Most poorly designed object on C4!
Drifting
Joined: Sep 2005
Posts: 1,575
Likes: 3
From: Lowell Arkansas
OK... Let's pretend you are all mechanical engineers for the moment.
Tell me what you would do differently to fix the things you have complained about. Don't forget the car has to meet target weight and performance goals and has to sell for whatever the one you are complaining about sold for when new.
The high frame rails were necessary to produce a stiff frame with the roof removed or you would have complained about Honda Civics beating you through the turns at the local autocross. The roof is bolted in to stiffen the frame even more. Want latches? Buy a Miata.
Optispark has greater timing resolution and accuracy than anything else available at the time which was partly responsible for making 10:1 compression available again. Accuracy comes from unique square wave output which magnetic trigger cannot do. Want reliable Opti? Hose the car all you want, just leave the engine alone. Your buddies won't notice dust on the valve covers anyway. Didn't hear anyone complain about the waterpump, why not? If waterpump was better you guys wouldn't be talking about the Opti so much. Besides, waterpump is driven off the cam, You lose your belt and you get to still drive home, not a bad feature to have.
Plastic parts: Plastic is a clever way to produce a good looking part to perform a function without incurring a weight penalty. I didn't hear anyone complain about Corvette's competitive weight. Want a tank? buy from a competitor.
Tell me what you would do differently to fix the things you have complained about. Don't forget the car has to meet target weight and performance goals and has to sell for whatever the one you are complaining about sold for when new.
The high frame rails were necessary to produce a stiff frame with the roof removed or you would have complained about Honda Civics beating you through the turns at the local autocross. The roof is bolted in to stiffen the frame even more. Want latches? Buy a Miata.
Optispark has greater timing resolution and accuracy than anything else available at the time which was partly responsible for making 10:1 compression available again. Accuracy comes from unique square wave output which magnetic trigger cannot do. Want reliable Opti? Hose the car all you want, just leave the engine alone. Your buddies won't notice dust on the valve covers anyway. Didn't hear anyone complain about the waterpump, why not? If waterpump was better you guys wouldn't be talking about the Opti so much. Besides, waterpump is driven off the cam, You lose your belt and you get to still drive home, not a bad feature to have.
Plastic parts: Plastic is a clever way to produce a good looking part to perform a function without incurring a weight penalty. I didn't hear anyone complain about Corvette's competitive weight. Want a tank? buy from a competitor.
Ok Mr. Gore............
You seem to be smarter than the average bear.
Maybe you can explain the reasoning behind:
The inexcusable way in which the tail lights were designed in the early C4.
It makes a simple chore; like changing the bulbs in the tail light, into a terrible experience. You end up scratching and bruising your forearms. It also takes much longer than it should.
Why in the world would anyone design a tail light in such a way?
Instructor
Joined: Aug 2007
Posts: 230
Likes: 1
From: Covington GA
OK... Let's pretend you are all mechanical engineers for the moment.
Tell me what you would do differently to fix the things you have complained about. Don't forget the car has to meet target weight and performance goals and has to sell for whatever the one you are complaining about sold for when new.
Tell me what you would do differently to fix the things you have complained about. Don't forget the car has to meet target weight and performance goals and has to sell for whatever the one you are complaining about sold for when new.
Optispark has greater timing resolution and accuracy than anything else available at the time which was partly responsible for making 10:1 compression available again. Accuracy comes from unique square wave output which magnetic trigger cannot do. Want reliable Opti? Hose the car all you want, just leave the engine alone. Your buddies won't notice dust on the valve covers anyway. Didn't hear anyone complain about the waterpump, why not? If waterpump was better you guys wouldn't be talking about the Opti so much. Besides, waterpump is driven off the cam, You lose your belt and you get to still drive home, not a bad feature to have.
I'd probably have removed the distributor altogether at this point. Remember, at this point even Luminas and Cavaliers had distributorless ignitions. Perhaps they could have used the system they put on the Northstar.
Last edited by Matt Cramer; Oct 16, 2007 at 12:42 PM.
Instructor
Joined: Aug 2007
Posts: 230
Likes: 1
From: Covington GA
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
The engineers job is to produce something the marketing people want, test and perform all the tweaks to make it work properly and it get it to meet all the requirements. Packaging engineers then get involved with getting it to fit whatever space is available in the car and while meeting certain appearance goals too and of course all this has to be brought in within budget constraints. In the case of tail lights the bumper reinforcements and energy absorbing parts share space with those parts behind the bumper cover along with room for a cargo area within a budget. I would say ease in servicing tail light bulbs while important was a lower goal than how the car looks, what it weighs and what the cost to produce it was. Corvettes are admittedely not the easiest cars to work on and lots of things on a Corvette are hard to get at. If you have ever had the dash out of one you would see the packaging engineers have made use of every ounce of available space; it's very tight in there. It is much easier to be a rolls Royce engineer; you just spend whatever is needed to go get the best of everything but it is an entirely different thing to be a good Ford or Chevy engineer. You are still expected to do a good job but now you have to get it done at a low cost.
