Mods and What It Takes to Get 500 RWHP
#1
Mods and What It Takes to Get 500 RWHP
This is the second of two posts (here and on the Corvette forum) and discusses mods I have actual done on my cars or on friends cars and SEEN the dyno tests myself. All #s given are on the same Dynojet dyno and corrected using the SAE correction method dynojet uses. I'm not saying this is the best you can do, only just what I've actually done:
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Here are the results of modifications and tests I have participated in and witnessed myself over the past years, on Corvette or Corvette-type drivetrains. All numbers are RWHP
346 cubic inch LS1 in a 1998 Camaro Z28 M6
A. Stock, as from the dealer, 2800 miles: 294
B. Stock but dyno-tuned for max power: 302
C. with short-tube headers, sealed cold air box and ram air scoop, LS6 manifold, ported MAF and throttle body, “mid-range” aftermarket cam: 349
D. all of C above but with long-tube headers instead, 358
D with catalytic converters removed, 365
D with cats removed and open exhausts, 360
E. all of D plus “75 shot” of NOS: 403
and a “100 shot” 425
and a 175 shot 470
346 LS6 in a 2002 Corvette M6
A. Stock, as from the dealer, 2500 miles, 357
B. dyno tuned but otherwise stock, 363
C. with long-tube headers, air box, retuned: 385
D. C with Magnusen SC kit, no intercooler, 6.5 lbs boost,450
E. D with a lot of fiddling and fine tuning, higher pressure fuel, 465
346 LS1 in a 2004 Corvette M6
A. Stock, from the dealer, 1980 miles, 309
B. Returned on the dyno, 314
C. Long tube headers, halltek air box, aggressive street cam, Magnusen w. intercooler, 7.2 lbs boost, 485
D. As C above but a smaller-than recommended SC pulley, 8.3 lbs boost, 514
(This engine blew up spectacularly only 500 miles after this mod)
408 LS6 (bored and stroked cast iron block from a 6-liter Silverado/Escalade)
A. With AFR 225 heads, 11.25:1, radical cam (255/265/.670 lift, lumpy @ 1200),
all forged internals and APR, LT 1 7/8 LT headers, 3 inch exhaust, no cats, LS6 manifold and stock throttle body, cold ram air, etc. 465
B. With FAST 90 mm, 512
C. With 175 NOS, 648 (and 700 ft lbs of RW torque at 4100 RPM)
427 cubic inch “LS1” (GMPP C5R block)
A. Patriot III heads ported by Justin Engineering (347 flow @ .6 inch rise), 10.2:1 c.r., custom grind Crower cam (232/236/.594 lift), Blackwing airbox, 1 7/8 LT headers, largest size cats available, 3” H pipe, 2.75” GHL catback, LS6 intake manifold and throttle body, underdrive pulley 485
B. A above with FAST 90 mm: 507
C. As B above but with an ATI Procharger at:
4.5” pulley: less than 1 lb boost, 470 HP
4” pulley, only 2.5 lbs boost – 510
3.75” pulley, only 3.5 lbs boost – 535
3.4” pulley, 4.5 lbs boost – 565
3.4” pulley, 4.5 lbs boost, no cats, open exhaust, 594
3.25” pulley – slips about 5250 RPM, test not completed.
The engine has been built with forged internals and only 10.2 c.r. so that it should take up to 10 lbs boost at which it should be around 700 RWHP. The problem I have is that I am driving the SC with a under-drive (small diameter) crank pulley and not spinning it fast enough, but below 3.4” on the SC can’t get enough traction to power the SC (it takes about 85 HP at full RPM). I can’t add a stock diameter pulley on the crank because only the underdrive aftermarket pulleys will clear the double roller timing chain I added to handle the big cam. I’m having a new crank pulley custom machined when I can afford it).
