New PB - 10.81@128 1.44 60 foot
 

We had a cool day here in S. Fla and the track was open so Theofel, Justasheet and I all hit the track and left with new PB's.

I ran 4 times, two 1.44 60 foots in a row though I missed 3rd the first time. This run was a hot lap and an identical 1.44 60. I launched at 6746 rpm and the track held twice.

Enough beating on my daily driver - stock OE clutch, 61,869 miles and 466 drag strip runs, I didn't go back for a 10.7 slip.

DA was -581 per Drag Times and we had a stiff 25 mph head wind due to the cold front that came through last night.

With the AFR 205 heads I dyno'd at 472/414.

We had a fun time tuning Justasheet to get him his first 10 second slip, but I'll leave that for his post which I'm sure will be following shortly.

Here's the video:



Here's the slip:

http://i56.photobucket.com/albums/g1...g/a001ab53.jpg

Pretty sweet Joe, congrats. That launch sounds so nasty. It certainly sounds like you've got your launch technique back with back to back 1.44s. Congrats!

Can you email me your log from this pass too?

:iagree: 1.44s?! :eek: I think that might very well be the absolute BEST sixty foot time out of a stock ('non Z06/non ZR1' but maybe still including those as well?) Corvette clutch in the history of time! :thumbs:
At least among stock cubic inch NA applications I would think.

Car sounds GREAT too, congrats Joe. :cheers:

Thanks for the kind words Justin & Marc.

Yea can you believe it's the OE clutch...60,000 miles bumper to bumper traffic. That has to be some sort of record!

Here's the slips to show it. Two in a row.

http://i56.photobucket.com/albums/g1...g/b54f30f9.jpg

Here's the video. I blew third. I know better than the look at the board, every time I see a good 60 it throws off my rhythm.

SICK!!!!! Joe! Congrats!

:party::party:way to go Joe:cheers:

Hm--that sounds like a challenge Marc :D

Wow, thats killer on a stock clutch'd ls2!! Congrats Joe!
Im gonna need some serious practice to get anywhere near that 60' time! LoL

"Holy Smokes".......:eek:

Absolutely fantabulous Doc Sparky! :cheers: :woohoo: :flag:

WOW! 1.44 and even twice. :thumbs:

Congrats on the PB 10.81. :rock:

:D It does show that it really is possible with the right combo/driving/track prep, I thought for sure that 1.49 or maybe 1.48 was going to remain the lower limit on the stock LS2/LS3/LS7 clutch but apparently it's not.
Go for it man. :steering:

Thanks. That was only my 465 and 466'th launches on that clutch. So it did take me a few times to get there.

My first clean run in the car (2nd run in the car when new) was a 1.964 60 foot on my way to a 12.970@109.98. I have learned a few things (and made a few mods) in the last 6 years in this car.:lol:

Nice... Kind of where im at right now, 1.94x - 60's, and 11.80x @ 121, on run flats of course! Poor 60's, Still new to launching a car with low profile street tires, my 74 C3 had 70series aspect ratio and then MT DRs, so was so easy to launch and get good 60' times!
But drag radials getting mounted on some C5Z front wheels this Tuesday, and cam going in next week! Hope to get close to your 1/4 times, but gonna have to learn all over how to launch the car!

In any case, great work man! :thumbs:

congrats!!!! :rock:

Damn that's fast!!! Good job dude!!

Great job Joe!!!

When Justin throws in the towel for a new clutch, maybe we can have a clutch party...

Holy smokes..............1.44's? That's amazing - congrats! :thumbs:

wow congrats joe, i didnt even know they were open yesterday. if i would have had my exhaust on i would have been up set i missed it. i should have my exhaust fixed in a week or so then ill proably go out again before i leave for cali.

I'm optimistic that this clutch will hold on for awhile longer. I've identified the issue I was having and have adjusted to make sure it doesn't happen again. IF I do in fact have to put one in, a clutch party sounds like a good time to me. :cheers:

The rest of my C5 front brake conversion should be here tomorrow so I should be able to get it all fixed up for an event this Saturday. I'd love for another cold front to come on through. . .

What's wrong with your exhaust? Or did you get something new?

Ridiculous 60'

Thanks Gents!

