1 (edited by jamesohoh7 2017-05-10 05:20 AM)

Topic: Congrats to #45 Napa truck crew! .. and then our race-recap

Texas Tippin' 2017

Congrats on your victory ... y'all's program is buttoned down and squared up indeed.  It was fun talking with y'all, hope to see you again. 

Also! thanks for the great food and so on.  Those pork sandwiches hit the spot after the diff replacement thrash!


Recap for anyone interested in the panda car:

Specs: since this was asked about a bit on Friday.

motor: LM7 (5.3) out of a suburban.  LKQ, 40%-off holiday-special... complete with harness and ECU.  After core (the well-violated 13b we blew up seemingly every other race), we're in for about ~250? on that combo... cheaper than trying to acquire another 13b by a BUNCH.  Converted to throttle by cable w/TB from an Express van.  We fabbed our own mounts for motor + trans (not as hard as it sounds, if you have a welder).

trans: aka 'weak-link-in-waiting'... 3rd gen F-body V6 T5.  Yep.. not a t56, a wonky T5.. and the V6 one at that.. with the ~4:1 first gear. We drive it as a dog-leg 4speed and pretend 1st doesn't exist... yeah, it's weird.

diff: aka 'weak-link-prime'... stock FC3 non-turbo, open 4.10:1 diff... so, the worst possible gearing for a motor that redlines at ~5300... which, if you heard the car come by on the rev-limiter, you now know why.... lols. 

clutch: Chevy Astro-Van 11", mated to a standard LS-family truck (IIRC?) flywheel (heavy as lead), housed under an 'old-school' Chevy large-diameter bellhousing (168tooth)... sometimes referred to as the big-block BH, but more accurately it is the one used for large diameter flywheels, vs. the 153tooth 'small-flywheel bellhousing'.  There is no difference in bolt-pattern between SBC and BBC for block-to-BH interface.  There are depth and center-hole-diameter differences (that are trans-specific), so measure carefully.

Bolts right up to 'LS' family blocks, minus one bolt hole.  Allows use of old-Chevy 'wide-4 bolt-pattern' transmissions (which we thought was a positive (cheap 4speeds everywhere!), but turns out is a negative b/c there are few choices that work for road-racing in that pattern with our super-crappy rear-end ratio limitation.   You also need an extended-length pilot bushing to ensure good engagement with trans input shaft.  I think it is a Z06 part, like ~$30 or something.

So yeah, with our awesome gearing, we run the whole track in 4th and hit 5th on the back straight.  The fewer shifts and shocks put into the trans and diff, the better.  Optimal?... hardly.. but it seems to be holding...well, other than the diff blowing up, which was due to oil-loss from a shunt.

Race Recap:
~45 min into 1st stint on Saturday, the brake master cyl gave up... probably 2 or 3 races old.  OEM one lasted from 1986 until then.  Luckily we packed a rebuild kit and got back on track in like 90min (we spent 30 thinking it was just a bad brake bleed and bled/re-bled brakes... oh well).

~60min from end of day 1, diff exploded, ending the day... after a wheel-on-wheel shunt 2 stints prior that pushed out the LHS axle seal, allowing fluid to start leaking.  Diff was so hot, it melted the delrin bushings.  We had brought a spare (that we almost didn't b/c we lug it to every race and have never needed it from 2008 until now).  Swapped it in, good to go for Day 2. 

~3hrs into day 2, hood pin mounts fail, resulting in smashed windshield, hood, and roof.  Race over.  At that point, no one was in the mood to thrash on the dang car anymore, and we didn't know what to do about it anyway... no way we'd find an fc3s windshield on a sunday, get it delivered and installed in ~3hrs (figuring it only to be worthwhile if we got 1hr of track time after).

Various vids are on our FB sub-page:  facesnark.com/P4P-Racing  ... yeah, not a real URL, but find P4P-Racing on FB and that should be us.

Re: Congrats to #45 Napa truck crew! .. and then our race-recap

Thanks for the shout out! and you're welcome for the food. We really enjoyed meeting/hanging out with you guys. Looking forward to seeing y'all in November.