So they are claiming to go from 313hp/314ft-lb (engine dyno with no accessories) to 420hp/354ft-lb (quite a bit higher in the rpm range) with the only change being a set of Livernois stage 3 heads! They then added the Comp stage 4 cams and VTC lockouts and got it up to 451hp/401ft-lb...
Ok. I personally have a VERY hard time believing these numbers! I realize this engine was run on the dyno with long tube headers (all runs) and no CAI (using a FAST XFI system with no MAF), but STILL! a 33% increase in power from ONLY a head change???
I've seen bogus numbers in there mags before, so I decided to run the numbers through Excel to verify the HP numbers. Remember, HP is a CALCULATED value (there is no such thing as a HP gauge. You have to measure torque and rpm and then calculate HP from that) using the equation hp=torque*rpm/5252 (for the Emperial numbers at any rate) Here is what I got, starting with the stock numbers:
RPM Torque Stock Claimed HP Stock Actual HP Stock Delta Stock
2500 0 0
2600 0 0
2700 0 0
2800 0 0
2900 0 0
3000 0 0
3100 258 163 152 11
3200 261 171 159 12
3300 261 182 164 18
3400 263 193 170 23
3500 266 204 177 27
3600 272 213 186 27
3700 278 217 196 21
3800 279 221 202 19
3900 285 224 212 12
4000 292 232 222 10
4100 301 241 235 6
4200 308 247 246 1
4300 314 252 257 -5
4400 314 259 263 -4
4500 312 264 267 -3
4600 309 271 271 0
4700 307 276 275 1
4800 304 279 278 1
4900 303 284 283 1
5000 303 292 288 4
5100 302 296 293 3
5200 301 301 298 3
5300 298 306 301 5
5400 297 310 305 5
5500 294 313 308 5
5600 290 309 309 0
5700 286 302 310 -8
5800 280 301 309 -8
5900 0 0
6000 0 0
6100 0 0
6200 0 0
6300 0 0
6400 0 0
6500 0 0
6600 0 0
6700 0 0
6800 0 0
Torque is in the first column, claimed HP in the second column, calculated (aka: actual) hp in the third column and then the calculated delta between the claimed and actual HP number (=Claimed - Actual). Did you notice how different the numbers are? Perhaps you noticed that down low, they seam to be artificially inflating their claims, but in the meat of the power band (from 4100 to 5800 rpm), they are either close to or LESS than the actual hp. Strange how they could have such a gross error in their stock numbers, now isn't it???
Now let's look at the Heads only run, again the columns are setup exactly like the stock run:
RPM Claimed HP Heads Torque Heads Actual HP Heads Delta Heads
2500 130 249 119 11
2600 134 255 126 8
2700 142 261 134 8
2800 158 267 142 16
2900 166 272 150 16
3000 171 276 158 13
3100 174 282 166 8
3200 182 288 175 7
3300 201 289 182 19
3400 215 292 189 26
3500 223 293 195 28
3600 238 295 202 36
3700 245 298 210 35
3800 250 298 216 34
3900 254 301 224 30
4000 260 308 235 25
4100 265 312 244 21
4200 271 319 255 16
4300 278 324 265 13
4400 288 329 276 12
4500 299 335 287 12
4600 310 338 296 14
4700 322 342 306 16
4800 331 346 316 15
4900 336 349 326 10
5000 344 351 334 10
5100 351 352 342 9
5200 354 354 350 4
5300 363 349 352 11
5400 369 346 356 13
5500 374 342 358 16
5600 380 339 361 19
5700 385 333 361 24
5800 390 330 364 26
5900 398 326 366 32
6000 408 320 366 42
6100 420 315 366 54
6200 408 309 365 43
6300 412 302 362 50
6400 410 296 361 49
6500 405 291 360 45
6600 404 284 357 47
6700 401 280 357 44
6800 398 276 357 41
Look at those numbers!!! The claimed hp is being boosted ACROSS THE BOARD by a MINIMUM of 4 hp and a MAXIMUM of FIFTY FOUR HP!!! I'm sure that was all just an innocent mistake... Maybe they just screwed the correction factory... Oh. Wait. That would have affected both the torque AND the HP, so the calculated "actual HP" would NOT be off from their supposed correction factor numbers.
