Finally got around to doing the rear suspension on Berlinetta #1. This is a daily driver that gets raced during the summer.

The rear is from the '86 donor car - 7-5/8", 2.73 open stock. Welded the tubes myself. I had the 4th gen posi carrier and gears, and Moser 28-spline axles installed by a shop. I got the carrier/gears on-line, guy asked me if I really wanted the 3.42 gears he advertised, I said yes; he sent me 3.23's anyway. Not a biggie, it is a street-primary car, not strip-primary.

My welds always look better after paint. Not primary welds, so the old Forney stick welder gets the call. Love the new auto darkening welding helmet.

Used 1-1/2" x 1/8" weldable steel strap from Ace for the boxing. Fits just inside so it's hardly visible from the side.

UMI welded LCARB's, Energy Suspension poly bushings (did the fronts a few years ago, just never got around to the LCA's).

Didn't do anything with the track bar. Still feels a lot more firm in general, but not at all harsh. Haven't broken the tires loose yet, including one "aggressive" 1-2 shift, but haven't really tried yet, either. On the street and highway, the engine seems a lot more "comfortable" than with the 2.93's.

We'll see soon how much, if any, difference it makes at the track.

 

Support cover from Summit (duh).

About the only deviation from the "ultimate" 10-bolt is the stock gears. But, with auto and not all that much power, don't expect problems.

And, aluminum driveshaft is also new since last season

Oh, yeah, I think I had a bent or off-center 26-spline axle in the old rear - a vibration that I always had that felt like a tire (but didn't matter what tires were on, same vibration) is now gone.

 

did you have a solid pinion spacer installed? i think you'll be happy with the results from boxing the lca's, poly bushings, and rb's. having adjustability is always a good thing in my book.

 

I talked to the shop about the spacer vs. crush sleeve, they said don't bother. It only helps when you replace the pinion seal - it isn't loaded in normal operation. Although they did do it when I had them set up the 8.2" in the '57 five years ago.

Adjustability would be more of a factor with more gear, more stall, and more power. For now, I think it will be an adequate improvement. Consistency is really what was lacking, as traction was not a problem 80% of the time - that 20% just tends to rear its ugly head at inconvenient times.

 

Oh, something I forgot to mention.

The original LCA's from the donor car had these dog-bone spacers bolted in the front two holes (the holes visible in the side view). The stock V6 Berlinetta LCA's didn't have them (which didn't even have a rear sway bar - neither does Berlinetta #2, which has a V8). I didn't have them in when I took the photos. However, I ended up putting them in the LCA's after boxing (if you look really close, you can see the bolts in the 3rd picture), not being comfortable with the welded-in straps being able to totally eliminate the flex in the stamped steel. Not sure if anyone has any "data" on their effectiveness one way or the other.

 

Took it to T&T today, a little disappointed in the results. It was a lot easier to turn the tires for the burn-out (I don't really heat them up, just clean and dry them off). It feels like it's really hooking hard, but it didn't show in the 60' or ET. Never heard a chirp or felt a slip off the line. When I wasn't playing with launch RPMs, the 60' was within .005 second, so that was nice. The DA was terrible for a spring T&T, the weather station showed it was running basically the same (+.05 sec) as it did last year. Could be the 3/4 tank of gas (weighed 3600 lbs, I remembered more like 3550 last years), and the to-the-full-mark crankcase. To say nothing of spark plugs that haven't been out in two years.

I made 5 runs and took the slicks off, put the 235x60-14 all seasons back on and thought, let's see what happens. Did a dry clean-off to the side of the water (made more smoke than I intended), gave a very, very slight chirp at the hit, then took off. 60' was .02 worse than the worst slicks run, and MPH highest of the day. Almost makes me wonder if it's worth it to switch to the slicks at the track every race.

Oh, the .023, .015, and .001 lights went down easy, too. . .