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
I love second guessing the factory, so I'll play along on some of them. I won't go after the tall sills / frame rails, though - I once started a design of a kit car that was exactly that way for torsional rigidity.
I'm not sure I buy the resolution arguement for the Optispark. The LS1 doesn't use that kind of resolution. Neither did the Bosch Motronic systems used in European market GM products at the time - they used a 58 toothed crank trigger and magnetic sensor. And this worked for BMW M cars that ran more RPM and compression than a LT1.
I'd probably have removed the distributor altogether at this point. Remember, at this point even Luminas and Cavaliers had distributorless ignitions. Perhaps they could have used the system they put on the Northstar.
I'm not sure I buy the resolution arguement for the Optispark. The LS1 doesn't use that kind of resolution. Neither did the Bosch Motronic systems used in European market GM products at the time - they used a 58 toothed crank trigger and magnetic sensor. And this worked for BMW M cars that ran more RPM and compression than a LT1.
I'd probably have removed the distributor altogether at this point. Remember, at this point even Luminas and Cavaliers had distributorless ignitions. Perhaps they could have used the system they put on the Northstar.
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
I'm not sure I buy the resolution arguement for the Optispark. The LS1 doesn't use that kind of resolution. Neither did the Bosch Motronic systems used in European market GM products at the time - they used a 58 toothed crank trigger and magnetic sensor. And this worked for BMW M cars that ran more RPM and compression than a LT1.
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
You're absolutely right, in fact GM used distributor less ignition in the late '80s as well. My '87 Buick Lesabre had one with a crank trigger. It's design is very similar to the one on the LS1, but it had only 3 coils, 2 plugs per coil. I dont know of any other manufacturer that used something like the Opti.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Instructor
Joined: Aug 2007
Posts: 230
Likes: 1
From: Covington GA
But if you want to make the sine wave go away and replace it with a square wave, you can use a Hall effect sensor instead of an inductive one. These are still magnetic - and can still be made waterproof - but generate a square wave that looks just like the output from an optical sensor.
In fact, the Buick C3I ignitions from the mid '80s used Hall effect sensors that generated square waves instead of sine waves. Here's a picture that was to show GM techs what waveform to look for on something like that Buick Century:
No other domestic manufacturer did this, but it's pretty similar to designs in the import world. The Opti was built by Mitsubishi, and similar versions appear on Mitsubishi, Nissan, and Mazda motors. The Nissan triggers come closest - they have the same 360 slot outer ring. But GM was the only one who put it behind the water pump.
Last edited by Matt Cramer; Oct 16, 2007 at 02:33 PM.
Advanced
Joined: Apr 2007
Posts: 72
Likes: 0
From: Greenville SC
The thing I dislike most about my car is the fact that parts like wheel bearings are crazy expensive compared to other cars with very similar designs. Other than the expense of maintainence which my car has been exceptionally reliable I love it.
Racer
Joined: Jan 2007
Posts: 322
Likes: 0
From: Chapin South Carolina
Le Mans Master
Joined: Dec 2002
Posts: 6,715
Likes: 2
From: Santa Teresa New Mexico
Many systems trigger off the point where the sine wave crosses zero; this doesn't move around very much with RPM. The Bosch Motronic systems supposedly can trigger off the leading and trailing edge of each tooth, but how they do this is beyond me.
But if you want to make the sine wave go away and replace it with a square wave, you can use a Hall effect sensor instead of an inductive one. These are still magnetic - and can still be made waterproof - but generate a square wave that looks just like the output from an optical sensor.
In fact, the Buick C3I ignitions from the mid '80s used Hall effect sensors that generated square waves instead of sine waves. Here's a picture that was to show GM techs what waveform to look for on something like that Buick Century:
No other domestic manufacturer did this, but it's pretty similar to designs in the import world. The Opti was built by Mitsubishi, and similar versions appear on Mitsubishi, Nissan, and Mazda motors. The Nissan triggers come closest - they have the same 360 slot outer ring. But GM was the only one who put it behind the water pump.
But if you want to make the sine wave go away and replace it with a square wave, you can use a Hall effect sensor instead of an inductive one. These are still magnetic - and can still be made waterproof - but generate a square wave that looks just like the output from an optical sensor.
In fact, the Buick C3I ignitions from the mid '80s used Hall effect sensors that generated square waves instead of sine waves. Here's a picture that was to show GM techs what waveform to look for on something like that Buick Century:
No other domestic manufacturer did this, but it's pretty similar to designs in the import world. The Opti was built by Mitsubishi, and similar versions appear on Mitsubishi, Nissan, and Mazda motors. The Nissan triggers come closest - they have the same 360 slot outer ring. But GM was the only one who put it behind the water pump.
Melting Slicks
Joined: May 2007
Posts: 2,382
Likes: 2
From: Kathleen FL
On the flip side, I think the bread box in the early C4s is pretty well designed as a stress reliever. Durable indeed! Each time I'm frustrated about something breaking, I just bang my head repeatedly on the bread box and the stress goes away. 
Drifting
Joined: Sep 2005
Posts: 1,575
Likes: 3
From: Lowell Arkansas
Greg
I just read your profile.
