I've previously posted my own experiences with the excellent DeWitts fan. For me it was the final piece of the puzzle for cooling my motor. I easily have double your investment in my engine and would not think twice about using a DeWitts product to cool it. I tried literally everything. I have computer fans in the wheelwell to suck out the hot air. A/O engineering used to make a kit like this. BeCool radiator, different water pumps, pulley ratios to speed up or slow down the coolant, coolant mixtures, thermostat, no thermostat and finally resorted to putting louvres in the hood to let the hot air escape. Our cars are low and are bottom breathers. Once the air gets in, it has nowhere to go. Combine that with the ambient heat, which in your case is extremely high and you have issues. Hot air rises and with nowhere to go only sits at the top of your hood. Only compounding the problem. Some have removed the weatherstrip at the back of the hood to release the stagnant hot air. This works too to some extent. So cooling a modded C4 in heat may be the sum of all parts. Not just a radiator, a fan, water pump or even vents. For me the final piece of the puzzle that made my car driveable in traffic on hot (100 degree days) was the DeWitts fan. For your situation where you have sustained high ambient temps, no one item will solve your cooling woes. And your combinations of solutions will vary depending on your particular engine combo and mods, so as usual YMMV. Your approach to cooling needs to be multi directional if you are to succeed in the desert heat. Hope this helps

 

What is a condenser coil ? I know what a ignition coil is but condenser coil ? Never heard of that ? 1988 C4. I searched it on ebay and nothing came back.

 

I don't know if this comment was meant to be "sarcasm" or NOT but you failed "miserably" in your search of eBay to "research" the term that you weren't familiar with.

The air-conditioning condenser in some terminologies is referred to as a coil, in others a core. Regardless I would have thought you might have "stumbled upon" the terminology.

You've commented several times "EVERYTHING IS NEW" but I don't see anywhere that you mention the condenser condition.

"desertmikes1" comment should be taken into consideration and checked, it's certainly a possible contributor to your situation. Not to further destroy your day but I believe the '88 is a "single year" only condenser.

 

Do you have the optional factory Boost Fan mounted in front of the radiator?

My previous 89 Vette had the boost fan. In any case, the Spal fans are the Best in the industry! I've tried several High Flow High CFM fans from Summit and Jegs and none came close to the torque and CFM rating as the Spal fans!...

Spal rates there fan cfm's mounted behind a restrictor such as a radiator, not Free Air like so, many others which bog down when actually mounted to the radiator.

 

It's the part of the air conditions that sits in front of the radiator. It looks like a smaller, thinner radiator...which is kind of what it does. Air goes thru it...and gets hotter when the A/C is running. I bet older ones get pretty clogged up and restrict air flow thru your radiator.

At the very least it would need to pull more air around the coil versus through it.

Can't say I've read/seen much on owner diagnosing overheating conditions as a result of condensor age. OTOH, plenty have posted about the need to clean it, around, and between the radiator. Many a problem cured from simple cleaning.

On a side note, I can see it seeming logical to assume a high-performance fan could pull as much air -- at idle -- versus running down the highway. In fact, it's more reasonable to ASSUME that than to assume your AE unit is the problem (when it can cool at speed). That was an even more wishful comment.

 

I should have been more specific W/description, but it looks like you got the answer anyhow.

When I had my Radiator removed the Condenser coil was out in the open, and very easy to Back blow/Vacuum. I was amazed had how much crap had accumulated inside of the Fin area. From a casual observation the coil looked just fine.. but when I got up close it was a differant story..

 

I replaced my stock radiator with an American Eagle made in china 2row 1" and cleaned my condenser with a hose up close and personal. If there was any dirt in those fins I cleaned them out. So no my condenser is not an issue. In a nut shell the problem and everyone who lives in HOT climates deals with are ambient temps over 105 degrees. Today I took my car on a 60 mile drive. Outside temps today were 85 degrees because it rained so a bit more humid than usual for AZ. However I was quite comfortable and had my windows open. I averaged 80 mph. I took the car up over 100 to 130 mph when open road permitted. My oil temp never went over 230. Average 217. Coolant temp never went over 210. Average 180. Reason 2 row radiator and yes the Dewitt fan. Maybe I unfairly titled this thread ? But at least now its out in the open that the Dewitt fan is not worth $200. That radiator was $180 delivered to my door and worth EVERY penny. The fan does make my A/C blow ice cold at red lights. It does make my car run cooler when driving. 105 degrees and up well not so much.

