best manifold for l98 test
Cool vid though. Thanks for posting.


http://xtremecarzone.com.au/STORAGE/...akeOptions.pdf
Back when the article came out I painstakingly used a triangular ruler to chart the HP numbers to be able do a better comparison.
RPM -- TPI -- TPiS - ASM -- ASR -- HSP -- HSR - MR
2600 - 200 -- 207 -- 198 -- 188 -- 190 -- 190 -- 186
2800 - 222 -- 235 -- 221 -- 205 -- 206 -- 206 -- 202
3000 - 260 -- 271 -- 262 -- 240 -- 230 -- 237 -- 215
3200 - 290 -- 308 -- 290 -- 278 -- 258 -- 270 -- 258
3400 - 316 -- 332 -- 319 -- 314 -- 286 -- 297 -- 282
3600 - 338 -- 355 -- 340 -- 337 -- 307 -- 320 -- 308
3800 - 360 -- 381 -- 360 -- 359 -- 332 -- 340 -- 328
4000 - 379 -- 410 -- 383 -- 382 -- 357 -- 363 -- 348
4200 - 390 -- 420 -- 408 -- 405 -- 377 -- 387 -- 370
4400 - 400 -- 438 -- 422 -- 421 -- 398 -- 411 -- 388
4600 - 406 -- 441 -- 440 -- 430 -- 418 -- 431 -- 409
4800 - 410 -- 448 -- 450 -- 443 -- 440 -- 449 -- 425
5000 - 409 -- 453 -- 457 -- 453 -- 456 -- 460 -- 449
5200 - 410 -- 447 -- 463 -- 470 -- 465 -- 475 -- 468
5400 - 407 -- 445 -- 460 -- 474 -- 475 -- 485 -- 475
5600 - 409 -- 448 -- 452 -- 480 -- 488 -- 497 -- 485
5800 - 407 -- 450 -- 450 -- 474 -- 493 -- 499 -- 500
6000 - 406 -- 450 -- 449 -- 453 -- 490 -- 501 -- 501
6200 - 404 -- 448 -- 448 -- 452 -- 486 -- 495 -- 504
TPI - Stock TPI, unported plenum, 47mm t/b
TPIS – Stock Extrude Honed base, TPiS LTR, ported plenum, 52mm
ASM - BigMouth base, AZ S&M Semi-Siamessed Tubes, ported plenum, 52mm
ASR – BigMouth base, Accel SuperRam Upper, Accel 1000cfm
HSP - Holley Single Plane MPFI, 1000cfm 4bbl T/B
HSR - Holley StealthRam, 58mm
MR - TPiS MiniRam, 52mm
Regardless of the discrepancy of the heads used, the main point of the test (article and video) is how the power curves react to different intakes. My biggest complaint when the article came out was the lack of information on the engine (explained why in the video) and the use of different sized throttle bodies - so keep that in mind when comparing the curves.
Stock throttle body bores.
I was going to use my pneumatic die grinders but found some 1/8" burrs that would allow more delicate material removal using a Dremel at lower speed. The burrs on the right are good for hogging out aluminum and the ones on the left are more for steel.
Took my time and got it close with the burrs.
I was going to finish it off with abrasive rolls on the pneumatic die grinder but Eastwood sells a Dremel size mandrel so I can control the speed better. Need to remember to use Grinder's Grease on the spinning stuff.
I was concerned about the holes in the bottom of the manifold. I assume they are to draw off any fuel or oil that ends up in the manifold and the wall in front of those holes (visible in the first photo) served some purpose to help that process. Then I saw a photo of the ported stock manifold in the video and those holes are visible like mine. I'll still have to use the pneumatic die grinder to get to the back of the manifold but this will allow me to smooth the bores up front.
Not sure this modification is going to have a huge payback but for the money it seemed like a good gamble.
Last edited by Bob Heine; Jun 28, 2020 at 04:47 PM.











