|
|
A-Arm Install - Searching For Seconds, Part 2We bring in STI Killer to install some new suspension. From the December, 2011 issue of GM High-Tech Performance By Justin Cesler Photography by The Author
|
|
After two full sessions at Sebring Raceway, several trips to Gainesville Raceway's test track and roughly two thousand donuts in the parking lot of our World Headquarters, we're finally starting to get a good handle on the STI Killer's persona. In testing, we've found that the BMR suspension mixed almost perfectly with the Toyo R888 tires and that the Killer's rock-solid drivetrain combination (bolt-on LS6, D&D-built T56 and a narrowed 10-bolt) has been as reliable as we could have ever dreamt of, especially for the amount of abuse we've doled out. Of course, we did see a little room for some small improvement here and there, and now that we've got some miles under our belt (506 on-track miles according to the odometer) we plan on attacking those "issues" over the next several months. This time we were focused on improving the STI Killer's stance, which was already nice, and adding another degree of camber to the front wheel/tire combination to help with initial turn-in and front grip throughout the corners. We were looking to go low -- like, can't get it on the trailer, can't use the lift but looks amazing low -- and refused to give up any suspension travel or tire clearance in the process. With our goals clearly defined we made a quick call to the pros over at BMR Suspension and ordered up a set of the company's 1-inch lower A-arms, complete with ball joints, and a pair of BMR tubular upper A-arms. Constructed from a combination of 1.625- and 1.250-inch DOM tubing, these upper and lower arms are more than capable of handling the abuse we plan on throwing at them (road course, autocross and drag strip) and will reduce our total weight over the nose by almost 10-pounds. Of course, the major advantage with the 1-inch lowering A-arms is the, well, 1-inch drop in the front suspension, which comes without negatively affecting the front suspension travel. Combined with the upper arms, we could also have our local alignment shop, Weaver's Tire and Automotive, get really aggressive with the front camber, which would improve handling and steering feel drastically. As usual, we turned the STI Killer over to Greg Lovell at AntiVenom and followed along with him as he worked. If you're intimidated by tackling a project like this yourself, consider that it is less complicated than it may seem and took Greg, a seasoned professional, just a couple of hours to complete. While it does take a little bit of time to install the parts and get the rod-ends in the correct position, it is worth the effort and we noticed an improvement in stiffness and feel almost immediately. Our alignment team had no trouble dialing everything in once we had it close and we were able to drive away with a whole new feel and 2.8/2.5-degrees of negative camber in the front end, which was much improved from our 1.3/0.9 that we were able to run with the heavy stock parts. On track, we picked up almost a full second around on our tight and traction limited course, which really gave us hope for the next round of modifications, which you will have to check out in an upcoming issue...  1 Our search for maximum...  1 Our search for maximum stance and shaved seconds started here on the front end of our Camaro. To some, that wheel gap may be reasonable and it is certainly much better than the factory 4x4 look, but we wanted to really close it up and gain a performance advantage at the same time.  2 With our massive 18x10-inch...  2 With our massive 18x10-inch Weld Racing RT-S wheels out of the way, Greg sprung into action and began our install by removing the gigantic 6-piston Bear 6S brake calipers and rotors from our stock spindles.  3 Fighting intermittent ABS...  3 Fighting intermittent ABS issues, Greg also decided to replace the passenger’s side wheel bearing and hub assembly, which simply unbolts from the spindle. You don’t have to remove this during your install, but you should always check the wheel bearing for excessive wear or play before you head out on track.  4 Up top, Greg removed the...  4 Up top, Greg removed the factory-installed cotter pin and then loosened the spindle-to-upper ball joint nut. With the nut out of the way, you will need to free the upper ball joint from the spindle using a ball joint separator or a big hammer, which is the way we prefer.  5 Now that the spindle was...  5 Now that the spindle was free to rotate away from the upper A-arm, Greg was able to unbolt our single-adjustable Koni shocks from the lower A-arm and move the wheel speed sensor wiring out of the way.  6 The lower ball joint-to-spindle...  6 The lower ball joint-to-spindle castle nut was next up in the removal process and came off easily after pulling the cotter pin and hitting it with the largest ratchet we could find. Forward of the ball joint you can see the nut and cotter pin that holds the tie-rod ends in place, which must also be removed.  7 Up in the STI Killer’s...  7 Up in the STI Killer’s engine bay, Greg removed the 4 upper strut mount bolts, two of which take a traditional socket and the other two require a Torx bit. If you can’t easily access the Torx bolts with your ratchet (who can?!), it is easy to unbolt the stock master cylinder and swing it out of the way to make some room.  8 Up, up and away! The Koni...  8 Up, up and away! The Koni shock, spring, upper A-arm and upper strut mount pull out all as one piece and can be put aside for the time being. If you were only changing the upper A-arms, you could do that now and move on to begin reassembly…  9 …however we still needed...  9 …however we still needed to get the lower A-arms off of the STI Killer. Only two-bolts hold them in place, but you will need to remove the sway bar endlinks to ultimately swing the A-arms out of the way.  10 It’s a tight squeeze to...  10 It’s a tight squeeze to remove the front lower A-arm bolt, but it can be done without removing the steering rack if you are as crafty as Greg. The rear simply slides out the top of the subframe mount and that will free the A-arm to be removed from the chassis. Try to ignore the power steering fluid leak… we’re working on a fix for that soon!  11 Compared to the rusty...  