I have to say, my clutch is one reliable piece of machinery. I just drove it for an hour in stop and go traffic on i-95...creeping along...it's just like a Honda Civic clutch in traffic.

Yet it'll hold a 6700 RPM 100% throttle launch, matter of fact, two of them within 4 minutes.

Roger Preston of Horsepower Sales and I were just laughing about it this morning. I'm not sure how I got so lucky with that clutch. I tell all my friends that God loves me and it's true.:yesnod:

What was the issue you were having with your clutch Justin... how did you remedy it...



Joe_G... Have you done anything to your clutch system to make it last soo long, other than say Ranger fluid flushes??

I did a few things.

1) Removed the clutch spring. Well, Joe removed it the first time we met at PBIR, but ya-it's gone.
2) Removed the inspection plates on the bellhousing.
The problem with the corvette hydraulics is that the clutch dust has nowhere to go when it is generated and it then penetrates the vulnerable slave cylinder which is why the fluid turns black.
To assist the clutch dust from exiting, I removed the 2 plastic inspection ports on the lower sides of the bellhousing. I did this a few months ago and my clutch fluid has been remarkably clean ever since. I still do the fluid swap, but what used to take 3 or 4 cycles of clean fluid to 'repair', now only take 1 cycle.
3) My burnouts are now only 3-4 seconds. I used to do longer smokier burnouts to get my Toyo drag radials hot, but these Mickeys don't take much to get them ready.

I also swap the fluid before and after the drag strip as Joe recommended to me awhile ago. I don't expect to get 450+ passes on it, but I'm knocking on the door to the 150+ pass, 70+ of which have been with the cam installed.

Hope that helps.

Big thanks again to Joe for his invaluable information he has so graciously shared with me. Thanks buddy :cheers:

I do the Ranger method before and after each event religiously since new. The fluid is pretty much always clean, even yesterday evening after those events.

Removed pedal spring as soon as I put in a cam. It was sticking to the floor after the cam (but not with only bolt ons).

I don't think my car has anything plugging the inspection ports on the bell housing, I've seen tracks of clutch dust on the bell housing.

Check out the clutch dust on the video! My buddy said it looks like a pro stocker belching out dust. :lol:

I've lost count of the pedal spring-ecotmies I've done at the track. Two or three in the last couple of months.

That's interesting Joe. I think I may have misphrased that--not the inspection ports, the 2 plastic 'covers' on either side of the front of the bellhousing. The starter goes through one of them, and the other side is just attached with 2 10mm bolts.

Removing them lets a nice amount of air flow through the bellhousing and out the 2 inspection ports which should help with dust exit. At least, that made sense to me.

:rofl:

I've not done the mod to remove the front inspection plates. I hate crawling under the car on stands. Easy to do or a pain?

Jeremy Formato did a nice post on it.

http://forums.corvetteforum.com/c6-t...ur-clutch.html

Exactly! Ya, he's the one who suggested it in the first place. He also suggested boring out the inspection holes but I didn't feel like doing that at the time.

Removing the starter-side one is a huge pain. I actually had to loosen the passenger side header so I could wiggle the starter far enough to clear the inspection plate. It's a little piece of plastic but it certainly gave me hell. :lol:

Congrats Joe! 1.44 is insane on a stock clutch, I can't wait to see pics of it if you ever take it out! Must have magic ferry dust sprinkled on it lol For sure would have been a 10.7 without the head wind, but don't suppose you can complain too much as that's a nice DA with the sun out:thumbs:

I believe it'd be possible for you with a gear swap as your coupe is lighter:thumbs:

Yes notice I haven't made any excuses thus far, but here we go... I was running 1/2 tank gas yesterday along with a 25 mph headwind and DA only -589. :toetap::lol:

I was hoping to get close to Andrew and Dennis but alas, seems it's not going to happen as I'm done beating on my car that gets me to and from work.

I hadn't planned for a track event, so I had almost 3/4 of a tank. I went to siphon out some gas (which I've done before) but couldn't find my 1/8 plastic line. 1/4 plastic line doesn't work BTW, but 1/8 does, just takes a while to do it. I did drive up in 5th to burn off some gas. Al Gore would not be proud.

