1976 Chevy Camaro - Nitto NT-555RII Install - Popular Hot Rodding

1976 Chevy Camaro - Project g/28 Part 6

When we started Project g/28 (our resident '76 Camaro) back in the April 2005 issue of PHR, we laid out four performance goals and one cost goal: run 12s in the quarter-mile, run the 420-foot slalom at over 46 mph, stop repeatedly from 60 mph in 120 feet or less, grip the 200-foot skidpad at .90g or better, and do it all for under $20,000 including the price of the car. To add insult to injury, we learned at about the same time that the rolling 30-year smog exemption was repealed by California's Governator, so we also had the added expense of building a California-legal smog motor which would cost a lot more and do way less.

Our last two installments of Project g/28 have focused largely on building the smogger 383 stroker (put together by the fine folks at Speed-O-Motive) and installing said motor into g/28 with new driveline goodies from TCI (manual valve Turbo 350, 11-inch converter, shifter, tranny cooler, and flexplate). After struggling through that we wanted to attack the track in mind-bending fury once again, but one problem: the car still wasn't up to it.

The problem was that a more powerful engine wasn't going to help us corner better. We needed more grip, and our Falken FK-451 street tires just weren't going to meet our lofty goals. What we needed was a street-legal R-compound tire with a DOT rating. We've used Nitto NT555RII R compounds before with great results. In fact, we have them on a '94 Camaro Z28 that had already run our Fontana course. On that car, the 60-0-mph braking test fell in 111 feet; the 420-foot slalom was run in 46.6 mph; and the 200-foot skipad ripped and gripped to the tune of .94g. The Nittos were a proven commodity, and at $149 each (Discount Tire Direct), they were very affordable. The only minor issue we faced was tire size. The Nittos were only made in 275/40ZR17, and we had 18-inch rims.

As fate would have it, we sustained major damage to one of our front rims. The Weld ProStar XP wheel is a rolled forging designed for maximum weight reduction, which means it's also not meant for the mean potholes of Torrance, California. No problem, just buy another rim, right? It turns out Weld has stopped building the ProStar XP, so we needed another set of hoops. Fortunately, we found some new, more affordable 17x9s from American Racing that would work with the Nitto 275/40ZR17s. Our new wheel design, which ARE calls "Rebel," is a heavier chrome-plated aluminum casting, but it's also a good bit sturdier for street use and only costs about $245 each (street price).The total cost for four Nitto 275/40ZR17 R-compounds and four 17x9-inch Rebel wheels came to $1,636 (including special lug nuts), which beats the price of our original Weld/Falken rolling stock by some $442. Some readers will cry foul that we've subtracted out the cost of the old and substituted the new in our cost break-down, but we don't know anybody who'd quote the build cost for their own car with every wheel, tire, nut, bolt, or can of oil it had ever consumed in its life, so why should we? Besides, the exercise of track-testing two sets of wheels and tires isn't something readers can reasonably bitch about since they are the benefactors of such comparisons. For now, we'll repair our damaged rim and hold onto the old wheels and tires. If complaints arise, we'll just sell them and recalculate the spreadsheet. The same goes for our original set of cut springs that needed to be replaced with new, uncut springs (which had to be used to fit the bigger tires). The guiding principle here is that the cost breakdown for Project g/28 is the amount it would cost for you to duplicate our test results.

All bickering about the budget aside, the new rolling stock wasn't the easiest fitment we've seen. With a 6-inch backspacing, the Rebel wheels will probably interfere with the upper control arm at full wheel lock on unmodified '70-81 Camaros, but we were saved by our thicker Baer rotors, which acted like spacers (to which we added another 7/32-inch with spacers for hub clearance). You may recall that our first set of Weld wheels was a 6-inch backspacing (18x9-inch), and they contacted the UCA at full lock. At the time, we had to change to an 18x8.5 wheel with a 5.5-inch backspacing to cure the problem. Now however, the 6-inch backspacing works without any interference, due to the thicker Baer rotors. Problem averted, but keep an eye on UCA interference whenever swapping any wheel over 8.5 inches wide onto a Second-Gen F-body.

Our biggest wheel-fitment challenge came after we bolted the wheel/tire assembly on and lowered it to the floor. It looked totally bitchin', only the tire was sitting on the steel inner fenderwell. The springs were right for our old combination, but these rims and tires were wider and taller. We ordered up another identical set of springs from Hotchkis (the supplier for the PST drop spring kit), and instead of cutting them 1.5 coils (like we did the first time) we cut them only a half coil. Voila! The wheels fit perfectly. The stance, however, left much to be desired. Our thinking is that we'll do our testing, get the headers and exhaust system on, then see how much ground clearance is left. We've got a set of smog-legal full-length headers (from Hedman) that may also play a role in the stance/ground clearance equation. We will revisit this topic later once we see what we can get away with.