Now, the results for the run with the cams are very interesting indeed:
RPM Claimed HP Cams Torque Cams Actual HP Cams Delta Cams
2500 150 301 143 7
2600 154 302 150 4
2700 161 304 156 5
2800 166 305 163 3
2900 171 306 169 2
3000 178 307 175 3
3100 184 312 184 0
3200 211 322 196 15
3300 222 331 208 14
3400 232 340 220 12
3500 241 345 230 11
3600 246 348 239 7
3700 252 351 247 5
3800 260 355 257 3
3900 271 357 265 6
4000 276 359 273 3
4100 282 361 282 0
4200 291 362 289 2
4300 302 362 296 6
4400 311 364 305 6
4500 322 365 313 9
4600 332 366 321 11
4700 341 366 328 13
4800 350 368 336 14
4900 354 370 345 9
5000 362 371 353 9
5100 370 373 362 8
5200 376 376 372 4
5300 382 384 388 -6
5400 387 394 405 -18
5500 391 401 420 -29
5600 394 388 414 -20
5700 398 365 396 2
5800 406 362 400 6
5900 410 360 404 6
6000 414 358 409 5
6100 421 355 412 9
6200 433 341 403 30
6300 439 336 403 36
6400 445 322 392 53
6500 451 310 384 67
6600 445 299 376 69
6700 440 291 371 69
6800 439 285 369 70
I'm not sure WHAT they where doing here. Small boost through 80% of the run, but they take out quite a bit of "real" power from 5300 to 5600 rpm, then go INSANE adding up to 70 hp at 6800 rpm!!!!
The numbers do NOT lie here: Someone is making shit up to post in the magazine article. Look at it this way: There is NO WAY IN HELL that a simple head + cam swap will increase your VE enough to get a 50% increase in power! It's just NOT going to happen on these 3V heads. Think of it this way: People are running superchargers with 6 psi of boost to get these kinds of numbers (at the wheels). Do you really think the stock intake has 4 to 6 psi of vacuum in it at WOT??? I don't...
So the real question is this: Is MM&FF intentionally trying to blow smoke up people's asses here? Is the dyno shop (this case, Livernois) playing games with the numbers they are giving MM&FF? Or does MM&FF have some stupid ass intern that doesn't know a thing about torque and hp randomly pull numbers out of his/her ass for their articles???
And just for the record, this is NOT the first time (or even the second time) that I have caught MM&FF playing games with dyno results. The last biggie that I dug into was the infamous BBK throttle body + tune + CAI that game 50hp. That one was even easier to spot: they had a fixed "offset" in the calculated values for the after that boosted up the hp by something like 30 hp across the board (I don't remember the exact number, it's been too long).
So, am I nuts and have completely forgotten how to calculate hp? Can someone from Livernois post the real dyno shots, or explain this junk?
Ok. I personally have a VERY hard time believing these numbers! I realize this engine was run on the dyno with long tube headers (all runs) and no CAI (using a FAST XFI system with no MAF), but STILL! a 33% increase in power from ONLY a head change???
I've seen bogus numbers in there mags before, so I decided to run the numbers through Excel to verify the HP numbers. Remember, HP is a CALCULATED value (there is no such thing as a HP gauge. You have to measure torque and rpm and then calculate HP from that) using the equation hp=torque*rpm/5252 (for the Emperial numbers at any rate) Here is what I got, starting with the stock numbers:
RPM Torque Stock Claimed HP Stock Actual HP Stock Delta Stock
2500 0 0
2600 0 0
2700 0 0
2800 0 0
2900 0 0
3000 0 0
3100 258 163 152 11
3200 261 171 159 12
3300 261 182 164 18
3400 263 193 170 23
3500 266 204 177 27
3600 272 213 186 27
3700 278 217 196 21
3800 279 221 202 19
3900 285 224 212 12
4000 292 232 222 10
4100 301 241 235 6
4200 308 247 246 1
4300 314 252 257 -5
4400 314 259 263 -4
4500 312 264 267 -3
4600 309 271 271 0
4700 307 276 275 1
4800 304 279 278 1
4900 303 284 283 1
5000 303 292 288 4
5100 302 296 293 3
5200 301 301 298 3
5300 298 306 301 5
5400 297 310 305 5
5500 294 313 308 5
5600 290 309 309 0
5700 286 302 310 -8
5800 280 301 309 -8
5900 0 0
6000 0 0
6100 0 0
6200 0 0
6300 0 0
6400 0 0
6500 0 0
6600 0 0
6700 0 0
6800 0 0
Torque is in the first column, claimed HP in the second column, calculated (aka: actual) hp in the third column and then the calculated delta between the claimed and actual HP number (=Claimed - Actual). Did you notice how different the numbers are? Perhaps you noticed that down low, they seam to be artificially inflating their claims, but in the meat of the power band (from 4100 to 5800 rpm), they are either close to or LESS than the actual hp. Strange how they could have such a gross error in their stock numbers, now isn't it???
