I don't think the 2 or 3 row would make much of a difference at this point regardless of the number of fans used. If you still have a "temp still climbing but only at idle" (with the AC "ON") on super hot days you'll want to swap up to a higher volume H20 pump (your choice of mechanical or electric) to resolve the issue.

 

Or a higher cfm fan.

I may also be able to improve the situation by pulling the shrould back off (outdoors), stick cardboard between the radiator and condenser and spray/clean the condenser. When I installed the 2-row (in my garage), I didn't want to drag the garden hose in there and make a mess. More air thru the condenser may help when it (condenser) gets hot.

FWIW, My temps stay between 190-200 w/o the A/C turned on (according to the dash). (Temps are 10-deg less at the thermostat.)

Occasionally, it will eek up to 201-202 if I sit long enough (10-min). If I turn on the A/C on a 100-deg day, it'll climb 1 or 2-deg each minute. But, only if I'm sitting still, idling. Once rolling, temps will fall back into the 190-200 range even with the A/C running full blast. (My A/C is super cold and has never had freon in 22 yrs!!!)

My compression is 10.25 SCR and 8.25 DCR. My DCR is higher than many 11:1 engines with 220-230 duration (intake) cams.

 

And, reprogram the fans for lower turn-on. This is AFTER you review Vizzards' chart on recommended temps vs compression. Your temps are going much higher than mine.

Seems like you'll be better off with LOWER temps than I'm running. Your compression is higher. (Hence my comments to you in this thread).

You may also need a higher CFM water pump (or electric pump) as Engle, jfb, LT4Bud, and others have suggested in this thread.

 

Results will Vary.

Quit Burring Greg's dick in the dirt.

He has been honest & I appreciate his input.

No 2 C4's are the same.

Neither are driver's.

Any of you guys find a radiator to cool a C4 down the highway at 140 F running at 160 MPH do let me know.

 

Yes I happy with the car.

Like I stated before when not so Hot outside the car Temps are great today it was 108 outside I drove my Expedition today the Vett stayed in the Garage today.

The fun part about driving the Family car reminds you how fast the Vett is and when getting back into the Vett put that stupid grin on your face when you fire it up and take off from the stop light.

 

Just a random question, read through about 9 pages before my eyes started to pop lol.

My question is, i saw it mentioned about how the temps read by the gauge at the cyl head is about 10 + deg hotter than what is read at the front of the plenum near the thermostat.

Is it possible to route the wire that normally goes to the pass head up to the sensor in the front of the plenum? I know the one in the head is a single blade and the other is a dual. But maybe it could still pick up the signal off one of them? it will still go to the comp but that way you can get a more accurate reading in relation to what the thermostat and fans will be doing.

Then again the fan is based off of a sensor in the drivers side head if i'm not mistaken?

 

Cool stuff, after I put mine in %^&.O-Well..I have a 96 needed a new Rad. called Champion said 6 to 8 weeks to get one ? Called Dewitts said would put on truck when I hang up the phone ,got it 4 days latter.. I have a new T-Stat. A/C Delco a chevy one $36.00 worth I just look at it on the work bench I may just put in a aftermarket one ..Sounds like the GM not that good.... The old 96 runs @ around 200 with new parts with air on in 100+ heat some bolt ons.. With old Stat. How to figure out witch new stat. to put in , not the GM.. Thanks for the input... Pic are cool.. big help..

 

WOW thats a long wait can't take that long to make . . . . How much was the Dewitts one?

 

Yea ,I was thinking the same tryed to go cheaper just did not work out was not going to wate that long ..NOT cheap $495.00 but drop in ..No BS just make a few little cuts on the rubber things and drop in and go.. Sounds easy .I cut some conners I cut the three little screws off from the inside with my mini sawsaz and poped the little speed nuts off and turned them around and was way easyer.. The three little screws on each side down at the botton can be a pain.. I just read what everybody had to say about it and came up with a new plain, it worked... I'm happy with it ,just couldn't get cheap goining on this tryed..

 

Three listings on that popular auction site for 3-row Champions RIGHT NOW. Doubt if you'd have to wait.

Also, the new 2-row models just came out. Gotta think they have lots of those too.

Good question about converting/connecting the CTS with the PS head coolant sensor. However, for someone tuning their motor, I wouldn't consider that necessary. Just observe the temps at the cylinder head and program accordingly.

For example, if you want your fans to come on when the passenger-side sensor is sending your dash 200 for a temp, you'll probably be around 190 at the stat. Code 190 as the turn-on in your BIN and see how close you get. Adjust if necessary.

Set your turn-off point about 5-degrees lower than the turn-on point.

To adjust the AUX fan function, you need to find an aftermarket DS sensor with different on/off points. There are a few.

