Ask DJ Race Archive

Answers provided by Danny Kellermeyer. Danny Kellermeyer is a force to be reckoned with in the Corvette racing world. Danny and his team of Corvette drivers have dominated several Corvette club racing series. He has no plans to rest on his laurels after capturing the 2010 and 2011 Sports Car Club of America (SCCA) Great Lakes STO National Championships, as well as the Waterford Hills Road Racing (WHRRI) 2010 and 2011 STO championships. Send us a quick email with your name, location, and a short question.

Q:

1967 327/350 w/transistor ignition - new battery. Car starts easily, sometimes runs "forever", sometimes just quits - no warning or symptom of impending quit (not a fuel problem), just loses ignition. Will often restart after a wait. Ideas?

– Jim Fitzgerald

A:

Jim, Thanks for asking your question on your 1967 (327/350) Corvette. Happens to be one of my favorite engines too. Intermittent problems have to be one of the most hated problems to diagnosis. Your right, the quitting with no warning, sounds like electrical for sure. Then your statement "Will often restart after a wait" tells me that you do have some good diagnostic time. You're going to have to check some things right then. When this happens, don't touch anything especially the ignition switch. Is the power to things like lights, radio, horn, and etc still working? If yes then it is not major electrical feed like battery cable (both ground and positive cables and connections). This includes fusible link and junction block. If no, then start looking at major power feeds. I like using the Fluke meter, but a good test light for a '67 works great. If the power is okay, Check spark to see if you have any. If you don't, that is the time to consider ignition switch, to ignition problems. The feed to the ignition system goes right out thru the white wire to the distributor and the amplifier box. Don't ever forget that ground is as important as power. Does the amplifier have a good ground? If it is failed you have a good chance to root cause the problem and fix it. If it fails very randomly, I would take some time and do some quality looking at all connections and grounds starting with the ignition switch thru the ignition system (again that is considering that you have power at the time the engine stops). I find first, carefully looking with your eyes. Second light touching, to feel for broken or loose wires. Third, disconnecting to look for open terminals, corrosion, and broken wires, is a good way to inspect and diagnosis properly. You could of course have a transistor board problem, but don't jump to big expense items before you prove it is bad. That coil is different too, so check the ohm resistance to make sure it hasn't partially shorted. The shop manual says that coil should be 8,000 to 12,500 Ω . A partially shorted coil or a wrong coil would tax the transistors and the heat would not be able to soak away, giving you an intermittent quit. Once cool it could restart again. Best of luck and quality checks may just pay off with little cost out of pocket.

Q:

I own a 1980 vette with the pathetic 305ci California engine. It is in poor condition and needs a lot of work. I can't decide whether to invest in overhauling the 305 or replacing the engine with something like GM's E-rod engine. If I decide to rebuild and overhaul the original engine, I need to do something about the carburetor. It is in really poor condition and should have been rebuilt about 20,000 miles ago. Should I replace the carb or have it overhauled? I would really like to improve the performance of the vehicle, maybe even beyond it's stock original factory performance. I do have to be conservative in my spending, since I do have a limited budget for the project. I may have to do this in stages over a period of a few years. What would you recommend? I also really like the idea of putting side exhaust headers on the car, like the '69. Maybe even dress the car up with some chrome on the front like the early C3's. I don't want to sell this vehicle, since it has been in the family since 1980. It belonged to my mother originally. Thanks for your time!

– Dan

A:

Dan, Thanks for a good question. I see a lot of Corvettes of the late 70's to early 80's with the questions you have. I think you have to consider a lot of things. Car value, cost of improvements, sentimental family feelings, performance improvement, emission considerations and retaining originality. Your going to have to balance all of those questions on your own, but maybe I can help. First lets look at an E-rod engine. Outcome would be nice. The E-rod LS3 with harness, computer and all runs approx $8,000 and that is the beginning. More for different exhaust, radiator, wiring and lots of dollars for labor to fit in and get it running. It just goes on and on. Second: Lets look at a rebuild. Cost is reasonable, Originality is retained, you can do a lot of labor yourself and no additional fabrication will be required. The problem after this is you end up with the same 180 horse "pathetic 305 California engine" you started with. We won't go into the performance or sheer lack of performance. Third: (This would be my choice) Pull the 305 and put it on a pallet and keep it if you ever want the matching number engine. Find a 350 or even a 383 (a 350 with a 4" stroke) and do some light modifications to it. Look for good steel heads and keep the compression under 10:1 so you can run regular gas. Keep it a 350 block under 1985 and it will fit right in with no modification. Exhaust are the same, dipstick is on the left side, oil pans fit, radiator hoses fit right on, trans flywheel starter bolt on, and all brackets like power steering and alternator fit directly. Boy how nice is that. You can make it look original and if you do it right with a nice drivable cam, you can still get 300-350 hp. Cost would not be anymore than your 305 rebuild, nice power improvement and the originality looks the same. Nice combination I think. This should give you a little extra cash to outfit a side exhaust or do some body improvements. I hope this gave you a little insight.

