Vorshlag 2011 Mustang 5.0 GT - track/autocross/street Project
- Thread starter Vorshlag-Fair
- Start date
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Quick Update for Jan 18, 2013: I've been waiting for something to be published before I posted again, so I'll hold off on a big thread update for maybe another week or two. A lot has been going on in the background.
NASA Time Trial classes had a bit of a shake-up for 2013 but it was only minor tweaks and things worked out in our favor, for a change. We've gone from TTS (now called TT2) essentially down one class to TTA (now TT3), and we can run now run this car at the limit of the power to weight ratio. No more "well, it was overweight/underpowered", it is maxed out. Apparently this new mix-up has made TT3 the most popular class, at least for this first NASA Texas event. We have 9 cars signed up in the TT3 class, so far.
We're loading up the trailer right now to take the red 2011 Mustang down to the NASA Texas event at MSR-Houston later today for races on Saturday and Sunday. Amy and I are splitting up the driving duties over both days. Will post a much more detailed pre-/post-race report when we get back. Well, then I'm flying to New Orleans for a couple days to drive on some new BFGoodrich tires, so it might be late next week or the following. Hoping to get some good intel on this new "Rival" street tire they are making (for autocrossers and track guys that need a 200+ treadwear tire) as well as bend the ear of tire engineers about the R1 and R1-S race tires.
More soon,
NASA Time Trial classes had a bit of a shake-up for 2013 but it was only minor tweaks and things worked out in our favor, for a change. We've gone from TTS (now called TT2) essentially down one class to TTA (now TT3), and we can run now run this car at the limit of the power to weight ratio. No more "well, it was overweight/underpowered", it is maxed out. Apparently this new mix-up has made TT3 the most popular class, at least for this first NASA Texas event. We have 9 cars signed up in the TT3 class, so far.
We're loading up the trailer right now to take the red 2011 Mustang down to the NASA Texas event at MSR-Houston later today for races on Saturday and Sunday. Amy and I are splitting up the driving duties over both days. Will post a much more detailed pre-/post-race report when we get back. Well, then I'm flying to New Orleans for a couple days to drive on some new BFGoodrich tires, so it might be late next week or the following. Hoping to get some good intel on this new "Rival" street tire they are making (for autocrossers and track guys that need a 200+ treadwear tire) as well as bend the ear of tire engineers about the R1 and R1-S race tires.
More soon,
neema
forum member
pleaaaaase let there be slightly larger OD tires and good prices. The two don't like to mix very often. thanks for the update Terry
FR500GT
forum member
I saw you on TV the other night Terry
dontlifttoshift
forum member
Everything I heard about the Rival sounds promising. Much better grip than the KDW and longer useful life as well. I keep hearing "dry version of a supersport" There were a select few running the Rival at Optima and the tread design is impressive.....there really isn't any design. It kind of looks like a supersport but there are only 3 circumferential grooves and the outer tread blocks are huge. It sounded like there would only be 18s at first.
Obviously going for the track guys first.
In a 200+ treadwear. Sign me up.
dontlifttoshift
forum member
Project Update for January 29, 2013 : We have a lot of ground to cover on the S197 Mustang thread. so look for several updates over the next week or two. Our last real S197 thread update was in November, and a LOT has happened behind the scenes since then - with respect to future competition in our 2011 and 2013 GT's in SCCA Solo ESP for 2013, plus several track events. We will also cover the new NASA TT3 classing and our first 2013 competition (with a track record + double-win), a track event in December with both of our S197s, the whole Watts Link/SCCA debacle, a new shock/spring set-up we've been testing on S197s, and then the BFGoodrich Rival tire launch event that I attended, where I got to test with four different types of cars and seven types of tires at the NOLA Motorsport park, including FR500S Mustangs (former Miller Cup cars). This set of updates will be broken up into multiple thread posts over the next several days, otherwise it will be too long and I won't get any sleep - and I've been on the road, racing various cars for four of the last five days, then sick with a stomach bug, so I'm beat. Let's back up and start with the preparation on the 2013 GT before the December track event first...
2013 GT Coilover Shock Install
The last time we took the 2013 Mustang to ECR, it was on the OEM shocks and springs and the handling was "frightening", to say the least. The car was hopping and flopping around, like a fish out of water. Lots of lean, roll, dive, and all that bad stuff we are used to on OEM sprung/damped S197s. Our long term plans at the time still included SCCA E-Street Prepared class preparations, but we would still do a track event or two before we got too far down the rabbit hole of autocross-only modifications.