Now let's look at the Heads only run, again the columns are setup exactly like the stock run:
RPM Claimed HP Heads Torque Heads Actual HP Heads Delta Heads
2500 130 249 119 11
2600 134 255 126 8
2700 142 261 134 8
2800 158 267 142 16
2900 166 272 150 16
3000 171 276 158 13
3100 174 282 166 8
3200 182 288 175 7
3300 201 289 182 19
3400 215 292 189 26
3500 223 293 195 28
3600 238 295 202 36
3700 245 298 210 35
3800 250 298 216 34
3900 254 301 224 30
4000 260 308 235 25
4100 265 312 244 21
4200 271 319 255 16
4300 278 324 265 13
4400 288 329 276 12
4500 299 335 287 12
4600 310 338 296 14
4700 322 342 306 16
4800 331 346 316 15
4900 336 349 326 10
5000 344 351 334 10
5100 351 352 342 9
5200 354 354 350 4
5300 363 349 352 11
5400 369 346 356 13
5500 374 342 358 16
5600 380 339 361 19
5700 385 333 361 24
5800 390 330 364 26
5900 398 326 366 32
6000 408 320 366 42
6100 420 315 366 54
6200 408 309 365 43
6300 412 302 362 50
6400 410 296 361 49
6500 405 291 360 45
6600 404 284 357 47
6700 401 280 357 44
6800 398 276 357 41
Look at those numbers!!! The claimed hp is being boosted ACROSS THE BOARD by a MINIMUM of 4 hp and a MAXIMUM of FIFTY FOUR HP!!! I'm sure that was all just an innocent mistake... Maybe they just screwed the correction factory... Oh. Wait. That would have affected both the torque AND the HP, so the calculated "actual HP" would NOT be off from their supposed correction factor numbers.
Now, the results for the run with the cams are very interesting indeed:
RPM Claimed HP Cams Torque Cams Actual HP Cams Delta Cams
2500 150 301 143 7
2600 154 302 150 4
2700 161 304 156 5
2800 166 305 163 3
2900 171 306 169 2
3000 178 307 175 3
3100 184 312 184 0
3200 211 322 196 15
3300 222 331 208 14
3400 232 340 220 12
3500 241 345 230 11
3600 246 348 239 7
3700 252 351 247 5
3800 260 355 257 3
3900 271 357 265 6
4000 276 359 273 3
4100 282 361 282 0
4200 291 362 289 2
4300 302 362 296 6
4400 311 364 305 6
4500 322 365 313 9
4600 332 366 321 11
4700 341 366 328 13
4800 350 368 336 14
4900 354 370 345 9
5000 362 371 353 9
5100 370 373 362 8
5200 376 376 372 4
5300 382 384 388 -6
5400 387 394 405 -18
5500 391 401 420 -29
5600 394 388 414 -20
5700 398 365 396 2
5800 406 362 400 6
5900 410 360 404 6
6000 414 358 409 5
6100 421 355 412 9
6200 433 341 403 30
6300 439 336 403 36
6400 445 322 392 53
6500 451 310 384 67
6600 445 299 376 69
6700 440 291 371 69
6800 439 285 369 70
I'm not sure WHAT they where doing here. Small boost through 80% of the run, but they take out quite a bit of "real" power from 5300 to 5600 rpm, then go INSANE adding up to 70 hp at 6800 rpm!!!!
The numbers do NOT lie here: Someone is making shit up to post in the magazine article. Look at it this way: There is NO WAY IN HELL that a simple head + cam swap will increase your VE enough to get a 50% increase in power! It's just NOT going to happen on these 3V heads. Think of it this way: People are running superchargers with 6 psi of boost to get these kinds of numbers (at the wheels). Do you really think the stock intake has 4 to 6 psi of vacuum in it at WOT??? I don't...
So the real question is this: Is MM&FF intentionally trying to blow smoke up people's asses here? Is the dyno shop (this case, Livernois) playing games with the numbers they are giving MM&FF? Or does MM&FF have some stupid ass intern that doesn't know a thing about torque and hp randomly pull numbers out of his/her ass for their articles???
And just for the record, this is NOT the first time (or even the second time) that I have caught MM&FF playing games with dyno results. The last biggie that I dug into was the infamous BBK throttle body + tune + CAI that game 50hp. That one was even easier to spot: they had a fixed "offset" in the calculated values for the after that boosted up the hp by something like 30 hp across the board (I don't remember the exact number, it's been too long).
So, am I nuts and have completely forgotten how to calculate hp? Can someone from Livernois post the real dyno shots, or explain this junk?
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