With some careful cutting to angle the 4-5 inch elbow, I managed to get the 5 inch intake tube in place. The new radiator is 1/4 inch thicker, so I’m planning on notching the edge of the plastic fan housing by the elbow to make sure there’s adequate clearance. Moving the upper hose to the passenger side will let me drop the pipe down to clear the hood, plus keep the heat out of the intake charge.

 

Need to update your signature (LOL!!!)...

 

haha I know. I'll get around to it eventually!

 

Wow i was about to make a thread basically with the exact same issue but worse since T/A bumper have worse airflow to the rad than a Camaro. To the Op, love the channel and the work you do. Hopefully you figure this out as soon as Im about to dive into remedies also. Im running stock 3rd gen rad and dual fans, I have the original airdam but its beaten up. I dont have those under belly pieces to funnel air to the rad support mentioned above but i think that would help alot for my situation while moving. I do not have the original overflow tank since the turbo resides in that are and put a small canister style purge tank in. Im seeing the same temps and doesnt come down even with both fans on all the time.And after a hr drive,when i park the car..it would push water out of the surge tank, freshly rebuilt lq4. Ive tried burping it 5 times and running the 4 port steam vent,heater core is functional and coolant hoses are all new accordian style metal tubes bent to fit. Im getting a 3row rad and will try slim dual fans since space is non existent. However i have noticed each yr when i spray ceramic coating on all my hotside and coldside..my temps come way down per season.Extracting the hot air out the engine bay is the bigger issue imo. At this power level alot of ls motors are tuned leaner at idle and run hot from what Ive seen.

I think your onto something though LsxMatt with the foam to seal off the rad...but I equally think getting the hot air out has to be addressed. Im thinking about opening up more area around the fender vents for flow, made the t/a hood vents functional,any other place to allow more fresh air in and extract hot air out cant hurt at this point.

 

14.7 is not ideal. In magazines and on the internet it is for some reason. My engine idles at 13.8 with good tan plugs. I would start reading plugs and adjust your idle af ratio.

In addition that fan shroud isnt sealed to the radiator it will pull from the path of least resistance so no air through the radiator , though gaps around shroud.Usually the condenser is sealed to the back of the radiator as well.

 

So I ended up trimming away at the core support to get everything where I wanted. I’m most likely gonna end up with a tubular support some day, so cutting this really didn’t bother me. Anyway I trimmed the over hang off to move the radiator closer to the condensor. This gave me just enough space to fit the 5 inch intake tube and keep the vacuum cleaner fans. I really couldn’t be happier with the way everything fits. I have the new dual pass dropped in place so now the 5 inch tube clears the hood being the upper hose is on the passenger side now. In addition the radiator is very close to the condenser so minimum foam is needed to seal the two together. The cherry on top is the fact that I can pull the fan shroud without having to remove the throttle body anymore! Everything just fell together so well.

I’m waiting on a longer upper hose and I just need to re-fab the brackets. Tomorrow I’m going to clean up the cut and paint the exposed metal. I also want to get some rubber edge guard just to keep a soft edge against the radiator.

 

Its not how many cores it's how big are the cores. You can have a 2 core 1-1.25 inch each core or a 3 core with .63- .85 inch cores. Getting less but bigger cores is a less thicker radiator the fans will work less to pull air though it. Look at the Champion 3 row(core) the tubes are .63 inch thick. The 2 core( row) is .75 thick. Surface area on larger cores is what you are looking for and 16-18 fins per inch. Here is a nice pricey unit. Dont know if your shroud has the cutouts in the bottom of it.

 

ROWS, not cores. Almost all radiators are single core

 

I wasn’t specifically looking for a 3 core, I needed a dual pass so I can move the upper hose. This one just happened to be a 3 core and was the only one I could get in the time I need it for. The overall thickness of the core is just slightly larger than the summit it replaced. I’m not concerned about the radiator thickness inhibiting fan flow, these Derale’s move massive air. I get more suction on the front of my heat exchanger with these fans than I did on the condenser with my old fans!

 

Have you tried driving around without the hood on to see what your temps look like? And would that black piece you have extending from the bumper back towards the bottom of the radiator be impeding air flow? I removed everything underneath and in front of my radiator(except the air dam) so there's a large open pocket there now and my car runs substantially cooler.

 

That black piece came with the air dam kit I got on ebay. The only thing I left off were the ducts that go behind the fog lights into the condenser. I’m also wondering if that hole in the upper plastic trim where the hood latch use to be is an issue. I really have no idea how air flows through the front of these things, but maybe air is going up through that opening and avoiding the radiator a little? Also it could be that the fans are pulling hot engine bay air down from there. I might try covering that up temporarily to see if it helps. I haven’t tried driving without a hood, but idling with it open made a massive difference.

