Buttonwillow Raceway - From Failed Engine and Clutch to New Personal Best

[Orange Crush 1LE]

I had an over the top fun day at Buttonwillow, after fighting clutch issues the previous month.

Back story - Blown engine and a FUBARed clutch

Some of you know that the last 7 months have been frustrating to say the least. My engine had blown mid-last year on the 4th lap of my first NASA time trial, and it took 5 months to have it rebuilt. Then I took it to Laguna Seca for the new engine's maiden voyage only to find that after running a few hard laps, the clutch wasn't disengaging and the pedal would stick to the floor. Talk about distracting! Trying to threshold brake at turn two only to find out that you can't get it in gear, it was all I could do to keep from going off track. I then bled the clutch and was really hoping that the old nasty fluid that came out was the culprit.

Hoping for the best, I took it to Buttonwillow a couple weeks later (a four hour drive from home), and not only did the problem come back, but the clutch failed hard while on track. Something had let go so badly that the clutch pedal was completely non-functional- as if it weren't connected to the clutch at all. I had it towed off the track only to find a puddle of fluid under the car. This was a dangerous failure because the brakes and clutch share a common reservoir. I was damn lucky that I didn't completely lose my brakes while going 125+ mph on track.

I had Sevens Only Racing, a shop located at the track, drop in a Quarter Master Optimum SR Two-Disc Clutch along with a new slave cylinder with a billet steel bearing housing. What caused the failure is the stock plastic bearing housing got chewed to nothing until the slave just came apart. Here's picture of the bad slave along with the Quarter Master clutch. It is a work of art, rated at 1,400 HP / 1,000 Ft-Lb and has race-proven reliability as it is used in the Continental Series Z/28s. It is lighter than stock and has a lower inertia flywheel which makes it free revving and easier to heel-toe shift, even the force to release the clutch feels lighter and smoother than stock. I also had them install a Tick Remote Bleeder and a separate clutch reservoir. Here's the clutch:

http://www.quartermasterusa.com/qm/o...kit-14214html/

[Orange Crush 1LE]

Trying out the New 416

After picking up the car and seeing that clutch was solid, I was about to take it on track and run it hard for the first time since I had put in the new 416 c.i. forged stroker. This is an all forged engine with Trick Flow heads with hollow stem valves, and a Brian Tooley custom cam, designed for the rigors of road racing. The new engine is just a beast, 514 WHP and 497 FT-Lb to the rear wheels, much of which is available way down low in the RPM band. The blue curve is the new 416, the other curve is for the previous stock bottom end build that blew...

[Orange Crush 1LE]

Hitting the Track

With the new engine and clutch finally working together, it was time to see how the new set up performed. The car just hooked up! My previous personal best at Buttonwillow was a 1:57.4 that I had set on a brand new set of Hoosier A6s. I am happy to say that even on old worn out Hoosier R6s I was able to beat my old best and posted a 1:53.9. Very happy with this result, as the GT-R, Audi R8, Viper, C6 Z06s and modded M3s and Mustangs couldn't keep up with this big heavy muscle car, LOL. There were two cars faster, both were open wheel cars.

For perspective, the production car record at Buttonwillow is held by a Gen IV Viper ACR, which ran a 1:55.7. My Camaro has better tires with the Hoosiers Vs. the Viper's Sport Cup R-compounds. The Camaro has about the same horsepower, a lot less downforce and is a full 500 Lb heavier than the snake.

Unfortunately I didn't get any on-track photos, but here's a video of my new personal best:

[Orange Crush 1LE]

Sparring with an Ariel Atom

Probably the most fun lap was this one- I had chased down my friend Richard in his Ariel Atom. He wiggled hard in Riverside, a big sweeper with speeds exceeding 100 mph. Shortly after that, I passed him and turned my personal best with him nipping at my heels. Richard and I have tracked together in the past, he's a solid driver that I trust. He set the fastest lap of the day with an impressive 1:51.9. This too was his personal best.

What's surprising is how well-matched our cars are on track, despite being polar opposites - mine a 3,850 LB muscle car, his a 1,300 Lb open wheel machine. Good times, can't wait to hit the track again!

[X25]

Awesome! I'm dying to get back to track myself (but it will take time here in Pacific Northwest).

Would you mind sharing the data on where to get the billet replacement part for the slave cylinder? I think anyone who replaces the clutch should do that. I ordered the tick bleeder, and will try to install it without having to remove the transmission. Hopefully it will be a huge step forward to ensure longevity of the clutch...

[Orange Crush 1LE]

Originally Posted by X25

Awesome! I'm dying to get back to track myself (but it will take time here in Pacific Northwest).

Would you mind sharing the data on where to get the billet replacement part for the slave cylinder? I think anyone who replaces the clutch should do that. I ordered the tick bleeder, and will try to install it without having to remove the transmission. Hopefully it will be a huge step forward to ensure longevity of the clutch...

