Cylinder Head Temps, My Experience + lessons learned Options

[rwilner]

I drove down to Chris Foley's shop to get his shift linkage installed this weekend. At the charlton plaza on I-90, I stopped to fill up. I usually put premium in the 914 but this time put regular in because it's what I put in my other cars and I was on autopilot. Oh well, I thought...let's see how she runs on 87, maybe I'm wasting my $$ on the good stuff.

Before the fillup, I was running between 300 and 325 F in 5th gear around 70-75 mph.

After the fillup, I was running between 380 and 400! (IMG:style_emoticons/default/ohmy.gif)

I spent the rest of the trip in 4th gear at no less than 3500 rpm to try and keep the head temps down. When I got to Chris' shop, we put the car in the air and drained out 5 gallons. I replaced them with 93 octane before getting on the highway for the ride home. My cyl head temps were back down to 310-350 for the return trip.

Here's what I learned:

• A cylinder head temp sensor and gauge are critical to know what's happening in your engine and should be on everyone's short list. Without it I would never have known of the dangerous operating conditions for the engine. The aircraft spruce gauge/probe are short $$ and a quick install.
• The state of tune has a major impact on running temps (duh). I am still tuning my car with the microsquirt and it's clear I have work to do.
• Higher octane gas makes your car run cooler.

As always YMMV but thought I'd share my experience.
Rich

[r_towle]

Observation
It was warmer on the way down than on the way back.
From charton to foleys is all long ass highway hills.
Your car is not tuned
You never answered me about last weekend.

Rich

[rwilner]

Observation
It was warmer on the way down than on the way back.
From charton to foleys is all long ass highway hills.
Your car is not tuned
You never answered me about last weekend.

Rich

Rich

80-100 degree differentials are due to more than a few degrees difference in ambient temps...plus, I noticed the spike right after the 87 fill up.

I missed your request for last weekend?

Anyway my O2 sensor isn't working and I've given up on the innovate setup. I bought a completely different AEM setup that doesn't require goofy free air calibrations and doesn't require mounting a separate brain under my car. I'm going to put in this weekend if I can find a few hrs to get into the garage again. After that we can tune it up...until I have a working AFR gauge, we're just guessing.

[mrbubblehead]

Observation
It was warmer on the way down than on the way back.
From charton to foleys is all long ass highway hills.
Your car is not tuned
You never answered me about last weekend.

Rich

Rich

80-100 degree differentials are due to more than a few degrees difference in ambient temps...plus, I noticed the spike right after the 87 fill up.

I missed your request for last weekend?

Anyway my O2 sensor isn't working and I've given up on the innovate setup. I bought a completely different AEM setup that doesn't require goofy free air calibrations and doesn't require mounting a separate brain under my car. I'm going to put in this weekend if I can find a few hrs to get into the garage again. After that we can tune it up...until I have a working AFR gauge, we're just guessing.

rich do you have an innovate a/f gauge you are having trouble with? error codes?

[rwilner]

rich do you have an innovate a/f gauge you are having trouble with? error codes?

yep.

No error codes...the LED stays on solid. I just get either full rich or full lean, all the time...like a narrow band. The gauge was showing me I am idling at 9:1 which of course is impossible, especially when I'm fairly certain I'm running lean.

I've tried 3 O2 sensors now, calibrated probably 10 times, updated the firmware, and swung a dead cat over my head at precisely midnight...no joy.

The innovate forums are littered with people having similar problems and the AEM seems more well regarded so I'm going to try it.