Project Update for Dec 27, 2013: Been a busy busy month here at Vorshlag since I last posted, after the 2013 race season ended. There have been a lot of updates on a number of other project build threads, such as our
shop parts hauler "Truck Norris", our
E38 740iL restoration project, the
Chumpcar Firebird build, and
Matt's 95 M3 LS1 swap. We've also had a few things brewing with our two main in-house S197 projects - including several repairs, updates, and possibly even a major change of course for our 2011 GT - and it is time to share that here. Don't worry, its good news.
Many projects have kept us busy in the shop, as well as gobbled up my time updating project threads on several forums
2013 PRI Show + 2015 Mustang!
The annual December "ECR Toy Run" track day event we had hoped to attend was rescheduled due to a massive ice storm in Dallas. The new date ended up happening when we were at the 2013 PRI Show in Indianapolis. This is a huge racing industry trade show we attend almost every year, and where we had some important business meetings and saw lots of new parts. I was really bummed about missing the Toy Run, and missing some automotive TV show filming that happened out there that day, but I got a great consolation prize: getting to see the 2015 Mustang first hand!
This year PRI moved from Orlando to Indy, but even with the terrible downtown parking and horrendous Winter weather it was the biggest PRI show I had ever attended. We learned a lot being there, but not much was shared on social media for the folks outside of the racing industry that aren't allowed to attend. Balls to that, you can feel free to rummage around in
my photo gallery and get an eye full of next year's parts.
To me, the highlight of this show was seeing the 2015 Mustang in person. I got to crawl under the back of the car and see the IRS up close as well gawk at as the exterior shape and body lines. I spent a bit of time and made an
"S550 vs S197 Mustang: An in depth comparison" article, which you can read
here. In this, the 2nd part of our preliminary S550 investigations, I compare the S550 and S197 Mustangs styling side-by-side, then go "up skirt" and look at the suspension on this pre-production car to verify the rumors and images we've been shown. If you are interested in that new fangled Mustang,
give it a read.
Throttle Body Replacement + Front Splitter Updates
As I mentioned in my last update, we took the car to True Street and had them put the car on the dyno, load it up, and try to diagnose the part throttle stumble that bit me in the backside at the November ECR event. Turns out that they found something wonky in the throttle body circuit... the pedal would send a signal for a certain percentage of opening yet the throttle body would refuse to open by that amount. Some wiring bugaboo, but we first swapped in another stock throttle body - which has electronics inside, since it is a drive-by-wire setup.
Luckily that fixed it. I have driven the car 2 or 3 times since that was replaced and it runs like a top, from 1500 rpm roll-ons to 7000 rpm shifts.We didn't have to repair any wiring harness gremlins, which was a relief. The 3 year old Odyssey PC680 battery finally gave up the ghost, so we swapped in a new $125 replacement. This battery managed to never let us down on the street for years of daily driving, and it was long term storage that killed it (sitting for weeks between races without a battery tender). While the TB was being replaced the entire front end was then blown apart for inspection and updates.
This was another area I discussed last time: the front end and splitter refinements. Our custom splitter development has spanned several months (August - November) and we've learned a lot along the way, and noted some areas that could be improved. Extra fasteners added here or there, a better alignment on the captured mounting pins, and some better sealing on the radiator ducting.
Some of it was just normal track wear and tear. The black painted finish on the splitter took a lot of bug hits at ECR (grasshoppers are brutal at 125 mph!) so the splitter was removed and completely repainted during the above work. It all went back together better than before, and we kept the "short" splitter on the car (the 6" vs 10" extended length) for now.
Goofy Oil Catch Can + Crankcase Vacuum Routing
After the weekend of the NASA@TWS race in September, we noted a bit of oil residue under the car. It got worse by NASA@ECR in November, when we noticed a bit more oil leaking under the car and showing up on the floor of the trailer. It wasn't a lot, but was more than a little, you know? Looked like it was coming from the rear main seal of the engine, just dripping out of the transmission bell housing. That's not good. We kept cleaning it off and watching it all weekend, and it got progressively worse.
Dammit, why did this happen? I think it was my fault - having something to do with the improper routing we ran on the oil catch can/PCV system. See, we were trying to follow the routing of the Boss 302-S oil
breather system, but that doesn't really have a sealed catch can like we run. Instead that car just has a crankcase
breather system, with no real vacuum source, and uses a fresh air filter in the top of the catch can. With the crankcase breather routing we ran (since our August test at ECR, see above) we pulled a high amount vacuum from the intake manifold, through the catch can, and then back to the tops of
both valve covers. With no fresh air inlet it was too much for the system to hold and it was collapsing the hoses. We chased the horrible honking noises, hoses that kept getting sucked flat, pulled the PCV valve out for a straight thru unit, and overall just ran too much vacuum on the crankcase. This likely pulled the rear main seal out of place during this time.
We have since switched this system to more conventional OEM type PCV routing, shown above, which is how the stock Coyote 5.0 positive crankcase ventilation (PCV) system runs. The only difference is that we have added an oil catch can/filter in line with the hose on the passenger side head (the vacuum side).
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