Q:

Wondering if I add headers to a 1999 corvette how much horse power would I gain I have different exhaust and air system?

– Pat Harlan

A:

Pat, It sounds like you already have air cleaner and exhaust changes. That is where the major horsepower increase is. The LS6 is a little more responsive to changes than your LS1 engine. That is because of the better head flow and the better camshaft. The air cleaner is pretty straight forward, as most systems open the air up well and are not as restrictive as the production ones. If you have only put a filter element in your production air cleaner housing, you should look at getting a complete air filter assemble. The exhaust is a little more technical. The big question is do you still have your production cats in the system. The cats are restrictive. High flow cats are better but still have some restriction. Placing headers on a system with restriction such as production cats will maybe give you 5 extra HP. With no cat or high flow cats, your HP maybe up by 8-12. Short vs Long tubes don't make much difference with your stock cam and heads. Long tubes will start to gain you more when a cam and head change is made. Bottom line: Make sure your air cleaner and exhaust system changes are allowing good flow. Headers on your stock engine will give you another 5-12 depending on your cats situation.

Q:

Danny, a performance, not a racing question, but I hope you can help. I like the C3 Corvette and have an opportunity to buy a very well maintained 1982. Can the engine be uprated? Are there better years for the C3 than 1982? Thanks for any guidance you can provide.

– Steve Goldman, Bala Cynwyd PA

A:

Steve, thanks for your performance question on your 1982 Corvette. As you know your C3 was the last of one era and the first of another. The pull-ahead engine crossfire systems would be the start of something new and different. The only problem, they found quickly the customers wanted higher RPM, so the crossfire was out. It did do what it was designed for, and that is low torque and smooth operation. The torque at 285@2800 overshadowed the 200@4000 horsepower, so add on performance stuff usually didn’t make much improvement. Exhaust system makes a little improvement but basically due to low flow cats or cat elimination. That means you would need to go inside to make any improvements. Compression ratio is the best and easiest. The factory CR of 9:1 was on the low side, but they burn clean to meet emissions. Your heads are 76cc chambers and they can be surfaced to raise compression if you ever have them off for valve job or head gasket. Remember calculate the CR before doing anything. Your engine was built with a .021 head gasket. I’ve seen too many people improve their head cc and then put on an aftermarket gasket (like a Felpro), which is .038, and lose compression in the final result. So check your calculations. If you don’t care about your engine looking production, an aftermarket set of heads could be put on to raise compression and flow better for additional improvement. A camshaft with a little more lift and duration is an improvement also. Both of these improves need to be carefully thought out for your Corvette. You don’t want to go very BIG at all. A slight change in each makes a nice driving car and too much makes it turn to a temperamental piece of junk. So be careful. It all stems back to that Crossfire intake that has low-end performance and no high-end flow. So the cam, head flow and CR all want to complement the intake and not fight it. Talk to your engine builder and make sure he realizes your engine must idle good, and not run over 5,000 rpm. Your whole package must meet those demands. We did one crossfire with just raising the CR by .6 and a quite exhaust with no cat and it was a great driving unit. Hope this all helps a little and thanks for your question.

Q:

I asked you several weeks ago for suspension settings for my 2007 Corvette. I was very pleased with your info. Along the same lines, I would like to know what setting of the three available on the Automated Handling System should I use at VIR and what each of the three does as Chevrolet does not shed much light on this subject. Also the last time I was active in the sport I was in a 1969 Small Block coupe, some help on tire air pressures for the C6 would be of great aid.