It is also worth noting that our front wheel hubs interfered with the wheels and needed a small spacer. We ordered some 7/32-inch-thick Mr. Gasket spacers from Jeg's for $11.99, and they kept the wheel from interfering with the hub. We can't say whether this would be a problem on the stock hubs and stock brakes, but it was a concern here with the Baer GT brake system. One other niggling thing concerning the ARE Rebel wheels: ARE supplies really nice center caps made of billet aluminum that have an attractive clear plastic center. They also have a rubber O-ring that is too thick and no amount of banging will get the center cap to fit into the wheel. In fact, after totally smashing (and destroying) two of them with a hammer (we wanted to see how much force was actually required) we quit trying.

Now, on to the driver's seat. The addition of a substantial amount of lateral grip is going to play havoc with a driver's ability to control the car. Typical seats from the '60s and '70s have no side or thigh bolstering to speak of, and that leads to driver control problems under high-lateral g's. It's hard enough to control a car on the skidpad, but when it comes to critical car placement on the track, a great seat can make the difference between a mediocre lap and a really fast lap. Anticipating this problem, we ordered up a Jeg's GS-1 sport seat for $199 (plus a universal pedestal mount for another $21.99). The original plan was to go with two seats, but we felt we could only justify the driver's seat for the purpose of reaching our performance goals within the budget.

We found the Jeg's GS-1 seat to be of surprisingly high quality (it's covered in durable leather-look black vinyl) and it even includes adjustable seat-back angle and a quick release for back-seat access. The Jeg's piece is comfortable and supportive in all the right places, and is designed with redundant controls to work in either driver or passenger positions. As we said, we ordered the universal mounting bracket, but you are still responsible for mounting that bracket to the floor, and that's where the hard work begins.

Here's the deal: the Jeg's seat mounts to the universal Jeg's pedestal, which has the seat adjuster built in. That bracket must mount to a custom frame that you must build yourself, and attaches to the floor of the car. That piece must adapt the attachment point on the Jeg's universal pedestal to the floor attachment points where your stock seat was bolted. So it sounds like just a matter of taking measurements and welding up a square that has all the right holes drilled into it, but it's not that simple. Second-Gen F-bodies have a floor that curves up under the seat, so your homemade bracket will be a pain to fabricate. That floor bulge also determines how low the seat bottom can go, and that isn't very low. Our advice is to make the bracket as short as humanly possible because you'll need the headroom in a Second-Gen Camaro or Firebird. Our seat is barely short enough--any higher and we couldn't get our right leg under the steering wheel. In all, we used $26 in steel stock to build the bracket, which we added to our miscellaneous tab.

Test Results
After fitting the new wheel/tire combo and installing the new driver's seat, we put a few hundred miles on the street just to verify that everything was working okay. We still hadn't tested anything since the new engine and trans were installed, so we wanted to be double sure before beating on anything. The new engine and trans worked well, but the green mill is still way down on power due to the stock exhaust. We felt that for the purpose of break-in and troubleshooting, the stock exhaust manifolds and crappy 29-year-old catalytic converter exhaust would be adequate. Just going by our calibrated butt-o-meter, our 400hp 383 feels like it's down 150 hp, which is quite believable given the restriction. For this reason, we didn't think it wise to drag test g/28 because serious damage to the exhaust valve guides and seats could result. We will, however, dyno-test g/28 prior to building the exhaust just to see how far down we really are.

Test day loomed and we still hadn't gotten a frontend alignment for g/28. The new, taller springs had changed things a bit, but we were confident we could do well enough to show a vast improvement, and we did. Our first test was 60-0-mph braking. With staffer Nick Licata manning the Stalker radar gun and the laptop, we made a series of runs, all of them shorter than 120 feet and one run measuring an impressive 112.7 feet. We had just shattered our previous best in the car (134.1 feet) by an astounding 21.4 feet--that's a gigantic difference at the low end of the braking threshold. By comparison, an '05 Z51 Corvette (with up-sized brakes) stops in 113 feet.

On the skidpad, g/28 knocked down .94g (average of CW and CCW). Our project goal was a lofty .90g, so that mark fell by a handsome margin. Our previous best with the Falken street-compound tires was .79g, itself a pretty good number considering the estimated 3,600-pound weight of the car and the small 255 cross section of the Falken tire. Still, as good as the Falken was, it was just child's play for the Nitto.

