TireSmoke.org

From 11/2 track day

Well I replaced the MAF in order to fix the lean condition at WOT, but it did not fix it. I now suspect the TPS has a dead spot after 1/2 throttle (or maybe the guy installed it wrong!). I have a spare from a TPI I bought going to try it next.

I also
* fixed the power steering leak - just a loose hose clamp. And well yes I replaced the fluid it was brown from just 150 miles.
* cut open the oil filter - no metal shavings at all but yikes there was a bunch of carbon in there
* fixed the headlights - the low beams are burnt out I needed to replace the RF adjuster it was rusted so I can point the bulbs lower. Test drive got no high beam flashes from oncoming traffic so it must be OK
* made a to do list and shared it with the team. If this car is going to race next year I will need help
* started a spreadsheet to help determine value of various year C4s based on the parts that are interchangeable with the 89

Please tell me that oil filter was left over from when you acquired the car. That can't be a fresh one after the engine work you did? Any thoughts on how all that carbon happened to be there?

wxo wrote:Please tell me that oil filter was left over from when you acquired the car. That can't be a fresh one after the engine work you did? Any thoughts on how all that carbon happened to be there?

That filter was brand new. Thing is this is the backup engine that I threw together so the car would run. Truck heads and cam, replaced the valve seals and the crank bearings, and fixed one of the valve seats. None of this engine was tanked I just cleaned the gasket surfaces and reassembled it. I underestimated or forgot how "unclean" it was on the inside. I may have aggravated the situation by scraping off some of the carbon buildup then doing an inadequate job cleaning it up, not to mention detergents in the fresh oil and all that extra heat loosening things up.

The current oil filter will be on there for maybe 100 miles then I will change it again, and repeat until it stays clean.

Updates:

1) Hood:
a) was hitting the passenger door. Adjusted the hinge to make it clear
b) had to adjust the passenger side hole. Fortunately it all fit under the hood pin plates, which I have now secured to the hood.
c) removed the old hood latch mechanism
2) driver comfort
a) blocked up the holes in the A pillar with cardboard
b) bought a 150 watt heater need to plug it in and see if it can actually defrost anything - Harbor Freight special we'll see
3) Lean at WOT:
a) TPS. Tried the spare TPS I got from a Camaro TPI it has different resistance readings and throws check engine code. Must be from an earlier year. Did some checking - TPS is showing steady increase in resistance on the ohm meter. Have looked around can't find a spec on what is acceptable range. Decided it would be easier if I could doing some real time diagnosis, and ordered an ALDL to USB cable along with software to turn my PC into a scan tool.
b) checked all around the wideband O2 bung looking for air leaking in but no signs of exhaust leaks
4) Fixed the windshield wipers - spent a bit of time reading wiring diagrams. Step #1 was check the fuse. Fuse was missing. Installed fuse and fixed the problem
5) Wipers do not clear the hood. Raised the hood but still hitting. Note to self: get lower profile wipers next time. In the meantime I ground a bit off the rear lip of the hood to make room
6) left front marker light out. Took some debugging to figure out the ground connection in the socket was bad. Replaced the socket with a spare from Saturn inventory - even the wires were the same color! I am still trying to figure out how the prior owner managed to break that little tab? His legacy is leaving the car one item at a time.
7) build research:
a) found the specs for the factory fuel sending unit (0-90 ohms) and located an aftermarket gauge.
b) radiator research: current radiator is .75" thick. V01 heavy duty is 1.25" thick - this is pretty much all you can get new these days. Can get a 1.6" or 2.2" thick radiator at Summit for under $300 before discount. Don't want to carry more than we need.
c) tried to locate pre-fabbed C4 brake duct to hub/rotor adapters. Currently no one making them. Ugh thought aftermarket parts would be available. did find pics so I have ideas how to make them
d) front hubs: can get an adapter kit to use some heavy duty bearing on front of C5, which can be adapted to C4 based on what I read. The bearings were $350 each and another $300 for the adapters. Seems a bit steep. According to another C4 team they are using stock bearings no issues so far. That is likely where we will start.
wiring: decided to clean up some wiring. Removed the evap canister and horn wiring from under the hood. Separated the wiring connector at the firewall on the driver side and removed all the circuits no longer in use. Chased these back through the interior wiring harness and cut them at the source. This was not a big yield of weight or complexity, but it was a break from the less certain problems that need addressed.

Since last update:
* removed the power window mechanisms and set up a method to install the windows for storage and driving around on cold days. The windows, mechanism and wiring was 37 lbs
* acquired ALDL cable and software to tap into factory ECU. Install on my laptop and run some tests. Nothing obvious wrong
* got the wipers working it was just a fuse lol
* horn wires and evap canister wires are out of the harness, as are the remaining parts of all unnecessary circuits on the driver side wiring harness, all the rear view mirror and visor vanity light wiring and the spare wires in the passenger side harness also removed

Since last update:

* Autometer AFR gauge installed
* Third brake light now flashes under braking just like F1 cars
* Prep for the new to us fuel sending unit - clean up the rust, open up the filler neck for our fuel cans, add some vent holes to reduce the air pocket at the top of the tank
* Test drive confirms the AFR is not pegging lean, rather our Innovate Motorsports gauge / possibly O2 sensor was wonky. We seem to be around 13 at WOT which seems a bit lean
* Acquired the rest of the engine where the heads/distributor came from. It was a flood car which seems to have wrecked the pistons but inside the crankcase was clean which means we have the roller cam, lifters, pushrods and other supporting hardware, oil pan, factory oil cooler, flex plate.
* Also Z51 rear spring and both Z51 sway bars. Learned the spring codes and bar diameters before this
* Acquired a spare hood - it has a hole in it as often happens when the latch seizes up someone cuts a hole. It was cheap and I want to experiment with aero by cutting holes in it for improved cooling and reduced lift on the hood
* Purchased Frostbite 3 core aluminum radiator, aftermarket fuel gauge and race seat manual slider

Today Fred32v was over and we went to work on the paint. Lots of improvement!

On the front bumper cover and the right rear, the clear was failing so I sanded it off with 320 and we buffed it with DRX-16 buffing compound

You might have to paint the roof panel now. At least black if not red. Looks good!

-BP

I like black on the roof and all MostMint cars have had black headlight covers so make them black also!

Basement Paul wrote:You might have to paint the roof panel now. At least black if not red. Looks good!

-BP

Roof panel is going to be red. No way we want black absorbing heat we want to get rid of heat not add more.

Now the headlight covers are much smaller and not over my head so probably not an issue. It is interesting that pop up headlights are the thing for Mostmint Racing.

A fifty year old buffer with 25-30 year old DRX 16 and some equally old glazing compound.
It was what was available and the finish was so incredibly bad there was nothing to lose.

This polish job didn't real make the Vette faster, but it surely helped improve the motivational factors.

A rewarding fun time.

Looks like fun stuff for you guys. A slick body will make it go faster (theoretically).
Now here is an idea that will definitely make it go faster...(theoretically). You could get the actual cut-back racing plugs or just experiment with modifying regular plugs.

Motor Week review of two 1985 Corvettes

https://www.youtube.com/watch?v=M9FwU9iUmfo

13.9 quarter mile with the automatic, and it is lighter

That 13.90 is impressive. I didn't think it would be that fast. My stock C5 turned 13.65.
What gears does the Vette have that keep it at 95 MPH in the quarter?

GM