kwhiteside

Please tell me how you did it.

I ran 207 degrees ECT with both fans on all day long last week at RRR. I currently have a dewitt's radiator, stock thermostat, stock water pump.

Would a Evans 180f High Flow thermostat keep me below 190f at the track, in the sun?

Ken . . .

wallyman424

whats wrong with 207?

Falcon

207? You ain't running hard enough.

Hell, I, along with a lot of other Vette guys, see 230's during a race.

kwhiteside

I'm getting Knock and having to reduce my timing so much I'm losing ponies. GM states 180-190 is the preferred LSX racing temperature. The guys at EFILive brought it to my attention, I thought my temps were good too.

Falcon

There's no way these LS6's will run at 180-190 if they are on track.

You might want to check your tune or go to 100 octane gas. Maybe Raftracer can give you some advice.

wallyman424

yeah, if you're getting knock theres something wrong with your tune, the gas or even the spark plugs youre using.

LSx engines run hot. 200-220 is the sweet spot.

AU N EGL

207 is a stroll down the paddock

rustyguns

i hit 250 on summer days! go faster!

Aardwolf

A lower thermostat won't help lower your temps as your temp is already well over the opening temp of the thermostat you are using. They would both be full open.

6SPEEDZ

I would suggest the following
1.check the quality of the fuel
2. calibration if its not the stock tune
3. you can change the coolant vent system to the old LS1 four corner vent system you will need to due a little grinding on the bottom of the manifold. this will help to even cylinder temps out.
4. as for the temp it looks pretty cool to me but you can make sure there is no debris in the radiator or condenser, the air dam is not bent up, no tears in the fascia, the foam sealing strips on the condenser are not blown out and lastly the lower your car is the hotter it will run.

kwhiteside

Hey Guys,

Believe me, I'm working the tune and many other things such as cooler plugs, possible clanks under high G's, lowering my AFR in PE mode, incresing knock recovery rate. My EFILive thread would make your head spin.

This thread was to hit just this one piece of the equation. Water temp needs to come down. I realize I'm wide open at the thermostat. It seems that what needs to happen is more flow from that wonderful Dewitts radiator I have. The suggestions are lower temp HIGH FLOW thermostats and a better water pump.

For those of you that are happy with a temp like mine, I'm happy for you that it does not present a problem. Perhaps your engine is a bit more fresher than mine. Perhaps you have knock and don't know it. How many of you are doing black box logging every session at the track?

Here are the premises

ripped from Pumba
The GM Engineers recommend that engine coolant for peak LS engine performance should be between 180 degrees F and 189 degrees F. In fact, the C6 race Corvettes built by Pratt and Miller turn their idling engines off if the coolant temperature reaches 190 degrees F. That being the case, you shoul purchase and install a Vinci Hi-Performance 170 degree F thermostat that will stabilize the coolant at approximately 185 degrees F.

ripped from geerookie
If you are looking for better air flow and cooling at the track you can do two things.
One, look at DRM's instructions and cut out the fan shroud as they show for the rad install. The fans will never flow as much air as you can at speed at the track.
Next, a 160* thermostat won't help anything other than causing your car to run too cold at colder temps. The proper solution is a high flow thermostat at 180* or 195*. Evans makes one. A lower thermostat doesn't make a car run cooler unless the temp is too cold to warm the car anyway. Water flow and rad size cool the car. The proper thermostat just regulates the flow of coolant to maintain the temp.

ace996

Power-robbing knock at 207degrees is a problem that needs to be examined. Lowering the coolant temps to under 190 will be a band-aid...there's still something wrong.

I've never heard of a vette running under 200degrees on track.

Good luck,
TomK

kwhiteside

Do Vettes from up north in the colder weather run faster trap times? Yes

Why do all the Vette guys open their hoods to cool things down?

I pulled my plugs today and found them white (see attachment). I'm attacking all contributing factors. Water temp is probably the least of them. Still, its worth exploring.

tjZ06

207 ECT is way low to start seeing knock. I was just at THill and it was about 105 degrees F out, I actually saw about 230 ECT (which is way, way higher than I've seen before, Ron Davis radiator w/ EOC etc). I had no knock and no timing loss that I know of. I wasn't logging but power delivery seemed great all day. I actually pulled dead-even with a new ZR1 out of 15 down the main straight. The driver has 200+ days at THill, though not a lot in the ZR1. I think I got a bit of a run on him through 14/15 but still, my car at last dyno only did mid 420s RWHP and ZR1s dyno a LOT more than that. He was obviously heat-soaked and in low-timing tables, my car was pulling fine.

-TJ

rustyguns

supercharger=heat

RedLS1GTO

The temperature of the thermostat has absolutely no bearing on the temperature so long as that temp is higher than the thermostat setting. I don't know where exactly the info is coming from, but 207 isn't too hot for an LSX. Period. I see that on the way to work.

Colder air = more dense = more power = bigger trap speeds. It isn't because the water is cooler.

Opening the hood after a run cools down everything. You have a lot of heat coming from the engine, headers, and everything else under there and when stopped there is nowhere for it to go, and no cool air coming in from outside. So... open hood lets it out. Again, it has nothing to do with water temp. It isn't just Vette guys that open the hood. It's pretty much everybody.

I agree with the others that have said 207 degree temps are not the cause of your knock.

AU N EGL

The C6R is a different car. Huge Dewitts 4 core radiators that lay forward PLUS extractor hoods.

Putting in a bigger radiator and extractor hood to get that air though the radiator and out the engine bay.

Ideally temps right around 190-205, But that just does not happen.

kwhiteside

Thanks guys, enough of you well respected guys seem to agree (which is actually quite unusual), so I'll consider my water temp good and focus on other areas.

wallyman424

I'm more concerned about why that one spark plug looks different. Easy stuff to check would be the injector, plug wire, and coil. I'm sure you're all over that stuff already though.

tjZ06

Also, looking at your plugs I'd say your tune is very suspect. Take a look at this chart:



Keep in mind these things are not the law, but general rules of thumb. However, your "white" plugs do read like you're getting pre-ignition (which obviously you are, since you heard the pinging).

Are you still a stock compression ratio LS6? If so you're either way short on fuel, way too high on timing, running entirely wrong plugs, or have a major mechanical issue.

Also, I really hate to say it but that #7 plug looks bad. It looks like you were running lean enough to melt or crack a ring land and start to get oil into the combustion chamber. It looks like that's what you're seeing on your plug.

The Gen III/IV motor is notorious for going the most-lean in cylinder #7. So if you're getting dangerous lean across the board, it's the first to go 9 times out of 10.

Sorry.

-TJ