View Single Post
Old 11-23-2016, 04:58 PM   #28
Vorshlag-Fair
Official Site Vendor
 
Vorshlag-Fair's Avatar
 
Join Date: Nov 2010
Location: Dallas, TX
Posts: 1,200
iTrader: 0 / 0%
Vorshlag-Fair is on a distinguished road
Default

Project Update for November 23th, 2016: The last post in this development thread showed our "summer mods" to the red E46 330, which were somewhat extensive. During that phase we replaced and upgraded the entire cooling system (except one part), added an SFI rated balancer, improved the oiling system reliability, added swaybars, fresh tires, and dropped another 250 pounds from this 330. We were finally ready in October to go back to TWS to race with NASA again, hoping to fight back after the drumming we took in April at this same track.

Click the image to open in full size.

We will cover that race write-up, the repairs and upgrades we did after that event. Then cover our TTD prep "points budget" for 2017, where we will reveal our continually changing upgrade path for this car. The bulk of these changes are planned for the short winter break we have before our 2017 NASA season starts in late January. We have several track tests planned before then, and we cover the first of those tests where we went back to MSR-Cresson (our main test track in 2016) in November to get an updated lap time with the latest setup, after running here with NASA back in March.

POST-SUMMER MODS TTD CLASSING / POINTS LIST

Before we get to the October race coverage, let's show how we classed the car 130 pounds under minimum weight for this one event - legally. I'm gonna nerd out on the TT rules bit here, so if that bores you, just skip below. Some folks do like reading about the intricacies and interrelated nature of NASA Time Trial rules in our posts, where we try to explain the clearest path to a given build's TT goals. Sometimes you have two do 3 layers of calculations to figure out your car's class limits.

As I have gone over in this and many other threads, NASA TT-Letter class cars all get a "base classing" which shows which class they start in as well as the minimum weight they are assigned. This weight number has little to do with the actual weights of a car, but is an assigned number for a given model based on where the rules maker thinks it needs to be for competition reasons. And they can change. Every year. Anything printed in the current rules shown in blue text is an update from last year. #FontColorsMatter

Click the image to open in full size.

The "Base Trim Model" 01-06 BMW 330 (non-ZHP) has a base class of TTE* and a min weight of 3285 pounds. This means our measured race weight (with fuel, safety gear, and driver) should be no lower than 3285 pounds. Some cars get "weight added" in the classing sheets to slow them down - the FR-Z/BRZ had 100 pounds added to their min weight in 2014, and another 100 pounds in 2015, and our C4 Corvette had weight added in 2016.

Click the image to open in full size. Click the image to open in full size.

As you can see from our beginning (left) and current (right) weights we have dropped this 2001 BMW 330Ci from 3180 pounds (no driver + virtually no fuel) down to 2960 pounds (no driver + about 10 gallons of fuel). So we have dropped 220 pounds + have about 60 more pounds of fuel on board in the current pic, so really we've dropped closer to 280 pounds out of the car. This is why we post images of weights showing fuel levels.

Most weight loss modifications are legal in TT-Letter (there are exceptions - subframes, engine components, etc), as long as you account for the final weight below the class minimum in your final declared race weight. Adding the heaviest driver from our Team Vorshlag entries (of the 3 registered this year) bumps that 2960 pound weight above by 210 pounds (me) and gets us to around 3170 pounds minimum race weight. We won't run any less fuel load than what is shown for fear of fuel starving in turns - in some of corners we're seeing over 1.7 g lateral now (in banked corners; see video below).

Click the image to open in full size. Click the image to open in full size.
Left: The weight box we built into our TTC Corvette. Right: Your car can be weighed after any session, and it often is if you are fast

To meet the 3285 class minimum weight we should be adding 115 pounds of ballast, which has to be secured a certain way. Normally you add a little bit more weight than absolute minimum, to "be safe" from the scale. I've seen people bounced for being 5 pounds under their stated min weight, which can happen if you don't keep an eye on fuel levels or if the scale is flaky one day (something as simple as the wind can change your car's weight - yes, literally the wind. Seen it happen). In over ten years I've had maybe two sessions DSQ'd after being weighed below my declared weight, but it is rare - we usually run at least 25 pounds over our declared minimum weight, just to be safe.

Click the image to open in full size.

