Well, I finally got to drive the GT, though not at Hallett. Just down Riverfront in Tulsa. My dad was signed up to track the car on Day 2, but it rained him out. I still drove in the rain, but the car was acting up (per usual
). I didn't have full power, but really couldn't use it all anyway. The GT was definitely an experience! I am a pretty hefty guy, so I barely fit in it. I definitely couldn't have fit with a helmet on.
We definitely had the best paddock out there, though!
No ribbing about how dirty the car is, I got enough from my family.
You can see some videos of my runs here:
https://www.youtube.com/user/GimpyHSHS/
I definitely wasn't "fast" out there, but the Mustang did pretty good up until my last run on Day 1. The car was acting up. It felt like it was "breaking up". That was also the run where I gave my dad a ride, which stunk, because I wanted to give him a good scare.
I did, however, give my cousin, Mike, a decent ride. The thing he liked least was a very fair pass on an old Torino. He also didn't like my late/hard braking in general. I put on a new set of rotors, Raybestos ST47 pads, and fresh Wilwood 570 fluid. The brakes performed flawlessly, and were probably the best part of the car. If I'm just gonna get out there and baby them, then I wasted money on a good setup and I might as well just cruise around the track in 2nd gear going 30 MPH.
I was having a little overheat problem at AutoX the Sunday before the track day, nothing too major, but the engine got up to 227* after several back to back runs. That isn't much of a surprise considering you're hammering on the engine but going fairly slow and in second gear the entire time. But I wanted to eliminate that as an issue at the track if possible. So prior to the track day, I removed the condenser, as it had some flattened fins and certainly wasn't HELPING cooling. I also flushed (and got some nasty trash) out of the radiator. Then I installed an air dam to help direct some airflow up into the radiator:
Those things seemed to help a bit at the track. Temps never got over 220* with the heater on. On the cool down lap, they went down to below 200* before even bringing the car into the pits. I need to verify that the temp gauge on the Sniper is accurate anyway, since it's a common issue for it to read high.
I'm not sure where the loss of power came from. I sent the guy who does my tuning datalogs from the run with my dad on the Thursday night we were at the track. He modified the tune and sent it back. We put new spark plugs in on Friday morning at the track and uploaded the new tune. The car still felt pretty flat. Lurched and chugged in gear at anything below 3000 RPM. Even at 3000 RPM, it had no power, then around 4000 it would take off, then wouldn't rev over 5000. Not cool, car, not cool. I took some datalogs that I am planning to send back to the tuning guy tonight.
I started doing some diagnosing this weekend. Started off verifying the fuel pressure was still at 60 PSI. Looked good, at least with the car off and at idle. Then I wanted to rule out a worn distributor gear being the issue. If the gear were worn, it may cause timing at the engine to be different than what the Sniper is programmed to command. So I set the Sniper to "static timing" at 20* and put a timing light on the engine. Timing was dead on 20* and stayed there perfectly while revving the engine up and on decel. The better thing to do would probably be pull the distributor, BUT I think the static timing check is good enough to eliminate that for now. With how bad it was running, it would've had to be REALLY off, and it wasn't even off by a degree when I was checking.
So I pulled the valve covers next. I checked the rocker arm adjustment, and everything looked ok. I'll put a feeler gauge on the rockers in the near future (since it was about time to adjust them anyway), but none of them were loose enough to have caused the breaking up I was feeling on the track. No excessive play in the pushrods that would indicate a wiped cam lobe. No wear on the valve stems.
Compression was 120 on all cylinders, which is what it was last I checked 6 months ago (That compression seems low for an 11:1 engine, but I think dynamic compression is just a lot lower because of the cam size and the 41* of overlap. I also was only letting each cylinder "hit" three times with throttle closed, mainly because that's how I had done it last time and wanted a good comparison).
That's as far as I got for now. I will do a leak down test as soon as the tester comes in (my cousin didn't have one at the shop, and wanted one anyway, so he went ahead and ordered it). Then I'll reset the rockers to .020" lash.
I have just been checking fuel pressure at the bypass regulator. I am going to try to check it while driving next. The Sniper has 3 inlets for fuel and one return port. I am going to hook a gauge up to one of the other ports on the Sniper and stick it under the windshield wiper so I can watch actual fuel pressure at the Sniper while driving.
Anyone have anything else I ought to be checking? Advice is very much welcome and appreciated!
