Re: Brianne Corn's Pike's Peak Subaru STi
Project Update for July 16, 2012: Well the Subaru has been here for a hair over a week and we've accomplished a good bit. Let's take a look and see what has happened. If you have never read one of my build thread posts before... I add a lot of pictures. We try to share race preparation tips whenever we can, so people can see what it takes to do what we're talking about. Since we tend to "over-share", we can see lots of second-guessing and internet criticism, which is fine. Just know that we have nearly a dozen experienced race techs working and/or "supervising" on this build - so rest assured that each modification shown has had a lot of criticism before the first cut was made.
The first day it was here it was put in the air for a look inside, out and underneath. It was grimy, dirty and covered in muck after many years of hard race use, including blasting up Pikes Peak last year. Our guys wheeled it outside and put it up on jack stands. After a couple of hours with the pressure washer, suited up in rain gear + face shield, the underside and wheel well grime was mostly gone. The engine bay was washed with a bit more care and less pressure. Now it could be worked out on without too much nastiness getting on us. The Subaru is going to be wrapped from the shoulder line down, so all of the decals in those areas were removed and the panels cleaned.
After a look by the plumbing experts at Pirtek Plano South, they made a list of items and systems to tear down further for a closer look (fuel tank, rear subframe, cooling system, etc). It quickly became apparent that they wanted to do a major plumbing upgrade on every system of the car, front to back. That seems a bit overboard, and it is a huge undertaking, but the Pirtek guys are friends of ours and Jason's and they wanted to show off some of their race car worthy hardware. Vorshlag uses Pirtek for all of our plumbing needs. This car was purchased and then prepped a whole two weeks before the 2011 Pike's Peak event, so some of the race preparation work done in that short timeframe, or by previous owners, was probably rushed. We've got about three weeks to go back and do some updates and us and the Pirtek guys will need every bit of that time to get this updated. Hill climbs are brutal on every system on a car, so going in with all new race parts should add reliability.
After that first look few days later Pirtek came back with a three man team (Ed, Mike and John) and with JasonM's help they pulled the stock tank (full of E95!), then removed a tangled mess of OEM rubber and hard lines, as shown in the big box above. The long jumble of fuel hard lines from the tank to the engine bay are also gone for good. This box includes dozens of patches, fixes, and updates over the many years this car has been a race car. Not atypical when a race car has passed through several owners.
The rear subframe was removed, along with the differential assembly, to make room to extract the fuel tank. Once the fuel tank was out the factory fuel pump + pick-up assembly was removed and upgraded. Deleted the in-tank filter, TIG-welded -6 AN bungs in place of the stock push-lock ends, and securely mounted an in-tank Walbro 255 lph pump to the pick-up. The Pirtek guys new submersible fuel line to connect it all, as the outer jacket is of course covered in fuel (alcohol). These new feed and return line connections on the exterior of the fuel tank will with be connected to the rest of the fuel system with braided -6 lines using proper AN fittings everywhere.
It was noted that the subframe to chassis mounts were still OEM rubber, so a call was made to TurnInConcepts, who are sending a gaggle of their custom race bushings to install. Thanks! Once those arrive, we'll pop them in and reinstall the rear subframe; the fuel tank is already back in place.
With the OEM fuel hard + soft lines and fuel rails out of the way, a new set of billet fuel rails were purchased and installed. A new Kinsler fuel pressure regulator is now mounted on the left front strut tower, which will regulate fuel supply to the new rails. A fuel pump surge tank made by Integrated Engineering and supplied by AWD Tuning (which uses a Bosch 044 pump mounted in the top), will be fed from the stock fuel tank by the 255 lph Walbro in-tank pump (see above), acting as a lift pump. A 100 micron pre-filter will be used before the surge tank/pump and a 10 micron filter will be in-line after the final fuel pump stage. I will show this area in more detail once these filters and the surge tank are permanently mounted and plumbed.
With the Tein struts still installed, we mocked up the 18x10" wheels first with the 295/35/18 Nitto NT-05s that I ran on these wheels and our 2011 Mustang GT at the Optima Challenge event in June (200 treadwear minimum required - but even with that stipulation, these tires were terrible). The next day we rounded up an old set 285/30/18 Hoosier A6s from the shop that were mounted to the D-Force wheels, as Brianne will be running this wheel and tire package (on fresh A6s) for the Pike's Peak event. This now gave us the perfect package to build the steel box flares around (the custom flare work will be shown in my next post - it is well underway).
