Sizing a BOV and WG
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TECH Enthusiast
Joined: Nov 2004
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From: Coppell,TX
just was planning out a single T76gts on tubular manifolds and 3.5in downpipe 1 5/8 primaries 2 1/4 collectors . Goin through a stock TB and MAF. Was thinking of running anywhere up to 2bar. Was planning on intercooling it and upgrading to meth later also wasnt sure on the intercooler sizing. Is bigger better or will bigger than needed cause problems (intercooler)?
About primary sizing- will 1 5/8 be too restrictive. I think it wont cover the port but im not completely sure. 1st set of LS1 headers. Also im trying to maintain velocity in the exhaust in order to reduce lag. so selecting 2 1/4 collectors come to mind as being able to not produce to much back pressure. Although with the turbo's back pressure it might be an issue. because i know equal length headers are more effective on low back pressure situations. where as stepped headers and unequal headers generally do better with high restriction mufflers.
About primary sizing- will 1 5/8 be too restrictive. I think it wont cover the port but im not completely sure. 1st set of LS1 headers. Also im trying to maintain velocity in the exhaust in order to reduce lag. so selecting 2 1/4 collectors come to mind as being able to not produce to much back pressure. Although with the turbo's back pressure it might be an issue. because i know equal length headers are more effective on low back pressure situations. where as stepped headers and unequal headers generally do better with high restriction mufflers.
Launching!
Joined: Apr 2003
Posts: 243
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From: Phoenix, AZ.
Think air volume, the more power you make/want the more you'll need to move. If you're running a T76 or GT42 then I'd recommend going 1 3/4" runners to 2 1/2" collectors. Downpipe and exhaust should be 3 1/2" or 4". If you're going to push 800+HP you'll want to use a Blowzilla or 50mm Tial BOV and a 44mm waste gate or larger. You'll get boost creep with anything smaller on the waste gate so that's a definite.
Just do lots of reading on this forum and other like it. Check out Turbo Mustang Forum, lots of good info and they have a Chevy section but it doesn't get much traffic. You can still get a feeling for what's working for others and their power level.
Brett
Just do lots of reading on this forum and other like it. Check out Turbo Mustang Forum, lots of good info and they have a Chevy section but it doesn't get much traffic. You can still get a feeling for what's working for others and their power level.
Brett
1 5/8 will support just about any level power an LS1 has made already. We have made 1500+ hp with 1 5/8 headers...hehe. The downpipe is the most crucial part. Bigger is better for that application.
Jose
Jose
Thread Starter
TECH Enthusiast
Joined: Nov 2004
Posts: 600
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From: Coppell,TX
alright well, Jose, 1 5/8 headers you think its better than using say 1 3/4? heck if i was to go down to 1 1/2 would it be restrictive in the pipes or restrictive in the turbo? Cause my point of view on the subject is a 1 lane road works great for keeping higher speeds but lacks in volume.
As of now, my future combo is looking like 6.0, or stock heads (not sure), and LS6 cam. 6.0 manifolds, and a single T70 or T76. 3.5" downpipe. What do you think Jose? Im starting to round up parts now. Another question, what comp ratio do the 6.0 heads give when bolted to a stock LS1.