You can get them from either SNL Performance / Monster Clutch or from Quarter Master. I think JDP Motorsports may also sell them. That plastic bearing support in the stock slave cylinder is definitely the weakest link in our system. Here's a good thread on the subject:

http://www.camaro5.com/forums/showthread.php?t=383607

[BigBlock69RS]

Congrats, its great to hear of your come back, especially with the engine troubles. Nice Video of you passing that Atom, impressive!

[tw78911sc]

Car is full beast mode!! Congrats, you've got that track dialed.

[90503]

Congrats on the times!....Good to see all the hassle pay off in better lap times...Great info on all the clutch problems...I think there are good lessons and options for all of us to one degree or another...

Somebody sure made a mess at the bottom of the hill....Surprised they didn't clean that up any better...

Any Z/28 times?....lol....I think a Z/28 would be hard pressed to come close...(And besides, I believe even the Z/28 starts out with the same clutch basically as the rest of us)....and you've already jumped that hurdle, so why do it again with a different car?...lol...

Anyway, keep it up....See you on campus!...

[Orange Crush 1LE]

Originally Posted by BigBlock69RS

Congrats, its great to hear of your come back, especially with the engine troubles. Nice Video of you passing that Atom, impressive!

Thanks Ed. I'm hoping to meet up with the SoCal guys again soon. I will likely be tracking Buttonwillow 1/24 - 1/25 with Speed Ventures, spread the good word

[Orange Crush 1LE]

Originally Posted by tw78911sc

Car is full beast mode!! Congrats, you've got that track dialed.

Thanks man. However I don't quite have it dialed, I did go off the track at about 100 MPH and into the mud. It literally took about an hour with a pressure washer to get the ~30 pounds of mud out of the underbelly of the beast, LOL.

[Orange Crush 1LE]

Originally Posted by 90503

Congrats on the times!....Good to see all the hassle pay off in better lap times...Great info on all the clutch problems...I think there are good lessons and options for all of us to one degree or another...

Somebody sure made a mess at the bottom of the hill....Surprised they didn't clean that up any better...

Any Z/28 times?....lol....I think a Z/28 would be hard pressed to come close...(And besides, I believe even the Z/28 starts out with the same clutch basically as the rest of us)....and you've already jumped that hurdle, so why do it again with a different car?...lol...

Anyway, keep it up....See you on campus!...

Hey Tom,

I have yet to track my Camaro with a Z/28, I think it'd be a blast to see how my car stacks up. I've got about 100 HP over the Z, more downforce and a well-tuned coilover set-up thanks to Justice Pete, I don't believe a stock Z even with Hoosiers could turn a faster lap than my car with same driver. But after all the hassles and expense, I see the wisdom in the Z. Honestly if I were to do it all over again, I'd buy a Z, throw a roll bar, harness, seats and a wing on it, maybe long tube headers and a tune. It would be a force to be reckoned with, and a lot more reliable than mine has been. That would be a good race.

[Orange Crush 1LE]

By the way, a word of caution to the track rats- The oil in this modded motor runs DANGEROUSLY HOT. I don't know how hot it gets in a stock LS3, but my guess is too hot on a warm day.

My coolant runs very cool but man the oil is ready to cook. I have an oil temperature sensor added to a sandwich plate under my oil filter and my Aim data acquisition system continually monitors oil temp. Whenever you see a constant red LED illuminated on my Aim unit to the left of the steering wheel, I'm over 280 F. You can see it turn on 14 seconds into my Best Lap video above. Believe me, I'm aware of oil temperature the whole time I'm on track because I don't want to lunch another motor.

In 60 degree F ambient temp, my coolant ran no hotter than 210 F all day. However, my oil temp hit 287 F on just my third lap, so the whole day I had to add cool-down laps between my fast ones to keep from killing the oil.

I'm in the process of having two air-to-oil coolers installed to replace the crappy little stock coolant-to-oil cooler. This will be a double-win: Now my radiator will no longer have to cool my oil, so my coolant temps will be cooler. And my oil will run a lot cooler too. The coolers will go to the left and right of the radiator, and the shop is doing a little fab work to shroud the coolers so that air is channeled through them. That ought to do it.

Yes, one more mod, this is getting expensive...

[X25]

Even my stock LS3 got pretty hot very quickly. LS engines can quickly overheat if you keep them in high revs.

Especially since your shop will install 2 oil coolers, I'd recommend going with biggest line available to keep the oil pressure drop to the minimum. In my case, I used -12 AN. High # of rows on cooler cores will also reduce the pressure drop. This is actually the main advantage of using one big core instead of two smaller ones (assuming they are installed in series). Looking forward to your results.