SnakeFeeder

Is anyone running one of these systems?

http://www.v12s.com/indxcc.html

http://www.v12s.com/images/porsche928twinfansblack.jpg


If so, any comments on performance, ease of installation etc?

jpitman2

No, but have a SPAL 2 x 11" en route now . $203 + $88 shipping (USD). Fits 928 radiator within 1" , 2780 cfm, 20A.
check out here...

http://www.the-fan-man.com/shop/size....html?cPath=33

jp 83 Euro S AT 52k

danglerb

One would hope nobody fell for one of those.

As long as your radiator and basic cooling system are in good shape, most any fan will keep you out of too much trouble, and if your basic cooling system is clogged or not in good shape no amount of fan or air flow will fix it.

SnakeFeeder

Thanks for that...it looks similar to the one sold by 928 Motorsports - but a lot less $. Can you tell me how yours will be secured to the radiator? The 928 Motorsports one seems to be connected with clip ties through the core (?).

By the way are you anywhere near the Gold Coast?

blitz928

I have the same fan as the 928 motorsports fan, It was around $250, I got it from www.smithmotorworks.com

jpitman2

I am in Melbourne. One of the specialist 928 fan offers, if you read the install notes, uses small angle brackets, so I propose to make my own out of aluminium angle.
As for a 928 'with cooling system in good order' working fine with any fan.....Think about an English spec S with viscous and a pathetic 5 blade alloy fan being shipped to Saudi first (summer maxes seen as high as 52C/125F), then to Oz - 40C/014F yesterday, I dont think so. Look at the number of overheating threads here.
jp 83 Euro S AT 52k

SnakeFeeder

Cheers JP...I'd love to see pics when you've finished the job. Any notes on wiring would be a great help too.

I agree with your comments re "with cooling system in good order". Mine is fine (C&R about a year ago with all new hoses) but still hits the 3/4 mark on the gauge when stopped in traffic on hot days.

.

jpitman2

I have spent some time looking at electric fans, looking for something that will do the job I want (keeping gauge between half and the next white line under ALL circumstances). I have a 928MS Zirgo fan on the front, and another 16" on the back of the rad, and they cant handle it in temps past 30C. On the move my temp stays at halfway, which I believe is close to sitting on the thermostat.I have had Discoverys that could idle all day in 45C with AC on, and barely move the gauge. One US supplier of SPAL fans lists the 3000cfm 16" unit as having a 12 month warranty and some 1000 hrs life, when SPAL themsleves say its for racing and special cases, and carries NO WARRANTY at all. Also, the 2 x 11" unit coming is listed by SPAL somewhere as having 10,000hr life , where Davies-Craig list only 1500hr life on their fans.
Somebody elsewhere opined that the inlet area was inadequate, but I disagree. The best air cooling effect is produced when the air can come fast into a large space and slow down, which increases its pressure, and it cools best. There is a Reno racer Sea Fury with an air cooled Wright Cyclone with only a 1.5" gap between the spinner and the cowling, and it has adequate cooling. I see the same effects in my R/C model Sea Fury .
Will advise when the fan arrives, and try to take some pics of the install.
jp 83 Euro S AT 52k

ROG100

928MS sells V12 fan kits IIRC

jpitman2

My fans arrived OK - about 12 days via USPS.
I already had my own alloy angle frame for previous try, but it needed mods. Basically it needs to be 23.5" x 16.25" inside dims. Its made of L shaped angle, some 3mm(1/8"), some 1.5mm. It has a second L on the top that bolts to the top mounts, and enables a cut down std top shroud to be fitted and connect to the air tubes . I' ll post a pic soon.
The fans have 2 power input connections. I stole the original ac condenser fan connection for the left hand fan. I then connected a fresh relay to +12V from the hot post (with fuse) to relay switched power input, output side to a connector (same as ac fan, from Autobarn - called quick-connect), with other lead from connector to earth. Earthed one side of relay coil, and powered the other side from the +12V side of the OTHER fan. If you are happy to run both fans from the one original relay (ac condenser fan), you could avoid this second relay, but I wanted to split the load. Initially I messed up , and had first fan running backwards and no second fan, but it was just a matter of swapping the active/earth connections inside the nylon connector body.
I went for a run on a hot day recently (35C/95F), and after getting everything right up to temp, sat idling with AC on for 10 minutes - needle crept from almost horizontal to 2/3rds between first white to second white line. Fans did not cycle out at all though, but AC was icy cold set on 18C. Fans did not cycle out even while moving. After I got home and parked, fans kept running as long as key was at posn 1. After a cool down, they did not come on again with power, so a little more testing is needed here, but its a sensor and/or relay/wiring issue I suspect. I dont recall what temp setting switch I have in the radiator now, but its not a std one, which is marked 92/87C (ie come it at 92C, cut out at 87C). I have a couple of others (dual range) ready to test, aiming at keeping temp at/under second white line .
The std fan relay inside (original, marked 9/82) was too hot to hold on to when I stopped, which is curious as its marked as a 40A unit. I have replaced it with a new one rated at 20A. The new fans running were pulling so much air through that the condenser fan in front (a 16" Zirgo from928motorsports) was spinning too fast to see the blades without power applied.
Below is the fan mounted in frame. all of the L shaped alloy are facing you. the top piece bolts to the top plate mounts, and the original top piece fits to feed the air tubes. This section is thin ~1.5mm, the rest is 3mm. I had to modify the original mounts (note bottom holes diagonal enlargements) because I moved it left so avoid cramping the auto cooler hose connections on the right. The corners are fixed with 2 pop rivets each. This means it needs ~1/8" spacer washers at the mounts so the rivet heads dont rub on the side tank bases. One possible important issue is the difference in radiators from S to S4. The S has low clearance from the mountings tabs at bottom to the core face (6mm/.25"), where its at least double on a late radiator. I borrowed a late core (damaged tank tabs) to build the fan frame on, and didnt notice this difference until very late. The S core is also 4 row and 428mm high, S4 is 3 row and 438mm high.
Also the Spal fan body has a profile you should take account of. Looked at sideways its like:
rear of fan motor
_______________________
/ \
_____________/ \___________
|__ __| <- bottom
|____________________________________________|

