cams and headers
Posted: Sun Jun 19, 2005 3:46 am
16 Jun 2005 "Ryan R. La Mothe" ryanrlamothe@yahoo.com writes on Engine Management and Induction in Subaru-Tech@yahoogroups.com
I want to raise my redline to about 7500RPM and with the EJ22T valve design there would be considerable valve float. \
>>SPOON: (yes most people are after top end)<<
Also, turbo cams are another interesting discussion. It basically depends on your boost goals and where you want your power.
>>SPOON: (i am probably a bit of a rarity in that i want low and midrange torque and will be happy with whatever top end)<<
Usually, unless you are running extremely high boost levels, the stock cams are almost always the best
>>SPOON: (that's what most of my research shows, and i don't intend to go too boost crazy. i like to talk to people that have lots of experience with cams but that are not in the biz of selling cams if you know what i mean)<<
If you are just going to be building your Legacy into a turbo monster, then you are pretty much set.
>>SPOON: (yes i am comitted to a legacy turbo monster, but one which is durable and reliable. trying to juggle everything so all components in the combo compliment rather than cancel other components.)<<
At the Rally America Headwater ClubRally I competed in last month, there was a beautifully built 1993 Legacy Turbo Sport (identical to mine at home) that consistently stayed 1 to 2 places ahead of us the entire Rally
>>SPOON: (very encouraging to hear about the legacy in the rally. please turn me onto the contact if you have the opportunity. he may have a source for headers)<<
HEADERS HEADERS HEADERS HEADERS HEADERS HEADERS
>>SPOON; One of my fave subjects. Was one of my fave subjects before most of this list was born. Back then it was tuned headers that were said to actually help give a 7 liter engine better than 100% volumetric efficiency at certain designed RPMs as wild as that may seem. There is a magical site that gives amazing header design info that will help you build your own headers way better than some generic you can buy from some bigname pusher. But this guy is old school and the work he has done is for normally aspirated cars. If you want N/A header info go here
http://www.headersbyed.com/
A lot of what makes headers work for N/A cars get thrown out the window when you go to forced induction. But a lot of it is still good. And like cams, headers can be designed to work better a higher RPM's or lower down in the band where max torque is desired. I also found a NASIOC post where a Turbo Development Engineer for Garrett Engine Boosting Systems goes into a discussion of turbo headers in response to "Midrange power loss ---> downpipe" posted by jlevy on 06-22-2003 at 07:01 AM, which can be found as the 6th thread at the following URL
http://forums.nasioc.com/forums/showthr ... ng+systems
Between the two of them, I think I know what custom build would be optimum for me, and I'm trying to balance that against something which would "work just fine" and be a lot easier to come by, but goes against my grain for wanting something just right, if you know what I mean. So I would appreciate any header source feedback out there.
Larry Spoon Witherspoon
92 Turbo Legacy
spare EJ22T block for the buildup arrived last week (13 June 05)
doesn't mean I'm close, just closer
I want to raise my redline to about 7500RPM and with the EJ22T valve design there would be considerable valve float. \
>>SPOON: (yes most people are after top end)<<
Also, turbo cams are another interesting discussion. It basically depends on your boost goals and where you want your power.
>>SPOON: (i am probably a bit of a rarity in that i want low and midrange torque and will be happy with whatever top end)<<
Usually, unless you are running extremely high boost levels, the stock cams are almost always the best
>>SPOON: (that's what most of my research shows, and i don't intend to go too boost crazy. i like to talk to people that have lots of experience with cams but that are not in the biz of selling cams if you know what i mean)<<
If you are just going to be building your Legacy into a turbo monster, then you are pretty much set.
>>SPOON: (yes i am comitted to a legacy turbo monster, but one which is durable and reliable. trying to juggle everything so all components in the combo compliment rather than cancel other components.)<<
At the Rally America Headwater ClubRally I competed in last month, there was a beautifully built 1993 Legacy Turbo Sport (identical to mine at home) that consistently stayed 1 to 2 places ahead of us the entire Rally
>>SPOON: (very encouraging to hear about the legacy in the rally. please turn me onto the contact if you have the opportunity. he may have a source for headers)<<
HEADERS HEADERS HEADERS HEADERS HEADERS HEADERS
>>SPOON; One of my fave subjects. Was one of my fave subjects before most of this list was born. Back then it was tuned headers that were said to actually help give a 7 liter engine better than 100% volumetric efficiency at certain designed RPMs as wild as that may seem. There is a magical site that gives amazing header design info that will help you build your own headers way better than some generic you can buy from some bigname pusher. But this guy is old school and the work he has done is for normally aspirated cars. If you want N/A header info go here
http://www.headersbyed.com/
A lot of what makes headers work for N/A cars get thrown out the window when you go to forced induction. But a lot of it is still good. And like cams, headers can be designed to work better a higher RPM's or lower down in the band where max torque is desired. I also found a NASIOC post where a Turbo Development Engineer for Garrett Engine Boosting Systems goes into a discussion of turbo headers in response to "Midrange power loss ---> downpipe" posted by jlevy on 06-22-2003 at 07:01 AM, which can be found as the 6th thread at the following URL
http://forums.nasioc.com/forums/showthr ... ng+systems
Between the two of them, I think I know what custom build would be optimum for me, and I'm trying to balance that against something which would "work just fine" and be a lot easier to come by, but goes against my grain for wanting something just right, if you know what I mean. So I would appreciate any header source feedback out there.
Larry Spoon Witherspoon
92 Turbo Legacy
spare EJ22T block for the buildup arrived last week (13 June 05)
doesn't mean I'm close, just closer