Obviously a big improvement we could tackle that worked for both autocross and track use was to add our normal monotube adjustable coilover upgrade. Since Vorshlag sells AST and Moton monotubes, plus some others, we had several options that would work. We picked up some AST double adjustable coilovers with remote reservoirs for an S197 (AST 4200-RR), a custom test set made by AST-USA for a former employee. These were built with racing style "eye-to-eye" rear shocks, just like the Motons on our 2011 GT. On this car, however, I wanted to keep them "pin" style on top, to allow for the rebound knob to be located in the trunk for easy rebound changes (see above, left). An eye-to-eye shock tends to have the rebound knob located under the trunk floor and, like in the case of our Moton CS shocks on the 2011 GT, we have to remove a rear wheel to adjust rebound. It is a hassle, and that adjustment almost never gets tweaked. so we end up using the same setting for street and track use (which is a shame). So we asked AST-USA to re-work the rear shock shafts to have a traditional top pin and used it with the OEM style shock mount. They swapped out the shafts and adjusters to our favored eye lower/pin upper style and now the rebound knob is easy to access.
Once these were built to our liking, Vorshlag fabricator Ryan fashioned some reservoir mounts for the rear shocks, and cut holes in the trunk floor "spare tire well" to route the reservoirs through without disconnecting the hoses (which is a PITA) - just like on the 2011 GT. I asked him to tweak the angle of the reservoirs to be able to see the knobs easier from behind, which he did. The reservoirs were mounted into the spare tire well using the 2-piece "Seals-It" brand grommets to make this hole water tight. He mocked-up the seals with temporary Clecos, then used small machine bolts and nuts to hold them in place. If the shocks need to be removed from the car, the 2-piece grommets can be unbolted then the reservoir can slide right through the now open hole... no mess, no fuss. The other mounting/routing option for shock reservoir hoses is to drill much smaller holes/grommets and add (very costly) quick-disconnects on each shock line. Even then you still have to bleed off the Nitrogen charge before disconnecting the hoses, and re-fill the N2 when reinstalling. We feel this "big hole/2-piece grommet" arrangement is easier to deal with in the long run, and it is less expensive - but there are a dozen ways to skin this cat.
The front struts were not that unusual, being a typical non-inverted 22mm shaft monotube with rebound knobs on the strut shaft top and the compression knobs on the remote reservoirs (just like the rears). The hoses were long enough to route underneath the inner fender structure and mount the reservoirs just about anywhere in the engine bay. Ryan made some additional reservoir brackets for the front struts, but unlike our 2011 GT this car still had the factory airbox in place (everything is still bone stock under hood, for the lower 380 whp output). This meant we couldn't mount the reservoirs in the same place as on the '11 (which was blocked on this car by the giant OEM airbox), so we thought about it and placed them vertically in the airstream behind the headlights.
Shock reservoirs need to shed heat when they are working (they turn motion into heat), so we always try to keep them cool. Mounting them so that they get cool air from the front end seemed like the best idea. This location doesn't "show them off" as well as elsewhere, but so be it. I've seen some racers place remote shock reservoirs near the worst sources of under hood heat - like above a turbocharger (I've even done this myself) - but you really have to think about where you mount these things to keep them cool. A boiling hot reservoir will not allow the shock to perform nearly as well as one that stays closer to ambient temperature.
As you can see in the "Before and After" shots above, the ride height on the 2013 GT is significantly lowered, with the front dropping 1.25" and the rear dropping nearly 1.75". This gets rid of the huge front-down rake these cars come with and lowers the CG significantly. The spring rates we used were somewhat mild, with 450#/in in front and 225 #/in in the rear. This makes for a very decent ride on the street, but still a sizable bump in spring rates over stock, for better track handling (well, at least the front rates). See the updated spring charts below for the base 2013 GT OEM springs, the 2011 "Brembo GT" OEM springs, and the '07-08 Shelby GT spring rates (equipped with the FRPP M-5300-P springs).
Click the charts above for larger image... LEFT: 2013 Base GT. CENTER: 2011 "Brembo" GT. RIGHT: M-5300-P/'07-08 Shelby GT.
Since I first posted several OEM S197 Mustang spring rate tests, we noted two problems: first, we weren't compressing the springs nearly far enough. We were barely getting them compressed enough to even approach static ride height. So we upgraded our digital spring rater to a new "ram" to allow for 15" of spring compression vs the 4.5" it came with, which let us test over a wider range. These newly tested Mustang spring rates then become much more linear as we tested them over a wider displacement range. Second there was an error in our calculations for "rate at compressed height" that has also been fixed in our default spreadsheet. The measured force numbers never changed, just how we were showing them (rate of rate change vs rate at position). Sorry for the confusion.
