C4 Aerodynamics

[Guest PURPLE95]

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later. I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

[FNBADAZ06]

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later.

I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

Agreed.

You might wish to check in on the big board's General "Corvette\Autocrossing and Roadracing" section, as there are a number of C4's actively campaigned by owners.

http://forums.corvetteforum.com/autocrossing-and-roadracing/2466796-rear-aero-help-with-the-c4.html

There's even one being converted over to run an Ecotec Turbo 4 !!!!!

http://forums.corvetteforum.com/autocrossing-and-roadracing/2951047-my-xp-c4-build-is-in-full-swing-build-log.html

and, the ever popular GN V6 turbo C4 ...

http-~~-//www.youtube.com/watch?v=_JQ-UiRV_4M

Or, just move up to a C5

Dawg would allow this in his Auto-X

[JLs Mistress]

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later.

I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

Are you having fun yet. Rich ..... by the way Carol is very happy she has her car back. Thanks for the body work and working with my insurance company ... John

[NicD]

During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out.

Here's a little blast from the past Rich! I save everything including 11 year old videos... I remember recording this and helping take lap times back in 01.

http-~~-//youtu.be/PKmn3qQk4yE

Good to see you still around in the game!

[Guest PURPLE95]

During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out.

Here's a little blast from the past Rich! I save everything including 11 year old videos... I remember recording this and helping take lap times back in 01.

http-~~-//youtu.be/PKmn3qQk4yE

Good to see you still around in the game!

[Guest PURPLE95]

Nic, DUDE! Thanks for the blast from the past. I still have the car, but it is in "storage" until the next road race day. Things have been tough lately read: the last 10 years, but my passion for cars is still there. I keep telling myself this year I'll get back to the track, but it never happens, usually due to the expense of getting the car ready. Just a set of tires is 800 and change, no biggy at least I won't have to build another car again. I know that I asked you about the LT1 thing a couple of weeks ago, but I really need to get my fans to turn on @ 200 instead of 230. I took the radiator out and flushed the cooling system then blasted all of the crap out of the fins and did the same to the condenser. Now the car stays about mid guage when moving but if I sit still too long it goes up to 230 until the fans come on. Also the a/c stays cold while sitting still now that the condenser isn't full of dog hair, etc. Let me know if you know someone that can handle the fan thing for me, I would rather have you do it as I trust you, but I really need to do this soon, I don't like the engine running hot. Later, thanks again.

[Guest PURPLE95]

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later.

I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

Are you having fun yet. Rich ..... by the way Carol is very happy she has her car back. Thanks for the body work and working with my insurance company ... John

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later.

I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

Are you having fun yet. Rich ..... by the way Carol is very happy she has her car back. Thanks for the body work and working with my insurance company ... John

[Guest PURPLE95]

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later.

I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

Are you having fun yet. Rich ..... by the way Carol is very happy she has her car back. Thanks for the body work and working with my insurance company ... John

I appreciate your input. Unfortunately I don't have alot of money to throw around so I bought the Corvette that I could afford. Where the car may suffer in short comings, I myself have alot of high performance driving training and lots of track days under my belt. During my training I found myself surrounded by some of the best drivers in Arizona. Personally I would have no problem racing a track day against a C5 or C6 because most drivers can't use what the factory provided them in the first place. The more that I drive my C4, the more I like it. With a few tweeks here and there the car will serve me just fine and I won't owe the bank 30 or 40 grand. During the track days I attended I ran an 85 IROC Z with a 385 fast burn and a 6 speed T56 trans. Some upgrades for the suspension from Global West and the 1LE front brake system. There wasn't a Corvette or any other car I couldn't pass and that includes some heavily modified cars that were just overkill. You don't need all of the fancy stuff to go fast. You just need to know when to put the gas to the floor and when to brake and turn in and out. I had to save for quite awhile to get this car and it was hard to find a 6 speed that I liked. Anyway, I understand where you are coming from, I just don't find myself in the financial bracket that you are in. I'm making one third of what I made 10 years ago. Maybe one day I will be rich and famous again. Later.

I might not have the newest Vette out there but I still wrap my ass in fiberglass!!!!!!

