Hey guys, everyone has helped me out a ton with getting my Procharged 89 running right and helping me understand how the car is supposed to run so I was looking for some overall feedback on what coolant temps you guys average on these L98 engines, especially you guys running a supercharger.

I live in Southern California by the Coast so the temperature rarely gets over 95 degrees here and I have a 1989 ZF6 Z51 model with Procharger's Intercooled kit and the car has a 3 row Aluminum radiator and today I am going to be throwing in a 160 Degree thermostat. I have the front fan turning on with the ignition and that is functioning and I have no leaks anywhere and the compression test had 175 psi on each cylinder. I also only run 93 Octane in the car. I have removed all AC components from the car except for the Compressor as I am waiting for the delete pulley I ordered from TPIS (If you are going to order from them expect to wait awhile)

I do know that supercharged engines produce more heat although when I am cruising and not beating on the car I average around 215-225 around town with a bit of stopping, on the Highway I average about 205-210 and I am fine with both of these as these cars do run hot but when I do drive spirited and then stop or let it idle the temps go up to 230-240. Is this normal and I am being crazy or is this something to be concerned about? thank you.

 

Not unexpected. Make sure the thermostat is a "high flow" . Also program the rear puller fan to come on sooner-or even put a switch on it to toggle on. You have to keep in mind that the intercooler is a big block to airflow to the radiator. Do those 230-240 temps come back down fairly quickly? Something else to keep in mind when looking at coolant temps-the dash reads from the right head/the computer sees the sensor from the front of the intake manifold, so your dash is usually reading 10 degrees higher than what the ecm sees and uses to turn on/off the fans.

 

I think I am going to do just that and add a toggle switch for the rear fan. The temps always come back down easily when driving.

That is good to know that the temps are a bit lower, on that same note what would be considered dangerous in terms of coolant temps?

 

If it's past 240 headed to 250 I would be stopping to let it cool off.

 

Thank you, I've been seeing mixed opinions on this. I do know that you're in California as well so are you running the intercooler that goes in front of the radiator or are you running a different setup?

 

Prochager P600b-printed off the CARB website says intercooler has to be on the front of car-so I just redirected the air thru it. A lot of work....


A lot of folk don't care for a scoop, but I figure if it's functional then it isn't rice LOL!

 

I think I've done everything possible to make it run cooler and on a 100 degree plus day I will still see 220 and change on the dash in stop and go traffic with the AC on. Only project left is to add an engine oil cooler-going to shoe horn it in behind the radiator-where the power steering coolers sat. Not as much airflow there but it was good for the factory to put the steering cooler there and it'll be 36K BTU.

 

These are my recommendations target temps for engines made in the era near the SBC (pre-02) with forced induction
1. coolant temp 202-218*F
2. Oil temp 205-220*F
3. Intake air temp as measured before throttle body by plastic isolated IAT gm genuine sensor : No higher than 112*F for 93 octane gasoline with less than 9.8:1 compression

-IF compression is higher than 10:1 I do not recommend forced induction on gasoline fuels with these type of engine platform
-If IAT rising above 114*F on gasoline I recommend stop and resolve this before the engine can be truly reliable for long term (more intercooling)
-cooling the oil and air is priority, coolant temps of water can be indirectly influenced by the oil temps, e.g. an OIL cooler may be a more appropriate response to uncontrollable rising coolant temps on the daily driver applications (oil is a more important, pivotal role in cooling the engine internals)
-invest in quality fan and extra capacity radiator system if possible
-locate the intercooler in the bumper, do what it takes, cut and fabricate elegant solution, no need for stuffing in the hood or whatever
-Do not recommend a water coolant temp less than 196*F for normal operation and wide open throttle
-never run the engine hard with thick cold oil temps < 190*F or so

 

So it looks like you built an LS turbo'ed in a 240SX that actually has a front grill. It does look like a really nice build. You could never build that in Kali and pass smog (yes jealous!) However on a C4 bottom feeding air it is much more difficult to make it all work. Also on a side note-it's not just static CR but also add in the cam/boost for dynamic CR. I'm 8:1 static but max on dynamic.

