Z/28: improving radiator and oil cooler?

[LagunaSecaZL1]

I ran my ZL1 at Thunderhill and it was 100* last month.
See this thread.
http://www.camaro5.com/forums/showpo...4&postcount=11
Summary - water temp 248* and oil temp 270* I also think that the ECM was pulling the timing and reducing the power. So lowering the water temp would really help. I ordered the Ron Davis heat exchanger for the supercharger, which I did not install yet because I have too pull of the front bumper cover. I just ordered(from JDP) the Ron Davis radiator, but it is on 6-8 week backorder from Ron Davis.

I am hoping to accomplish two goals. Reduce water temps with radiator and reduce IAT with the bigger heat exchanger. Since the LSA engine is sensitive to IAT, reducing both temperatures can only help, but it may not solve the problem. If these two items don't solve the problem, then I'll address what I can do.

I would recommend installing a bigger radiator in the Z/28. I do not know if this would void the warranty and if Ron Davis or anyone else makes a direct fit radiator for the Z/28. On the ZL1 there was no easy way to just install a bigger or different oil cooler and this would do nothing for high water temps. I do believe that as water temps get higher, even on a naturally aspirated engine the ECM will pull timing to avoid detonation.

My armchair hypothesis on why this occurs, is that GM tests at the Milford Proving Grounds test track(in Michigan) and not at an Arizona test facility. If GM ran the Z/28 and ZL1 at a hot track location this situation would have been more noticeable. Also the Nurburgring is relatively cool compared to the 100*+ temps we see out west.

[McRat]

Datalog your car. When the engine goes into protect mode, you will see the timing fall.

The LS7 is not going to make the heat the LSA will. It's not just the extra HP, it's also the blower pushing heat into the oil and water.

[LagunaSecaZL1]

Originally Posted by McRat

Datalog your car. When the engine goes into protect mode, you will see the timing fall.

The LS7 is not going to make the heat the LSA will. It's not just the extra HP, it's also the blower pushing heat into the oil and water.

Agreed on the LS7 vs. LSA. What tool do you recommend to datalog?


Sent from my iPad using Tapatalk

[McRat]

Originally Posted by LagunaSecaZL1

Agreed on the LS7 vs. LSA. What tool do you recommend to datalog?


Sent from my iPad using Tapatalk

So far I use EFILive and ISSOPRO for our racing efforts.

But for late GM's today, it seems like HPTuners is more accepted.

I used to be both an EFILive dealer and HPTuners dealer, and at the time, EFILive was a better product.

But going with the "norm" gives you more support. While I will continue using EFILive for my existing race efforts, when the Z/28 arrives, I will tune it with HPTuners most likely.

[McRat]

Off the top of my head, here's what I would record:

Throttle Position
RPM
MPH (can be used to calculate gear)
Total timing
Knock Retard
Side1 O2 sensor reading, volts, Bank1 and Bank2
Reported Intake Air Temp (may be incorrect)
Fuel rail pressure
Oil Temp if available (might have to use external sensor)

And for LSA's,
Manifold pressure
Barometric pressure reported

You will filter for 95%+ throttle position first

[wakespeak]

The Pirelli challenge guys were at COTA with camaros around F1 last year I would talk to them in the pits if you are here in Nov.

I would think a larger radiator and/or oil cooler would fix the issue. it may not take much. The lowered temp thermostat would just delay the heat soak. Keep in mind Chevy has to meet cold start emissions requirement which is why our oil cooler is warmed with the radiator in the SS.

Still your temps may be fine even at that level.

[cdb95z28]

One thing I noticed on the Z/28, the oil tank sits right behind the radiator, soaking up all that heat. This cannot help oil temps.......

[brt3]

Originally Posted by cdb95z28

One thing I noticed on the Z/28, the oil tank sits right behind the radiator, soaking up all that heat. This cannot help oil temps.......

Makes me think some reflective heat shielding might help?

[backtotintops]

great idea brt...I don't think that would mess with the warranty....cover the front of the oil tank.

on the Stohr we used the gold shielding...apparently the same as nasa uses and the only place I could ever find it was here http://www.britsinc.com/

anyone know any other sources? It's the best.

[backtotintops]

Originally Posted by wakespeak

the issue.

Is this really an "issue" on the Z? Seems like it likes to run in the upper heat levels if it's 82 or 102 it's the same and does not go over or overheat at all...at least not reported...just the ac warning light. I did not notice any power loss and all tracks I run require windows to be down...running ac would be counter productive.

I'm comfident gm tested this car in all climates.

[madmax13]

Originally Posted by backtotintops

Is this really an "issue" on the Z? Seems like it likes to run in the upper heat levels if it's 82 or 102 it's the same and does not go over or overheat at all...at least not reported...just the ac warning light. I did not notice any power loss and all tracks I run require windows to be down...running ac would be counter productive.

I'm comfident gm tested this car in all climates.

Road and Track did a Z/28 compro this month and it overheated three laps in (this was in the desert, but the other cars, Viper, GT-R, Aston, etc,did not). So... it sounds like this might be an "issue".

[backtotintops]

yes I heard about that...please explain "overheated" at that event?...was it spurting out coolant???...and do you know if they followed the guidelines as in using mobil-1 15-50, removing the rain shield and changing the coolant mix??? I never heard the answer to that so until I hear otherwise I'm very confident in this well engineered car. It has not been an issue for me so far but I have only run it 30 minutes at a time and at no more than 85 degree ambient.

[backtotintops]

looks like they forgot to take the rain shield out....doooooh...or more likely they knew nothing about the proper track prep for the car. sloppy sloppy!

[brt3]

Originally Posted by backtotintops

Is this really an "issue" on the Z? Seems like it likes to run in the upper heat levels if it's 82 or 102 it's the same and does not go over or overheat at all...at least not reported...just the ac warning light. I did not notice any power loss and all tracks I run require windows to be down...running ac would be counter productive.

I'm comfident gm tested this car in all climates.

I do NOT think it's an issue on the Z/28. After running it for two days at Thunderhill, and temps that hit 106 degrees (I think track temps were over 155), I can state that the car was great. During one run, before the temps peaked, I tried running the A/C for the hell of it. Near the end of the run, it gave me the "no A/C for you!" message and shut it down. I also changed my driving style to shift up in a couple of places where I was holding third at fairly high revs, which helped.

My only point was that I felt like I was skating on the edge in these conditions, and I'd like to have a slightly greater margin of safety. Basic American need for overkill, I guess...