Are you having fun yet. Rich ..... by the way Carol is very happy she has her car back. Thanks for the body work and working with my insurance company ... John

[Guest PURPLE95]

John, I'm glad that Carol is happy with her car and as always it was our pleasure to take care of your collision work. Thank you for the opportunity to earn your business. As far as if I am having fun yet, the answer is YES. I love my Vette and am glad that I could find something in my price range that wasnt' flogged and molested. This car is completely stock except for fluids, and tires. I plan of doing some mods to make the car more "racy" and add some parts to it to handle my driving style. We should plan a drive up north soon, like maybe a breakfast run or something. Talk to you soon, Rich.

[Marco]

I did aerodynamics at GM for a summer in college before I went to the aerospace industry. I've seen all kinds of crazy stuff done on cars in the name of aero or downforce, but the reality is that it's actually very difficult to get a car to be aerodynamically balanced at a variety of speeds. What's good at 40mph could be bad at 75mph and downright dangerous at 120mph. Likewise something good for 120mph is likely to be completely ineffective at 40mph. So without having ever actually done any wind tunnel or CFD on a C4 specifically, all one can do is postulate.

First, I'd be very surprised if the flow coming down the rear window of a C4 is still laminar. Fluids in general really hate expansion so the chances it doesn't trip turbulent going down the window are pretty slim. I'm not saying your wrong necesarily, I'd just be very surprised.

The primary reason that you see rear spoilers on race cars being mounted "ricer" style is because that's the easiest way to increase downforce in a predictable way. By raising the wing away from the rear deck lid (preferably above the roof height if possible), you get the wing out of all the nasty flow caused by the body of the car. This makes the wing behave more like it should in theory without having to do all the analysis to understand the interactions. Makes it a lot easier to figure out what kind fo wing you should use to get x amount of downforce.

That said, if you do all the analysis, you can sometimes get the same downforce with an integrated spoiler without as much drag. A good example of this is the C6 Z06. You'll notice that compared to the base model, it has an exaggerated lip where the rear brake light is. My guess is that provides just the right amount of exta rear downforce for the Z06.

All of that said, there seems to be a common misconception that adding spoilers to get more downforce is a good thing. The reality is, if you're not careful, it can actually be a very bad thing. Anytime you're creating downforce in the back, you are also creating drag (lower top speed). More importantly, both the additional downforce and drag create a rotational force (moment) on the car that can lighten the front end.

The point is, adding a huge rear spoiler without a properly designed accompanying front splitter can be very dangerous. Using your example of the C5R & C6R, they both had large raised spoilers, but they also both had well designed front splitters to keep the car balanced and prevent the nose from getting light at speed. Having both a splitter and a spoiler gives you balanced downforce.

In the end, it all depends on what you're going to do with the car. If you're doing road racing, a spoiler/splitter combo would probably be a good idea. If you're on higher speed circuits, a spoiler without a splitter would probably induce understeer (you'd have to play with your suspension set up too).

If you're jsut using the car on the street, just a spoiler probably won't hurt you. If you do a lot of freeway driving (read speeding) then you might want to be careful. Too much wing could at best cost you gas mileage (if you care) and at worst cause you to lose steering control.

Sorry if that reply got a bit long-winded. Just my 2 cents, take it or leave it. Reality is, most people use spoilers for looks more than anything else :-)

^^^^This^^^^ is AWESOME. This sets the bar high in the advice department. Damn, well done

[Guest PURPLE95]

Probably WAY beyond anything you're willing to spend money on, but this active wing is the shizzle ....

http://aeromotions.com/

Watch it in action on a GT-R

http-~~-//www.youtube.com/watch?v=p7l70Q6P-vU

Installed on a C6 Z06 Carbon Editon

Full down position for aero-braking

[Guest PURPLE95]

Man, I think I have wood. That is a bad ass spoiler. I checked out the website and eventhough the non automatic wing is 1600.00 I would consider that for the back of my C4. Just the fact that you can adjust it so you can dial in the back of your car makes it a deal. I will have to sell myself down on Van Buren to get it but what the hell. Thank you for the web site info, I have not been able to find anything that looks professional and eventhough it is "ricer" style, the part is so nice I think that it would be an addition to the style of the "purple unit". Have a great one......now I have to spend money on something else....sheesh, I guess it's better to be addicted to cars than dope. Later. Wrap your ass in fiberglass !!!!!