I did siphon out my washer fluid, and used the opportunity to show my 6 year old a little bit of science in the form of pressure differential via the siphon technique. He was non-plussed and preferred to do battle against aliens on his Wii. I didn't push the issue as I realized I really didn't want him getting a mouthful of gas like I did the first time I did it, but perhaps he noted the technique of how to NOT get a mouthful of gas which is what I was trying to show him.

My wife's plan is better, don't try to siphon gas. But hey, if the world goes to Mad Max I'm your man. I can do lots of things like siphon gas.:lol:

:lol: Joe, you crack me up.

Done beating on your car though? Say it ain't so! I can't believe you're done with the dragstrip. . .

Oh I didn't say that!:willy:

I'm looking forward to our new challenge series starting 3/17. But there's a huge difference bracket racing your car, dialing soft and launching easy, going for a good light and working the stripe, vs. launching at 100% throttle and 6700 RPM!

You can bracket race a car, dialing high 11's and launching for a 1.8 60 foot, for a long time.

You only get so many 1.5 60 foots, and I think the 1.44's count double against rear end life!

Very true--I was just making sure. I was worried for a split second.

I'm trying to get the #1 spot for LS3 internal mods as the car sits right now and I'll get there with your help :thumbs:

What tires and sizes are you using in the rear?

315/35/17 Mickey Thompsons on C5Z06 fronts.

They rub on standard c6 fenders, not so on z06/grand sport fenders.

Congrats Joe! :thumbs:

What's she weighing in at these days?

i was getting a bunch of knock retard on the shifts because of my cutouts hitting a heat shield. im going to a solid 3'' with Z06 mufflers and im waiting on the peaces that go from the X pipe to the axel back. i hope this will help get my mph up since i wont have any knock.

Nice time Joe and killer 60' :thumbs:

Last time I weighed 3195 (car only) with about 1/4 tank. Yesterday I had 1/2 tank or a little more, so I'd guess 3200 or so. I was probably 200 with my heavy winter coat.

I actually left my garage with a light jacket...as I rolled up the windows, went back in for my rarely used winter coat! We florida folks aren't used to the first digit of our temp starting with a 4...49 as I left my house.:lol:

Thanks! I am very happy with the 60's. That accelerate into the launch trick that Robz told me about is really the key.

You cannot let your car bog or it's a 1.8 60 foot. On those 1.445 launches the car never went below 4800 RPM throughout the launch process.

I have only 414 tq so I have to spin the engine. I think Z06's and Zr1's with 100+ more ft lbs are able to bog more than me (based on listening to their launches).

I think it's been proven that the stock z06 clutch will not handle a 6700 rpm launch no doubt given the much higher torque of the 427.

I wonder if a Zr1 would handle a 6700 launch with its dual clutch....

It's interesting you say that Joe--as I've had my car bog multiple times and I still get high 1.5 60fts. If I want a low 1.5, I have to keep the rpms up but these Mickeys really stick and cause my rpms to bog down to 3500 on a few of my passes.

You say you only have 414tq though? I thought you made more for some reason. Perhaps its the additional torque that lets me "recover" from the bogged launch?

That's in street trim though right? Surely you're not pushing 3200lbs with the drag pack and no passenger seat. :eek:


You Floridian's are something else. :lol: I was working outside in the elements Saturday night into the AM and weather.com showed 7deg's where I was standing. :crazy:

Thanks for the info guys... Between you guys, I might have to move to Fla for the killer knowledge you guys have in addition to the great weather! lol Ill look into removing the dust covers!
I be a big part of the problem was the first time the fluid was ever changed was when I got the car with 29k miles! now I do it all the time and removed the spring since last trip to the track... Curious to see if thatll help! But hope to get those covers out before next track day anyway

For me, even if removing the spring didn't do anything for performance, it was such a relief to rid the car of the 'staged' clutch pedal feel. I really disliked the feel of the pedal and much prefer the linear pedal travel.

Congrats Joe!! Appreciate the video as well :cheers:

Sick run! Congrats.

I think that's what it is. Remember I've only got 472/414 to your what, 494/445? That makes a big difference.

What's odd is we're both running 128. I compared our two best slips last night, I 60'd you by .06 but you et'd me by .08. It's all in the 1/8, your car pulls mine in the 1/8, I have 4 shifts in the 1/8 vs your 2.