So as you can see, we've upped the front spring rate considerably more than the rear on this car once again, which we have found - from a lot of coilover testing - works better with an S197, both on track and on the street. The bigger rate increase up front cuts down on brake dive, body roll and camber loss under cornering forces. It also reduces understeer caused by bottoming out of the front suspension. This 450#/in spring also makes the car transition much faster than with the ~100 #/in rates. Luckily the adjustable AST monotubes do a fine job of managing the 4.5 times increase in front rate. You won't see OEM-lowering springs in this spring rate range because the typical shocks these are used on (OEM style) cannot deal with those spring rates.
(continued below)
2013 GT Coilover Shock Install
The last time we took the 2013 Mustang to ECR, it was on the OEM shocks and springs and the handling was "frightening", to say the least. The car was hopping and flopping around, like a fish out of water. Lots of lean, roll, dive, and all that bad stuff we are used to on OEM sprung/damped S197s. Our long term plans at the time still included SCCA E-Street Prepared class preparations, but we would still do a track event or two before we got too far down the rabbit hole of autocross-only modifications.
Obviously a big improvement we could tackle that worked for both autocross and track use was to add our normal monotube adjustable coilover upgrade. Since Vorshlag sells AST and Moton monotubes, plus some others, we had several options that would work. We picked up some AST double adjustable coilovers with remote reservoirs for an S197 (AST 4200-RR), a custom test set made by AST-USA for a former employee. These were built with racing style "eye-to-eye" rear shocks, just like the Motons on our 2011 GT. On this car, however, I wanted to keep them "pin" style on top, to allow for the rebound knob to be located in the trunk for easy rebound changes (see above, left). An eye-to-eye shock tends to have the rebound knob located under the trunk floor and, like in the case of our Moton CS shocks on the 2011 GT, we have to remove a rear wheel to adjust rebound. It is a hassle, and that adjustment almost never gets tweaked. so we end up using the same setting for street and track use (which is a shame). So we asked AST-USA to re-work the rear shock shafts to have a traditional top pin and used it with the OEM style shock mount. They swapped out the shafts and adjusters to our favored eye lower/pin upper style and now the rebound knob is easy to access.
Once these were built to our liking, Vorshlag fabricator Ryan fashioned some reservoir mounts for the rear shocks, and cut holes in the trunk floor "spare tire well" to route the reservoirs through without disconnecting the hoses (which is a PITA) - just like on the 2011 GT. I asked him to tweak the angle of the reservoirs to be able to see the knobs easier from behind, which he did. The reservoirs were mounted into the spare tire well using the 2-piece "Seals-It" brand grommets to make this hole water tight. He mocked-up the seals with temporary Clecos, then used small machine bolts and nuts to hold them in place. If the shocks need to be removed from the car, the 2-piece grommets can be unbolted then the reservoir can slide right through the now open hole... no mess, no fuss. The other mounting/routing option for shock reservoir hoses is to drill much smaller holes/grommets and add (very costly) quick-disconnects on each shock line. Even then you still have to bleed off the Nitrogen charge before disconnecting the hoses, and re-fill the N2 when reinstalling. We feel this "big hole/2-piece grommet" arrangement is easier to deal with in the long run, and it is less expensive - but there are a dozen ways to skin this cat.
The front struts were not that unusual, being a typical non-inverted 22mm shaft monotube with rebound knobs on the strut shaft top and the compression knobs on the remote reservoirs (just like the rears). The hoses were long enough to route underneath the inner fender structure and mount the reservoirs just about anywhere in the engine bay. Ryan made some additional reservoir brackets for the front struts, but unlike our 2011 GT this car still had the factory airbox in place (everything is still bone stock under hood, for the lower 380 whp output). This meant we couldn't mount the reservoirs in the same place as on the '11 (which was blocked on this car by the giant OEM airbox), so we thought about it and placed them vertically in the airstream behind the headlights.
Shock reservoirs need to shed heat when they are working (they turn motion into heat), so we always try to keep them cool. Mounting them so that they get cool air from the front end seemed like the best idea. This location doesn't "show them off" as well as elsewhere, but so be it. I've seen some racers place remote shock reservoirs near the worst sources of under hood heat - like above a turbocharger (I've even done this myself) - but you really have to think about where you mount these things to keep them cool. A boiling hot reservoir will not allow the shock to perform nearly as well as one that stays closer to ambient temperature.