At our last test session we managed to conquer our slalom goal of 46 mph with a 46.2-mph speed. We attacked this last test with vigor, but were unable to improve upon that earlier number. We did manage to run two identical 46.2-mph runs (the same as before), but the steering kept hanging up due to a worn steering box. The slalom requires rapid steering input, but the more input we gave, the more the steering gear would hang up. The problem is that the ball bearings in the recirculating ball system have worn to the point to where they climb over one another inside the loop. When the balls climb, they snag, giving you that jerky sensation you're all familiar with on old, worn boxes. Even though we've reached our goal (was it set too low?), we know we can run the slalom faster, so we'll come back later after we've installed our new Flaming River quick-ratio box.

So where do we go from here? The only four things remaining are the steering box, the exhaust system, the rearend, and some chassis stiffening. For the exhaust, we'll be installing a set of smog-legal full-length Hedman headers, a new Dynomax 3-inch super cat, and a Dynomax crossflow muffler. For the sake of ground clearance and simplicity, we'll have a custom 3-inch single exhaust built by Muffler Man in Placentia, California, just down the road from our office. For the rear, we'll keep the budget under control by retaining the stock 8.5-inch rear and swap out the open diff and 2.73 gears for a Detroit Locker TrueTrac and some 3.73 cogs from Randy's Ring & Pinion. Then we'll fill it with Royal Purple synthetic and bolt some slicks on for the track. Will it hold? Will it run 12s? We sure think so!

Project g/28-Parts List Description: PN street price: Global West     upper control arms ('70-'81) CTA-71AP $535/pair PST, drop spring kit (front coils, 2-inch drop; rear leaf, 1.5-inch drop) n/a $559/set PST, KYB shocks n/a $129/set PST, G-Max front swaybar kit 1.125-inch dia. $159 PST, Super Front-End kit n/a $309 PST, Polygraphite leaf spring pads n/a $30/set PST body mount bushings n/a ${{{90}}}/set American Racing Rebel wheels, 5x4.75 bolt circle, 17x9, 6-inch BS 699-7963 $980 (4) Mr. Gasket wheel spacers, 7/32-inch {{{720}}}-2370 11.99 (pair) Nitto NT-555RII Extreme Road Race tires 275/40ZR17 $596 (4) Recessed hex-head lug nuts n/a $60 (20) Baer {{{GT}}} brake system (front) 1301057 $1,345 Baer Sport brake system (rear) 1302041 $875 Baer adjustable proportioning valve 2000035 $55 Speed-O-Motive 383 (complete engine, includes ${{{600}}} dyno bill) n/a $7,495 TCI Turbo 350 trans 312001 $859.99 TCI 11-inch Breakaway torque converter 240900 $234.99 TCI StreetFighter shifter 616443 $165.99 TCI 168-tooth SFI-spec flexplate 399273 $69.99 TCI universal trans cooler 820500 $41.99 Jeg's GS-1 driver's seat 555-70240 $199.99 Jeg's universal pedestal seat mount 555-70225 $21.99 Misc. total:   $293 Total:   $15,116.92 Cash for old parts (305-cid engine, Turbo 350 trans)   $500 Purchase price of car:   $2,{{{300}}} Running total:   $16,916.92       Budget For Future Mods:     Exhaust system (headers, muffler, cat-con, fabrication) $1000   Flaming River quick-ratio steering box $500   3.73 gears, Detroit Locker TrueTrac posi unit $700   Misc. (chassis, gauges, harness, etc.)   ${{{900}}} Estimated grand total:   $20,016.92 Part 1, Baseline Performance (stock) 420-foot Slalom Course:   40.3 mph {{{200}}}-foot Skidpad (averaged):   70g 60-0-mph Braking Distance:   216.9 ft. Quarter-Mile ET & Trap Speed:   17.63 sec. @ 78.6 mph       Part 2, PST suspension, Global West control arms, wheels & tires 420-foot Slalom Course:   46.2 mph 200-foot Skidpad (averaged):   0.79g 6-0-mph Braking Distance:   163.9 ft. Quarter-Mile ET & Trap Speed:   unchanged       Part 3, Baer brakes 420-foot Slalom Course:   unchanged 200-foot Skidpad (averaged):   unchanged 60-0-mph Braking Distance:   134.1 ft. Quarter-Mile ET & Trap Speed:   unchanged       Part 6, New Nitto R-compound tires & ARE Rebel wheels 420-foot Slalom Course: 46.2 mph Target: 46.0 mph 200-foot Skidpad (averaged): .94g Target: .90g 60-0-mph Braking Distance: 112.7 ft. Target: 120 ft. Quarter-Mile ET & Trap Speed: unchanged Target: 12.99 sec.