Actuated by the electric switch,...
Actuated by the electric switch, the butterfly opens, allowing the exhaust to freely exit just behind the collector.
This optional switch (PN 10200)...
This optional switch (PN 10200) from Quick Time Performance allows the cutouts to be opened progressively and has a reading to let the driver know how far the valves are open.
Open & Shut
Here are the detailed results of our two dyno tests. The first is measured with the 468-inch big-block's exhaust cutouts closed. The second is with open cutouts. The open position begins to raise the power near 3,300 rpm and continues to surpass the closed system results all the way to 6,500 rpm. We added 14 lb-ft of torque and about 14 hp at the peaks. But what counts most is that we raised the power curve overall.
| CLOSED |
| RPM | LB-FT | HP |
| 3,000 | 400 | 228 |
| 3,500 | 428 | 284 |
| 4,000 | 415 | 316 |
| 4,500 | 429 | 367 |
| 4,600 | 433 | 378 |
| 5,000 | 424 | 403 |
| 5,500 | 409 | 428 |
| 6,000 | 371 | 424 |
| 6,500 | 313 | 385 |
| OPEN |
| 3,000 | 356 | 203 |
| 3,500 | 438 | 292 |
| 4,000 | 443 | 337 |
| 4,500 | 444 | 381 |
| 4,700 | 447 | 400 |
| 5,000 | 434 | 413 |
| 5,500 | 419 | 438 |
| 6,000 | 387 | 442 |
| 6,500 | 340 | 420 |