[JLs Mistress]

John,

I'm glad that Carol is happy with her car and as always it was our pleasure to take care of your collision work. Thank you for the opportunity to earn your business. As far as if I am having fun yet, the answer is YES. I love my Vette and am glad that I could find something in my price range that wasnt' flogged and molested. This car is completely stock except for fluids, and tires. I plan of doing some mods to make the car more "racy" and add some parts to it to handle my driving style. We should plan a drive up north soon, like maybe a breakfast run or something. Talk to you soon, Rich.

That sounds like fun once I make it thru > Oct. which is family month ...It seems my wife has my weekends lined out for me . Or like she calls it non car time .... which is a pain because Oct has some kind of car events every weekend this month.....

Sorry guys did not mean to highjack this thread ....

[Bromley's Corvettes]

Nic,

DUDE! Thanks for the blast from the past. I still have the car, but it is in "storage" until the next road race day. Things have been tough lately read: the last 10 years, but my passion for cars is still there. I keep telling myself this year I'll get back to the track, but it never happens, usually due to the expense of getting the car ready. Just a set of tires is 800 and change, no biggy at least I won't have to build another car again. I know that I asked you about the LT1 thing a couple of weeks ago, but I really need to get my fans to turn on @ 200 instead of 230. I took the radiator out and flushed the cooling system then blasted all of the crap out of the fins and did the same to the condenser. Now the car stays about mid guage when moving but if I sit still too long it goes up to 230 until the fans come on. Also the a/c stays cold while sitting still now that the condenser isn't full of dog hair, etc. Let me know if you know someone that can handle the fan thing for me, I would rather have you do it as I trust you, but I really need to do this soon, I don't like the engine running hot. Later, thanks again.

I can wire your fans to come on with IGN. Makes a big difference it takes way longer to get hot and never lets it get as hot as stock. Also changing the thermostat helps. I do both at same time.

[Guest PURPLE95]

Nic,

DUDE! Thanks for the blast from the past. I still have the car, but it is in "storage" until the next road race day. Things have been tough lately read: the last 10 years, but my passion for cars is still there. I keep telling myself this year I'll get back to the track, but it never happens, usually due to the expense of getting the car ready. Just a set of tires is 800 and change, no biggy at least I won't have to build another car again. I know that I asked you about the LT1 thing a couple of weeks ago, but I really need to get my fans to turn on @ 200 instead of 230. I took the radiator out and flushed the cooling system then blasted all of the crap out of the fins and did the same to the condenser. Now the car stays about mid guage when moving but if I sit still too long it goes up to 230 until the fans come on. Also the a/c stays cold while sitting still now that the condenser isn't full of dog hair, etc. Let me know if you know someone that can handle the fan thing for me, I would rather have you do it as I trust you, but I really need to do this soon, I don't like the engine running hot. Later, thanks again.

I can wire your fans to come on with IGN. Makes a big difference it takes way longer to get hot and never lets it get as hot as stock. Also changing the thermostat helps. I do both at same time.

[Guest PURPLE95]

Thanks for the reply. I don't want the fans to run all of the time as that would wear them out prematurly. Also my concern with the t-stat temp being lowered is that it will stay open all of the time if the engine runs warm and above 180 really isn't that hot. If the stat stays open the coolant won't be allowed to do it's job by absorbing heat out of the engine and dissipating heat through the radiator. As I have been driving the car after flushing the cooling system and removing all of the junk that was stuck in the radiator and condenser cores the car runs cool until I come to a stop in rush hour, ambient over 100 degress a/c off. I noticed that the fans come on at about 230 degress which on the analouge guage looks like the needle is almost going to hit the grid at the hot end of the guage. The data that I am looking at is the digital info in the middle of the guage cluster in the speedo area. Once I turn the a/c on even though the condenser emits heat the coolant comes back down to nominal very quickly just because the fans are running. After watching this "dance" for the last couple of days, I think that the fans just need to come on at 200 degrees. The rest of the system seems to be working fine, but it must have air flow to stay nominal.

John,

I'm glad that Carol is happy with her car and as always it was our pleasure to take care of your collision work. Thank you for the opportunity to earn your business. As far as if I am having fun yet, the answer is YES. I love my Vette and am glad that I could find something in my price range that wasnt' flogged and molested. This car is completely stock except for fluids, and tires. I plan of doing some mods to make the car more "racy" and add some parts to it to handle my driving style. We should plan a drive up north soon, like maybe a breakfast run or something. Talk to you soon, Rich.