As you can see in the "Before and After" shots above, the ride height on the 2013 GT is significantly lowered, with the front dropping 1.25" and the rear dropping nearly 1.75". This gets rid of the huge front-down rake these cars come with and lowers the CG significantly. The spring rates we used were somewhat mild, with 450#/in in front and 225 #/in in the rear. This makes for a very decent ride on the street, but still a sizable bump in spring rates over stock, for better track handling (well, at least the front rates). See the updated spring charts below for the base 2013 GT OEM springs, the 2011 "Brembo GT" OEM springs, and the '07-08 Shelby GT spring rates (equipped with the FRPP M-5300-P springs).
Click the charts above for larger image... LEFT: 2013 Base GT. CENTER: 2011 "Brembo" GT. RIGHT: M-5300-P/'07-08 Shelby GT.
Since I first posted several OEM S197 Mustang spring rate tests, we noted two problems: first, we weren't compressing the springs nearly far enough. We were barely getting them compressed enough to even approach static ride height. So we upgraded our digital spring rater to a new "ram" to allow for 15" of spring compression vs the 4.5" it came with, which let us test over a wider range. These newly tested Mustang spring rates then become much more linear as we tested them over a wider displacement range. Second there was an error in our calculations for "rate at compressed height" that has also been fixed in our default spreadsheet. The measured force numbers never changed, just how we were showing them (rate of rate change vs rate at position). Sorry for the confusion.
So as you can see, we've upped the front spring rate considerably more than the rear on this car once again, which we have found - from a lot of coilover testing - works better with an S197, both on track and on the street. The bigger rate increase up front cuts down on brake dive, body roll and camber loss under cornering forces. It also reduces understeer caused by bottoming out of the front suspension. This 450#/in spring also makes the car transition much faster than with the ~100 #/in rates. Luckily the adjustable AST monotubes do a fine job of managing the 4.5 times increase in front rate. You won't see OEM-lowering springs in this spring rate range because the typical shocks these are used on (OEM style) cannot deal with those spring rates.
(continued below)
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(continued from above)
ECR Toy Run - Dec 8th, 2012
People sometimes wonder why we are based in Texas... "Your summers are so hot!", they say. And while we DO have 2-3 months of a little heat (okay, a lot of heat), we have 12 months of racing every year. This allows us to race and test every month, and we don't have an "off season" huddled away from the cold with nothing to drive. Sure, we had a couple of snow days around the holidays, but nothing that prevented us from missing a track day or autocross.
Vorshlag picture gallery for ECR Toy Run - http://vorshlag.smugmug.com/Racing-Events/Toy-Run-ECR-120812/
So, we were racing in December and back on track again a few weeks later in January, like we do every year. I wrote about the December 8th ECR "Toy Run" event twice already: in part three of my December 28th post in the BRZ Project Thread and in my December 20th update on our Firebird ChumpCar project thread - some of which I have re-inserted here. All of us at Vorshlag had gone down to Austin and driven Cadillac CTS-Vs all day the previous day (Friday) at the new Circuit of the Americas F1 track. That event was a TOTAL BLAST, but when we finished we bombed back up to Dallas, grabbed the Vorshlag race trailer, grabbed McCall's truck and trailer to tow the ChumpCar, and drove two more cars to Eagles Canon Raceway before dawn for Saturday's annual "Toy Run" open track event. We got there and stacked our trucks, trailers and cars in a big clump and set up shop.
With four cars on hand we were a little busy - luckily we had Pirtek Ed there to help "crew chief" all of us (shown above talking to me in the black '13). He wrangled the five drivers and four cars and kept us all going all day, so... thanks Ed! Matt brought his BRZ, we brought the 2011 Mustang and Amy drove it all day, and I drove our 2013 GT on the new AST 4200-RR coilovers. Two of my racing buddies (McCall and Magyar) and I are also building a ChumpCar using a V6 4th gen Firebird and we ran it for the first time that day. Since this was a charity event, they asked the instructors to take passengers for ride-alongs at $5 a pop, and for $10 donated we would ride-along with anyone and "instruct". Between me and about 7 other instructors we raised an extra $600 that was given to a local food shelter, and we gave some kick ass rides to people in some quick-ass cars. I lost count of how many times I went out on track in the '13 and the ChumpCar, or in other people's cars (I drove a GT500 Mustang at one point), but it was a LONG and busy day. Too much fun!
