this isnt tech, not gonna post pics, if you have one of the dewitts upgrade fans for the C4 with the single fan and you would like it to be quieter, there are several things you can do. the fix that I'm most happy with is to install an "S" blade fan in the excellent dewitts fan shroud adapter.you can do it either by drilling the rivets out and reattaching the new fan ( the same holes line up), or buying an empty shroud and installing the fan in that. I've tried several different 'fixes' in my quest for a quieter fan. the two speed taurus with a volvo two speed fan relay, worked very well, never had to use high speed. but after two used ones quiting, i decided not to reinvent the wheel. The "S" blade fan pulls over 2700cfm compared to the straight blade at 2370cfm, compared to the stock 1400cfm , and I can close the hood and hear the engine instead of the fan....the 2nd fix is for you tall folks, I took some manual seat tracks, beat the rear curved mount flat, and elongated the hole so it would bolt to the floor with out having to drill holes, theres more technical ways to do it, but this method gives me almost an inch of space between my head and the roof. is very nice not to have to slouch and I no longer need that magnifying glass clear roof to have head room, hope this helps

 

Hmmmm, dont have the overheat issues really but that extra inch of headroom is really interesting. I have power seats tho I will hafta check that out.

 

True the curved blade fan is quieter but they are less air flow, not more. Our curved blade is 2070 cfm


Q. What's the difference between the straight blade fans and the curved blade fans?

A. The straight blade fans provide maximum cooling for their size. The curved blade fans sacrifice a small amount of performance in return for a much quieter fan. If noise is an issue, go with the curved blade fans. If ultimate performance is the objective, use the straight blade fans.

 

I didnt use your 's' blade fan , went with another vender whos was rated at 2700 cfm, didnt see the 's' blade listed on your web site. Many thanks for your input , bob

 

if you're tall ,you probably never use the power function or move the seat foward or back, you could put one on the drivers side and put your power mech on the shelf for when/if you sell the car. hope this helps. you can get a manual track for bout $25

 

just looked again to make sure I wasnt fibbing, no 'S' blade fan listed, update the page?

 

this is the stock fan, bout 1400cfmthis is the spal upgrade, bout 2370cfm, works good but noisy...this is a cheap 's' blade fan, installed in the spal fan adapter, 2700cfm, quiet, works excellent, but no warrantee....I also tried the used taurus fan, didnt last...long...noisy.. this one is 3600cfm, also installed in the spal adapter, lifetime unconditional warrantee, no questions asked, C4 cooling on steroids, perfect fit, reused the spal fan adapter, low amp draw, very quiet, computer balanced blade, I can close the hood and dont hear it over my engine, same price as the noisy, no warranttee spal, only issue, it only comes in the red cage...hope this helps

 

So Bob, if you were going from a completely stock set up, I assume you would need to buy the spal adapter and the 3400 cfm fan --where can these be purchased?
Steve

 

spal adaptor from dewitts , and the fan, thats actually 3600cfm, sorry bout the mistake, from FF Dynamics, and checking their site now has a 'lifetime' warrentee. you can get the fan on flea bay for $120, on their site its more , but has the same warrentee from them. Dewitts doesnt list the fan adapter , you have to call or email. you could make the adapter out of thin guage alluminum. it needs the 4 bolt holes , a 16" hole in the middle and then attachment holes for the fan 1/4", hope this helps, I bought two of each.....just in case, but I dont think I'll need the spare anytime soon. this is a very quiet setup.

 

One big problem I have had is the amount of road dust my fan kicks up all over the car and engine.

Any chance your fan mod fixes this as well?

 

I havent noticed any increase in dust, course the roads down here are pretty clean, with the extra volum of air movement , I have noticed when I open the hood there isnt that heavy heat hitting me in the face. I'm going to do another mod to allow more heat to escape while running, but havent got to it yet.

 

Do you notice a significant drop in temps while in traffic ? I know it should cool off alot faster than stock fans while in traffic

 

thats the reason for doing this, it used to go to 220-230-with the stock fan and 200-205 with the other fans, now it hasent gone over 195. we arent having the 100 plus temps like a month ago, but it worked the same then. I did install a variable speed control that starts the fan slowly at a lower temp , and gradually increases speed as its needed, also reduces the amp draw for startup, although this fan only draws less than 20 amps without the vsc. BTW with the vsc you can adjust on and off temps , give it a short cool down after you shut the key off, and have it work with the A/C the same as stock, just more reliable

 

Do you havea link by chance never been able to pull up by a seller (ebay noob).

Would like to upgrade my 16" spal to a 3600 IF its a plug in deal like the spal. Dont want to use those clamp on probes.
Last fan cooled a pretty stout 350 Ok but worried the stroker will be a little too much.

Like to find some specs ie amps etc prior to purchasing.
only have a 50 amp alt and no room for a bigger one.

 

http://ffdynamics.com/..... here you go, you can remove the plug from your old fan and install it on this one and plug it right in to the original from the car, works fine that way also, BTW bigger amp alternator doesnt mean bigger size case, you can get 90, 110, 140, and 200 amp alternators in the same size case.

 

found something else that 'just works' ,' C5ZO6' offset wheels , 17"-18", fit the front on an 87 and earlier perfect, and the rears only need a 1" hub centric adapter, it makes them stick out bout an inch, might help someone with an early C4 who's trying to figure out that chart