 

Might be worth temporarily removing that black piece that came with your air dam kit. I've learned over the years that air flow isn't always as simple as it appears - important factors such as high and low pressure(think vacuum) created during movement and convection are often overlooked.

 

My mistake. Do you have a comment on the row size? Or did you skip that on purpose?

 

The thing you are not looking at is the size of the rows or tubes. Core thickness, thicker doesnt mean better. Actually a thicker core requires a really powerful fan, plus your pulling the the ac as well. You want as big tubes as you can fit. Usually a 2 core with 1.25 inch tubes is really efficent and the fan can easily pull across it. A 3 row with .63 inch tubes is not even 2 inches total plus the pump has to work harder to push through smaller tubes. Rows of 1.25 gives you alot more surface area for the liquid to dissipate heat. Forget the 2-3 or 4 row radiator description. Look at the tube size.

 

I talked about this already in post 83, you're a bit late to the party

​​​​​​​

 

Sorry I didnt know this was a party? Guess the clown showed up early.
Maybe you need to repeat yourself like you always do. Your advice was unheeded if you havent noticed. I dont need a clown like yourself correcting my posts. Your not a moderator, and ignorant to say the least. Dont be another Drew.

 

Dude, you're using completely INCORRECT terminology. I WILL correct people when they say the wrong thing. The CORE is the whole part between the tanks. The TUBES are what the coolant travels through. The TUBES are in ROWS.

The only ignorant one is you You're the clown, you f**** moron

 

Gentlemen, please.

 

Matt, i had cooling issues with the original procharged 305 stock radiator, stock dual fans. temp was always high and the a/c made it worse. i swapped in the tuarus 3.8 fan and it helped some. when i put in my LQ9 6.0 it runs cool as can be although i don't have A/C hooked up yet. i went with a stock replacement thermostat, stock 3rd gen radiator and the same taurus fan. the one with more blades... i think they make a 5 and 6 blade.

get rid of that 160 degree thermostat. think about it. if you hit 160~ degrees it will be open most of the time and circulating coolant through the radiator and not allowing it to sit and cool in the radiator.

 

I can throw my 180 back in but I had the same issue before the 160. I might do it anyway, I haven’t filled the coolant yet.

 

Matt,

Can you recap what the car is doing right now? This really shouldn't be tough to solve. I feel like we've missed something.

 

Gonna watch this thread to see what ends up being the fix, rad ride mate

 

I'm the same way when people refer to wheels as "rims" . It's just plain wrong terminology. Not being a troll or trying to create drama...

 

Sure here’s the updated rundown:

So at the beginning of the thread the car will IDLE at 205 degrees, in 80+ degree heat without the a/c running. The fans are programmed to come on at 195 and off at 190. The car will just stay at 205 and never get low enough to kill the fans.

With a/c on at IDLE it slowly climbs 235+. Low speed driving it runs around the same temp with the a/c on. Getting on the highway my temp will drop down to 195. This is with the 2 core summit radiator and dual 12 inch 1328 cfm a piece Spal fans with the ebay aluminum shroud. Any ambient temp in the 70’s or below the car will maintain about 200 degrees or less idling with the a/c on.

I installed a Taurus fan later in the thread and this marginally improved. The car took longer to get hot, but eventually started creeping into the 230s again when the day was hot enough. A/c on theres really no issue. The car still sits a little warm for my liking, but its nowhere near the 230s it would be with the a/c on.

I tried changing the timing at idle but it made no difference. I then ran the car with the hood open and it would sit around 200 with the a/c on and not go any higher. Hood open and a/c off, the temp would
get into the 180s and the fans will turn off. Keep in mind this is ONLY when the outside temp is high enough. On a cool morning or later in the day, the fans will cycle down to 190 and turn off. This issue only plagues me in the warmer months!

I then tried the 4000cfm Derale fans. These seemed extremely promising as the car ran around 200 with the a/c on for much longer than the other fans I tried. But once again, after enough driving and getting enough heat in it the temp creeped to 229.

Soooo my current progress as of today. I just installed a champion DUAL PASS radiator. I’m hoping this will help cool the car being my old radiator was a single pass, but it really just seems to be an issue with getting the heat out of the engine bay. I’m looking into alternative hood options in case I need to go to something with better venting. My primary reason for the new radiator was to move the upper hose over to the passenger side. Being I went to a larger intake it has been sitting on the upper hose heat soaking my air charge. I also modified the upper core support so I can fit those massive fans being they worked the best.

 

You open the hood and it makes a huge difference in the coolant temp.
This suggests that the hot air from the engine bay is being sucked up by the fans and blown through the radiator, cooling nothing.
It's plausible. Get your face down at the ground all around the car and find out where the heat is actually going.

