In reference to your exhaust issues you might try what I did on our 1988 C4. I left the WYE pipe in front and removed the catalytic converter and replaced it with High Flow Unit and then I added on a set of Chambered Exhaust from the catalytic converter back. I bought my set from Allen's Stainless Exhaust and I installed them on my C4. They sounded so nice I went back and they had a cat back Chambered system for my 1968 C3.

With a functional catalytic my emissions pass the requirements allowing me to use a regular tag on both my C4. The Chambered System is where they use baffles inside the pipes to quiet them down. There are no big ugly mufflers hanging out the rear of the Corvette. The sound is nice, a bit loud behind you but not inside the Corvette. With the swap out of the cat back exhaust system my Corvette gained almost 14 HP over the previous factory system with 90k mileage catalytic converter.

 

So I did a pretty big thing, new Ridetech HQ shocks should arrive tomorrow and I'll hopefully have them installed quickly. Its about time the 136,000 mile original Bilsteins get replaced. I'll update when they're on and let everyone know how they are for the early C4

 

looking forward to that!

 

So I probably have around 500 miles on the new Ridetech HQs. I began with their suggested setting which was firm but not too crazy. It handled bumps in the road and cornering great, no drama involved. Two weeks ago I adjusted them for a softer ride. Accessing the fronts to do so is not an issues, however the rears take a little more work. Jacking the car up gives more room to reach in but removing the rear wheels is certainly the easiest. The adjustment was 4 clicks and makes a huge difference. It still corners great as a corvette should and rides very nicely. I would definitely recommend the HQs for someone looking to replace or upgrade shocks. When I autocross next year I will post more on them.

Next project to tackles is the glass top. The frame and plastic separated on the passenger's side so I bought SikaFlex as recommended on other threads and will try to fix it myself. As of now the plan is to separate it fully, clean, then reattach and hope for the best. I've got the fiberglass top on now.

 

I have been very happy with the Ridetech shocks so far. I have an 85 Z51 and I went one click firmer than recommended. It is a firm ride but I no longer scrape the front spoiler in large dips at speed. My Bilsteins were still usable and still had some gas in them, but these Ridetech shocks were a night and day change. I have a set of aftermarket 5 spoke wheels so I can make adjustments on the side of the road without much effort.

 

 

Current updates:

The glass top separated from the frame on the passenger side. Instead of just dropping a grand on a new one I decided to give fixing it a shot. I separated the two pieces completely and cleaned the old adhesive off. I have SikaFlex to use for bonding so we'll see how it works out. In the frame was some tape with writing stating that it had been repaired in 1999 so I don't feel bad about trying to fix it myself.

There's a loud banging in the left rear going over certain bumps now. All connections for the new shock are tight. Its right behind the driver's seat and I have no idea what it is.

The driver information center does not work all that well. Or MANY bulbs are burnt out, including the check engine bulb. Not too big of a deal but I would like to fix it.

Lastly I am still having heat issues. The blend door moves around curves(Hard right turns the heat on, hard left turns cool air on). Air blows under A/C settings and Vent, but the blower motor stops when it is under the heat setting. I called Eastern Corvettes about getting it in and was told 6-8 weeks around 10 weeks ago. I'll give them a call whenever I get a chance.

As always, any comments or suggestions are appreciated. Thanks for looking!

 

possibly the small plastic clip that attached the actuator bar to the door has broken. i cant remember exactly how it looks. i just know that there is a clip to reattach when reassembling after heatercore rnr

 

I'm still fighting the Code 32 which I have another thread on and have a step closer to solving the HVAC deal. For the 32 I replaced the EGR solenoid, EGR valve, and temp sensor after switching computers did not solve the issue. It still has the cold start issues where it idles fine but after touching the gas it will buck and pop through the intake. While I was switching the compute I moved the temperature setting in the HVAC control. I could see the arms moving as they should from underneath. Still the same situation though, turn right with the vent on, heat goes on. Left turn, it blows cold. Turn the heat on at the controller and nothing comes out of the vents. It goes to Eastern Corvettes in Batavia, Ohio in a couple weeks for that

 

So I finally did what I should have done years ago and I took the Corvette to Mike over at Eastern Corvettes in Amelia, Ohio. I told him some of the issues I was having with cold start and with HVAC. He said they could track down the issue but it would be far more labor intensive due to their lack of expertise in C4 Corvettes. Their shop specializes in C2-C3 restorations and general work. He referred me to a sho that could handle that quicker and in a more cost effective way. Most importantly he checked out the HVAC issues I had been having. I replaced a vacuum check valve which stopped the blend door from swinging freely. He disassembled the dash and tracked it all down. He said that the threads that move at the blend door were not retaining the rod as it should have. He created some sort of fix for it. While on his way out he swapped in new used speaker grilles, replaced missing or incorrect hardware, repaired the center console lid, and most importantly created a new support in place of the "C" shaped bracket behind the power seat switches to prevent them from falling back. This alone saved me 10 hours of labor as I had the replacement center console frame waiting at home because of that issue. Mike also sent an email every night with a summary, kept me updated on what was next and what was wrong necessitating the repair and photographed as he went. When I picked the car up he had a flash drive with all of the documentation and photos attached to the keys. He's definitely a true car guy and we ended up talking Corvettes for nearly an hour. Little bonus: he fixed my horn! It's the little things.

So after just a few days at Eastern, my dash looks a million times better, the interior is tighter than ever, my power seat switches are useable, I can control the air temp, and the horn works. It was worth the 6 month waitlist!

 

The car now has new injectors, wheels and tires. I found Z06 Speelines and put Michelin Pilot Sport All Seasons on them. The car runs better than ever and looks better than ever. Next step is to put the new seat cushions/mounted covers in