NASA allows us to race under the "classed minimum weight" legally, but "running light" hurts your car's competitiveness in THREE ways. First, you have to burn "class mod points" for every increment you declare under the base classed minimum (see chart above). Since we currently had points to spare for TTD class legality we could run at our measured 115 pounds weight under 3285 for only 9 mod points. That's the first way you lose competitiveness running under min weight - the pounds come off at the expense of mod points, and its EXPENSIVE: one point for every 15 pounds. Ouch!

Click the image to open in full size.

For much of the 2016 season we declared the assigned 3285 minimum but ran much heavier than that. Our adjusted P-to-W ratio is 13.45:1. I've covered that calculation before: TTD has a P-to-W of 14.25 but we get a -0.8 bonus for running a 245mm tire (see Appendix B chart above showing that).

Click the image to open in full size. Click the image to open in full size.

At the MSR-H event in January I rolled the 330 across the scales at 3434 pounds, which was 149 pounds over the 3285 minimum. And at the normal 3285 pound min weight we could run as high as 244 whp (3285 / 13.45). That's why I've been saying all year we're 150 pounds over and -50 whp under class max prep (car still makes 195 whp). Doubly screwed.

Click the image to open in full size.

We didn't have any power adding mods yet (still stone stock drivetrain from paper air filter to exhaust tip) but we DID drop a lot of weight. We actually had 12 mod points to spare for this upcoming October TWS race weekend, so we went ahead and declared 170 pounds under min weight, which comes to 3115 pounds (+12). That way we we could accidentally run the fuel tank DRY and still be extra safe from the scales.

The second way you get penalized running under the classed minimum weight is that it affects your ultimate dyno'd horsepower number. The P-to-W ratio is well... a RATIO of Power to Weight, right? So if you are declaring less weight your calculated maximum horsepower number goes down, too. So at 3115 pounds we could not make more than 232 whp (3115 / 13.45), down from 244 at the higher declared minimum weight.

Click the image to open in full size.

The third way "running light" can hurt you is when the declared weight falls into the "penalty" area of the Appendix B weight table above. At 3285 pounds the car is in the "safe zone" between 3201 - 3399 pounds (no penalty or bonus). Running over 3400 gets a P-to-W bonus and anything 3200 and below gets a penalty. So at 3115 we should add a 0.15 penalty to our adjusted 13.45 P-to-W rario, or 13.60:1. That means at 3115 pounds the car cannot make more than 229 whp on the dyno. We're still almost 35 whp under that number at 195, so I wasn't worried. Nobody ever gets dyno'd at regional events. Well, almost never.

Click the image to open in full size.

So that was the TTD classing sheet we turned in for TWS, above, which has a mistake in it. Totally my fault, but we got no benefit from that. We declared 3115 pound minimum, burning 12 points for that 170 pound drop under the class assigned 3285. And we couldn't make more than 229 whp, which this engine won't get near right now. In a rush (I made this sheet moments before we left for TWS) I forgot about the 3rd P-to-W ratio hit from dropping weight (the .15 penalty from the Appendix B weight chart), but nobody caught it and frankly, we were so far below that adjusted P-to-W limit we were safe. My declared "232 whp" was off by 3 whp (should have been 229).

But at NASA Nationals you better bet they will catch a mistake like that, so you have to check your weight, points, declared horsepower, final adjusted P-to-W ratio and everything safety related before you go. The rules are tough, but they are all there for a reason. When you are building for the ragged edge of a class you gotta worry about a 3 whp mistake, damn straight.

NASA AT TWS OCTOBER 15-16, 2016

As I mentioned last time, we were working on the 330 up until the last minute before heading down to TWS. We had the car so much lighter that the rear ride height had gone up nearly an inch! We brought the car into the shop and quickly reset ride heights, checked camber and toe, then got it loaded into the trailer by 4:45 pm Friday before the race. That meant we hit ALL the traffic heading out of town for the normally 3 hour drive down from Dallas to College Station, TX.

Click the image to open in full size. Click the image to open in full size.

This is the same course layout (2.9 mile) and direction (CCW) as we ran back in April. This time we had a few changes that we had hoped would make up the 5-6 second lap detriment we had back in April. The upgrades included a FRESH set of 245mm Hoosier R7 tires, Whiteline swaybars front and rear, and that 280 pound weight loss. There were 3 cars signed up in TTD for this event, both Miatas, including one that clobbered me back in April and another driven by a friend who is quick. I was nervous!