Oh yes. I'm a convertible remember, I think it weighs 40 lbs more or so from the factory.

Here's my car nearly empty of fuel and nothing in the cubbies. Yesterday I had 1/2 tank of fuel and my usual assortment in the cubbies - 4 way tire iron, patch kit, small compressor, pliers, screwdriver to take out the clutch spring (Justin I forgot I had that in there when you were up at the track, I really do carry such a screwdriver!), etc.

http://i56.photobucket.com/albums/g1...g/e4c0aa0d.jpg

One time another evening when I weighed the car with drag pack, seat out, etc. but including my assortment of accouterments and 1/4 tank of fuel it was 3195. I didn't snap a pic.

The only other difference in our cars are the gears, right Joe? I make a hair more power, and you have a better gear for the 1/4 mile. My mph is a little higher in the 1/8 than yours, but you obviously come on strong by the big end. I'd love to race heads up one day-talk about a drivers race! :steering:

Oh, and :lol: at you having that screwdriver.

Because of my shift to 4th before the 1/8, I get 30 mph in the big end to your 26...but you get 102 in the 1/8 to my 98 so there's where that 4 mph is. The last 660 is exactly 1.563 seconds in both of our cars.

It would be a great race. I think you have the edge in power but I've got a slight edge in experience. :cheers:

:lol: That is pretty interesting actually. You are/were my Mr. Miyagi and I learned from your teaching and we run identical times? :rofl: Awesome

The mark of a good teacher is that the student surpasses the teacher Grasshopper...lol

Frankly, you have REALLY learned to drive that car and that's all you - you listened to a few tips and ran with it. Not many can get a 1.50 with a stock clutch.:thumbs:

I had a good instructor.

I only need another ~.1 to take the top spot for LS3 internal modification and all the guys ahead of me have way more mods than I do. I just need a nice cool day

Yes you do. You've come a long way in a short period of time. One cool day with good track prep and you'd have it. Sorry I didn't think to call you yesterday, you're a little far, but man, it was wide open track and negative DA in the sunshine all day. That's about as rare as hen's teeth here!

From my experience of swapping from 3.42 to 4.10 gears at my lesser power levels it was worth ~13/7
http://forums.corvetteforum.com/perf...o-results.html
Though the gears are actually worth 2-3 tenths ET, which fwiw turbovic has a non-z51 trans that held him to a 1.61 60'

That's true I forgot that 4.10 gears reduce dyno results but they do. I found a great explanation of why and posted it years ago.

Gears make it a lot easier to launch truth be known. I found a difference even between 3.90's an 4.10's. But 4.10's with H/C make it a lousy 1/8 mile car due to the extra shift. That was my first "6" second 1/8.

I might have made the trip. I just installed the battery and would have liked to try it out. My C5 brackets should be here tomorrow and that should allow another ~17lbs to come off the front end. If the weather is decent, I'll be going to bmp Thursday night.

That added nothing to the thread.... This isn't OT

Congrats Joe! Great run!

Crap, figures, I even woke up early but had lotsa paper work waiting for me at the office...........

Congrats

Yeah, that's the reason I don't run 1/8. I can't stand having to make the shift right before the traps, but sure would have liked to join the 6 sec club. Though I know if I had the non-z51 trans like before, so I didn't have to make that shift, it'd be done easily as I lost 3 mph in the 1/8 having to make that shift.

I went 7.09@101 on a 1.54 making two shifts previously and 7.03@98 on a 1.49 making three shifts with z51 trans.

Joe you are right about making up et in the first 1/8. My car dyno 445/428 . my best was a 6.82@99 on my 10.78 run I only back half ed 23.5mph. On another not so great run when I spun I ran 97.6 and 124.33(which is my all time best MPH)

Congrats Joe! Great driving. That launched looked perfect. :thumbs:

Thanks Gary! A complement from an experienced and proven master like yourself means a lot.

What is your launch technique? Are you accelerating into the clutch release too? What's your launch RPM?

