1988 Convertible for sunny day drives

[Tourmax]

Well, It’s still not what I would have hung on the back of the car, but the Greenwood spoiler is back on:

At least it covers the holes and scratches the last guy made installing it.

It will do until I get ahold of enough clay to sculpt a “Shinoda” rear tail cap:

and pull a fiberglass mold off it...

 

[Tourmax]

Well, after two days of misery, some very ripped up forearms and one bloody forhead cut, the Greenwood wing is back on the vette:

It’s still not the spoiler I would have picked, but I was able to fix a few things and make it “flow” better with the car.

Allow me to explain:

Whoever installed it last time made a few “errors” when they did it. Because the rear fascia it’s bolted to is all urethane and no structure underneath it, the oem includes two “struts” that go from the aluminum rear section up to the mounting bolts on each side.

Because it’s an authentic greenwood piece, it has 3 pedestals instead of the typical 2 pedestals you see on repo copies of it. But, the oem (greenwood) doesn’t include a strut for the center pedestal (or at least mine didn't have one), it just bolts through the urethane.

Now, the rear cap on the C4 looks to be straight and flat, but it’s not. It has a very slight arch to it where the sides are lower than the center. The spoiler itself does not mimic this curve, it’s board straight (or at least the pedestal mounts are). So what happens when the spoiler is bolted down is it makes a “dip” in the center of the urethane cap and it leans back towards the rear. Looks something like these:

You can see they all have that "rearward lean" and while you may not notice it at first, it will be registered by your brain as something is just not right.

We all know the C4 is shaped like a “wedge” so having the wedge shape with a big spoiler hanging off the back which slants the opposite of the wedge shape just looks.....well, bad.

So, i built a third strut for the center pedestal. Then I welded a washer to each rear bolt hole on all three of the support plates.

The end result is that when you bolt the spoiler down to the supports, it no longer deforms the tail cap. To the contrary, the struts actually push the cap back to its original shape and the washers help to push the rear of the spoiler up to give it just a hint of forward rake.

The end result is it just flows better with the look of the car.

Plus, now to can push and lift the car by the spoiler and nothing moves. It’s bolted down solid.

This will do until I get around to building a replica of the Shinoda C4 body kit. At least the tail cap portion of it:

 

[Tourmax]

Ran across these on ebay:

Crane cams, full roller rockers. 7/16 studs, 1.5 ratio. NIB, 210 Cad to my door.

The L98 has 113 heads,which means 3/8 studs. But those studs are stepped and the threaded boss in the heads are actually 7/16, so I'll just swap them out. I don't really NEED 7/16 studs as I won't be turning high RPM, but can't hurt either.

I went with stock 1.5 ratio arms. I made the mistake of posting on the "other" corvette forum and got a slew of F-ing stupid/asshole answers, mostly asking or repeating what I put in the original post. I should have known better than to post anything there. I wanted 1.5's instead of the 1.6's guy slap on thinking they will get a HP boost, mainly because if I want to adjust lift, duration and whatnot I'll do it through proper cam selection. 1.6's are just a backdoor way of getting more lift out of the cam you have. Pick the right cam and you don't need to go up to 1.6's. Besides, larger ratio lifters are not a free lunch either. You can get into coil bind, bad geometry, spring fatigue, etc, etc. With 1.5's, I don't have to worry about any of that until I spec a cam.

I'll also have to buy some hardened guide plates and measure/order some hardened pushrods. The OEM rockers are "self aligning" (rely on the valve tip for alignment) and these aftermarket ones are "non-self-aligning". Hense the need for the proper hardened guide plates. It's more expense, but it's a "do it right, do it once" thing.

With roller rockers, I'm after the reduced friction in the system, which will free up a couple HP and help the engine to run a tiny bit cooler. This is just a street cruiser, so it's not going to be about high RPM HP. I'm keeping it as a stump puller, with perhaps a little more rpm range than the stock TPI. I'm fine with the engine being "all in" around 5500 Rpm or so.

Most of the work on this engine is going to be about reducing parasitic losses and improving efficiency while (hopefully) maintaining reliability and MPG. Whatever numbers it cranks on a dyno I could care less about. I want it to shove you in the seat even harder than it does now, without spinning it to high heaven. RPM breaks things, can't enjoy the car if it's always being fixed.....

 

[V8!]

Nice thorough write up on your car and build. Very detailed!!!!