Click the image to open in full size.



The TWS track record for TTD here had been smashed and reset in April to a 1:58.871, which was 6 seconds faster than I ran in the 330 at this event (2:04.743). At this point in the season (October, final Texas event) we had pretty much given up on the points chase for the TTD regional championship, but we still wanted to try to win the class here both days, if possible. There were not enough entries in in TTD class (5 needed) to score any Hoosier contingency, so this was all about redemption.

Amy and I arrived at TWS with the 330 in the trailer on Friday night after the sun went down, so we fumbled around in the pitch dark looking for a place to park. Since the rumors of TWS closing (it isn't) have been going for the past 3 years, the number of entries spikes for these events and we had more than 250 entered for a NASA race weekend here, so the paddock was jam packed by Friday morning. We parked out on "the beach" again under the old TWS sign and unhooked for the night.

We got back early Saturday morning and I went to my instructors meeting then brought copies of the maps to the TT meeting, where we got an ear full about "playing nice" and avoiding incidents.

Click the image to open in full size. Click the image to open in full size.

We had 32 cars running TT on Saturday so I gridded early and went out in the TT Warm up and really pushed it, aiming for a good grid position for the next sessions (that count). I managed a 2:00.648 best lap, already 4 seconds quicker than in April, which put me 11th on grid. The original BMW clutch was slipping, so 5th gear was useless, which cost us some time. Luckily we had done the balancer and oiling updates so we could just rev out 4th gear on the front straight. Time for a light weight flywheel and clutch setup!

Click the image to open in full size.

I spent a lot of time running back and forth to grid, since I had an HPDE1 student in a 335i. His car was having major tuning issues but we worked on the basics anyway.

Click the image to open in full size.
The camber on the loaded front tire looks great but we had a tiny push. Will dial out some front bar

I went out in TT session 1 and ran a best of 2:00.027, then ran a 2:00.093 in TT session 2. The track temps were going up and times were getting slower, so I skipped the last TT session for the day. We ended up with the TTD win by 3.9 seconds for Saturday.

Click the image to open in full size.

The 330 was already 4.7 seconds faster than my best times here in April, but I was still frustrated that I couldn't break the elusive 2:00 barrier, and it was SO close (0.027 sec). As is almost always the case, the first (coolest) session on Sunday is when I usually set my best times, so I would shoot for the 1:59s and hopefully sneak up on the track record the next morning. We stuck around for the Saturday NASA party, ate some food, picked up a trophy for the day's class win, and went and got some rest.

Sunday session 1 was completely wasted on a "red flag drill" - on the first hot lap they threw red flags at every station and checked to see who blew past more than one station. Its a long story, but in a Saturday TT session there was a car that wrecked and a few TT racers ignored red flags at the nearby corner station, so this Sunday first session was meant as a lesson. I understand that safety is most important, but the golden session was wasted and I was none too happy about it. The best conditions of the weekend were gone.

Click the image to open in full size.

I went out again in Sunday TT session 2 and was quickly mired in traffic, only managing a 2:00.302 lap time. The car felt fine but I just couldn't get a clear lap in.

Click the image to open in full size. Click the image to open in full size.
Costas caught these pics with a little inside-left tire in the air, just for a split second

In session 3 I asked our Team member Paul Costas to drive the 330, for several reasons. First, I wanted to get his input on the car's setup. He does as much or more testing than I do and has decades of experience on track. Second, I felt like our finish placing was safe for Sunday considering our win margin the day before. Third, seeing another fast driver in the same car always teaches me something. Always. The two of us have co-driven the same track and autocross cars many times before and we are always within tenths of a second of each other, but we do have differing driving styles. I had seemingly hit a wall and wasn't getting the car under the 2:00 lap time and wanted to see if he could.

Click the image to open in full size.
Click here for Costas' best lap in TT session 3 Sunday

He hasn't driven this car before but co-drove in our other TTD prepped 330 back in 2010 (where he won then as well, when I was out of town). He ended up setting the fastest time of the weekend among the Team Vorshlag drivers (putting two tenths on me), getting the Sunday win by a solid 5 seconds. His best was a 1:59.838 and he backed that up with a 1:59.850.

continued below
Vorshlag-Fair is offline   Reply With Quote