front facing core

@#$^&(*)( diagram looks ok in edit mode, but when displayed, sorry. the core facing side has a step in it - protrudes further forward in most of the centre....
I mounted the face marked bottom to the bottom of my frame, and opposite to top of frame. the front facing core is also NOT STRAIGHT - it has a curved of at least 1/8-3/32" in it. I was tempted to dismantle the two halves and fix this but didnt bother in the end. Basically this shape means you need to work out the mountings differently between a 3 row and 4 row core, as the fan will sit further back on a 4 row core. On an S this may give you issues with the radiator hose on the LHS, and/or the trans cooler and AC hoses on the RHS. This one slips down behind rad quite easily without touching the hoses much.
hth..
jp 83 Euro S AT 52k

FredR

I have used the SPAL twin 12 inch fan unit for over two years and it seems to work fine and it can be purchased for around $300. My original fan system was compromised and I needed a replacement. 928 Specialists did not have their system in stock at the time and I found this after an internet search.

Fitting it was messy and I ended up butchering one of my wife's aluminum barbeque skewers to make some right angle brackets to mount it. I then butchered the stock fan mount to recover the inlet shrouds and bolted that to the fan frame- the whole assembly then bolts to the brackets on top of the radiator. If there is a problem with a fan motor then I hope that the Spal units will be easy to replace and hopefully, moderately priced. This set up improve clearance behind the radiator significantly and also gives a stock look to the thing.

I believe the stock fan control system [S4 +] does not deliver full voltage for some reason [maybe it feels it does not need it according to the temperature programme?]. I beleive some folks have relayed full voltage from the auxiliary 12V post when required.

Do not forget the fan system is only designed for tickover/slow traffic type situations. Air blast does the rest at speed.

If you have overall cooling problems due to warm ambient temps the first trick to remember is to use Redline water wetter and dilute the coolant to say 20% anti freeze/80% water. Water cools much better than glycol. The Water wetter contains its own anti corrosion package but of course be wary of winter temps if you have big extremes- I was frozen yesterday morning- it was 15C! I nearly had to wear a sweater.

Regards

Fred R

SnakeFeeder

Thanks for the update JP. As it happens I ended up ordering the unit from V12s a few days ago. Apparently they make each one from scratch so I'm delaying my cam belt job until the fan unit arrives.

Also ordered the powder coated upper trim plate from 928 specialists which is just slightly shallower than the top of the stock shroud - so it should solve my problem of the C&R radiator sitting a few mm higher than stock.

jpitman2

You may find that the 2x 12" will be difficult to fit in an S due to auto cooler and ac hose lines on driver side. The rad core is barely 24" wide, so the fan casing will probably go outside the end tank plates, which will push it further back, and exacerbate the clearance problems. The left hand rad hose is different from S to S4, and some have had to cut and splice that hose in an S to get clearance. In my case with the fan casing well forward (due to 3 row core), it almost touches the hose at rest, so I am watching for any signs of chafing, when I will pad it with something.
Do you have the dimensions of the C&R handy?
jp 83 Euro S AT 52k

SnakeFeeder

It's difficult to measure exactly because I have a heat shield over the top, but it (the C&R) appears to be approx 620mm wide x 420mm deep x 70mm thick (note the 620 width is just the core...not including the side tanks). Mine is not an S so it should just slot right in. The V12s people said it will definitely fit the C&R, and in fact on their website they show their own aluminium rad that looks pretty much identical to the C&R.

mark kibort

whats wrong with the stock fans. they work fantastic. Personally, i control them manually with two redundant relays. one controlled by temp switch and the other is manual.