 

[Tourmax]

Nice thorough write up on your car and build. Very detailed!!!!

Thanks, appreciate it.

The thread is more of a "log" or perhaps a "Diary" than a "write up" though. I'm just doing what I know how to do and writing it down as I go......

 

[V8!]

Copy that, it was interesting nonetheless.

 

[Tourmax]

So, just ordered asjustable guideplates and rocker arm studs. A few bucks over 100 all said and done.

Only thing to do now is wait.

once it all gets here, I’ll make myself and adjustable pushrod and see what length I need to properly center the roller tip on the valve stem. Then it’s going to probably be another 100-200 for hardened pushrods and the Vette will be a-rollin’.....lol!

 

[Dale124]

I am sure that I’m not alone in wishing that you lived next door to me. You would be such a handy neighbor to have for us “less than handy” individuals.
Dale.

 

[Tourmax]

I am sure that I’m not alone in wishing that you lived next door to me. You would be such a handy neighbor to have for us “less than handy” individuals.
Dale.

Yeah, edmonton is a little bit of a trek from halifax.

interesting story:

I was actually ”banned“ from Griesbach for life when I was in my late 20’s. We were delivering a couple j85-can40 jet engines to Spar aerospace (I was just a corporal at the time) and that night we got a little too......ummmm, “merry”.

Next morning my Sgt had to drive up from Moosejaw and we all got reamed out by the base chief warrant for a couple hours. Seems they really didn’t like the fact that I managed to put two MP’s in the hospital before the third managed to take me out. Funny thing was, they tried to throw us into cells becuase were were drunk, walking back to the barracks from the mess and were slipping/falling on icy walkways. basically, we were drunk, minding our own business and just trying to get back to our rooms.

It wasn’t my fault they tried to manhandle a bear and the bear turned around and mauled them Lol!

My Sgt pretty much laughed his head off the whole way back to home base....

 

[Dale124]

Yeah, edmonton is a little bit of a trek from halifax.

interesting story:

I was actually ”banned“ from Griesbach for life when I was in my late 20’s. We were delivering a couple j85-can40 jet engines to Spar aerospace (I was just a corporal at the time) and that night we got a little too......ummmm, “merry”.

Next morning my Sgt had to drive up from Moosejaw and we all got reamed out by the base chief warrant for a couple hours. Seems they really didn’t like the fact that I managed to put two MP’s in the hospital before the third managed to take me out. Funny thing was, they tried to throw us into cells becuase were were drunk, walking back to the barracks from the mess and were slipping/falling on icy walkways. basically, we were drunk, minding our own business and just trying to get back to our rooms.

It wasn’t my fault they tried to manhandle a bear and the bear turned around and mauled them Lol!

My Sgt pretty much laughed his head off the whole way back to home base....

Ahh, the good old days. They make for great stories.
Cheers.

 

[Tourmax]

Today I pulled the AC compressor off. Split it down to it's swashplate and pistons, removed any and all corrosion I could find at the body splits and sealing surfaces, cleaned it all up surgically clean, and bolted it all back together with new o-rings and carbon seals.

Bolted it back onto the car and charged it up. I only had 16 oz, but it was enough to get it running, even if it was short cycling. I'll pick up a few more cans tomorrow and charge it up to spec. Then I will see if rebuilding it was worth while or if I'm going to be looking for a 500-600 dollar compressor......

 

[Tourmax]

Coffee with a friend this am:

Then, with coffee properly downrange, I decided it was time to do something about that “bread loaf”:

You know, everytime I try to work on anything on this car, it reminds me why I can’t stand GM. What a major PITA to get that thing out of there! I swear to sweet zombie Jesus I have no idea how they got this bloody car put together! Everything is just impossible to get to and everything is in the way of everything else. if it were a small car without much room to place things, I would understand it being so impossible to work on something. But it’s not. It’s a big car and things are placed (what seems intentionally) right where they are in the way of something else with an acre of space on either side of it.

F’n GM engineers, never a thought that someone, somewhere, someday is going to have to fix the f-er!

5 mins, baseball bat, dark room and the entire C4 engineering team.....thats all I ask for....

Oh well, enough vetching, back to building:

And, the AL that will make the new glove box:

12”x8ft and 1/8” thick. Nice and chunky for welding and adding details, thin enough to fit nicely.

I just hope I can get my TIG skills together soon so I can at least weld up a proper cover. The “box” area will be small, probably literally only big enough for a couple driving gloves.