11 Compared to the rusty stamped steel arms that come on the Camaro, these BMR units speak for themselves. The lower arms, which are built from DOM tubing and are welded together in house at BMR, ship complete with an installed ball joint, a polyurethane front bushing and a single adjustable rod-end to allow for easy alignment changes.  12 Along with all of the...  12 Along with all of the traditional features found in an aftermarket A-arm, the BMR lowering A-arm units are built to drop the front end of a fourth-gen F-body without affecting the overall suspension travel. A word of warning, these A-arms combined with the BMR lowering springs will drop a car almost 2.25-inches in the front, which is low by even the most “stance is everything” of standards.  13 Installing the lower A-arms...  13 Installing the lower A-arms is fairly straightforward although it is best to lay them atop your stock arms to line up the two bolt-holes before sliding them in place. Although they are adjustable via the rod-ended Heim joint, the arms must be removed to make an adjustment, so it is best to get them close before taking it to the alignment shop.  14 Up front, the Polyurethane...  14 Up front, the Polyurethane bushing slides in place easily and the factory hardware can slide back in place to secure it. The Poly front, combined with the rod-end rear gives these a firm but serious road feel, which is great for anyone looking to take their F-body from a cruiser to a serious handler.  15 In addition to the new...  15 In addition to the new lowering A-arm, BMR Suspension supplied us with a set of the company’s tubular upper A-arms, which ship complete with new ball joints and two rod-ends for maximum adjustability. Built from 1.25-inch DOM tubing, they are also plenty strong.  16 After installing the required...  16 After installing the required spacers, the upper A-arm can be easily slid in place. However, just like the lower unit, we recommend you lay these atop your stock A-arms and adjust the lengths until they are similar. Pulling the upper A-arms once everything is installed is quite the chore, so get these close and save yourself some trouble.  17 Back on the ground, Greg...  17 Back on the ground, Greg bolted the new upper A-arms into the factory mount and slid the spring and shock assembly back into place. Notice that the upper A-arm features a greaseable ball joint, which needs to be greased before you head out on the street or track.  18 With the upper and lower...  18 With the upper and lower A-arms in place, assembly of the front end is as simple as the disassembly was. Two bolts for the lower shock mount, slide the swaybar endlink in place, bolt the tie-rod ends back in place and tighten everything down.  19 Call it big brake fever...  19 Call it big brake fever but for whatever reason, we just can’t stop messing with our front brake situation and curiosity got the best of us as we went to reinstall our Bear units. For the sake of testing, we decided to drop a set of fifth-gen Camaro 4-piston Brembo units on the STI Killer, which marks our 4th set of brakes to date. This helped us diagnose our braking issues, which turned out to be a bad wheel speed sensor (the rears were replaced as was one of the front hubs).  20 While not nearly as hardcore...  20 While not nearly as hardcore as the 6-piston Bear 6S brakes we have been using, the 4-piston Brembo brakes we robbed off a 2010 Camaro fit like an OEM set of brakes and bolted right on using a pair of C6 Z06 rotors and a couple of washers to space the caliper properly over the rotor. The brake lines and bolt-holes lined right back up and we were ready to rock.  21 Blam! On the ground, the...  21 Blam! On the ground, the 1-inch drop really shows, with the top of our Toyo tires getting tucked up neatly over the front fender of the STI Killer. Weaver’s Tire and Automotive was able to dial in 2.8/2.5-degrees of negative camber in the front, which was much improved from our 1.3/0.9-degrees with the stock stuff and that really helped front turn-in and grip out on track.  22 Speaking of “out on track”,...  22 Speaking of “out on track”, no STI Killer project would be complete without some laps around our test track at Gainesville Raceway. The Killer’s new stance looked great standing still, but you can see that it still provided enough weight transfer to get the brakes working and kept the front end off the ground and right where we needed it.  23 Around Gainesville’s high-speed...  23 Around Gainesville’s high-speed sections, the Killer remained firmly planted and felt controllable up to and even beyond the tires’ limitations. We managed to record a new best around the course, running a 64.45 second lap time, which beat our previous best of a 65.20 by a full three quarters of a second, a major improvement for the money.  24 Unfortunately, our test...  24 Unfortunately, our test session was cut short when our inept test driver (that’s me…) drove into a corner too hot, jumped on the brakes too heavy and induced a massive amount of rear axle brake-hop into the chassis of the STI Killer. Nothing could survive such heavy axle-hop, but luckily we drove out of it and only needed to replace a couple of torque arm bolts and possibly a pair of underwear. No big deal and we’ll have this back together and ready to rock for the next round of upgrades, which are coming soon!
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1999 Pontiac Firebird Trans Am - Street Heat
Almost no other GM model pulls off the aggressive look quite like the fourth-gen Trans Am, and when you modify one like Nathan Turjillo from Las Vegas has, well; you end up with a real showstopper....
more
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2011 Chevrolet Silverado LTZ LS9 Camshaft Swap
Seriously, the package we’re showing off here can be purchased for under 300-bucks if you shop smart (new parts, nothing used) and added 47-rwhp and 20 lb-ft of torque to our bolt-on equipped 2011...
more
|
|