That front bumper cover had to be trimmed considerably to fit around the massive Perrin front mount intercooler, which we did in four iterations until it fit juuuust right. The OEM front bumper crash structure is all gone, which is a requirement for this FMIC kit, I guess. The flexible plastic that the bumper cover is made of cuts like butter with an air powered body saw, or a cut off wheel and disc. Then you can fine tune the finish with a sanding disc in a 90° die grinder, as shown above. Once the melted slag hardens (in 30 seconds or so) use a de-burring tool to make the cut edge look clean and smooth. Those brake cooling ducts were done in years past, but we're going to re-make the lower corner sections of this bumper cover and relocate the duct openings, which are int he way of the FMIC piping.
Cooling, Heat Management and Insulation
This STi has seen the rigors of Pike's Peak before and Brianne's team knows you can never have too much cooling going up this mountain. At 14,000 feet the air is so thin that everything trying to radiate heat can't do it very well - there's not enough air particles to bump into the metal from the various radiators. Instead of leaving the engine oil cooler and transmission cooler stuck behind the new FMIC, we are going to place them in an unusual place - under the factory hood scoop. This area has a nice blast of cool, high pressure air which can be put to a new use - since the top mount intercooler is no longer there. This Subaru was not equipped with any sort of strut tower brace, but since the strut towers are so close to the firewall on a GD Subaru, it's not really necessary. Still, a brace does make a great mounting structure for these two oil coolers, so we built a strut brace for that purpose and mocked-up the coolers as far from the turbo as possible.
The turbo itself will have a thermal blanket, as will the downpipe. The transmission tunnel will get some heat insulation, as will the firewall, clutch lines, fuel lines, and anything close to the turbo. The co-driver of this car usually has melted shoe soles by the end of a run, so hopefully the addition of all of this insulation and thermal wrap will help. Last year the clutch fluid boiled so badly that Brianne lost the clutch actuation 2/3rds if the way up the mountain, having to shift "clutchless" with extreme rev-matching - hopefully that problem will be gone for the 2012 run. The factory cooling fans were also melted on last year's run, so more DEI insulating wrap will go around the exhaust headers that run next to the radiator. The old aluminum radiator also started to "expand", so a replacement was found and will be installed shortly. A Moroso crankcase evap system oil catch tank was added and the factory battery will now reside in the trunk, for some front weight bias improvement.
One thing we had to do to prepare for the rear flares was move the fuel fill pick-up tube and gas cap. It ended up being a bigger job than expected. The stock fuel fill location had a normal flip-out filler door that is right in the middle of the right side fender flare section, so we decided to move it into the trunk. There are no timed pit stops in hillclimb, so speedy filling is not a concern. With the gas tank removed, a hole was cut in the floor for the filler neck new routing and then opened up a bit more (this will be sealed once the location is nailed down).
The factory fuel fill tubing runs in the right rear wheel well (that tube is shown in the 4th picture of this post), which is too close to the wheel/tire debris for comfort. Moving it into the trunk will now make it safe from road debris, as well as making the right rear fender flare easier to fabricate. The fuel filler neck relocation took a bit of thought and some fabrication time this past Saturday (when the shop is normally closed). I was the only one on hand that could weld at that time (which is scary), so I got tagged for this work. First, a piece of steel tubing was swedged and added to the stock up-bent piece (by Pirtek, who had two of their service trucks on hand), to extend it near the trunk opening. Half a dozen OEM brackets were cut off, some extraneous holes were welded closed, and two new brackets were welded to the fill tube. An aluminum bolt-on bracket was built and added to secure the filler neck to the trunk structure. The "Unleaded Fuel Only" nozzle restriction was cut out with a hole saw and smoothed, then the entire tube was painted and bolted into place. It wasn't half bad in the end, and I can point to one small part of this 3-week project and say "I did that". The rest of the welding on this project will be handled by a much more skilled fabricator - Vorshlag's Ryan B.
I will discuss the custom box flares in my next post. They are progressing along nicely. The suspension we have in store is also pretty slick - stay tuned.
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 Fair!; 07-27-2012 at 04:40 PM.
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