cylinder head preference?
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
cylinder head preference?
I'm starting to plan my H/C upgrade. Being in Kali, I have to keep things mild to pass smog, so please keep that in mind.
I'm looking at a fairly mild CompCam http://www.compcams.com/Company/CC/c...csid=1089&sb=2 .558/.563 and 212/218 on 115
Current mods to the car are listed in my signature. I'm also looking at swapping to a Z06 trans and possibly doing either 3.73 or 3.90 gears at the same time. My goal is not peak power but overall response, driveability and torque - I'd rather make 400 rwhp with stock type response than 450 with something that only screams at the top and and has poor street manners. I've already put 22K miles on the car this year, so driveability is a primary concern.
I'm looking at the ported Patriot and PRC versions of the LS6 head:
https://www.patriot-performance.com/...age=1&featured
http://www.texas-speed.com/p-1172-pr...ted-heads.aspx
Any reason one is better than the other? Anyone had any unusual problems with either one?
The PRC's look a little better with the polished chambers, but they are still pretty similar pieces. Thanks for the input!
I'm looking at a fairly mild CompCam http://www.compcams.com/Company/CC/c...csid=1089&sb=2 .558/.563 and 212/218 on 115
Current mods to the car are listed in my signature. I'm also looking at swapping to a Z06 trans and possibly doing either 3.73 or 3.90 gears at the same time. My goal is not peak power but overall response, driveability and torque - I'd rather make 400 rwhp with stock type response than 450 with something that only screams at the top and and has poor street manners. I've already put 22K miles on the car this year, so driveability is a primary concern.
I'm looking at the ported Patriot and PRC versions of the LS6 head:
https://www.patriot-performance.com/...age=1&featured
http://www.texas-speed.com/p-1172-pr...ted-heads.aspx
Any reason one is better than the other? Anyone had any unusual problems with either one?
The PRC's look a little better with the polished chambers, but they are still pretty similar pieces. Thanks for the input!
Melting Slicks
Joined: Jun 2005
Posts: 2,396
Likes: 52
From: Sicamous BC
Your goals of under the curve performance would lead me to a cylinder head with a smaller intake & yet higher flow. You feel that as roll on, throttle response, under the curve torque = fun. I know the AFR head such as the 205 & 210 are smog legal, they come up used.
A very often overlooked option is your cylinder heads & this:
http://www.advancedinduction.com/LSX...CGM241Head.php
Gear change is one of the best modification I did & like most I did it last....should have been first. I stuck with the M6 & choose 4:10's, besides the performance aspect sixth became a very usable gear. You could use the Trans money for a clutch upgrade while you are under there, not that what you are doing is going to do be a clutch problem.
A lighter clutch & flywheel has some SOTP benefits.
A very often overlooked option is your cylinder heads & this:
http://www.advancedinduction.com/LSX...CGM241Head.php
Gear change is one of the best modification I did & like most I did it last....should have been first. I stuck with the M6 & choose 4:10's, besides the performance aspect sixth became a very usable gear. You could use the Trans money for a clutch upgrade while you are under there, not that what you are doing is going to do be a clutch problem.
A lighter clutch & flywheel has some SOTP benefits.
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
Thanks CTD. I'm looking at doing the trans for 2 reasons. It seems that the original owner wasn't a very good clutch driver. When it's cold it's pretty tough to get it into 2nd. Rather than pay to have the synchro work done, I'd rather just get a low-miles Z06 trans and swap it in. I also like the deeper, wide-ratios of the Z06 trans.
Racer
Joined: Jul 2004
Posts: 470
Likes: 8
From: Northwest Washington
I believe Patriot heads still use bronze valve guides, which are not a good combo with stock rocker arms, because of the scrubbing action on the valve tips. Prc heads I believe use a steel valve guide which would be better with newer style stock rockers. I went with Patriot stage 2.5 heads, milled to 59cc and Yella terra rockers, because of the bronze valve guides. Now I am looking for several extra Yella Terra rockers, just in case mine break, which is not uncommon. Not sure what valve guides AFR is using now, but if I was doing it again I would contact AFR and get something other than a bronze valve guide and go with AFR.