I have AN 84 T/A with the ground effects and had cooling problems also. I haven't figured it out yet. I wonder if the above is my problem also?

 

Thanks Matt.

It seems to me that by now the problem isn't the fans or the radiator. Both would keep that engine temp down at idle no problem. If I were you, I would now focus on the circulation of coolant. I would do two things at normal running temperature/fans on and then again at the elevated temperature:

1. Check the coolant system pressures at the radiator inlet and outlet
2. Check the coolant temperatures at the radiator inlet and outlet.

If you have a low pressure difference across the radiator, you may not be getting enough flow through the radiator.

If you have low pressure and a big temp drop across the radiator that would indicate to me that there may not enough coolant flow through the system- for whatever reason.

 

I got the radiator installed today so I’ll try this tomorrow. I’ll post the temps of both hoses.

 

Heres everything together. I just need to repaint the core support and fab some kind of cover to hide the radiator brackets. I managed to fit the 5 inch pipe with some room to spare. Just by moving the upper hose with the dual pass radiator my idle iat’s went from 130 to 90. Im also going to dig around tomorrow and see if I can find the rest of my air dam intake system. I have the two ducts and flat sheet of plastic somewhere I think.... I was gonna remove the heat exchanger, install those pieces and see where the temps go.

 

Wow, a 40*F drop in your IAT? That is a HUGE difference. Could heat soak from the blower and intercooler be a factor in the engine cooling issue? I doubt IATs that high could have been good for the blower/ heat exchanger. I'm curious if the open air filter picks up heat soak off of the radiator while driving.

 

Im trying anything at this point! Crawled through ticks and spiders to dig these out from behind the shed today. A little deformed from sitting under a bunch of other parts, but most of it is there. I’ll probably tape over the hood latch opening to seal it up.

 

Looks nice Matt! Curious to see if this fixes the cooling issues. I'd be curious if removing all the air ducting in front of the radiator had an effect as well as covering the hole where your hood latch used to go.
And I don't know how thick the material is on the lip of the radiator but it kinda seems like a good idea to run a strap to bridge the two lips together....appears to be alot of weight hanging off of it and it appears there is no structural support on the side/ends of it?

 

Matt, How do the two individual ducts mount. I found mine in my basement and am planning on doing exactly what you are doing. Did they just bolt in with clip nuts and body screws?

 

You know, I'm just thinking could the hot air could "short circuit" from the fan output down and under the radiator shelf and back into the radiator. This could explain why the cooling is weak.

https://www.thirdgen.org/forums/body...-plastics.html

 

Beat you to that one Tootie: >>> #124

 

Lol! I should have checked but I've read this thread several times. I'll be danged if I'm going to read it again!

 

So I found the two side pieces for the rest of the intake system and got it installed. I just taped over the hood latch opening for now. For one thing this thing will suck a paper towel through the grill duct, so the fan airflow is definitely coming from outside the bumper now.



So after doing quite a bit of driving some stuff has changed. First off it wasn’t anywhere near 90 today. High was 76 with 95% humidity. The most humid day yet, but I’m not sure how much that really stresses the cooling system vs. a high ambient temp. So all of this may have had no change, but I’ll tell you what it’s doing anyway. So first off idling temp with the hood closed was staying at 203, fans on full speed, remember I put the 180 stat back in. A/C on it got to 206-207 and stood there for a few minutes before I turned the car off. This could just be because of the low temp outside, but it was also very rainy all day so I’m sure the water was helping cool the condenser a bit. But regardless it didn’t go higher than 207.

The biggest change I noticed was low speed driving. Driving off idle to around 30mph the car runs much cooler. I can pull away from a light at 207 with the a/c on, then the coolant temp will drop down to 199 in a matter of seconds. Cruising on the highway it ran about the same temp a/c on or off, around 200. Remember I pulled the heat exchanger and joined the lines temporarily so I’m sure thats helping along with the factory air ducts in place.

I’ll check back in when I get a high 80s to low 90’s day and see where we’re at. My buddy who tunes the car said thats better, but it could really run cooler than that with an ambient temp in the 70s. Also my plan for the heat exchanger is to ditch the 3 inch core all together. I have a 10 gallon tank in the hatch, so I should be able to get away with a smaller heat exchanger that can allow me to keep the air dam duct in place. I’m eyeing this one with is half the thickness at 1.5, and will fit perfectly flush up against the bottom of the condenser allowing me to keep the ductwork in place.



Also I took some temp readings of the radiator hoses. The top hose halfway between the engine and radiator was at 175 with the a/c on, and the bottom hose around 135-140

 

Real promising. Bet you nailed it now.