Thanks Joe. We try to match the launch to the tires and track conditions. What works at one tracsk on a given day may not work at the same track on another day. We have found that different tracks require completely different techniques and adjustments. We have ran a number of different tires this year including DRs which have not been used in over a year. Our current setup prefers a slick but does run well on a DR. We have been very fortunate to be able to cut 1.3s almost at will on the slick when the track is there. The DR is not quite as cooperative but it does have its moments. As you know, different clutches require different technique and you my friend have optimized yours. :thumbs:
Keep the numbers coming.

That's certainly true...I have to say it's not every day the track will hold a 100% throttle 6800 launch.

Based on my experience I don't think I'll ever get a 1.3 with my setup, and frankly I don't feel compelled to try! :lol

In my case I guess it's the hundreds of passes I've got under my belt that dictates how fast to release the clutch given track conditions. Anybody can floor a car so that's not where the magic is when launching a manual. I was trying to describe what I do to Double A Vette who's coming up to MIR tomorrow and I was struggling how to describe it...I told him to listen to it, that's the best way I guess I can describe it.

I'm still amazed my OE clutch will do this for 62000 miles and 466 passes.

I have another 1.44 video I'll post up this weekend. I haven't even watched it yet, I wonder what it'll show.

It's something that's hard to teach in words.
And you do things subconsiously now that you might not even realize in order to compensate for minor varying conditions.
The driver needs to have some seat time using his/her own method proir to implementing this technique because one needs to have a feel for the car and what it's doing and see and feel the difference.

That launch style also varys from clutch to clutch but the theory never changes.
If people are interested I can put together a general theory of what one should be trying to achieve during a manual vette launch and how to work up to an agressive launch style like the way you do it.

I'd love that personally.

I feel like I have a good grasp of launching/driving my car, but I would love another resource.

I think your efforts would be well appreciated by many.:cheers:

I always credit you with a significant factor in allowing me to reach 1.5's at will...accelerate into the launch instead of just hold at RPM and release.

That one tip alone made a huge difference.

At the risk of showing my slow shifting to the world here is my scan of that run.

Three things to note:

Note how I was accelerating into the launch, see the RPM rising (red line top graph) before the car moves (green line top graph).

Also note, I was on the way to flooring the throttle before the tires moved (green line 3rd graph) but I actually lifted just a little on the initial bite. I frankly think it might have been the g-forces, as I see no spin off the line. But I often see little blips of the throttle in the launch sequence on the scans that I do not remember. I do it automatically as I feel the tires bite, or not, during the process.

By the way, notice how the RPM's drop in first gear despite the throttle being floored (green line third chart)...that's the clutch hooking up. Did I mention that this is the 466'th time I've done that to this clutch?

The secret to the good launch is that the RPM's never fall below 4800 during the launch sequence. Easy to say, harder to do.

The G-forces of a 1.44 launch feel pretty nice I can attest.:D

http://i56.photobucket.com/albums/g1...714460foot.jpg

And in the interest of full disclosure. The reason my shifting was so slow is because I hurt my trans in the run before this where I got a 1.44 but missed 3rd. I broke my 3rd gear blocker ring. It happened to me before - when this happens, you cannot get the car into 3rd without jamming it and it'll grind. Even with my hurt tranny, I knew it was my last chance to get some zero DA weather and daytime traction so I wanted my slip. I knew I could shift slowly and get a decent pass...results in sig.

Here's the part I broke last time, and again this time. I wish I had a 6060!

http://i56.photobucket.com/albums/g1...g/33f75a6b.jpg

Oh and there's another interesting nugget of information in that scan...let's see if anyone can guess what it is. It's scary information, that's a hint.

Time for some bigger injectors sir.

Nope. Good guess, I'm comfortable with 95% duty cycle, I can still command and get 12.5.

I see you log your oil pressure now. It takes a nasty dip on the launch--worried about oil starvation? Time for an accusump or something else to combat that?

And I want to add...I am putting my rear end in significant peril with these launches. Don't come crying to me if you end up with this....

http://i56.photobucket.com/albums/g1...g/edfcff30.jpg

If you want to play at this level you better be willing to pay because you are going to have to at some point.

Is that your carnage Joe?

Ding Ding Ding. Someone clued me into this when I noticed the LS3's have something in their tune to cut power for oil starvation. I scanned my car and the g-forces surely do have an effect on oil pressure with our wet sump.

