Modifying An Lt1 Corvette C4 Corvette Launch

Modifying an LT1 Corvette - To Top It All Off

We used the same launch technique for Round Two, staging as shallowly as possible, bringing the revs up to around 2,500 rpm, and rolling smoothly into the throttle as the light went green. The force of the initial "hit" suggested a record-setting run, but even we were surprised by the timeslip: a 12.866 at 105.60, the pass was more than four tenths quicker than our previous best. A follow-up blast produced a 12.870 at 105.60, proving that the C4 was not only a legitimate 12-second performer, but a consistent one at that.

Perhaps even more impressive than the e.t.'s were the car's 60-foot times, which came in at 1.706 and 1.704 seconds. That our stock-engine C4 can crack off such times using nothing more than a pair of drag radials to enhance traction speaks volumes about the fundamental soundness of the factory fourth-gen suspension. After all, attempts at similar antics in C5s and C6s have been known to end in violent bouts of wheelhop-and worse.

If you're interested in replicating our results with your own C4, it also bears mention that all of our quickest (and fastest) runs have come with the car's digital coolant-temp gauge reading between 170 and 180 degrees. Unlike the LS-series engines, whose all-aluminum construction does much to inure them to the power-sapping effects of heat, the iron-block LT1 always performs at its best when run cool. In the case of our C4, we've had the benefit of conducting our testing at private track rentals, making it possible to crank the car, drive directly into the water box, and start our pre-race routine before the engine builds much heat. While this procedure may not be practicable at a typical "test and tune" session, you can achieve similar results by simply leaving the engine off, putting the trans in Neutral, and pushing the car through the staging lanes.

But regardless of how closely you choose to mimic our drag-racing regimen, it's clear that a good high-stall torque converter and a pair of sticky rear tires are by far the most effective modifications you can make to an automatic LT1 Vette. And now that our low-buck C4 is a real, live 12-second runner, we're confident that the new Trick Flow top-end hardware will enable it to hit or exceed our previously outlined e.t. bogey of 12.5 seconds. Stay tuned.

Unlike bias-ply "street slicks" or full-on racing tires, the Nittos don't require a woolly, John Force-style burnout for optimum performance (unless, of course, you're staging a magazine photo). We dropped ours to 20 psi for testing, then refilled them to 32 psi for the drive home.

TRACK RESULTS
	60-ft.	1/8 mi.	1/4 mi.	1/4-mi. speed (mph)
Run 1*	1.867	8.693	13.519	104.46
Run 2	1.706	8.111	12.866	105.60
Run 3	1.704	8.113	12.870	105.62
*Fuel starvation at launch