topmover

My LS9 has 25 track hours with a total of 8000 street/track miles. I got flamed on the ZR1 board when I said 50 hours would be asking a lot. Any experts care to offer opinions of how long I should expect it to last and should I get the valve springs checked/replaced.

rayk

Subscribing. But the LS9 is a tough well built engine. Change the oil and run it. I don't think SM changes springs and their ZR1's get run a lot hard.

topmover

I agree with your comments on the LS9 however I use to try to see what SPM did with their cars as a gauge. After having gone to level two school there other than the toll of missed shifts those cars dont consistantly get pushed by the majority of the students the way a typical advanced driver pushes. Thats not a slam on SPM because I loved the place and the crew and will likely go back just my observation.

Katech_Zach

I don't think you should have gotten flamed. 50 race hours would be quite an achievement for a 638hp road race engine. That's like running the 24 Hours of Le Mans twice.

Valve springs are a different story because I don't have durability testing to back up my comment, so I'll run with an opinion. I would probably check them where you're at right now. The LS9 doesn't have as much lift as most of what we're running so they should last longer. Or, if I knew I had a missed shift, even if realized quickly and re-clutched, I would check spring pressures on at least a few.

froggy47

What are the (other) "weak links" on LS motors that are tracked HARD.

Sorry for a little side bar on the thread.

Han Solo

Not even close! Running five or six 30 minute track sessions in a day with rests in between could not possibly equate to running 24 hours non stop.

93Rubie

At least, you use your Corvette like it should be used. They are to busy discussing what is better Zanio or Adams's waxes. Ignore them.

rayk

I like that statement. My wife asked tonight when I going to get the rubber off the vette from the last track day. It ain't pretty right now.

After reviewing the LS9 specs, I just think it should last a long time as it's built right and the tune is everything with a boosted engine. I put a Kenne Bell running 10 psi on top of a 4.6 ford when new and it ran great when I sold with 32k and lot's of track time . Had powdered rods which aren't known for being strong. Dyno'd at 396 rwhp which equates to around 450 crank.

Just my opinion of course. I think GM took pains to make sure it wasn't a warranty dog.

froggy47

How hot does it get oil/water? There's lots of speculation & I have only driven one as instructor at an autox, so not a fair test.

topmover

I appreciate the input.

At Summit Point where I use 2nd and 3rd a lot the car gets temps of 250/300 if I dont dial it back.........VIR is not so bad due to less low gear running. I change the oil frequently.

Katech_Zach

Two of the most common problems we see are piston failure from too much horsepower or improper tuning. The LS9 has an advantage over other LS engines here because of the forged pistons. The second is oil starvation from modified cars with slicks. The fix for that is an upgraded dry sump system.

I know it sounds crazy but it is cumulative. All things being equal, 12 2-hour races is like one 24 hour. Now, most (all) of us don't drive as hard as Jan Magnussen or Johnny O'Connell, so the duty cycle we're putting the engines through is much less, and why he has gone double the hours that a pro team goes between rebuilds.

Whew! That is hot. At those temperatures wear is accelerated. It's good that you're changing the oil frequently. We're finding that our hardcore road race customers are needing to change the oil after ever event. They get done with a weekend and the oil is black like it has 6000 miles on it. If you could get your temps down you could prolong the life of your engine more. The ZR1 really needs a louvered hood available in the aftermarket but there isn't one that exists yet.

jvp

Joe -

You're nuts to run in 2nd and 3rd on that track, IMHO. And I say that knowing just how fast you are, too. Upshift. You have GOD'S own torque in that motor at all RPMs. Use it.

Given the temps, spring for an upgraded radiator as you were discussing in the ZR1 section (and BTW, I didn't notice any flames...). I agree with Jason that a properly built louvered hood would do that car wonders at the intensity you're pushing it.

jas (the slightly slower version of you)

AU N EGL

My oil is black as black after 500 miles or two weekends.

DIC oil Monitor goes from 100% after oil change to 65-70% after one weekend and down to 20% after the second weekend

rayk

I was reading the data on the LS9 and it states that if the IAT goes over 175, severe engine damage could result. Might want to monitor.

I put a cowl heat reduction hood on when I had the mustang. Made a big difference in temps.

Cobra4B

I'd really like to see this Tom I change my oil every 3 race weekends and my DIC barely moves more than a few percentage points. FWIW my car is a 2001 Z06 so maybe the recalibrated stuff.

I can't see the point of changing oil after every track weekend. Just because oil has turned dark doesn't mean anything about its condition. Send a sample to Blackstone labs if you care to check.

I run 8-10 track weekends a year (mix of TT/instructing and W2W). I change my springs every 2 years, but I have a stock 2001 Z06 which is docile compared to an aftermarket cam.

I'm surprised your car sees oil temps that high even with the factory cooling. Racing on the hottest days the hottest I've ever gotten is 269. I'm using a DRM cooler kit with a Setrab 625 cooler.

You going to be at VIR next weekend?

~Brian

0Anthony @ LGMotorsports

That is a lot of time on the car. We typically pull the race engines out at 30-35 hrs to have them go through them. Of course your not putting that kind of time on it, but your running a lot hotter than what the race cars see. We may see 180-210 water temp and 220-240 oil temp. Your seeing 230-250 water temp and probably 240-280 oil temp. That makes a difference.

Remember we have just over 12k street miles on Lou's car plus track and event use.

You need to get the temps under control first and foremost. That is going to put more strain on everything in the car from the bearings to the blower parts.

A bigger radiator, a better intercooler would be suggested before even thinking of adding power to the car.

I would also make sure you are running a good oil and change it often. I would even go as far as to run race oils in the summer during track season and change them every 500-800 miles and then go over to a street oil in the winter time.

Start a log book on the car. End of every season do a leak down and compression check.

I'm a bit **** on stuff like this, and as cheap as the parts are, do valve springs at the end of the year. If you know you over-reved the engine...change them. What's $200 in parts when your dealing with a $30k engine?

The engine itself has taken 18-21psi on a stock short block and taken it like a champ. Of course if you do something like that you need to make sure it's tuned right, your running the right plugs, and correct fuel. Stock boost levels shouldn't be of a concern to you right now.

0Anthony @ LGMotorsports

Depends on the oil....most of Redline Oil's race oils use a dye that will change the color of the oil from a blue-green to almost black once they become heavily used and fuel contaminated.

Cobra4B

10-4 good to know. Never used Redline motor oils. Currently always use Amsoil XL 10w40.

cruzin2

I was at Mid-O in May. Ambient 95. Track temp 103. I ran 235 oil temps but there were a few C6 base cars running in the 275 range which is pretty hot for oil.

topmover

I will be at VIR this weekend but will only use the ZR if the C5z doesnt hold together.

I plan to take the car into the dealer next week or the week after and have the springs checked and a leakdown if they will do it. After that I will probably start with water wetter at least until the winter as Im not sure if I will keep the car or get a new one/something.

I have no plans on adding HP as aside from the heating issue for this car I think weight and driver improvement probably is much further up the priority list(or that sweet LG areo Package).............besides one heavily modded car is enough headaches for me to deal with as it is.

I will post what I find out on the springs etc.