so i bought a controller today and am about to pull the trigger on some fans, but today for the heck of it, i decided to pull of my engine-driven fan to see what all the hype is about. now im excited, hearing people claim anywhere from 2-17hp gains, immensely better accel, and colder A/C. well i pull off my fan and take it down the road (carefully watching the temp, but it stays at a normal 200*) and i cant even tell the difference. A/C is still the same, the accel seems a TAD better, but from what i hear its supposed to be a lot stronger? the whole idea is not driving the heavy fan right? why arent i seeing any gains? i know i dont have the actual efans hooked up yet, but those arent the source of these claims.

 

thats why i cannot justify to buy them troyers kit is way over priced and 17hp seems a bit much but lets say 10hp are you going to notice 10 hp on something that makes 300 hp? but when you get them in let me know how it goes i would consider builting my own kit if it worth it

 

lol the 4.2 v6 doesn't make 300hp.

i don't know about the e-fans, i do know that in a case of prolonged idle, e-fans>engine driven. thats a good benefit i can see, as far as HP gains i can't testify to that. maybe tj can, he's got e-fans. or patman

 

well after reading testimony over testimony over the improved acceleration and how awesome it feels, this is kind of a disappointment. i was expecting something off the charts (for a V6) but i cant feel didly squat.

 

Alex, you will only notice the power increase in the upper range of the rpm, as that's where the power curve on the 4.2 is....is helps with better acceleration because the engine doesn't have to get that monstrosity of a fan going anymore. also it gives you better mpg because when your going down the road @ 70 mph, the fans are freely spinning unlike the clutch fan which is restricted by how fast the engine rpms are at...

JUST GO FOR IT!!

 

I'm planning on doing E-Fan's in the near future mainly for the M.P.G. gain.

 

FWIW, the guys who claim a big seat of the pants performance improvement tend to have 5 speeds.

I have an automatic - I could not tell any performance increase, but I did get better mpg. Also, the truck is quieter (when the fan is not on) and heats up quicker in winter.

 

okay. I put my fan back on because im driving around town now and like you said Derek, I do notice a slight hesitation in the uppers with the stock fan. i was hoping for a gain in the lowers, but eh. cant have your cake and eat it too, i guess. Like I sad before, I already have a nice 30A controller that controls two fans anywhere from 160-210 degrees, so the thermostat is adjustable, and a stick-in probe. I tried to go to the junkyard but the only two Mk. VIII there had the fans pulled I think i will just save up and get two 16" brand new ones.

 

did you check out the fans in the Taurus' I think it is the same fan as the Mark VIII if not its real close and also makes a good donor for our trucks

 

there were some late 90s models I think with a 3.0L but I heard that Taurus fans draw like 60-100A and my Imperial controller is only rated for 30A.

 

IMO, dual fans are unecessary on a 4.2.

I have a Flex-A-Lite 'Black Magic' Universal fan kit. Was a bit of a PITA to install, but it only cost at $180 (9 years ago). Ordered online from Summit and it was delivered to my door within 24 hours.

I live in a very hot climate and have had this fan for about 9 years and over 100,000 miles, and I've never had a cooling problem. I occasionally do some light towing and hauling, but I've towed a car and dolley 260+ miles in 100* weather, includiing over one pretty good grade.

Though I may have paid a little more than someone who peiced it together from a junkyard, the Black Magic was an all in one kit and it did not cost anywhere near as much as those expensive dual fan kits.

 

Ive heard it is wiser to have two, one to serve as a backup in case the controller fails, you can manually wire on/off in the cab. do you know the CFM of your kit?

 

what about just a flex-o-lite fixed fan? i used to run one on my 75 f100 and my 68 f250 and never had a problem there light pretty cheap and dont draw as much power as when a clutch fan is turned on.

 

I checked the Summit website, and I'm not sure they still sell the exact one I bought. I think the most similar one they have is rated 2,800 cfm, and it's more expensive than what I paid. I don't remember mine being rated that high; I thought it was under 2000 cfm. I remember when I bought it, it was listed as suited for up to 210 hp, and that other members had used it successfully on the 4.6. Some of the references for the 2800 cfm fan say it is suited for up to 250 hp, but they don't specify if that is crank or rwhp.

Flex-A-Lite also has a good website. Rather than the universal fan I bought, they recommend a dual fan set up of 5500 cfm for our 4.2 trucks. The same dual fan arrangement is recommended for the vastly more powerful Lightning, btw. IMO, 5500 cfm is huge overkill on a truck that is probably making less than 150 hp to the wheels.