 

You need the Dual Fan setup for driving in 105* stop and go traffic.

Two smaller fans are more efficient than one large fan.

 

Knowing how much additional flow...for what conditions would be helpful information. It' typical for any company to market their product as the end-all-solution.

I'm still dumbfounded about the flow numbers posted at the top of page two (of this thread).

 

Greggpenn is why I successfully and for under $200 brought my engine temps down ! Radiator was the key. That thread he posted pointed me in the right direction. The dual fan set up mentioned by GKK costs $350+ delivery ! For that kinda money I certainly hope it brings temps down at red lights in the desert heat.

 

The thing that bothers me about this whole discussion, and the thing many have failed to pick up on is, the OP at the beginning of this thread stating that the" Dewitt's fan is worthless". As most of us know from experience, the Dewitt's fan is far from worthless. The OP is operating his car in the worst environment possible, with air temps way over 100 degrees on most days in the summer. Other then" Death Valley" I can't think of a worst place in the US to try to keep a car cool, so to say he is operating under a unique set of circumstances is an understatement. He is also operating a car that is known to be hard to keep cool, sometimes even in much cooler weather..He was already corrected at the beginning of this thread for his statement about the fan not being a direct replacement, when he was told to just rotate the fan until the bolt holes lined up. So I really think the statement about the Dewitt's fan being "worthless" is a very unfair statement to make and should have never been made in the first place. To many people have had great success with this fan for any "one person" to make a statement that could sway others from buying a Dewitt's fan. In one of his posts he says he may have "unfairly titled the thread", but then goes on to say the fan is not worth $200.00. Maybe from now on he should give it more thought before making such a statement, because most that I have seen have no problem paying $200.00 for a quality fan with a Spal motor that gets the job done. If I were Tom Dewitt I would be quite angry .....WW

 

In Kansas, some summers have gotten well into the low 100's for several weeks straight. Seems we've seen temps above 110 a couple of times. When I replace my fan, I want it to handle that type of heat...and not be looking for a second upgrade.

I think there's some justified frustration (in general with the forum) if people continue to unconditionally tout their purchases w/o being realistic. IOW, there is a syndrome where people they what they've just bought is the bee's knees, the best thing since sliced-bread, the top-of-the-heap. So, this guy is just as frustrated with members as his purchase. He's just as frustrated with "the forum" as his purchase.

C4Mesa has backpeddled to a certain degree and said it's not worthless. I'm not sure an outright apology is in order though. No one has confirmed the ability (for this fan) to cool in 105-degree heat...or higher. I would call that basic needs for many areas of the States. And, maybe some have over-hyped it's ability? I'm not saying they have.

If there really are fans that pull 4k, 5k, 6k or 10k cfms of air, then 2350 isn't a big upgrade IMO. I haven't jumped on a fan yet -- as the needs, common ratings, and correct application haven't become clear to me yet. I don't think this thread is THAT clear yet either.

 

I am not arrogant by any means. I apologize to Tom Dewitt for the title of this thread. If I may explain yet again I bought this $200 fan with the promise of pulling 2350cfm. Stock is 1700cfm. I thought double cfm of air would have brought my red light ONLY temps under 230 degrees. It did not. I got pissed. Is the fan an imovement over stock ? Yes it is. Cold A/C at red lights. If I read that was what to be expected and not a cooler motor at red lights I would have known. Now a consumer can make a more informed purchase. I am sorry again for not wording my thread differently. Corvette Central offered to refund my money minus shipping handling costs. More money down the drain. I kept the fan and do like how it sounds and looks in my engine bay. Worth $200 ? No.