 

When you cross into the realm of forced induction, sacrifices are sometimes required, sometimes optional. I understand the corvette is a difficult package. Turbo apps require true master fabrication skill set and facility. The supercharger offers a uniquely compact solution, however the act of intercooling for gasoline applications is non-negotiable, and this is one of those sacrifices that should be made. Build the car around the intercooling and oil cooling. Remove the wiper bottle, relocate the radiator, cut the core support, fabricate brackets, order a custom core, have something with special high end tanks made for your specific setup, high mount or V mount. If you are careful planning it can be quite elegant and unobtrusive. If the intercooling isn't right, the engine will not be safe. It is your engine at risk, the sacrifice to be made offers protection, depending how you handle it.

I only list the max compression ratio for gasoline recommended based on the integrity of a block with factory internals from some era. I have enough experience with SBC and LS applications I can safely state the recommended Wattage throughput @ BSFC for traditional forced induction within a high confidence interval for success. We do not need to know the total Compression with boost, because boost is not compression. You can detonate an engine without boost, creating a very high spike of pressure with incorrect tuning or temperature. Boost is not the issue at all, the magnitude of boost is negligible with respect to cylinder pressure which is in the 1000's of PSI and the actual damaging potential. Heat (wattage), efficiency (BSFC), temperature of fluids (combustion reaction rate control variable), tuning (timing, EGT, EGP, a/f ratio, etc...) lead our setup practice ultimately to some integral of cylinder pressure over some useful range of rod and stroke ratios, which develops stress in the engine components pre-determined by engineering whether ductile or brittle. The fence of compression is another line of safety factor for mediocre tuning and variable setup practices, a sort of blanket or generalist point of view for random population samples. Ultimately the cylinder pressure is a control variable just like intake air temp, you CAN control it no matter how much power or boost is being used, up until the integral of cylinder pressure is extracting max useful work at whatever fuel quality (which is also variable) from however many cylinders. I tune all types of engines 4 6 8 10 cyl for automotive gasoline and luckily they all work with similar principles and follow similar thermodynamics, however technology has placed its shoe in that door and we must differential 'tell the difference' between modern chambers, modern injection strategy, and for engines which pre-date those the rules are different, making experience AND knowledge a requirement for tuning and setup principles in general, for safety, performance, reliability, etc... one size does not fit all. Nevertheless the general rule of 'cool the air as much as you can' when it comes to gasoline is still an acceptable approach, whether or whatever the max allowable temp may be, you can have a theory on that, I know I do, but its safe to just stay as far from that borderline/edge as possible in any case.

 

OK, whatever........

 

 

I Like the hood scoop you have but that is definitely a ton of work. I just threw in the 160 Thermostat ( I learned that the IAC needs to be reset on these cars after the throttle body is removed so the car ended up sitting for a day as I learned this) and at the moment it idles at about 180 and after driving at around 210.

I am going to install a toggle switch for the aux fan so I can have it on when the car is turned on. the goal is to keep temps in the sub 220. I am also toying around the idea of an electric water pump, I had one in my 92 LT1 and it was incredible but if anyone advises against this some input would be great.

 

F1a-94, 383 lt1 solid roller 6spd

stock radiator, 160 t stat and reprogrammed fan 1 and fan 2

i avg 174F, never more than 180F in 85F stop and go

i also run 40/60 antifreeze/ distilled water and water wetter

 

my 92 Lt1 ran significantly cooler than this one too, I believe the reverse flow cooling is the reason for that

 

Okay further update, installed a toggle switch for the aux fan and listened to the advice of Driveit and used a thing of Water wetter and the main fan comes on with the ignition. Aside from an oil cooler I don’t think I can possibly do anything to bring these temps down as even with all this, I average 225degrees after about 30 minutes of driving.

am I missing something? Is there a possibility there is still air in the system and I need to bleed it more?

I am running 50/50 premixed antifreeze with the water wetter, would straight water with the water wetter be more effective by chance?just looking for further ideas and advice as it seems like it is just impossible to cool this car down from factory spec.

 

You can run a higher percentage of water and it would help, however with the intercooler in front of the radiator it's blocking airflow-no getting around that. If we had a nice big open grill it would make a significant difference. I've also opened up the license plate area for more airflow and will open it up even more. Our temps hit 111F today-that's hard on any modded car.

 

I actually didn’t think of that, I have my front license on so I’ll leave that gap open and see if it helps.

 

Go to the hottest place on earth and operate your car at maximum power continuously and see what fails first.

 

You have to cut open behind the plate.