Or you can wire the aux and main fans together. I know people do that for manual turn-on BUT I don't know if they've done it for ECM control. It should be doable since the ECM is indirectly controlling them thru a low-power relay. If both fans [wired together] overload the relay, upgrade to a higher amperage relay.

As noted in another thread, the AUX fan's purpose may be to keep the A/C condenser cool. Makes sense, since blowing across the condenser would increase the load on the radiator.

 

Had the same thing when I called a few weeks back. I said seen your E-Bay thing need one then he starting telling about the wate .I said what and why do I have to wate , I got upset and said I need a cheep one now.. he said 6-to 8 weeks I said I seen them on the site what's the deal..Hung up on me . Maybe better now I was looking at what you are looking at and I didn't get it.. I guess no cheap for you.. NEXT..??????

 

^

I was thinkin of getting one of these greg
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F

They have alot of different varieties.

200 on / 185 off
195 on / 180 off (maybe this one)
190 on / 175 off (thinking this paired with 160 stat)
185 on / 170 off

 

Those are switches for the AUX fan. Even with a 160 stat, I don't see why the 200 on / 185 off wouldn't work. The AUX fan doesn't need to come on until after the main fan.

I bought mine for 1/2 that price at Mid-America Motorworks....also a vendor.
http://www.mamotorworks.com/corvette?frame=3.944

Part#609-106



Edit: OTOH, Mine seems about 5-degrees off. It comes on closer to 195 on / 180 off. Sounds like this would work for you. Make sure you lower the program points for your main fan.

 

Hey Greg this may be a REALLY stupid question but whats the difference between the aux fan and the main fan? My car only has on big fan right in the middle

 

Get on the ground. Look up thru the front intake hole -- just above the center section of the front spoiler. Do you see a fan that sits in front of your radiator/condensor?

If not, you don't have one, but it could be added. If not, you don't need the fan switch. The main fan (as you pictured) is controlled by the ECM.

 

Wow i think you may have just saved me 40 bucks. Yeah i don't have any fans in the front. The A/C system is gone from this car (i'm sure you can still have aux but this car doesn't.)

So i'm guessing then that i could just plug off that hole in the head then. wonder how hard it would be to add a aux fan or if it's necessary. Don't really have any extra cash . . .

 

GJ

I can't see the pics from here but I will def give this a read later.

 

Plug the hole in the head and run it as-is. Program the main fan for similar temps as you WOULD have picked for your AUX fan.

If that doesn't cool enough, a higher CFM main fan and/or ewp is your ticket.

 

Update: Today got up in the lower 100's. With the A/C running, my setup still couldn't cut it after running a few errands around town. It's still much better than the stock radiator but, as I wondered, I can't run the A/C unless the rpms and/or speed are high enough. After ~ 1 hour of errands, I was getting close to 220-deg. My idle started getting a little rough, so I could tell my high DCR situation didn't like that temp.

Since a higher CFM main fan is the easiest next mod, that's probably what I'll try next. Maybe I'll end up needing the ewp someday. If I didn't want A/C, I'd be good-to-go.

Another thing I could try is lower idle timing to bleed off compression. (I hadn't jumped on this option out of concern for my header coating. I've no idea how low [in degrees of advance] it takes to cook the coating. I bet it's related to DCR.)

Before judging, consider my 383 is running higher DCR that many/most strokers on this forum. My cam is shorter duration. (Marv is in the same boat.)

 

Theres the rub....

with the upgraded radiator and other minor cooling system upgrades these engines will run all day in traffic with 110* ambient temps and they will sit at 190 and never think about going higher.....

Until the driver starts to sweat and turns on the a/c.
The condensor heat from those high ambients is so great that its hotter than the radiator, so the condensor pushes the radiator heat UP by blowing hotter air into the radiator and driving the engine temp up.

Mine will do exactly as you described...and within 1 min of driving a steady speed again it starts dropping and will end up back around 189-190 everytime. The trick to this (best of both worlds) is to somehow create some fresh air flow at a good rate for the condensor. Sitting at idle the main fan draws air in and thru, but it gets pulled around the condensor thru the side ducts. Its designed that way to prioritize the fresh air and let the radiator get whats available when at idle or slow speed.
I'll be looking into sticking 2 or maybe 3 small 6" fans on the condensor face wired in a switch that I can turn on/off so the condensor is getting some air pulled in when idling in traffic. My belief is that IF I can keep that condensor cooled enough I can run a/c AND keep it from blowing hot air into the radiator.

I have some doubts that a bigger main fan will help because it would pull more air, BUT it would pull it around the condensor thru the side ducts as it does now, and the key to keeping the whole mess at a reasonable temp is that overheated condensor thats starving for air at stop lights...and making the a/c system go to high pressure and cutting it out until it gets some air flow again...

Then again, this could easily be a no-win situation with modified engines and air conditioning..and stop & go traffic.

This extraordinary summer heat sucks.......