Our 1998 Firebird V6 has been dubbed "F-Turd"... luckily it ran great.
The ambient temps were much colder than the November lapping day and Amy's and some others' lap times were a solid 1-1.5 seconds off their times at the Ford event, when the weather was a bit more favorable. Still, our black 2013 GT, which we base-lined in November, was a solid FOUR SECONDS faster with nothing changed other than the coilover shocks & springs (which were still pretty damned soft at 450F/225R). The same Vorshlag camber plates, same D-Force 18x10" wheels and 295mm Nitto NT-05 street tires, and same bloke behind the wheel (me). I have taken many hundreds of laps at this track since 2008 and wasn't "learning the line", but instead felt like I was wringing every millisecond out of this car. We went from a 2:07.7 to a 2:03.3. A keen observer will note that this 2013 GT, with no aero, bone stock power and the exact same set of wheels/tires, was faster than our 2011 GT was in June at the Optima Challenge event. A lot of that is probably the difference in temperature, but a lot of it was the fact that the car was easier to drive with less power. These Coyote 5.0 engines have plenty of go in stock form, so we would suggest upgrading the suspension, tires, wheels and brakes long before you start throwing more power at your track Mustang. Nobody listens to that, of course.
This was a pretty good suspension test, in my opinion. We know this track well and we ran this same car with the same set-up minus the shocks/springs a month earlier. Not only did we drop four seconds on a two minute lap, but we took the car from a bucking, portly pig that was rolling and brake diving and porpoising around this somewhat bumpy track and turned it into a calm, flat cornering car that was nothing like the OEM suspension'd Mustang any longer. I cannot repeat this enough: a bump in spring rate along with proper monotube adjustable coilovers will completely TRANSFORM these cars. The shocks that Ford installs are equivalent to $50/corner Autozone specials. Even the "adjustable" shocks that come on the Boss 302 LS are not good at all - Tokico adjustables are only a small step above the Autozone fare that comes on the GT's. The longer you run on track the more the performance in twin tube shock degrades in handling, as well.
Of course I couldn't resist a little hooning for the cameras... with the stock 380 whp, it's just too easy!
It isn't so much about how many adjustments the shocks have, or the reservoirs, but the type of damper being used. Monotubes are technically superior to twin tubes in every performance measurement, and their MUCH larger pistons can react to bumps much more rapidly and effectively. They tend to have more of an adjustment range and can deal with a wider spectrum of spring rates. We didn't make this a gut busting, over-sprung race car set-up (450F/225R), but instead mildly improved the front rates and kept the rear rates nearly stock. At the same time we lowered the car 1.25" or more at each corner, for a flatter "stance" and a lower Center of Gravity - which directly improves cornering grip. The lower ride height added negative camber, as it always does on McPherson strut cars, and this also helped improve front grip and lower front tire wear.
Andy Hollis giving the point-by from his OLOA race prepped CRX to Amy's '11 Mustang GT.
Amy had fun in the red Mustang and ran a bunch of 1:58 laps, sometimes with a string of 3 or 4 in a row within two tenths. Just couldn't get back down to the 1:57's she ran at the ECR event in November. These old Hoosier tires are just dead, and have "compounded out". We used and abused these for GTA, lots of autocrossing, and multiple track days. They still have tread left, and the wear is perfectly flat across the tread, but they are just getting ... slower. And we still used these same tires at the NASA event at MSR-Houston in January. Just like most folks, we have a fixed racing budget that isn't unlimited, so sometimes we gotta win some tires to get new ones. The rest of the car was flawless and the Carbotech brakes were phenomenal once again. The twice-rebuilt TractionLok differential is utterly gone but again, we need the budget to recover before dropping $700+ on a Torsen T2-R. Meh, we can deal with some imperfection - this is a stick axle pony car after all.
Matt had an uneventful, but fun day in the BRZ. We luckily didn't have anything explode, fall off or catch on fire in the ChumpCar Firebird. It was a big hot mess, and we uncovered some new issues in this fiurst track outing, but we made it through five sessions and three drivers and still drove it onto the trailer for the ride home. The 2013 GT suspension test was great and the 2011 GT was flawless all day. Overall, this ECR Toy Run event was a lot of fun and a very informative test. I have to thank the ECR track owners for putting this much-discounted event on for the 5th year in a row, and thanks also to Brad Flak for corralling the drivers and instructors. As usual, the Toy Run's ultra-low price tag attracted many first time track enthusiasts, including many local autocrossers. Hopefully this exposure to road course driving gets them a little more hooked on doing HPDE events. This worked in the past for myself and many other fellow (and many former-) SCCA autocrossers, like Vorshlag tester KenO - who was a blur around the track all day (above right and below left).
