LibertyCRD wrote:
Well, he came up with that fan mod because it is permanently fixed. I.E., it does not have a temperature controlled clutch like the OEM fan that can possibly fail. Therefore, once you install that fan in his mod...you have a permanent cooling solution.
The downside is added noise, decreased power, and decreased fuel economy, and slower heat-up times in the Winter. I am currently experimenting with NO fan. I've driven in the mountains, in 90+ degree heat, and towed a 6,500 lb. load and I have not overheated my engine yet. In fact, 99% of the time my temp guage stays below the half-way point. And that's with NO mechanical fan whatsoever. So the necessity of the fan mod is debateable. But...it's an alternative worth noting.
You list alot of "downsides" that may not be all that accurate. Feel free to read the thread started about it. I'm pretty sure these issues were discusse don the FFF mod thread, but I will re-address.
- Slower heat up times in winter. This is just plain wrong, not sure where you got this info, but you've been misinformed, sorry. I'll explain. The thermostat doesn't even allow coolant to flow through the radiator until the engine is warm, so how would a higher CFM fan cause slower engine heat-up time? It doesn't.
- Decreased fuel economy - Maybe, this has not been proven yet. As far as I know, I am the only one running this mod. In fact I just released the part numbers 2 days ago and I don't think anyone else at all has this mod. I have ACTUAL experience with this mod and am happy to share my unbiased thoughts on it. Hwy economy is same as far as i can tell. I have not seen a variance of more than 1mpg with either the stock fan and the FFF with city driving. The outside temp plays a bigger factor in economy than the fan does so it is hard to tell. If any loss, it is almost negligable. HWY economy is not effected because when traveling 60mph the air WANTS to go through the radiator at 60mph, there is no extra load from the fan on the engine at these speeds. In the city of course there is extra load due to being directly connected.
- Decreased power, ok, depends on how you look at this. Its a flex fan, it flattens out at high rpms freeing up power, it has roughly 1/3 the rotational mass than the factory fan. It frees up power compared to the factory setup (when it is locked). Compared to the unlocked factory fan (which in fairness, is most of the time) it will consume maybe a tiny bit more power due to being directly connected, but it also cools the air in the intercooler much more and more fuel can be added due to the cooler intake temps so may help power that way at WOT. This may or may not make up for it, but the cooling definately makes this mod worth a little unnoticeable loss of power...I should dyno it and see...you might be surprised, might make more power, idk. I did not notice any loss of power myself in the seat of the pants test.
- Added noise, a little yes. You're right on there. At cruise at 60mph it sounds like factory, but at mid rpm's and above, especially unlocked TC, more noise in city driving.
Now lets look at the benefits:
- Much MUCH better engine cooling
- Much better transmission cooling
- Much better Intercooler cooling and efficiency
- More efficient A/C cooling
- Completely reliable and will never fail (stock fan clutch has poor dependability and has been proven to fail many times)
- Cheaper than replacing a 150.00 fan clutch...so when yours fails, think about this mod...I have no regrets
- You will NEVER overheat with this fan setup unless your thermostat fails closed or your waterpump completely fails. (neither of these has ever happened that I know of on a CRD [correct me if I'm wrong and tell me who], thermostats on our CRD's fail in open position)
- Mark