– Ken Riebel, Baldwin MD

A:

Thanks for replying back. We don’t have any traction/handling options in our racecars, but we do track days with C5 and C6 Corvettes to have fun. Engineering keeps changing the pattern of operation on Corvettes year-to-year and model-to-model. As I recall this would be your 2007 C6 operation and this is how I would suggest new / intermediate / advanced drivers to set his traction/handling control. Believe me it does save you in the event you get too aggressive so don’t turn too much off in the beginning. Start Car: Traction control On / Active Handling On (Use for starting driver or wet track events). Press Active Handling button once: Traction control Off / Active Handling On (Use for track driving if novice driver). Press Active Handling button again-Competitive Mode: Traction control Off / Active Handling On but is not as intrusive (Use for track driving if intermediate driver). Press Active Handling button again and hold for 5 sec: Traction control Off / Active Handling Off (Use for track driving if advanced driver). Notes: You can’t take ABS off and you wouldn’t want to. If you have low tire warning you won’t be able to get into the completive mode or the Traction control Off / Active Handling Off mode. Hope this gives you a little more insight into track driving. Pressures: I would run the max pressure suggested on the side wall when hot. So you might have to start out 4 or 5 pounds lower than that when cool. Then you let it grow to the max pressure. You will have to play with this to see what works, depending on what tires you are running.

Q:

I plan to do quite a bit of open track days this season. Should I increase the frequency of brake and transmission fluid changes because of this? I have a 2007 Z51 Corvette Coupe. I would like to take it to a VIR Track day and posibly do some Autoxing. Do you have a good set of allignment settings for this car that would still allow it to be used on the street. The only change to the car is a new set of Bridgestone Potenza R-11s.

– Ken Riebel, Baldwin MD

A:

Your 2007 Z51 coupe makes a real good street and track car, and VIR is an awesome track. I would increase the camber both front and rear (more negative), and keep the caster still at factory spec. When the camber is increased the toe goes out, so it has to be brought back in. I like zero toe at the front and a slight toe-in at the rear. That gives a little stability on the straights. (It is the toe that scuffs off the tires and gives you lots of negative camber wear). I would run at your factory ride height also. If you are gong to lower the car slightly make sure you do that first and make sure the front is just slightly lower (3-5 mm measures at jack points on the frame) than the rear. Your new settings should look like this:

Camber Front (negative): 1.4° – 1.6°

Camber Rear (negative): 1.0° – 1.2°

Caster: 7° – 7.5°

Toe Front: 0

Toe Rear: 0 - .2 (toe in)

Good luck and keep everyone posted on your track experience.

Q:

Is it OK to use C5 street rotors and pads for open track days or autocross events? If not, what type of equipment should I get?

– Kevin Williams, Orlando FL

A:

C5 street rotors are fine for open track days or autocrossing, but your pads need to be upgraded. The difference in street pads, track pads and full race pads is the number of continuous stops you can do without getting brake fade. As long as either the track sessions are short, or the autocrossing does not involve back to back quick runs, a stock rotor and a track pad should be fine. Keep watching your rotors for heat cracks (small cracks on the rotor surface), your pads for wear, and keep your maintenance up. After all, you are using them harder. When rotor cracks become larger, rotors will need to be replaced. One thing to remember is your brake fluid. The boiling point diminishes as your fluid becomes older. Keep a good quality racing fluid in your car and keep it fresh for performance driving. Also remember that brake fade is due to the heat the brakes generate. Stock pads can handle around 800°F, track pads around 1200°F and racing pads up to 1600°F. As your performance driving becomes more intense, watch your brakes and upgrade your rotors and pads as necessary.

Q:

I'd like to autocross my completely stock 1996 Corvette. Do I need to be concerned about oil starvation?

– Travis Pintner, Des Moines IA

A:

The C4 Corvette L98, LT1 and LT4 oiling systems are good. They have a larger oil pan, windage trays and basically good oil system. Keep high quality oil in there and keep it full when going to the autocross event. If you have a C5 or C6, do as the owners manual recommends. Run an additional quart when doing performance driving. Corvette Owner's Manual — "Notice: If you use your vehicle for racing or other competitive driving, the engine may use more oil than it would with normal use. Low oil levels can damage the engine. Be sure to check the oil level often during racing or other competitive driving and keep the level at or near 1 quart (1 L) above the upper mark that shows the proper operating range on the engine oil dipstick."

Q:

I plan to do quite a bit of open track days this season. Should I increase the frequency of brake and transmission fluid changes because of this?

– Tom Rodriguez, Peoria IL

A:

Good maintenance is worth it. Change your fluids as often as needed. Race teams change their transmission and differential fluids twice a season if everything is normal. It could be more if high trans or diff temperatures are seen. If you are not doing track days or autocrossing that often, once a year may be enough. Brake fluid, on the other hand, should be changed often. Race teams completely bleed 3-4 times a season and check and monitor all the time. Good fluid and good maintenance is mandatory on your brake system, so inspect your fluid before each event. The boiling point diminishes as your fluid becomes older. Keep a good quality racing fluid in your car and keep it fresh for performance driving.

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