Another Vorshlag tester, and BMWCCA LSR president MarkW, was also on hand in his 1M (above, right), pushing his Vorshlag 1M camber plates and finally wearing front tires flat instead of chunking the shoulders. You 1M owners can thank Mark for the Vorshlag 1M camber plates. His constant stream of camera phone pics showing torn up front tire edges spurred the production of the OEM perches that make this fitment possible.
D-Force 18x10" S197 Wheel In Stock
Back by popular demand is the 5x114.3 bolt circle 18x10" D-Force Racing lightweight wheel. This ET43 offset wheel fits both the S197 Mustang and GR chassis Subaru STI without spacers. There are dozens of sets in stock in both Silver and Flat Black colors. These may not last too long, like last time, and will probably sell out before the next batch arrives. If you want a set, you can of course order them through Vorshlag. Thanks!
That's all we have on this December ECR event and the prep leading up to it, but I have a lot more writing to do to get caught up on this S197 thread. We have several more posts for this thread coming soon, so stay tuned for more.
ECR Toy Run - Dec 8th, 2012
People sometimes wonder why we are based in Texas... "Your summers are so hot!", they say. And while we DO have 2-3 months of a little heat (okay, a lot of heat), we have 12 months of racing every year. This allows us to race and test every month, and we don't have an "off season" huddled away from the cold with nothing to drive. Sure, we had a couple of snow days around the holidays, but nothing that prevented us from missing a track day or autocross.
Vorshlag picture gallery for ECR Toy Run - http://vorshlag.smugmug.com/Racing-Events/Toy-Run-ECR-120812/
So, we were racing in December and back on track again a few weeks later in January, like we do every year. I wrote about the December 8th ECR "Toy Run" event twice already: in part three of my December 28th post in the BRZ Project Thread and in my December 20th update on our Firebird ChumpCar project thread - some of which I have re-inserted here. All of us at Vorshlag had gone down to Austin and driven Cadillac CTS-Vs all day the previous day (Friday) at the new Circuit of the Americas F1 track. That event was a TOTAL BLAST, but when we finished we bombed back up to Dallas, grabbed the Vorshlag race trailer, grabbed McCall's truck and trailer to tow the ChumpCar, and drove two more cars to Eagles Canon Raceway before dawn for Saturday's annual "Toy Run" open track event. We got there and stacked our trucks, trailers and cars in a big clump and set up shop.
With four cars on hand we were a little busy - luckily we had Pirtek Ed there to help "crew chief" all of us (shown above talking to me in the black '13). He wrangled the five drivers and four cars and kept us all going all day, so... thanks Ed! Matt brought his BRZ, we brought the 2011 Mustang and Amy drove it all day, and I drove our 2013 GT on the new AST 4200-RR coilovers. Two of my racing buddies (McCall and Magyar) and I are also building a ChumpCar using a V6 4th gen Firebird and we ran it for the first time that day. Since this was a charity event, they asked the instructors to take passengers for ride-alongs at $5 a pop, and for $10 donated we would ride-along with anyone and "instruct". Between me and about 7 other instructors we raised an extra $600 that was given to a local food shelter, and we gave some kick ass rides to people in some quick-ass cars. I lost count of how many times I went out on track in the '13 and the ChumpCar, or in other people's cars (I drove a GT500 Mustang at one point), but it was a LONG and busy day. Too much fun!
Our 1998 Firebird V6 has been dubbed "F-Turd"... luckily it ran great.
The ambient temps were much colder than the November lapping day and Amy's and some others' lap times were a solid 1-1.5 seconds off their times at the Ford event, when the weather was a bit more favorable. Still, our black 2013 GT, which we base-lined in November, was a solid FOUR SECONDS faster with nothing changed other than the coilover shocks & springs (which were still pretty damned soft at 450F/225R). The same Vorshlag camber plates, same D-Force 18x10" wheels and 295mm Nitto NT-05 street tires, and same bloke behind the wheel (me). I have taken many hundreds of laps at this track since 2008 and wasn't "learning the line", but instead felt like I was wringing every millisecond out of this car. We went from a 2:07.7 to a 2:03.3. A keen observer will note that this 2013 GT, with no aero, bone stock power and the exact same set of wheels/tires, was faster than our 2011 GT was in June at the Optima Challenge event. A lot of that is probably the difference in temperature, but a lot of it was the fact that the car was easier to drive with less power. These Coyote 5.0 engines have plenty of go in stock form, so we would suggest upgrading the suspension, tires, wheels and brakes long before you start throwing more power at your track Mustang. Nobody listens to that, of course.
