critique my cam design!!
critique my cam design!! car:
2001 ws6 w/ m6, intake, cat-back exhaust, ls6 intake, 100 shot of spray
want to port heads (ls1 stock) and get head gasket (.041?) w/ tighter squish at the same time
personal needs/wants:
1. low end torque, max hp below 6k
2. no spring changes after initial install, not even interested in the chance of failure
3. will get efilive, but little concession on driving manners
4. emissions close
5. stock exhaust manifolds
6. no problems with pinging on typical fuel (91-93) and nitrous
in order to fulfill requirements:
1. 216/222 dur @.050
2. comp 918's and xe lobes (.561/566 lift)
3. 113 lsa, 111 ICL
4. -7 deg overlap
5. final valve events: IVO -3 BTDC, IVC 39 ABDC, EVO 46 BBDC, EVC -4 ATDC, so 46 BBDC for exhaust mani's and nitrous
6. final dynamic comp ratio: 8.26
i am currently in iraq, support the troops with your hotrod advice!
--SSG
2001 ws6 w/ m6, intake, cat-back exhaust, ls6 intake, 100 shot of spray
want to port heads (ls1 stock) and get head gasket (.041?) w/ tighter squish at the same time
personal needs/wants:
1. low end torque, max hp below 6k
2. no spring changes after initial install, not even interested in the chance of failure
3. will get efilive, but little concession on driving manners
4. emissions close
5. stock exhaust manifolds
6. no problems with pinging on typical fuel (91-93) and nitrous
in order to fulfill requirements:
1. 216/222 dur @.050
2. comp 918's and xe lobes (.561/566 lift)
3. 113 lsa, 111 ICL
4. -7 deg overlap
5. final valve events: IVO -3 BTDC, IVC 39 ABDC, EVO 46 BBDC, EVC -4 ATDC, so 46 BBDC for exhaust mani's and nitrous
6. final dynamic comp ratio: 8.26
i am currently in iraq, support the troops with your hotrod advice!
--SSG
Banned
Joined: Apr 2006
Posts: 1,875
Likes: 1
From: Naperville, IL
ASA cam will not even be close to passing any emissions.
That cam you specced should work decent with the nitrous and stock manifolds. You should bump the exhaust lobe to 226. To get all the gasses out of the exhaust valve through the factory exhaust, you're going to have to hold it open longer than a standard split. Especially if you are spraying.. you're going to have more gas to expel. Going to a larger exhaust lobe won't effect your DCR, but it will open the exhaust valve sooner. You'll lose a little low end torque, but that's what the gas is for. Nitrous burns faster so that's another reason to open early. You will still have -5 degrees overlap at .050, easy to tune, and will pass emissions. It will drive very close to stock.
That cam you specced should work decent with the nitrous and stock manifolds. You should bump the exhaust lobe to 226. To get all the gasses out of the exhaust valve through the factory exhaust, you're going to have to hold it open longer than a standard split. Especially if you are spraying.. you're going to have more gas to expel. Going to a larger exhaust lobe won't effect your DCR, but it will open the exhaust valve sooner. You'll lose a little low end torque, but that's what the gas is for. Nitrous burns faster so that's another reason to open early. You will still have -5 degrees overlap at .050, easy to tune, and will pass emissions. It will drive very close to stock.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by Asmodeus
ASA cam will not even be close to passing any emissions.
That cam you specced should work decent with the nitrous and stock manifolds. You should bump the exhaust lobe to 226. To get all the gasses out of the exhaust valve through the factory exhaust, you're going to have to hold it open longer than a standard split. Especially if you are spraying.. you're going to have more gas to expel. Going to a larger exhaust lobe won't effect your DCR, but it will open the exhaust valve sooner. You'll lose a little low end torque, but that's what the gas is for. Nitrous burns faster so that's another reason to open early. You will still have -5 degrees overlap at .050, easy to tune, and will pass emissions. It will drive very close to stock.
That cam you specced should work decent with the nitrous and stock manifolds. You should bump the exhaust lobe to 226. To get all the gasses out of the exhaust valve through the factory exhaust, you're going to have to hold it open longer than a standard split. Especially if you are spraying.. you're going to have more gas to expel. Going to a larger exhaust lobe won't effect your DCR, but it will open the exhaust valve sooner. You'll lose a little low end torque, but that's what the gas is for. Nitrous burns faster so that's another reason to open early. You will still have -5 degrees overlap at .050, easy to tune, and will pass emissions. It will drive very close to stock.
hey, predator, thanks for chiming in!
most of what i have learned about these numbers comes from you and patrick, so i am happy you are offering your 2 cents.
if i can keep the exhaust tight, it will probably offer a little more torque. nitrous is used sparingly, when someone has just completely asked for it....
what about different lobes/spring life?? what is a different lobe that might offer more performance?? perhaps OMC with dual springs and shimmed?? more flow from an aggressive profile??
SSG
most of what i have learned about these numbers comes from you and patrick, so i am happy you are offering your 2 cents.
if i can keep the exhaust tight, it will probably offer a little more torque. nitrous is used sparingly, when someone has just completely asked for it....
what about different lobes/spring life?? what is a different lobe that might offer more performance?? perhaps OMC with dual springs and shimmed?? more flow from an aggressive profile??
SSG
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Verdad Gallardo predator:
i see alot of cams that approach .600 lift, but which ones are more gentle on springs??
XE-R, XFI, OMC??
and if so, why?
would double springs be more appropriate in these cases? (100 bucks difference for maybe 5-10 ft-lbs, does this sound right??)
SSG
i see alot of cams that approach .600 lift, but which ones are more gentle on springs??
XE-R, XFI, OMC??
and if so, why?
would double springs be more appropriate in these cases? (100 bucks difference for maybe 5-10 ft-lbs, does this sound right??)
SSG
ok, try this:
1. 215/222 dur @.050
2. patriot duals, OMC int, XE-R exh lobes (.600/.581 lift)
3. 113 lsa, 112 ICL
4. -7.5 deg overlap
5. final valve events: IVO -4.5 BTDC, IVC 39.5 ABDC, EVO 45 BBDC, EVC -3 ATDC, so 45 BBDC for exhaust mani's and nitrous
6. final dynamic comp ratio: 8.32
looks initally like a cheatr cam, but has less duration on the exhaust.
the whole thing is just tighter than before but with much more flow on both ends
1. 215/222 dur @.050
2. patriot duals, OMC int, XE-R exh lobes (.600/.581 lift)
3. 113 lsa, 112 ICL
4. -7.5 deg overlap
5. final valve events: IVO -4.5 BTDC, IVC 39.5 ABDC, EVO 45 BBDC, EVC -3 ATDC, so 45 BBDC for exhaust mani's and nitrous
6. final dynamic comp ratio: 8.32
looks initally like a cheatr cam, but has less duration on the exhaust.
the whole thing is just tighter than before but with much more flow on both ends
