After a dreadful 2008 campaign full of broken optisparks and rear bearings, the car is back together and loaded up to head down to Mid-Ohio for the NASA National Championships.

It's a good thing you only have to start races to qualify, as I finished a dismal 3 of 8 races. Of course I won two of the three

Anyway, Thursday is practice, Friday and Saturday are Qualifying races, and Sunday is the one shot at glory National Championship race. I'll have my new Guru stickers in full effect down the straight.

Live webcasts will be available, I'll find the links and post here for anyone not watching football on Sunday.

Here's to the car finishing all three races!

yayayaya!

Good luck! And safe racing!!!

Looking forward to the links.

Good Luck!!

Win the sucker,Jon.

I've been to MidOhio 7 times (champ car) but haven't gotten to dirve it.

Good luck!

Did you get to Road America at all? I missed the NASA event due to a failed trans.

RICHMOND, CA – September 9, 2008 - NASA is pleased to announce that race fans will be able to watch race results from the 3nd Annual NASA Championships presented by Toyo Tires at the Mid-Ohio Sports Car Course live on the Internet. In addition, a live audio stream of the announcers calling the play-by-play action will be made available to those at home.

Simply visit http://drivenasa.com/liveresults and you will be able to watch and listen to the race results as they happen and follow the action from anywhere in the world. For more information on the NASA Championships, please visit www.nasachampionships.com.

RICHMOND, CA – September 8, 2008. Fans of the National Auto Sport Association will be able to view a live video feed of the racing action at the 2008 National Championships at Mid Ohio Sports Car Course. Speedcast Productions will be producing full-length videos of featured classes but will also offer a live picture of the front straight by streaming video via a satellite connection to a website.

Live coverage will begin on Sunday, September 14th and you can catch the racing at Speedcasttv.com. Users will be required to create a login but viewing the video feed will be free.

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I'll leave that to Ken Smith, Spectator-Racing's third member. I'll be running mid-pack. I spent all of the time and money I had this year trying to keep the car running instead of making it (and me) faster. I should be able to handle all the out-of-state guys, but there are two or three local guys in really nice C5-R's that I will only be passing if they spin...

Don't forget Matt Carlyle (mrc24x), our 4th driver. He's in a different class (PTA) but runs at the same time. He's already at the track, so he probably won't see this and weigh in...

He's got a great shot at a podium in his class, so wish him well, too!

Cool, thanks for the links.


Be sure to put the Guru stickers on the back of the car, otherwise none of the racers will see them.

Real C5R's ? If so, that's a damn tough class you're in.

Looks like the're having to deal with a lot of rain
http://forums.corvetteforum.com/showt ... 1567080304#post1567080304

If I'm reading this right, you finished 3 laps off the pace today, (or didn't finish).

What's the scoop?

I'll write a full report later, but whew...what a weekend.

Summary:

Thursday practice was great, weather held and we had a good time. Then it rained.

And rained.

And rained.

Friday had one purpose - survive. Practice and qualifying were fine (but slippery), but in the race Friday afternoon I parked it in a the kitty litter near the end of the race trying to make a pass on an RX-7. Oops. With all the gravel in the car I was able to make weight, though...

Saturday morning I put the car on the dyno to make sure I put in enough ballast. HP was where I wanted, but the A/F ratio was at 15!!! Not good. That explained why it was running so hot on Thursday. Thank goodness I didn't burn up a piston or two.

I spent all day Saturday trying to figure out why I had low fuel pressure, so I missed qualifying and started from the back during the race. Changed the fuel filter and adjusted the pressure...still not quite right but another trip to the dyno had the ratio back to a "safe" range, with a peak of 14.6 at the top of the RPM band. I played it safe and shifted early. I never checked where I finished on Saturday, somewhere near the back. It's hard to be fast when you're staring at your guages.

Sunday ended up being a fantastic day. I decided I didn't care if the car blew up or not, I have all winter to fix it. You don't get many opportunities to drive in the National Championships, so I drove instead of worried. Overall finish was 10th of 17. Not as high as I would have liked, but I finished...and with all that happened it could have been a lot worse. Will explain later, it was a drama filled race - big wrecks and car fires, red flags, high speed lawn-mowing session at the end of the back straight, etc. Film at 11.

