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- เผยแพร่เมื่อ 21 ก.ย. 2024
- July 16th 2019 SCCA Track Night in America Blackhawk Farms Raceway.
2004 C5 Z06 (heavy modified) hits the wall after turn 7. Not sure what happened exactly. Just before the turn the car wiggles during braking. Also the rear tire pressure was too high. Damage was only to body panels, car ran and drove fine after.
-------- Update 6/9/2020 --------
Car is repaired and running better than ever. So here is what nearly 1 year of reflection, comments, observations, data, and tear downs has come up with...
1. Tire pressures were significantly high, causing excessive tire temps
2. Aggressive behavior for a shake down first session, obviously setup issues
3. Oil line leak on the passenger side - bottom of car was wet with oil, look over your car carefully
4. Stability Control was disabled because of issues, should have fixed first for an added safety net
In response to all of the comments: This was a shake down session and I was not racing despite me passing cars, I was only pushing the car about 70% - which was a bit too aggressive for a shake down anyways. I am not rev-matching or aggressively shifting because I am not ready to yet, I am trying to assess two key things in this session that had changed since last track session - brakes, tires, power, alignment. The reason I am shifting gears often is because the engine setup has all the power up very high with very little power below 5k so I was trying to keep the car between 5,400 to 7,200 which is very abnormal for a C5.
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Sorry about the audio static - seems to be the exhaust is too loud for the mic.
Looks like you just got on the gas too hard too early. Glad it wasn't too bad!
Really need to practice heal/toe downshifts... I can hear the rears screaming for life when you jam it into 2nd and just let the clutch out without matching the revs. This has got to be aggravating your rear tire temps and upsetting the chassis.
Heal and toe was popular with slow cars and without synchro's. Brake to slow, its quicker.
@@SkyhawkTL you still need to match revs to put the car into a lower gear to accelerate out of the corner. You do it to keep the chassis and rear tires happy while braking, not to slow faster....
@@SkyhawkTL please stay away from me on track...
@@XanderxXxCageX That won't be a problem.
it's clear you have absolutely no idea of what you're talking about. Do u even kno wwhat heel and toeing means? do you actually have any idea of what revmatching means? Stop giving out horrible advice. literally NOBODY in this entire comment section agrees with you. you fail. @@SkyhawkTL
thanks posting video of track. very helpful for ppl coming to track. sorry about your car/wreck. glad you are ok brother.
Unless you actually race on the track, dont judge. This isnt gran turismo.
100% but If you race on track, you can clearly see the lack of expertise and too much excitement on the pedal. And complete disregard for downshifting properly, Ie heel toe
I see a lot of explanation related to the hardware but I would suggest that you start from first principles and do some rides with a good instructor. I see time and again folks start to play around with the car itself when they really need to work on themselves before anything else. But at least you’re out there using the car! Don’t get discouraged.
Going throttle on while the wheel was still turned is the culprit. If you're still putting in steering input and you feel the need to add throttle, that means you've over slowed through the corner. Trick is to carry enough speed through the corner so you don't need throttle in the corner then hit full throttle at track out when the wheel is straight. When you went throttle on, you asked too much of the rear tires, the front tires still had grip so around you went. Of course over inflated tires doesn't help either. At least you're out there!
Thanks
Data log of the car during the spin showed an apex speed of 45mph, exact same as previous lap. Throttle was applied after apex at a gradual rate similar to previous lap but maybe 10-15% more.
Also later found the PCV line was lose and oil was all over the right side from the engine to the back (under the car). Just over 1qt low on oil.
Probably multiple things played a part, but what I am taking away is to be a bit more cautious the first session to better dial in the car.
This was my diagnosis as well. Driver has a tendency to not track out enough before applying throttle. He got away with it quite a few times before the crash, but eventually his luck ran out.
I had a z06 that I pretty much did the same thing at turn 1. In my case and possibly yours too. Throttle induced oversteer.
At first I said man your missing the apex, late shifting, and just not really racing hard. Then I saw your explanation and makes sense. Best be safe looks like to me you hit the part of the corner with some tire pebbles and lost traction right when you gave it some gas. Glad it wasn't serious damage. Keep at it and can't wait to see more.
Great day turned into not such a good day! Even the best driver can make a mistake, looks like too much throttle on corner exit, and not enough correction as the wheel speed increased when it was hitting powerband throwing you for a spin even faster.
did you release the clutch in the corner?
looks like your tires were hot, the squirming is a common sign the tires are getting greasy. Glad you walked away (or drove away). Planning to fix the car?
I agree with you about the tires.
Working on an estimate now to fix - looking about $2k-3k, so not too bad.
It’s ok to increase gas early but not that much.
There is a lots of good advise to Mr. Glassmaker here. I hope you take it. Your lap times are; 1:46; 1:34; 1:39; 1:38; 1:30 and then when you finally got a clear lap with no traffic 1:27 At one point Cars and fishing mentioned getting an instructor to help you out and that is the best advise. Your car is capable of below 1:20 lap times but you need to adjust you line in many places and become a master of toe & heeling. I'll help if you ask or just ask the fastest guy when you are there at a track. The fast run group will have people running consistent 1:17s, 1:18s and 1:19s.
