Headers and exhaust question for LS3
Premium Supporting Vendor
Joined: Nov 2005
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From: Amityville ny 631-608-1986
Hank, Our 1-3/4" round port flanges are identical to yours. Both L92 heads we tried them on had a mildly CNC'd exhaust port and the 1-3/4 flange without the tube was conflicting exhaust flow. With the tube matter were worse. This led us to developing a new flange that not only follows the contour of the stock port perfectly but also allows porting without any interference. When I gain access to another L92 head I'll illustrate this in photo's.
Nick
Nick
Former Vendor
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Hank, Our 1-3/4" round port flanges are identical to yours. Both L92 heads we tried them on had a mildly CNC'd exhaust port and the 1-3/4 flange without the tube was conflicting exhaust flow. With the tube matter were worse. This led us to developing a new flange that not only follows the contour of the stock port perfectly but also allows porting without any interference. When I gain access to another L92 head I'll illustrate this in photo's.
Nick
Nick
Thanks for the clarification but your flanges must not be the same as ours. We still have .016" on a side to port the exhaust until we reach the tube.
Just please be careful when making statements like
"Brasil, Because we took the time to check." Implying other header manufactures do not.
Thanks
Hank
Premium Supporting Vendor
Joined: Nov 2005
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From: Amityville ny 631-608-1986
Hank, Fair enough but without getting into details it sounds like the I.D. of our 1-3/4" flanges are significantly different. Also we felt the L92 needed more than a round port. We all do what we feel works best for our customers.
Nick
Nick
Former Vendor
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Just making sure our customers know we are not blocking any flow.
If you guys will be out at SEMA please stop by our booth. #23551
Hank
Racer
Joined: Aug 2005
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I also wanted to show this in pictures. I had katech send me a trace copy of a mildly ported L92 cylinder head even with the port work there is no obscruction what so ever. Notice the white around the inner black shade of the exhaust port is over 50 thousands thick at the most narrow point and that is on a mild ported cylinder head. The silver ring beyond that is a piece of 1 3/4 S/S tubing.So as for an obstruction I cant see it possible. As for the shape of the flange at stock specs we tested a round exhaust port verses the d port on a flow bench and recored no difference in scavaging.
Last edited by KOOKS Headers; Oct 19, 2007 at 12:49 PM.
Burning Brakes
Joined: Sep 2007
Posts: 916
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From: Lexington Park MD
Very nice numbers, especially considering the minor mods. It's insane how well these cars react to subtle changes. One question, since I'm new and stupid
. What's torco?
Premium Supporting Vendor
Joined: Nov 2005
Posts: 1,779
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From: Amityville ny 631-608-1986
Here's a couple of quick photo's with our standard 1-3/4" flange which clearly indicates that with a tube there's an obstruction. With a larger round port flange the obstuction goes away.
Be that as it may we preferred to redesign the flange to follow the contour of the port. We did the same for the LS7 port.
Nick
Be that as it may we preferred to redesign the flange to follow the contour of the port. We did the same for the LS7 port.
Nick
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Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
Hello Nick,
Hank Daniecki from SLP Performance Parts here. Your statement about the L92 requiring a special flange specific to the port to keep if from being blocked is not correct for 1-3/4" headers. Please see attached photos. This same SLP flange is used on LS2 and L92 SLP 1-3/4" Headers. Please see attached photos of only the flange bolted to the head (L92) and photos of a 1-3/4" header primary welded in place bolted to the head (L92). You can see by the photos there is room for tubing thickness (.056" thk SLP primaries and welds) on the ID of the standard round flange on an L92 head. You can see on the photos attached when the tube is welded in place there is not blockage of the exhaust port on a L92 head using a standard SLP round port flange.
This is why most manufactures are using the same header for LS2 and LS3 C6 applications as the envelope is the same.
Also please view the attached links to the testing and videos SLP has completed on the LS3 C6.
http://www.slponline.com/view_product.asp?P=30125
http://www.slponline.com/view_product.asp?P=31078
http://www.slponline.com/view_product.asp?P=31079
AS WELL OUR NEW C6 HOOD!!!!! IT IS HOT!!!
http://www.slponline.com/coming_soon_100012.asp
Thanks, only trying to keep the information as accurate as possible.
Hank
PS:
Check out our FREE C5/C6 Exhaust install special. ACT NOW because it is over soon.
http://www.slponline.com/browse_list.asp?SPC=spc
Hank Daniecki from SLP Performance Parts here. Your statement about the L92 requiring a special flange specific to the port to keep if from being blocked is not correct for 1-3/4" headers. Please see attached photos. This same SLP flange is used on LS2 and L92 SLP 1-3/4" Headers. Please see attached photos of only the flange bolted to the head (L92) and photos of a 1-3/4" header primary welded in place bolted to the head (L92). You can see by the photos there is room for tubing thickness (.056" thk SLP primaries and welds) on the ID of the standard round flange on an L92 head. You can see on the photos attached when the tube is welded in place there is not blockage of the exhaust port on a L92 head using a standard SLP round port flange.
This is why most manufactures are using the same header for LS2 and LS3 C6 applications as the envelope is the same.
Also please view the attached links to the testing and videos SLP has completed on the LS3 C6.
http://www.slponline.com/view_product.asp?P=30125
http://www.slponline.com/view_product.asp?P=31078
http://www.slponline.com/view_product.asp?P=31079
AS WELL OUR NEW C6 HOOD!!!!! IT IS HOT!!!
http://www.slponline.com/coming_soon_100012.asp
Thanks, only trying to keep the information as accurate as possible.
Hank
PS:
Check out our FREE C5/C6 Exhaust install special. ACT NOW because it is over soon.
http://www.slponline.com/browse_list.asp?SPC=spc
For straighting that out!
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
I also wanted to show this in pictures. I had katech send me a trace copy of a mildly ported L92 cylinder head even with the port work there is no obscruction what so ever. Notice the white around the inner black shade of the exhaust port is over 50 thousands thick at the most narrow point and that is on a mild ported cylinder head. The silver ring beyond that is a piece of 1 3/4 S/S tubing.So as for an obstruction I cant see it possible. As for the shape of the flange at stock specs we tested a round exhaust port verses the d port on a flow bench and recored no difference in scavaging.
Race Director
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From: CA
2017 C5 of the Year Finalist
St. Jude Donor '08
This dyno gragh was done with 12 gallons of 91 mixed with one quart of Torco. This would yield about a 95+ octane mix.
