

 

Ambient temperature will often go around 110F
While a cooler might help you, i would find the source of the problem first before upgrading anything else.

 

Yes it might. Lift pump might be failing. Could be a tank pressure issue. I'm actually relieved that your temps are higher, I don't really want to add complexity to the fuel system.

 

are you supplying the fuel pumps with enough power ? if they are underpowered they will overheat

 

Power FC showed 13.1+ volts, one of the things I checked asap. Had to restart the car multiple times to limp it home without issue (apart from the fuel pressure) and no spark issues when I kept the revs up to stop it from dying

 

stick a multimeter on the radium terminals instead.

 

I will, but the pumps are wired directly to the battery in the trunk, so I don't think that will show much of a change.

 

So, I took a closer look at the voltages. Turns out the alternator is dying intermittently. 130amp replacement going in, fingers crossed it should be OK.

No need for a fuel cooler at the moment.

 

I ran some monster 450s in a B2A drop in surge tank, and eventually realized that I'm not making the kind of power that requires a 450Lph supply. All it does is taxes the electrical system and makes fuel scream through your plumbing. I had the stock low/high voltage paths and it was drawing way too much amperage. I put a 255Lph single in the stock sender, and life is much easier.

 

255lph isn't enough. Walbro "450" (274) flows 382lph / 6360cc/min a good match for 5500cc of injectors. With E20 I need to be able to flow a little more volume

 

I thought about this too—you don't really need a 450 as the lift pump, its not under pressure so a 250 should flow plenty into the surge tank along with the return.

 

Radium suggests running the same pump, so that's what I did. I'm not willing to risk an empty surge tank, that defeats the whole purpose of having a surge tank.