Lucky just keeping it on the track in that kind of weather!

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Yeah, too bad I didn't

How are these things catching you by surprise? Are you like me and wrenching on it, then taking it untested to the track (or 500 mile road trips)?

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Great question. I've been asking that over and over.

Really "these things" have been the optispark problems again and again.. And each time I think I've got it permanently fixed - spending $500 on an MSD, carefully assembling each one with loc-tite, etc. Still not good enough.

This fuel issue actually was a surprise, and I would never have found it had I not dyno'd the car. I have changed absolutely nothing which would affect this since my last dyno (last season), where the A/F ratio was a comfortable 13.2. The motor was running hot (about 10* over normal) on Thursday, but I assumed I was running hard on a hot humid day - it's never been a cool running car. I would not have linked this to a lean condition, but rather a cooling issue.

The only two things done to the motor since the last test were the addition of the dynaspark and the change back to a stock throttle body. I can't see how either of those would affect A/F, with the possible exception of the computer misreading something and leaning out the mixture. In fact, logically, the smaller TB should have made the car run rich, as less air was drawn in at the same throttle position. I transferred the sensors from one TB to the other, so it's not like one was bad on the new TB.

The logical explanation is that the fuel filter change was the problem, as pressure was more stable after the new one went on. However, it's not a very old filter and the car really doesn't have many miles since it was changed. Unfortunately, due to the circumstances I couldn't make one change at a time, so I don't know which fixed it. I still think the pump may be weak, which is not something I would expect as it was replaced last year (Walbro 255 l/hr). And lastly, it could be getting poor voltage, this has not yet been checked.

I keep thinking I've finally made the car reliable, but keep getting bit. I'm really struggling with what else can be done, there is no good solution for stuff like this. It appears that the dynaspark has ended my optispark woes, although I did have a check engine light on the whole race...it's gone now so I can't check what code was set, I think I have to pull of the "opti" again and inspect it just to be safe.

Perhaps the fact that the car runs hot is exacerbating an already harsh environment. My plan is to improve that over the winter. But aside from that, it's tough to anticipate anything other than wheel bearing or dirtributer problems. The rest should be a bit more robust.

One final comment: keep in mind that there is really no way for me to test changes other than fire the car up in the garage with no load. I can't take it out on the street and see if it runs hot or fails under high RPM's. I'm sure that's a big reason why I find my problems at the track.

I will definately end some of these woes once and for all this winter, the stock 1993 computer and harness are GONE. I'm not sure if I'm going to add a '94+ computer or something else altogether, but the simple ability to tune the car on the fly and see what's going on via laptop should alleviate many of these types of problems.

I guess I'd rather discover those problems at a HPDE for $200 than at a race.

Why can't you pull the inactive codes? Computer saves them in memory unless you unhook the power source.

My car was running really hot at my last event, and on a cool day. 260F coolant, 305F oil, after no changes from the previous event where it was fine. So I'm thinking the extended high RPMs at the different track did me in. I'm not going back until that's addressed. I blocked the gap under the condenser to keep debris out of the radiator, probably will have to undo that, along with cleaning and flushing, new tstat, and putting a screen on the front of my bigmouth instead. And maybe a racing radiator.

How hot do you get? (assuming your guages are accurate at all.)

Spectator, any mods to the cooling system?

I've got a BeCool radiator, still no oil cooler, and an electric water pump.

I may put the stock pump on it, it's great at the drags and autoxing, but I was seeing 244 up at NHMS and I wasn't really on it.

BTW I learned a neat treat for the stock pump is to install a line to the weep hole just in case it decides to take a dump it won't take out the opti.

The throttle position sensor could trick the engine into running lean, or a gasket leak.

Started a thread on cooling, etc over in C4tech:

http://www.corvette-guru.com/modules/ ... t_id=50521#forumpost50521

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Test days at a race track run about the same price unless you go to Infineon where they're insane.
And a test day is just as expensive as a race weekend so it eats into your budget. You do get more track time and usually can go out when you want to.

Jon's actually pretty much on schedule as far as debugging a race car. It usually takes 2 full seasons to get a car reliable (if that's even possible) and it doesn't matter if you bought a used racecar or you're building a new one.

