I know you dont like the 160* stats. I am using one just to help keep my car cooler, longer before the temp gets over where I want them at the races.

Background:
I have a basically stock, peanut cammed 305 (w/ 175k on it), TES, no cat, flowmaster (basic ignition mods, ported plenum, 19# injectors, AFPR set at 50psi, and using a Wells maf, fluidamper, a built trans, aluminum driveshaft, 3.23 gears.... and suspension and other mods that dont have anything to do with engine operation. My BLM's are not perfect, but they are in the 132 range which is a LOT better than the 140-150 they were running at.

Now here is the question.

If cooler engine temps are not better for power, Why do I run quicker ET and MPH when my engine is cold? By cold, I mean the coolant temperature gauge is at 100* or below. Oil temp is still "warm" at 100*. The plenum is slightly warm to the touch, but not hot.

I know a cooler air charge will increase density of the air, but this happens regardless of the outside air temp. Of course, if the outside air temp goes down, I even go faster/quicker.

This obviously plays havok with a bracket racer, unless you keep the car at full temp before, and during your rounds... but if you do that, then your ET's are usually less than stellar. If I run at full temp (for me with the 165*-170 with both my fans running), my ET's can be 1.5-3 tenths of a second SLOWER than if the engine was cool. Using a hotter stat(180* or 195*), I run even slower.

I know that with the cooler engine I am not running as EFFICIENT, but it is making much more power... which is the reason most of us are here, right? You have implied in other posts that if your car runs better when it is cool, then it is a programming issue, and that we should be running as well or better with normal engine temps. Is this the case, or have I misunderstood? If so, where can the improvements be made? I want to get my current motor running as well as possible, learning all I can about tweaking my setup, before I go dropping my 406 in there and changing everything.

Thank you for any light you can shed on this,

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Mike Metzler (Desert86Roc)[*] Webmaster: SpeedWorldMotorplex.com[*] Click Here For 86 IROC 305 TPI (406 build in progress) Page

ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.365 @ 86.785 mph (uncorrected, headers, no NOS)
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It's not a matter of what I like. It's a matter of what works.

Remeber, first off your starting with a chip designed to run well under ALL circumstances. From ALaska, to New Mexico. In having the tune that generous, some compromises are made. Just has to happen to keep the EPA, and Joe Average Driver happy.

Even under varing weather conditions you should be very consistent. VERY....

Several things happen when you run a cool thermostat. One often ignored item is oil temp.. There is 2+ quarts of oil just whipped into a foam in the crankcase, all the time blowing againt the pistons. Hmm, guess what?. Ping time. I also always use a valley pan on the SBCs. If the pil temp is over 250dF a cooler goes on.

Not to forget tranny temps., if an auto. I use the large B+M AFTER the radiator heat exchanger. I want to get the tranny fluid as close to ambient as I can, not as close to engine temp that most folks suggest. But, I also, let the car warm up before any WOT...

Runner cooler means the ecm is slightly richer, and more timing.

As an experiment install a 180dF themostat and a 200 ohm resistor inline with the coolant temp sensor and see what happens. Remember the rad fan control will be fubar'd.

You might be having a heat soak problem.

I fully optimised 3 CCC Q-Jets for 160-180-195dF thermostats, and did back to back testing, each pass within 30 mins., and the 180-190 were just as fast. And they were much more consistent.

In my GN, just fooling around, my trap speeds are about button on pass to pass. What screws my ETs, is wheel spin, and shifting into high at about 1250'.

Just a matter of experimenting more with your chip, AND car.

 

Thanks for the reply. I have run a 180 before, and all it did was get the engine hotter quicker. In the 115* summers, thats a bad thing. But for my testing, I will switch back.

As an example, when the motor was completely cool, I ran:
15.362 @ 88.238 w/ 2.114 60ft (normal) 85* outside air temp.

The next run, I let the car warm up to 140* and it ran:
15.450 @ 87.765 w/ 2.124 60ft

With the car at full temp: (165*) I ran:

15.514 @ 87.753 w/ 2.150 60ft


I will try my next runs as you suggested just to see what happens.

Thanks
I usually launch very consistently, with little or no wheelspin.

As soon as I get an adapter for my laptop, I will be recording my runs

 

MPH is how HP is guaged,
so .5 MPH, isn't alot, tune wise. I'd bet you can find that in tuning.