This was a pretty good suspension test, in my opinion. We know this track well and we ran this same car with the same set-up minus the shocks/springs a month earlier. Not only did we drop four seconds on a two minute lap, but we took the car from a bucking, portly pig that was rolling and brake diving and porpoising around this somewhat bumpy track and turned it into a calm, flat cornering car that was nothing like the OEM suspension'd Mustang any longer. I cannot repeat this enough: a bump in spring rate along with proper monotube adjustable coilovers will completely TRANSFORM these cars. The shocks that Ford installs are equivalent to $50/corner Autozone specials. Even the "adjustable" shocks that come on the Boss 302 LS are not good at all - Tokico adjustables are only a small step above the Autozone fare that comes on the GT's. The longer you run on track the more the performance in twin tube shock degrades in handling, as well.
Of course I couldn't resist a little hooning for the cameras... with the stock 380 whp, it's just too easy!
It isn't so much about how many adjustments the shocks have, or the reservoirs, but the type of damper being used. Monotubes are technically superior to twin tubes in every performance measurement, and their MUCH larger pistons can react to bumps much more rapidly and effectively. They tend to have more of an adjustment range and can deal with a wider spectrum of spring rates. We didn't make this a gut busting, over-sprung race car set-up (450F/225R), but instead mildly improved the front rates and kept the rear rates nearly stock. At the same time we lowered the car 1.25" or more at each corner, for a flatter "stance" and a lower Center of Gravity - which directly improves cornering grip. The lower ride height added negative camber, as it always does on McPherson strut cars, and this also helped improve front grip and lower front tire wear.
Andy Hollis giving the point-by from his OLOA race prepped CRX to Amy's '11 Mustang GT.
Amy had fun in the red Mustang and ran a bunch of 1:58 laps, sometimes with a string of 3 or 4 in a row within two tenths. Just couldn't get back down to the 1:57's she ran at the ECR event in November. These old Hoosier tires are just dead, and have "compounded out". We used and abused these for GTA, lots of autocrossing, and multiple track days. They still have tread left, and the wear is perfectly flat across the tread, but they are just getting ... slower.
And we still used these same tires at the NASA event at MSR-Houston in January. Just like most folks, we have a fixed racing budget that isn't unlimited, so sometimes we gotta win some tires to get new ones. The rest of the car was flawless and the Carbotech brakes were phenomenal once again. The twice-rebuilt TractionLok differential is utterly gone but again, we need the budget to recover before dropping $700+ on a Torsen T2-R. Meh, we can deal with some imperfection - this is a stick axle pony car after all.
Matt had an uneventful, but fun day in the BRZ. We luckily didn't have anything explode, fall off or catch on fire in the ChumpCar Firebird. It was a big hot mess, and we uncovered some new issues in this fiurst track outing, but we made it through five sessions and three drivers and still drove it onto the trailer for the ride home. The 2013 GT suspension test was great and the 2011 GT was flawless all day. Overall, this ECR Toy Run event was a lot of fun and a very informative test. I have to thank the ECR track owners for putting this much-discounted event on for the 5th year in a row, and thanks also to Brad Flak for corralling the drivers and instructors. As usual, the Toy Run's ultra-low price tag attracted many first time track enthusiasts, including many local autocrossers. Hopefully this exposure to road course driving gets them a little more hooked on doing HPDE events. This worked in the past for myself and many other fellow (and many former-) SCCA autocrossers, like Vorshlag tester KenO - who was a blur around the track all day (above right and below left).
Another Vorshlag tester, and BMWCCA LSR president MarkW, was also on hand in his 1M (above, right), pushing his Vorshlag 1M camber plates and finally wearing front tires flat instead of chunking the shoulders. You 1M owners can thank Mark for the Vorshlag 1M camber plates. His constant stream of camera phone pics showing torn up front tire edges spurred the production of the OEM perches that make this fitment possible.
D-Force 18x10" S197 Wheel In Stock
Back by popular demand is the 5x114.3 bolt circle 18x10" D-Force Racing lightweight wheel. This ET43 offset wheel fits both the S197 Mustang and GR chassis Subaru STI without spacers. There are dozens of sets in stock in both Silver and Flat Black colors. These may not last too long, like last time, and will probably sell out before the next batch arrives. If you want a set, you can of course order them through Vorshlag. Thanks!