Drifting
Joined: Jan 2004
Posts: 1,419
Likes: 6
From: Alamosa CO
I would seriously consider AFR 205's with a 224/228 .581 cam on a 114 LSA. This is a proven combo that'll get you great gains in HP and TQ and still pass smog and have great driveability. As far as rear gears go with the M12 trans, I would definitely consider 3.73's. I ran that combo when my car was still running the H/C LS6 and it was "just right" on the street, strip and road course. Hope this helps.
Jimbo
Jimbo
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Safety Car
Joined: Aug 2011
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From: Portland OR
When looking at various heads flow numbers (doesn't tell the whole story) look for heads with the smallest intake port and highest flow numbers. So if 2 heads have very similar flow numbers, the ones with the smallest port will have the broadest power band and require less cam.
I believe this is where the AFR 205 or 210 shines.
I have some 205's tweaked by Tony along with a 223/227 114 cam on the way and am real exceited to find out how they perform. My expectation is a nice crackle to the idle, but not lopey, and an excellent torque band. Perfect for an A4 car.
Won't be until spring before I know though, it's a big project.
Ron
I believe this is where the AFR 205 or 210 shines.
I have some 205's tweaked by Tony along with a 223/227 114 cam on the way and am real exceited to find out how they perform. My expectation is a nice crackle to the idle, but not lopey, and an excellent torque band. Perfect for an A4 car.
Won't be until spring before I know though, it's a big project.
Ron
Pro
Joined: Jun 2010
Posts: 535
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From: CA
just keeps you LSA wide (i.e. 114 +) and you will pass no problems
Le Mans Master
Joined: Apr 2005
Posts: 8,077
Likes: 4
From: Scarborough ONTARIO
You already have pretty good choices mentioned above posts, specially CTD/vettenuts/ZZoomZ06 or call tony mamo and buy everything from him as package 425-450 rwhp without driveability issues and most power under the curve to left side...lol. Or do scrap H/C package and instead spend another $2k and go with Andy's kit SC A&A.
Melting Slicks
Joined: Aug 2008
Posts: 3,451
Likes: 27
From: Bay Area CA
When looking at various heads flow numbers (doesn't tell the whole story) look for heads with the smallest intake port and highest flow numbers. So if 2 heads have very similar flow numbers, the ones with the smallest port will have the broadest power band and require less cam.
Look at Advanced Induction and TEA ported 243 heads. Also - strongly consider a bigger cam. For smog - I suggest a 224/228 .581 .588 115 LSA....this will pass the sniffer and provide over 20hp over the cam you mention
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,882
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From: Bangkok, Thailand
Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
Burning Brakes
Joined: Jul 2006
Posts: 968
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From: Regina Sask
I would not change the axle ratio, the 2.97 M12 first gear is like having 3.81 gears. And as you add power, with street tires, first gear traction becomes useless.
http://www.vibratesoftware.com/html_...ons.htm#6sptrn
Russ Kemp
http://www.vibratesoftware.com/html_...ons.htm#6sptrn
Russ Kemp
Melting Slicks
Joined: Aug 2008
Posts: 3,451
Likes: 27
From: Bay Area CA
It's the same duration and lift as the AFR cam, but it's on a wider LSA to give 4 degrees of negative overlap and keep it emissions safe
Burning Brakes
Joined: May 2007
Posts: 829
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From: San Francisco CA
I just put an M12 in my 02 coupe while I was doing my clutch, the car is much snappier now. I can usually start off in 2nd gear now from a stop unless I'm on a hill. I would say either ported 243's or if budget the allows , AFR's would be a good CARB legal head choice matched to EPS cam like a 222-230 115 (-4* overlap & good exh. split for your shorties) would make killer low end power, good top end pull and superb drivability .
Melting Slicks
Joined: Jun 2005
Posts: 2,396
Likes: 52
From: Sicamous BC
I would not change the axle ratio, the 2.97 M12 first gear is like having 3.81 gears. And as you add power, with street tires, first gear traction becomes useless.
http://www.vibratesoftware.com/html_...ons.htm#6sptrn
Russ Kemp
http://www.vibratesoftware.com/html_...ons.htm#6sptrn
Russ Kemp
Agree on the gears, if you don't do tires & traction it's all a waste!