I'm not frankly worried about it, it's been doing this since day one and it's fine. YRMV.

Yes that is the result of my 302'nd launch on my OE 2005 rear end.

Ya, I was thinking about logging that PID myself but it's not like it'll change anything. I'm not putting a dry sump on the car anytime soon(if ever) so it's one of those "I'd rather not know" things I guess. :lol:

I had to google "YRMV" as I had no clue what you were saying.

Nice carnage, did you keep it for the memories?

True.

Do you think being the first year of the C6, you're prone to more problems than others?

The 05 rear is known to be weak.

I was surprised I got 301 launches out of it.

What rear is in the car now? Also what tire pressure (cold) are you setting the Mickeys at?

A c5 rear with 4.10's.

17 psi cold. Which is also about 17 psi in the lanes after driving up. I check it when I put on my DR's at home, I drive with them at that psi and I typically forget to check at the track but when I do it seems to be at 17 psi.

I used to pump them up for street driving, but I found the centers wear out more quickly when I do that so I just leave them at 17 all the time. Plus it was a pain filling them with the little compressors. PBIR doesn't have a compressor anymore.

Joe, I agree with you on the metal fatigue that eventually leads to a broken diff case over time no matter the precautions taken. We had looked at making a billet case, but didn't feel it was cost effective. Do you think that poorly disengaging clutch is possibly causing the slower shifts and leading to the broken blocker rings? Also what's your new 0-60 time?:)

I have a theory based on my and Retrotech's experience that about 300 passes is all you'll get out of an aluminum diff in a manual car. Would like to hear your thoughts on that Chris.

No the clutch is disengaging just fine, I missed a gear. It happens sometimes...unfortunately I hit it wrong this time and broke the blocker ring. I did it once before. The good thing is you can drive the car like that though I have it at Horsepower Sales to be fixed before our Challenge series starts.

I can't imagine you could ever make the math work for a billet case...though I note that they built one for the Camaro's! I suspect we'll see more Camaros drag racing than we do Corvettes, just like the old days so the numbers make sense to me.

0-60 is 2.59 seconds...:cool: I'm telling that is a great feeling.

I wish I'd had a photographer or video man on the left for those runs...I swear the car lifted a tire on those runs.:thumbs::lol:

I wish I could prove the stress on the case cracking is what actually breaks the mainshaft from the tranny as in my case, but I don't know how that is possible. Yeah the cost of the block and the amount of material wasted, doesn't make it feasible enough for the hardcore guys like yourself;) I was just curious being that it's happened to you twice now. FWIW I cracked the 3rd gear synchro as well years ago from a Centerforce clutch that wouldn't completely disengage from a mismachined pressure plate come to find out. Hanging with a Veyron, that's awesome...good luck at the Challenge!

I'm pretty sure I speak for all, when I say any info you share is always appreciated:flag:

Well, I can hang with the Veyron to 60 mph...and I 60 foot him handily....

But you cannot overcome the laws of physics forever...1000 HP is gonna kick 472 if the race is long enough!

Thanks.. I pulled the Hoosiers off and out some 315 MTs ..

Another 1.44 60 foot video
 

Here is my previous run, with another 1.44 60 foot.

I know better than to watch the board...everytime I see a good 60 come up it throws off my rhythm. :willy:

nice launch joe, ill have to try and get my 60 down a bit to keep up with you now

Amazing 60' Joe on stock clutch! Stellar driving! :cheers:

Thanks!:thumbs:

Dicky I think your next mod is a cam to go with your QTP cutouts.

Theofel and I ran 10.81's as our PB's last Sunday, me with a 5 and him with an 8...so I'm quicker.:lol:

I think with a cam you will join us.

Do it Derrick!

Joe: Your right. This is my best ET with this stall converter and baby cam set-up. But I did run a 10.76 and a 10.79 with the larger cam and higher stall. Just wanted to clarify why my ET on the forum shows a lower ET than the 10.81.

Having ridden in your car with both setups.....I think you chose wisely. Your current setup is docile, yet very fast and very reliable. You click off the 10.8's and 10.9's like clockwork.

Happy Birthday!...Joe

Thanks.:D

birthay
 

yes happy birthday Joe:thumbs:

Calls for a drink!!!! :cheers:

or two...