Re: Vorshlag 2011 Mustang GT 5.0 - auto-x/track build
Project Update for April 27, 2012 - Part 1: A lot has happened in the past week and a half so this might be a long-ish update. I will break it into two parts - ESP preparation work from a week ago to get the Mustang ready for the ProSolo last weekend. Part 2 will cover the ProSolo results and a list of new issues that cropped up. I posted some of these pictures below on the Vorshlag Facebook page over a week ago - I put previews of upcoming thread/blog posts on FB first, so follow us there!
ESP Rear Spoiler
In my last "quick update" from 4/13/12, I showed a picture of some rear spoiler bracket and element parts we got from a circle track supplier, as well as some machined washers and struts. We didn't use that bracket or the spoiler elements - they were too tall for use on the Mustang trunk. The manufacturer's website didn't have any dimensions so we took a gamble and it didn't pan out. Oh well, the rear support struts and the machined washers were useful. Instead, we made an all new rear spoiler from scratch using some 1/4" thick plexiglass we bought locally and some aluminum sheet we had at the shop. If you haven't been following along, SCCA Street Prepared rules come from pre-historic times and still do not allow a rear wing, only a rear spoiler. It can be as wide as the widest part of the car (excluding side mirrors) and can extend 10" away from the body in any direction.
This spoiler was built to fit a spare red Mustang trunk we located a couple of weeks ago - one we weren't afraid to drill into for the ESP-legal rear spoiler or for the upcoming TTS/AI legal rear wing. The trunk was set up on a bench at the same angle as it sits on the car, so it could be built while it was off the car. Some of the scrap aluminum we had at the time was anodized, which made it a royal b!tch and a half to weld to, so it wasn't the artwork-like welds you typically see coming out of our fab shop. No worries - it was strong, worked great at the ProSolo, and was built to an insane deadline in only a day and a half. It looks pretty good for a prototype made out of scrap, but the next one we make will use some virgin aluminum.
The spoiler bracket bolts to the trunk using four "nutserts" installed into the trunk metal with a special rivet gun. The four points are shown above, where the black lower strut supports are placed. This aluminum spoiler bracket extends past the trunk and covers the width of the rear of the car, to about the edge of the sheetmetal. It could be another 4" wider per side (to extend out to the rear fender lips), but we felt this was wide enough to make plenty of rear downforce to match the Leguna Seca front splitter. The lower sections where it overhangs the rear fenders was later trimmed out so it wouldn't rub the paint and some Xpel paint protection film was added to the fenders "just in case".
Once Ryan had the bracket laid out and tacked up, he and the guys made a cardboard template for the spoiler element itself. It is 10" tall and laid back at about a 65° angle. The next step was transferring the template to the plexiglass sheet and carefully cutting that out. There's a trick to cutting plastic with a saw - too fast and it melts back together behind the blade, too slow and it won't cut cleanly. My cheap "one speed" jigsaw (he had to pulse it on-off-on-off) was a nightmare to work with and it eventually burned up the motor after about 40" of cutting. A trip to Lowe's produced a variable speed Bosch jigsaw that worked like a charm and cut the 1/4" plexiglass sheet like butter. Drilling holes in plastic also takes ... patience. They managed to get everything cut and drilled without cracking the plexiglass. The machined washers are placed on both sides of all bolted joints in the plexi and held up after a weekend of ~30 autocross runs.
The plexiglass spoiler element was simply bolted in place - it was flexible enough that it did not need to be heated and bent to follow the curvature of the trunk or the two "bends" at the edges, where it meets the rear fenders. The struts hold the element well enough, but we might go back and mount two tension rods to the widest points of the spoiler, with the rods attaching at the forward edge of the trunk. A little testing (and video aimed at the spoiler at speed) will tell us if that is needed.
The rear spoiler was finished up minutes before the car was loaded into the trailer Thursday night and it definitely got a lot of looks at the ProSolo. This was the first time we'd made a rear spoiler here at Vorshlag and we learned a lot. The guys were very careful during mock-up and construction (lots of painters tape used!), there were only 4 holes drilled for this part and not a single scratch was added elsewhere in the paint. Good stuff.
Another new ESP modification we added were 315/35/18 Kumho V710 R compound tires mounted to Forgestar F14 wheels in 18x11" (front) and 18x12" (rear) sizes. We had been eying Forgestar (a division of iForged) for a while now and decided to give these wheels a try for larger widths like these. We called the guys in California there and they knew about Vorshlag and our Mustang, and our propensity for using big wheels. After speaking with them for a bit, they wanted us to become a dealer. So now we are a Forgestar dealer - if you see anything in their catalog you like, we sell at their MAP price.
They did a super-rush build and made these wheels (from flow-formed/semi-forged blanks they keep in stock) in an extremely short time frame for us. These were machined to our 5x114.3 bolt pattern, hub bore, and backspacing. We have done a ton of testing to see how far we can push wheel widths on this car and we sent them our specs... and no, I'm not sharing those with you. If you want wheels that fit like these, call us and we'll be glad to sell you a set. It's the only piece of the puzzle we can hold onto, and we've spent a lot of time and money learning these wheel specs on this chassis.
Even being careful as we measured for backspacing, then calculated offset, we still missed the numbers a hair in the rear and had to add a small spacer. So ... that meant longer wheel studs in the rear were needed. AJ pulled the rear axles out and used our new 30 ton press to remove and install the studs. Now we have ARP long studs on both front and rear axles (and the front/rear studs are different spline diameters and part numbers, so don't just order 20 of one part). All of this final wheel fitting was happening as the spoiler was being built and other race prep work was being performed, all while we had customer cars coming for service and orders were being built and flying out the door. It was a hectic week to say the least.
That final rear spacer tweak got us to this fitment with 11's in the front and 12's in the rear. The front is too tight for 12's under stock contours, hence the 11's, but the rear has the room for a race application (I wouldn't recommend either of the above for a pure street car). I'm very happy with the wheels, which have insane amounts of front brake caliper clearance and a pretty low weight. I will talk more about Forgestar costs and weights in a future post - after we do some more testing on them. They worked flawlessly at the ProSolo and next we'll see how well they do at a banked/high speed track tomorrow - with a NASA time trial at Texas World Speedway.
Delays and Improvements
Now here is the part I hate. Many of you reading these posts have pre-purchased or put your "name in line" for some products we've helped develop on this very Mustang, including D-Force 18x10" wheels and AST 4150 shocks. Both of those products, which Vorshlag ordered in large quantities in 2011, are over 3 months late being built and delivered to us. We have already refunded many of our pre-purchase wheel customers due to the continuous delays. AST stopped giving me dates and we received news this week that the D-Force shipment was delayed yet again. That's after we were told that the container was already here in the USA at port! Now they're saying May 14th. I'm pulling my hair out in chunks! I just want to apologize here to anyone waiting on parts, and I did so publicly in this blog post yesterday.
In that blog post I also talk about several improvements we've made to the Vorshlag branded products that we can better control deliveries on, such as several coating and plating upgrades we've made to various parts in our Vorshlag camber plates. Also, we finally received the machined and laser cut parts for our all-new S197 Mustang camber plates, which went to the electro-plater yesterday. I need these for my own Mustang and we have lots of patient customers waiting for these unique camber plates, so that was exciting. These should finally start shipping next week. So that's some good news to go with the bad.
Terry Fair - www.vorshlag.com
Vorshlag project cars: $2010 GRM Challenge E30 V8 + E46 DSP Autox Build + 2011 Mustang GT autox/track car
Last edited by Faerus; 04-27-2012 at 12:01 PM.
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