Yep........like I said.........smarter than the average bear.
Still, I would like you to acknowledge that the early C4 tail lights could have been easily designed, to be much easier to change the bulbs in, while still looking good.
If you don't agree with me, then I guess you had a hand in designing the darn things.
I just read your profile.
Yep........like I said.........smarter than the average bear.
Still, I would like you to acknowledge that the early C4 tail lights could have been easily designed, to be much easier to change the bulbs in, while still looking good.
If you don't agree with me, then I guess you had a hand in designing the darn things.
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
Greg
I just read your profile.
Yep........like I said.........smarter than the average bear.
Still, I would like you to acknowledge that the early C4 tail lights could have been easily designed, to be much easier to change the bulbs in, while still looking good.
If you don't agree with me, then I guess you had a hand in designing the darn things.
I just read your profile.
Yep........like I said.........smarter than the average bear.
Still, I would like you to acknowledge that the early C4 tail lights could have been easily designed, to be much easier to change the bulbs in, while still looking good.
If you don't agree with me, then I guess you had a hand in designing the darn things.
Melting Slicks
Joined: Oct 2006
Posts: 2,314
Likes: 3
From: In a van down by the river! Florida
One offender that I haven't seen mentioned: The parking brake handle that goes back down when you set the parking brake. At least mine does. I'm still trying to figure out if this was by design or if it's broken. I keep forgetting if it's set because it doesn't stay up like a handbrake should
OK... Let's pretend you are all mechanical engineers for the moment.
Tell me what you would do differently to fix the things you have complained about. Don't forget the car has to meet target weight and performance goals and has to sell for whatever the one you are complaining about sold for when new.
The high frame rails were necessary to produce a stiff frame with the roof removed or you would have complained about Honda Civics beating you through the turns at the local autocross. The roof is bolted in to stiffen the frame even more. Want latches? Buy a Miata.
Optispark has greater timing resolution and accuracy than anything else available at the time which was partly responsible for making 10:1 compression available again. Accuracy comes from unique square wave output which magnetic trigger cannot do. Want reliable Opti? Hose the car all you want, just leave the engine alone. Your buddies won't notice dust on the valve covers anyway. Didn't hear anyone complain about the waterpump, why not? If waterpump was better you guys wouldn't be talking about the Opti so much. Besides, waterpump is driven off the cam, You lose your belt and you get to still drive home, not a bad feature to have.
Plastic parts: Plastic is a clever way to produce a good looking part to perform a function without incurring a weight penalty. I didn't hear anyone complain about Corvette's competitive weight. Want a tank? buy from a competitor.
Tell me what you would do differently to fix the things you have complained about. Don't forget the car has to meet target weight and performance goals and has to sell for whatever the one you are complaining about sold for when new.
The high frame rails were necessary to produce a stiff frame with the roof removed or you would have complained about Honda Civics beating you through the turns at the local autocross. The roof is bolted in to stiffen the frame even more. Want latches? Buy a Miata.
Optispark has greater timing resolution and accuracy than anything else available at the time which was partly responsible for making 10:1 compression available again. Accuracy comes from unique square wave output which magnetic trigger cannot do. Want reliable Opti? Hose the car all you want, just leave the engine alone. Your buddies won't notice dust on the valve covers anyway. Didn't hear anyone complain about the waterpump, why not? If waterpump was better you guys wouldn't be talking about the Opti so much. Besides, waterpump is driven off the cam, You lose your belt and you get to still drive home, not a bad feature to have.
Plastic parts: Plastic is a clever way to produce a good looking part to perform a function without incurring a weight penalty. I didn't hear anyone complain about Corvette's competitive weight. Want a tank? buy from a competitor.
Shade clips. Yeah they suck. $15 fix.
High door sils: WTF are you kidding me? thats like my favorite part of my car, go buy a buick.
Opti: What greg said. Mine is at almost 90k with no problems.
Bolts for the targa: Buy a vert, I would rather tear my face off around the corners.
Battery Location: where would you suggest it be put?
Leather: by a lexus
Door panels: yeah, they get floppy, I replaced mine, 12 year old car.
I mean cmon, Half of these complaints tell me you either A: don't need a Corvette, or B: you don't need an older car.
People complaining about opti would probably have their eyes explode when trying to replace and adjust points and a condenser.
Burning Brakes
Joined: Dec 2003
Posts: 1,183
Likes: 1
From: MidOhio
I would have to say the tall frame rails that you have to physicly lift your foot up and over everytime you get in and out of the car. I can't imagine for a older person trying to make this a daily driver. What was GM thinking???? I realize that their budget got cut early in the developement stages, but what the heck! Oh well, I bought one anyways.
You're getting warm 
but the high door sills were a required result when Lloyd Reuss, then Chevy Gen Mngr "declared" that the C4 would be a targa top without the intended center tie bar under a one-piece roof panel. That one stupid, cosmetic decision
caused the sill problem, the "shake-rattle-roll" without the top in place and the cracking of both the "glass" and the solid tops. If anyone ought to be burned in effigy at C4 rallies, it should be Reuss. He single-handedly screwed-up a whole generation of 'vettes. 