That's all we have on this December ECR event and the prep leading up to it, but I have a lot more writing to do to get caught up on this S197 thread. We have several more posts for this thread coming soon, so stay tuned for more.
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LindsayEOD
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A 4 second drop by just adding the AST's is impressive Terry. Thanks for the write up.
dontlifttoshift
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Thoughts on the BFGs? I have read all the other reviews already but they may be biased, I know you'll shoot it straight.
Napoleon85
forum member
+1 - I'm dying to hear about these. Seems like the price point is very close to Nitto NT05s so I'd like to hear how you feel they compare since you have ran those before iirc.
The BFG Rival tires were incredible. I'm in the middle of writing my review... and 5 other thread posts. I am way WAY behind - sorry guys.
more soon!
claudermilk
Senior Member
Yay! Updates on the 2013! I've been waiting to hear what you will do with it since you got it. Now I'm desperately hoping you hang on to it & continue development despite the ESP issue.
Well, some of us do. That has been my plan from day 1.
These Coyote 5.0 engines have plenty of go in stock form, so we would suggest upgrading the suspension, tires, wheels and brakes long before you start throwing more power at your track Mustang. Nobody listens to that, of course.
Well, some of us do. That has been my plan from day 1.
SoundGuyDave
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I haven't driven on the Rivals yet, BUT just reading the lit, and looking at the specs, this is a 200 UTQG street tire (perhaps a soft 200, but 200 none the less), and that won't even come close to competing with an R-compound tire like the NT-01. Now, granted, the Rival is marketed to be at the pointy end of the stick for a street tire, and the NT-01 is an entry-level R-compound (100 TW vs. 40 for the Hoosiers and BFG R-1), but I would be willing to bet that the Rival will NOT perform better.... Assuming, of course, your definition of "performance" is in terms of grip, and not longevity.
Well I've been running a couple sessions on my Bridgestone Potenzas, which are also my DD's, and I was wanting to get a set of track tires. I'm still somewhat of a newb to the road course scene and am still trying to research stuff like what you and Terry post.
SoundGuyDave
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All to the good! My advice (posted frequently!) to anybody that is getting into the scene is to stick with street tires until you can make them sing all the way from turn-in through apex, and into the track-out phase of EVERY corner, EVERY lap. At that point, you know, for a fact, that you're getting 100% out of the tire itself, and have reasonably good consistency. Now you can be certain that the tires are the limiting factor in the grip equation! At that point, make the move into R-compounds. The difference in grip between a street tire and an R-comp is absolutely astounding! This does, necessarily, come with a few trade-offs, though. Tire life is certainly one of them, and lack of feedback short of the limit is another. While the street tires (generally) start with that thin screech, if you push them a bit more, you get a nice singing noise, and if you go over the limit, they howl/scream before the get loose, and when they do, they're generally easy to recover. R-compounds, though, are silent, then there's a hint of noise (really more of a subtle shake in the wheel), and then you're spinning.
Also, getting into R-compounds too soon can cover a LOT of driver-error and still make you look like a hero. The real goal is to learn how to drive the car at the very limit of adhesion; get it balanced on that knife-edge. Once you learn how to do that on street tires, you do the EXACT same thing on R-compounds, only at much higher speeds. You still want that knife-edge feeling. The raw grip, as I mentioned, can cover a lot of bad habits and errors. If you go in too hot on street tires, you push the front end past apex, screaming all the way, until you bleed off enough speed to get the car turned (tire noise dies away), and then motor out of the corner far too slow. With R-comps, the raw grip lets you pitch the car in, balls through on sheer power alone, and make an exit looking like a hero, yet STILL far too slow. Because you made the corner, you'll THINK you did it the right way, but all you did was scrub too much speed while destroying the outer shoulder of the loaded front tire. If you get your chops together first, the only difference will be a slight tweak of your line through the corner, and increased velocity throughout all phases.
Having separate wheels and tires for street and track is still a good idea. There's no point in taking the risk of chunking your street tires, and no point in putting on extra heat cycles on your track tires, if you follow.
Making the tires sing:
This is Terry Leroux, a NASA instructor, and a fantastic driver. Check out how much of each corner he's getting the tires singing, and also how consistent the pitch and tone are (particularly when he's not in traffic). THAT'S what you're shooting for. Then, switch to the R-compounds, and do the SAME THING, but using the wheel shake as your indicator.
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