----------------------------------------------------------
Here are the results of modifications and tests I have participated in and witnessed myself over the past years, on Corvette or Corvette-type drivetrains. All numbers are RWHP
346 cubic inch LS1 in a 1998 Camaro Z28 M6
A. Stock, as from the dealer, 2800 miles: 294
B. Stock but dyno-tuned for max power: 302
C. with short-tube headers, sealed cold air box and ram air scoop, LS6 manifold, ported MAF and throttle body, “mid-range” aftermarket cam: 349
D. all of C above but with long-tube headers instead, 358
D with catalytic converters removed, 365
D with cats removed and open exhausts, 360
E. all of D plus “75 shot” of NOS: 403
and a “100 shot” 425
and a 175 shot 470
346 LS6 in a 2002 Corvette M6
A. Stock, as from the dealer, 2500 miles, 357
B. dyno tuned but otherwise stock, 363
C. with long-tube headers, air box, retuned: 385
D. C with Magnusen SC kit, no intercooler, 6.5 lbs boost,450
E. D with a lot of fiddling and fine tuning, higher pressure fuel, 465
346 LS1 in a 2004 Corvette M6
A. Stock, from the dealer, 1980 miles, 309
B. Returned on the dyno, 314
C. Long tube headers, halltek air box, aggressive street cam, Magnusen w. intercooler, 7.2 lbs boost, 485
D. As C above but a smaller-than recommended SC pulley, 8.3 lbs boost, 514
(This engine blew up spectacularly only 500 miles after this mod)
408 LS6 (bored and stroked cast iron block from a 6-liter Silverado/Escalade)
A. With AFR 225 heads, 11.25:1, radical cam (255/265/.670 lift, lumpy @ 1200),
all forged internals and APR, LT 1 7/8 LT headers, 3 inch exhaust, no cats, LS6 manifold and stock throttle body, cold ram air, etc. 465
B. With FAST 90 mm, 512
C. With 175 NOS, 648 (and 700 ft lbs of RW torque at 4100 RPM)
427 cubic inch “LS1” (GMPP C5R block)
A. Patriot III heads ported by Justin Engineering (347 flow @ .6 inch rise), 10.2:1 c.r., custom grind Crower cam (232/236/.594 lift), Blackwing airbox, 1 7/8 LT headers, largest size cats available, 3” H pipe, 2.75” GHL catback, LS6 intake manifold and throttle body, underdrive pulley 485
B. A above with FAST 90 mm: 507
C. As B above but with an ATI Procharger at:
4.5” pulley: less than 1 lb boost, 470 HP
4” pulley, only 2.5 lbs boost – 510
3.75” pulley, only 3.5 lbs boost – 535
3.4” pulley, 4.5 lbs boost – 565
3.4” pulley, 4.5 lbs boost, no cats, open exhaust, 594
3.25” pulley – slips about 5250 RPM, test not completed.
The engine has been built with forged internals and only 10.2 c.r. so that it should take up to 10 lbs boost at which it should be around 700 RWHP. The problem I have is that I am driving the SC with a under-drive (small diameter) crank pulley and not spinning it fast enough, but below 3.4” on the SC can’t get enough traction to power the SC (it takes about 85 HP at full RPM). I can’t add a stock diameter pulley on the crank because only the underdrive aftermarket pulleys will clear the double roller timing chain I added to handle the big cam. I’m having a new crank pulley custom machined when I can afford it).
#3
RE: Mods and What It Takes to Get 500 RWHP
Christ Almighty! Where do you get the $$ for all this stuff!
Nonetheless, pretty intense list...unfortunately none of it will help me...but that's life. Time to go and start modding my Dad's vette...
Nonetheless, pretty intense list...unfortunately none of it will help me...but that's life. Time to go and start modding my Dad's vette...
#4
RE: Mods and What It Takes to Get 500 RWHP
its funny to see the numbers of no exhaust, some exhaust, and full exhaust and the loss of power with open headers. and how adding a supercharger robbed the car of 40 hp. thats great.
so how did the other one bolw up of 8lbs of boost? id think it would hold up more.
so how did the other one bolw up of 8lbs of boost? id think it would hold up more.
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