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Stratosurfer
08-29-2007, 16:47
All,
I ran the board and couldn't find any data on what the posted data from Stanadyne (or any other unofficial source) is on what is the max rated operating temp for our FSD's. I have moved my FSD Sync heatsync behind the front bumper centerline behind the license plate using a 1/2" aluminum angle held on the backside by the license plate frame bolts: works super.
I am recording Digi thermo scan temps of the heatsync of maximum 126.5 F at 97F ambient with the vehicle parked at idle with both A/C's full power. When driving at anything much above 25 mpg or so for even small distances if I get out and take a temp real quick, it is ambient or even a degree or two below ambient. It is normally cool to the touch.
I am wondering if this approx 30 deg F over ambient at idle should be of a concern? I am struggling with messing with PC fans and airswitch activation for when idling to extend this FSD's life, yet I wonder if this is over kill. I know I have probably doubled the FSD's life just getting out from under the hood, but should I try to go further and reduce this heat load when idling? Can one make an FSD last forever (or 7 years as Heath guarantees)??
Any comments/experience greatly appreciated.
THX

More Power
08-29-2007, 23:44
Can one make an FSD last forever

Some do, but it's the luck of the draw... I heard from a 6.5 owner a short time ago who had 450,000 miles on his electronic 6.5 without much at all in the way of failures. He still had the factory original fuel injection pump and pump mounted driver (aka FSD).

It's likely more of a problem with thermal cycles and expansion/contraction that eventually causes a circuit continuity problem. Locating the FSD on a cooler can help keep the thermal swing to something less that it might see while mounted on the fuel injection pump.

The highest FSD temps should come when the engine is being worked the hardest. A low fuel tank level and/or a dead lift pump can raise FSD temps as well, cuz the fuel injection pump has to work a little harder to get the fuel. FSD temp at idle should not be a concern.

Jim

moondoggie
08-30-2007, 06:29
Good Day!

What he said, &...

"I am wondering if this approx 30 deg F over ambient at idle should be of a concern?" IMHO no concern whatsoever. Most semiconductors don't get into temp trouble until junction temps of 125°C or so, which is ~ 257°F.

"I am struggling with messing with PC fans and airswitch activation for when idling to extend this FSD's life, yet I wonder if this is over kill." Again, IMHO, based on what I've read here over the years, this is definitely overkill.

"I know I have probably doubled the FSD's life just getting out from under the hood, but should I try to go further and reduce this heat load when idling?" Again, IMHO don't waste your time. Bill Heath warrants his FSD/ PMD solution (similar to what you've done) for 7 years, even though the FSD is only warranted to him for a year - he must be pretty confident in this solution, eh? ;) I moved mine in front of the driver-side (US) battery.

As with all such advice, keep clearly in mind who pays if I'm wrong- you do. :rolleyes: My advice is based on not only what I've read here over the years, but what I'm doing with my own stuff.

Blessings!

noelb
08-30-2007, 16:34
I think you will find that bumper mounted is a good position and no need for any extra cooling.:) I couldn't work out an easy way to mount mine there on a Heatsink, so, I have mounted my FSD on a Heatsink between the headlight and battery on, what you would call, the drivers side.