That sounds like fun once I make it thru > Oct. which is family month ...It seems my wife has my weekends lined out for me . Or like she calls it non car time .... which is a pain because Oct has some kind of car events every weekend this month.....

Sorry guys did not mean to highjack this thread ....

[Guest PURPLE95]

John, Ok sounds good. Let me know if you want to drive down to the "Cruise on Central" together. I don't usually park at the mall, it's too hard to get in and out of and I do like to do some cruising. During our last conversation about this matter we both had a place to park and enjoy the evening. If you want to try something different you can try my spot or vice versa, doesn't matter to me, I just want to relive some of my teenage years by going there. Later.

[Desertdawg]

I noticed that the fans come on at about 230 degress which on the analouge guage looks like the needle is almost going to hit the grid at the hot end of the guage.

I'm not sure about the C4, does it have seperate fan and display sensors?

or

Whats the chance your temp sensor or gauge is wrong, out of calibration?

[JLs Mistress]

Check out the photo I just posted in the Cruise On Central . After the sun goes down we move out on the sidewalk .Then brake out the water bottles for burnouts . We all know Corvette owners do need stinking water bottles ....

[Guest PURPLE95]

I noticed that the fans come on at about 230 degress which on the analouge guage looks like the needle is almost going to hit the grid at the hot end of the guage.

I'm not sure about the C4, does it have seperate fan and display sensors?

or

Whats the chance your temp sensor or gauge is wrong, out of calibration?

[Guest PURPLE95]

The C4 has a set of analog guages and you can select from the dash if you want the information to be displayed digitally in the speedo area in the center of the IP. I checked it this morn on the way to work. Got caught in traffic and both guages started to climb. I noticed that the dual LS1 style fans came on at 230 degress. I just need to reprogram the ecm to turn them on at 200 and that should keep the engine happy

[F22trainer]

1. Get new bushings and ball joints. 2. Add a pair of Heim rear adjustable arms - no more hula hop on expansion joints or manhole covers. 3. Check sway bar bushings. 4. Shocks Mine cruises very nice and solid at higher speeds than 55, one cruz long ago at 2 miles a minute for most of the ride back from Coolidge...top off! It has always been an amazingly solid car since the first time I drove it on the highway.

[Guest PURPLE95]

1. Get new bushings and ball joints.

2. Add a pair of Heim rear adjustable arms - no more hula hop on expansion joints or manhole covers.

3. Check sway bar bushings.

4. Shocks

Mine cruises very nice and solid at higher speeds than 55, one cruz long ago at 2 miles a minute for most of the ride back from Coolidge...top off! It has always been an amazingly solid car since the first time I drove it on the highway.

[Guest PURPLE95]

1. Get new bushings and ball joints.

2. Add a pair of Heim rear adjustable arms - no more hula hop on expansion joints or manhole covers.

3. Check sway bar bushings.

4. Shocks

Mine cruises very nice and solid at higher speeds than 55, one cruz long ago at 2 miles a minute for most of the ride back from Coolidge...top off! It has always been an amazingly solid car since the first time I drove it on the highway.

Thanks for the reply. I have had the car now for about 4 weeks and as I drive the car daily, I try to figure out what is making the car feel weird. I think one of the rear shocks are going away. It feels like the compression dampening is lighter on one shock versus the other.

My plans for the suspension are:

1. 295 front tires and 315 for the rears.

2. The car is a FE1 car. I want to put Z51 Bilstiens on it.

3. Install Poly sway bar bushings front and rear.

4. Install a "smart link" system on the rear.

5. Lower the car about 1/2 inch.

6. Performance alignment.

I have noticed a "whirring" noise coming from the car almost right after I picked the car up. Today I found the noise. The throw out bearing is taking a crap. I whirrs while running, no pressure on the bearing. When you put your foot on the clutch pedal and depress it all the way to the floor you can hear the bearing slow down and it makes a rattleing noise as it comes to a stop. Looks like I'm driving my Trans Am again. I have really enjoyed driving this car, but like anything that you buy used, you run the risk of something taking a dump. Later.

[Cross]

Rich... that name sounds very familiar... how about this IROC do you know it?