 

If it isn't doing the job for you , why keep it? I would accept there offer and return it and look for something that will handle your special circumstances.. Im sure if you have the money there is something out there that could pull the amount of air your looking for...The Dewitt's is an excellent option for most of us, but like most things Im sure there are situations like what your experiencing where the 2360 cfm won't do what you need...As for what Gregg is saying about us over stating what the fan is capable of, I say, how would we know what the fans maximum capability is, if all we have to judge it by is the temperatures where we live, I don't live in a dessert so I have no idea how the fan will work in a dessert. All I know is it works great in the area I live in , with the temperatures we have .... I really hope you get your problem sorted out, there's nothing worse then having a Corvette, and not being able to drive it when you want......WW

 

I agree 100% with that. The cost of return shipping is better than worrying about future temps. Plus, they will only get worse as dirt collects in your coil/radiator.

More-so, I just think people could be more specific. On the flip-side, I'm surprised that NO ONE else has reported dissatisfaction over 105-degree temps. Could C4Mesa still have a problem? Maybe.

With the give-up attitude (for keeping the unit), combined with an apparent impatience with matching up factory holes, I wonder if enough patience is being given to solving the problem. Spending money and slapping on parts isn't always the best approach.

Oh yeah....How does 2350 cfm compute to double the stock 1700cfm?

 

I don't know what size the DeWitt fan is or what it's supposed to move but SPAL actually I believe advertises CFM and also the amp draw required to make that fan produce. There's way more to the electric fans and water pumps than just a quick cut/splice with whatever wire is close by. There's a good bit of thought that's required. I don't know and haven't looked to see if DeWitt mentions amp, wire size and a wiring scheme that's desired for it to produce.

This is a link that just "popped up" for SPAL fans and there's a "comment" that most could learn from, The rated CFM for any fan is highly subjective! This does have what I would guess are the SPAL "rated CFM:

The Mark/Taurus I understand takes 40AMP to start. Here's the SPAL info I guess:

http://www.a1electric.com/catalog/cat_spal.htm

If the SPAL wasn't a quality piece I doubt it would be the choice of C&R for most of their systems. They display "fuse required" @ 13V some as high as 60 most 30 - 40 or so.

 

I upgraded to the DeWitt fan a few years ago, and posted results in a similar thread to this one.

With the wind meter (as stated) I went from about 6 mph to 9 mph flow thru the grill opening, about a 50% increase from stock.

From the CFM numbers stated in this post:

1700 CFM (stock) compared to 2350 CFM (DeWitt), is about a 38% increase in flow.

So I saw quite a bit more of an increase than the CFM's imply.

Either way, a pretty decent upgrade.

 

Have you checked the Freon charge to make sure you are not overcharged? Especially if you have converted to 134a it will run a higher discharge temperature (this is the temp. coming off of the condenser) The charge with 134a is usually about 80% of the factory r12 charge. If its overcharged with 134a it compounds this problem.
IMO I doubt the radiator is causing it to overheat at idle. My experience has been when a radiator is bad, it overheats under a load driving down the road. An example of that happened to my vette. At 70mph in 90+ weather and ac on it would overheat. Turn the ac off and it would get by, or slow down. This was with an automatic and a 4.09 gear. But now I have a Champion 3 core, stock fans and so far it seems to stay around 180-190 on 90+ days and the highest I seen at idle has been 201. These temps are with ac running. The champion radiator, 160 t-stat, fans reprogrammed, and an electric waterpump are the only mods to the cooling system I have done.

 

C4inMesa,

My 88 vert is a stock 47k car. I changed tstat to 180, added an old mid america fan switch (205 on, 190 off) for the aux fan and added a prom to turn my main fan on at 200 and off at 180 like others have. My freeway temps in town in 105 degree heat is about 195 consistently.

At idle in city traffic I hit can still hit 218. At idle, the heat pulled out of the radiator just soaks into the motor, regardless of how many CFMs you have. With yours hitting 230, I would make sure that your mixture is 50% water, 50% antifreeze + 2 Bottles of Wetter Water. If that doesn't bring it down, you must have your timing advanced as others have stated.

Heat is a killer! Good luck!

 

Last engine (388 ci solid roller lt4) idled around 200-215 in traffic and easy 190s at speed. Stock original 93 rad, fan and a mezziere HD.


Does anyone consider the water pump is barely flowing coolant at idle ? Can't blame the fan for not being able to cool the coolant that's barely flowing through a radiator.