While you are heal and towing, you will be passed. This car is higher performance than a normal sportscar, and the brake cycle will be extremely short.
@@SkyhawkTL I was trying to help explain what you could do to be faster. ( as politely as I could) If you have a VERY fast Corvette, then you are 10 seconds or more slower than your car's capability. The weak link is 1. bad fuel? 2. poor quality track? 3. rain and snow? 4. know it all driver? 5. Drag strip parachute kept deploying at the start line? 6. Tires filled with helium eliminated needed downforce?
it's clear you have absolutely no idea of what you're talking about. Do u even kno wwhat heel and toeing means? do you actually have any idea of what revmatching means? Stop giving out horrible advice. literally NOBODY in this entire comment section agrees with you. you fail. @@SkyhawkTL
Nice C5 man with a cam! What tires were you running? How did you mount the camera? I'm planning on going this season and getting things together this winter..
Thanks! Tires were Hankook Ventus V12 Evo2 all around in slightly wider than stock. I used a suction cup mount for the camera, attached to the back window just behind my right shoulder.
The crash happens in the last 10 seconds of the video.
Man i remember you, you were parked next to me. Glad your fine
Thanks! You were a good pits neighbor! Car should be back together this weekend so thinking about the next track session I want to go to.
That sucks buddy. Did you ever get her fixed?
Mostly fixed, needs a bit more paint job work and an alignment yet.
Your hands moved pretty quick to counter the skid but I guess it was too late. I did something similar in my C5 but mine was a low speed corner and I trail braked which brought the bit around and I spun out. I fortunately didn’t leave the track though. That is a nasty cam btw, sounds great!
A bit ham-fisted throughout. You are shifting too much. With the torque from that V8, you don't need to shift all the time. And you are not rev matching when you do shift. Heel and toe plus finese with the throttle should improve your laptimes and save the car and tires.
I have to shift to keep the revs above 5k, with the cam there is little HP or torque below 4k. It is a cam that peaks near 7k. This was a shakedown first session so I was taking it easy and not even concerned about lap times, I have an auto-blip system that I didn't even turn on yet. Because I was passing cars it looks like I was racing hard but I really was not.
@@JoshGlassmaker throttle application is matter of finesse especially with big horsepower cars on the exit of turn 7 especially when one tracks out onto the alligators. All I can say is that you did well to get out of it unhurt. As an amateur road racer and a constant SCCA & Midwestern Council track worker at Blackhawk Farms, I've rarely seen hamfisted throttle control end well especially at Turns 7 & 3A. I wish you a better session next time. Regards.
@@brigidovillena8516 Thanks. I have seen plenty of other crash videos from Blackhawk Farms on turn 7 prior to mine, so I should have been more cautious. This instance was only my 3rd or 4th time at the track with a car that was very different from the last time I was there with it. I hope to get to Blackhawk Farms this year yet.
The track workers were awesome! Concerned first for my well-being, respectful of my needs, made sure I knew what was going to be happening next, and open about questions I had after. Thanks for taking the time to be a track worker!
@@JoshGlassmaker I'm happy to volunteer my time and I have learned a lot about the ins and outs of the corners from very close observations. Yes, a lot of drivers tend to get excited coming out of turn 7 especially after they have made a pass through 6 -6A. At that point, you're off your rhythm as you have to scramble to get over to the left side at corner entry of turn 7. Then it's easy to goose it through and at exit, or drift out to the gators because you apexed too soon. Those gators on turn 7 exit are very rough and combined with big throttle will snap the rear around real fast. Anyway, hope you get back on track soon. My first race of the season is on the 19th with VSCDA at Blackhawk. Best of luck!
I screamed as if it were my car when you went to wreck. I have a yellow z06 as well.
lol, it was not a great day but could have been worse.
You spun to the inside, the car could make a tighter turn than necessary. Looked like an oil spin. Tire pressure is what you chose AFTER taking pyrometer readings.
The audio from 1:15 to 12:20 is better than any rock and roll song.
Your foot was still on clutch going into the corner. You left off of clutch trying to power out mid corner but broke loose to tires. You need to really learn how to heel and toe. You disrupted the car letting off clutch. You should have gotten a person to drive with you before even attempting this honestly.
Honestly your assessment couldn't be more incorrect about what actually happened regarding the clutch - 100% wrong. When the car wiggles BEFORE turning into the corner is when I have completely disengaged the clutch and already in the gear that I carry all the way through the corner and even into the wall.
Josh Glassmaker man I dunno. I don’t mean this as criticism really, but you did constantly drag the clutch out, literally in the corners, while downshifting.
It’s very easy to hear how you’re shifting and the timing with a set of headphones while watching this. You, again, dragged it out mid-corner, and not even a second after, you were right back on the throttle.
The car’s balance was off, so was your input. I don’t think it was the PCV or whatever you mentioned in other comment.
@@garagers6667 I would agree totally.
If you decide to heal and toe, do it off the racing line...
@@SkyhawkTL it's clear you have absolutely no idea of what you're talking about. Do u even kno wwhat heel and toeing means? do you actually have any idea of what revmatching means? Stop giving out horrible advice. literally NOBODY in this entire comment section agrees with you. you fail.
Sunova..