But I also plan to make it with a small “hatch” in the back so I can mount the Moated APU1 tuner interface in there.

Then, when it’s time to “tune” or datalog, pop open the glove box, plug in the usb and go for a run. Since it’s going to “realtime tuning”, its just pull over, make your changes and do another run right away. Real-time is the way to go. I used to burn chips for obd1, but that was a major pita and slow as hell. Once I went obdII, it opened up real time changes to me (flash memory inside the PCM) and I never wanted to go back to obdI. But with the Moates apu1, I can do real time changes just like obdII.

Once you get your calibration sorted, you can just burn a chip and pop that into your ecm for full time running. You can also leave the Apu1 plugged in if you want.

another bonus of the apu1 is that it lets you run “multiple” calibrations with a few more bits of hardware. A simple switch boxis remote mounted and you can swap ”tunes” on-the-go.

I’ll probably make on general use tune (what you usually run 99% of the time) and I’ll probably make a second one to deal with electric exhaust “cut outs” for when I want to make a few dragstrip passes.

you can also do stuff like ”hyper-mile” and “towing“ calibrations, but I can’t see a lot of use for that in the Vette.

Hmmmm, maybe the mpg tune might be useful for those lazy summer drives.

Or perhaps a ”valet” calibration to hold it to no more than 45-40 mph?

Perhaps I have some more thinking to do about how many calibrations I need to create.

I’m also thinking about that front license plate filler. I might make one of those cold air intakes you see in place of that filler piece.

I’ll have to make it out of fiberglass myself as I’m pretty sure they’re out of production these days, just like the dash piece I have to build.

The C4 is just too old for those “C4 specific” performance parts. The C4 is at that stage in a cars life where it’s no longer contemporary and treading into “classic” territory.

Restoration parts? No problem.

Performance parts? Not so much ....

 

[Tourmax]

Not a bad start:

Not a bad start at all!

 

[RockyPM]

Love your posts and seeing the progress. This car is and will be a beauty for a long time to come as I see the detail and care you are putting into it.

 

[Tourmax]

Love your posts and seeing the progress. This car is and will be a beauty for a long time to come as I see the detail and care you are putting into it.

Thanks.

But I’m just a retired guy in his garage making his corvette.....well, ”his”.

 

[Tourmax]

Getting there:

The “roughness” you see on the plate is from melting through with the TIG. Its not a big deal since the panel will be painted like the rest of the dash. Those “blobs” will just get sanded flush and a skim coat of filler will smooth it all out.

that may not look like much progress, but theres tabs welded to each end (for screws) and a bracket on the outer end to bolt it to the dash. It’s shaped so the two side pieces (center column plastic and fuse cover piece) a fit to the aluminum plate.

now to make the housing to hold the hvac vent and then on to making the glove box cover.

lastly, I’ll make the box for the rear space. Won’t be big, but it will at least be some storage space. Plus, it will be a nice spot to hide all the ecm software/hardware interfaces....

 

[Tourmax]

Ordered up a few bits:

Stingray emblems. They’ll go on the “fenders” above the “tpi” writing for now. I’ll think about the hammerhead emblems for a while longer.

picked up a mag as well:

Article on the mears/shinoda kit. The more info the better before I take a hand at trying to replicate that tail piece...

 

[Tourmax]

Went on a little bit of a “buying spree”.

dealer press kit, 1988:

Neat piece of Vette history from 1988, but not good for much of anything outside of maybe a car show display board.

Shinoda/Williams/Mears press kit and a couple articles/magazines:

Again, not so important in and of itself, but every extra viewing angle I can get of that body kit helps....

 

[Tourmax]

Still plugging away. Vent is now installed and hooked up to the ducting:

The vent still stands proud of the plate, although it’s several inches less than it was with the breadloaf. Good thing is I was able to fit it without cutting the corrugated hose, so should I ever want to go back to stock, it’s just unbolt the new piece and bolt the breadloaf back on.

Right now I’m trying to figure out how I want to do the box lid. I can put a “box” around the vent and then make the door next to it or I can just make the door to go over the vent and leave a opening in the cover for the vent.

A single “lid” would be much less of a hassle to create, but the “split lid” might look more “factory”.

Have to sleep on it I think.....

 

[Tourmax]

It’s fighting me all the way, but progress is being made:

Door open:

The new TIG is giving me fits. Having a hard time getting good technique down. More practice is required...