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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
Thanks fellas. I am parking the car for a few weeks to freshen it up in preparation for time trials with NASA in September. Got the whole thing ripped apart right now. I'm also moving my brake ducts to the fog lights to get more air to the radiator. Just ordered a brand new set of sticker R7s. 315 front and 345 rear. I've got like 10 sets of Hoosier scrubs now from previous races haha. Good for practice and screwing around.
Yea Jason, 2:00.748. My best lap yet. I will break two minutes this year!
And I can put down 2:01s pretty consistently. The "Go-Fast" list for road courses on this forum puts the best Vette time around 2:04 at WGI. I don't post to it though. https://www.corvetteforum.com/forums...ke-a-look.html
I'm a few football fields or so ahead of the next fastest for what it is worth, and these aren't hero runs I do but endurance style consistent laps. Pretty confident I could take that whole list down if I had the time and inclination. This was on Hoosier scrubs:
Yea Jes, they were PAC. I'll post a pic up of the broken one when I get a chance. They cycled about 10,000,000 times or so on this run. I'll also test the pressure on them when I get a chance. I bet they are down about 20% from their rated pressure.
Anyhow, I ran out of shims so I am waiting on PAC to send me more then will finish up. In the meantime, I'm doing the brakes on my C7Z as I'm instructing at the track next week and since the race car is down I'll bring the C7Z and bust some heads.
From post 25, Hib Halverson, https://www.corvetteforum.com/forums/c6-corvette-zr1-and
Originally Posted by Mordeth
After the first belt ate itself, I just put on a Katech tensioner last week. Unfortunately, she chewed up another belt yesterday. Thankfully I brought three spares this time. So it isn't the tensioner. It is a new IW balancer as well. Everything looks to be aligned properly and nothing is moving, so I am not sure why the belt keeps eating itself. I looked at the pulleys and don't see any burrs. Going to have to put a laser on it. Unless someone has any better ideas.
Did you see this before?
With #2, initially, because I never had the problem previous to Katech's work, I thought it was caused by the ATI crankshaft vibration damper Katech installed. I contacted Jason looking for a solution. He got in touch with ATI and they told him the problem was the A/C belt tensioner. I replaced the OE tensioner with an aftermarket unit from Continental, but to no avail. The the A/C belt kept jumping grooves. I bought a second tensioner, this one a Dayco. That didn't solve the problem, either. At that point, I decided it was unlikely this was a problem with belt tensioners.
The solution came from a likely source, this forum site after I posted a question about ATI dampers. Subsequently, CF Senior Member "double06" and I had a PM discussion about his experiences with the ATI Super Damper for LS7s. The original ATI design had no shoulder behind the A/C drive belt grooves. Apparently, this was the cause of a widespread A/C "belt throwing" problem which had ATI changing the design by adding a shoulder about .100-in high. The stock damper's shoulder is .160-in high. The belt I was using, a Continental Elite (which is the Goodyear Gatorback design which Conti now owns) had failed, so I reinstalled the stock belt which, I had kept as a spare. The stock belt stayed in place during repeated high rpm tests.
That got me thinking about slight differences in belt lengths. It was difficult to find effective length information about some of the belts on the market, but of belts for which I obtained data, the Continental Elite was the longest. I physically compared it to the OE belt, which is branded "Mitsubishi" and found it visibly shorter. Using listings on rockauto.com, I found the belt with the shortest effective length of belt makers which published lengths was a Dayco, so I ordered one. It didn't fit. There was no way, working by myself under the car, that I could get the Dayco on, so I went back to the OE belt. I'll save the Dayco to when I have someone to help me install it–one person underneath holding the tensioner back and another person working from the top to pry the belt over the A/C compressor pulley.
Bottom line: the problem was the "second design" ATI Damper and its sensitivity to belt length.
Just shredded a belt on mine on Friday. It was a dayco brand and I run the ICT billet tensioner and ATI balancer. The belt had already stretched once during some dyno pulls and was riding the center grooves on the lip of the tensioner. I tightened it up a bit but I believe it was already fatigued. Lasted a little while but 4 back to back 7500+ RPM pulls killed it on Friday. Going to purchase another of a different brand and possibly a back up of another brand to see if there is any difference.
I have no AC system. I ditched that long ago. I think it is the alternator. I put on a different AC Delco alternator over the winter that had a better clutch system in it and have been warrantying it everytime it gives out. But it looks like the pulley might be one tooth off when I put a laser on it. It's either that or the IW balancer. I really hope it isn't the balancer as I have no interest in pulling the rack AGAIN to deal with it. So I will put an OEM alternator back on and see what happens. I just warranty them anyhow when they give out.
Also, I stopped using the Dayco belts and now use Continental Elite. They last 4 days on the track instead of 2. Tells me they are made better.
Some pics from this weekends races with NASA at WGI for those that are interested. Took home 1st place on both days. Car ran like a champ. Won me some Hoosier R7s which will come in handy in a few weeks in New Jersey.
Could you please elaborate on ANY wear detected on the CHE trunions? Your feedback on the guide wear is excellent, looking forward to your comments on the CHE components.
Last edited by Dan_the_C5_Man; 10-03-2018 at 04:25 PM.
That is really ironic that you wrote that! I was actually thinking that you might see/comment on that as I was typing it Probably our Supplier Quality commonality!
Thanks fellas! I really appreciate it. Car was run very, very hard this year.
Jason: You definitely need to get down to the track next year. I instruct with a bunch of groups: NASA, CHIN, Phoenix, Porsche Club of America (National Instructor for all regions), Trackmasters, NARRA etc etc. I'm pretty confident you can and will get one of those Zs of yours around the track pretty well and I'm happy to help. Let's hook up for sure and you as I told you the when you stopped over the offer always stands!
Few other notes: My wing was producing so much downforce that at speed it compressed the rear fenders onto my new wider/taller R7s (345s) and so they would rub badly. My buddy actually took pictures and videos of it happening. Luckily I brought my spanner wrench and jacked the rear up 1.5" with the adjustment nuts on the coilovers. Screwed up my corner balance and still rubbed some but wasn't cutting the tire any longer so I could race. Will have to go back to 335s as they tuck under the wheel well lip. So the tires I won from Hoosier that I requested will be 315 front and 335 rear for the next race. You can see in this pic where it rubbed down to on the tire.
Also, forgot to post some carnage from a few weeks ago. Inner rubber coupler/giubo disintegrated in the torque tube. Internal bolts sheared off and busted right through the tube. Found a few of them on top of my tunnel plate.
08-18-2018, 09:59 AM
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