I think Jon's coming up on 2 years now form the start of the serious build.

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Even more than that is the cost and effort required to get the car there. Remember Kevin, it's not like I can hop in the car and head over. It's at least $150 - 200 in gas alone just to get to the closest track. Mounting tires, changing fluids, etc also adds up fast. The other issue is schedule - I already have a race about every two to three weeks, taking additional weekends to go to the track kills time for anything else, including working on the car...

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That's the most depressing thing I've ever heard...another season?

I think getting the car to run cooler is going to help immensely. From the engine standpoint, 230* isn't horrible, but that means exhaust gas and underhood temps are much higher than they should be. I'm sure that's contributing to some of these failures. I'm melting wires and overheating lubricants quite quickly.

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Shouldn't be depresing, it's just the way it is. I was building brand new formula cars out of the crates, shipped from England. No engineering, no modifications allowed, nice clean new parts. No problems, yea right, it still took 2 seasons to get the cars really fast.

Besides, about the middle of next season, you'll be thinking, wow, nothing major's breaking. Towards the end of the season, you'll be in your chair watching the guys across the paddock thrashing.

Didn't use Teflon wires huh?
I was also going to talk to you about the connectors when I saw the pics of the wiring but you were done by then. That's what I use to do for a living.

I consider myself lucky that I haven't even broken something in 180 passes down the strip or the handful of auto-x and HPDEs. It's not for lack of beating the hell out of the car. I guess it pays to have such low hp! I may keep it that way. See too many high hp guys at the track chasing their tails and having less fun.

More info from the "other site"

http://forums.corvetteforum.com/showt ... 1567140395#post1567140395

[QUOTE]Vector Vette:
Mark,
The (electric) water pump is not a problem. I ran it on my SCCA racecar for years. It is a 383 LT4 with 465 rwhp.[/QUOTE]

Electric pump is going to free up some hp on the track also.

I'd love to see a pump curve for the mechanical pump... I would bet its efficiency goes to the toilet at high rpms.

And just remember, at 240F, your radiator is effectively much larger than at 200F.

I disagree with anyone that says running 240F makes it on the verge of overheating. The hotter it gets, the LONGER it takes to rise in temp.

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Good point. And putting bucks into your suspension like you're doing will give more enjoyment than the HP right now.

So you gotta get to the track and see if all those pretty new rod ends are working.

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From the Edelbrock site.

I wish that table would go up to 7k

Still very enlightening.

~40 for each bank or ~80gpm overall.

[QUOTE]Aardwolf:
I remember reading somewhere too that the pump uses 6-7 HP but I can't find that reference now. It would be interesting to see the RPM go further. Maybe on another pump makers site.

Edit, from the Stewart site:

http://www.stewartcomponents.net/Merc ... TGY&Category_Code=ChevyS4

Chevrolet High Flow Water Pumps

Stewart Stage 4 pumps are the cutting edge in performance water pump technology. The Stage 4 pump utilizes the Stewart Components DRV-8 impeller. This exclusive 8 vane impeller is fully CNC machined from 6061-T6 billet aluminum. It's special design flows up to 160 GPM, while consuming less than 3 horsepower at 4,500 pump RPM. Stewart Stage 4 pumps are the ULTIMATE water pump for any application!

This would suggest to me that the flow rate just keeps on climbing.[/QUOTE]

160!
Of course as one poster already wrote, if the water goes by the pump too fast, the raditor won't be as efficient.

Hogwash, and you should know that. There's no such thing as too much flow.

Must be cavitating then.

I was talking about pump efficiency. Loss of efficiency doesn't necessarily equal cavitation, it can be simply turbulence, heat, and short-circuiting.

But judging by the flow curve shown, it appears to be doing pretty damn well at high rpms, it's practically a straight line. Inefficiencies would cause that line to taper off towards the top.

I believe Qack made the curve to show what it would do if it stayed exactly efficent as in the chart. This may or may not be true. Judging by the stewart pump flowing, what 160? I would say it's pretty close though.

Ok, where'd his post go?

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It's in a different thread, "Re: Cooling issue and lean condition concerns".

http://www.corvette-guru.com/modules/ ... php?topic_id=5296&forum=1