No point in going back, but part of me wonders how much of the improvement was radiator vs. stopping recirculation of hot air over top of radiator. If you're super duper curious, or want your own episode of Myth Busters, then I guess you could undo the air flow improvements and find out.

 

Yep, it definitely will lose coolant. Those small aftermarket bottles don't have enough capacity for cooling system expansion. I once got my engine hot after throwing a belt and the stock bottle was full nearly to the brim. Level dropped back to normal after cool down. Seems the old engineers knew what they were doing with those big bottles.

 

I'm going to do this on mine. Plus, next oil change I'm going to fabricate a cover from the radiator support to the oil pan, full side to side to block recirc. Car got too hot today and it shouldn't have. Stock L98, functional hood grills, Taurus 2 speed fan, three core aluminum radiator. Must've been 85 only and it got too hot with AC on. Fan was hauling too. This is bull!

 

Is that really a concern with a stock hood? LSXMatt has an aftermarket cowl hood that is maybe the real culprit.

I have a stock Firebird hood and my radiator wash goes back and out under the car. Stand next to my door and you'll get a heat wave blowing on your legs.

 

I dunno. But I gotta try something. My factory hood grilles have been modified to be functional. A lot of heat comes through there with the car running. I just don't get why it's so challenging to keep these low temperature engines cool.

 

I think I know why. There's an engine under the hood.

 

Ok I think I’m finally seeing the light at the end of the tunnel with this. We had an overcast but hot and sticky day today so I took a drive up through the city. The hottest the car got was 209 while sitting for a while with the a/c on. Once the again the improvement in low speed cooling is phenomenal. Everything the coolant temp did was completely predictable. Come to a stop, temp gets around 205-207, start moving and its down to 198-200 within 15 seconds. I actually drove the entire time with the a/c blasting, I even had to low the fan speed because i got a little cold! Not once did I even come close to having to turn the ac off. When I finally got to my destination I sat idling for about 10 minutes and the temp actually went down a degree from 209 to 208 and just held there the whole time, still with the a/c on.


Now these temps were all without a heat exchanger hooked up. I just looped the cooler hoses together and ran the pump that way for today. Thats why the iat is so high, so once I get the new exchanger installed the temps might drop some more. The only thing I’d like to improve on is the idle temp with the a/c off. That sits around 200-205 and it won’t get low enough to cycle the fans off. I did put the 180 thermostat back in, so I’m considering putting the 160 back to see if that helps any. Maybe even drilling the 180 will improve coolant flow through the dual pass radiator some.

Regardless this has been a massive improvement so I couldn’t be happier with it right now. Aside from swapping the thermostat I’m still going to eventually wrap or coat the headers, as well as move the vented catch can. Adding a heat extractor in the hood will probably also help a lot. I found a carbon fiber one with a zl1 heat exchanger that doesn’t look TOO bad, but I’m still really on the fence about it. I’d leave it alone but I’d really love to try some road racing with this thing someday, so the car can only benefit from it. I also have a parallel flow a/c condenser on order so that will improve the a/c performance even more finally ditching the old tube and fin.

 

That is good news! It's gotta be low speed/stopped recirculating of the hot air. The fans pull plenty of air so what's the difference when you are moving or not? You aren't recirculating the hot air.

 

Well done! I'd consider it a huge success to be in low 200's on a hot day with AC blowing.

Yep, I think you had really good insight on that earlier. I don't know what others think, but to me it seemed like that was the Aha! moment in this thread.

 

I think the fans aren’t moving up to their full potential yet either. My alternator is only charging at 12.7 when loaded with the ac, fans, heat exchanger pump, and blower motor. I have a 270 amp dcpower alternator on order. It puts out like 200 amps just at idle. Even moving the 140 I have in their now only puts it around 13.1 volts. No loads its around 13.4

 

Thanks, this really is a huge improvement and now I finally feel like driving the car in the summer again😂. I think the thing I love most is the fact that I can actually get into a little boost, do some quick shifting on the street with a little rpm and the car actually cools itself off. Before it would just gradually get hotter with any kind of low speed driving and rpm. I think most of it has to do with that upper air dam guiding in air from outside the car. Before it was just sucking hot air from under the hood. I’m sure the radiator helped a little, but I’m glad I got it because I needed the hose relocated for my intake anyway. I’ll keep the updates coming as I dial this in to cool even better!

 

That wasn't me the first time, that was NoEmission84TA in post #124! Well done!

 

Thanks, but I am just glad some progress was finally made with this cooling issue.
Now I finally have some good ideas of what to look when my car gets back on the road.
I will never understand how this can be cooled, even at a lowly 145 HP. There is nowhere for the air to go!

 

Here’s the hood I’m considering. They make it in glossy carbon fiber as well. I don’t know, I’m also trying to think of a nice way too add vents to my existing hood.