fastest log set up
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From: cape cod mass
fastest log set up i know theres not much talk about log man. turbo kits i figured that out being such a pain in the ***. but i'm really happy with it this year thanks to slowhawk and boosntTBSS. if theres anyone out there with my kit what times have you run with stock motors. mine has done alright traps 123 with a 11.16 Et. on pump gas. all stock besides 6.0 heads and nitto drags...so it dosnt launch to well with a best 1.79 60's so far 
log style manifolds i assume. basically short primaries that go right into a strait piece...known to not flow too well and thus not be the most efficient setup but rather inexpensive....The old PhamSpeed kits had log style manifolds if i remember correctly...
he was kidding
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From: cape cod mass
haha thanks derek. made my day. 123 and 11.1's prety efficient for a low comprsion stock motor. its going 10.60's with susspension mods. but on a built motor kits like this have gone 10.00. u just need to logs thats all 
6.0L manifols are more less cast iron logs. The have been proven to make the numbers. Steel logs both MS and SS have cracking issues. That is the biggest factor. I belive the cracking is more of a support issue than anything. Heat plus weight will weaken steel. I am looking to do a street style setup that keeps the A/C. It will more than likey be a log based setup. It will howevre be braced and reinforced to support the weight of the turbo. Logs are great for street style setups.
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From: cape cod mass
6.0L manifols are more less cast iron logs. The have been proven to make the numbers. Steel logs both MS and SS have cracking issues. That is the biggest factor. I belive the cracking is more of a support issue than anything. Heat plus weight will weaken steel. I am looking to do a street style setup that keeps the A/C. It will more than likey be a log based setup. It will howevre be braced and reinforced to support the weight of the turbo. Logs are great for street style setups.
i know theres not much talk about log man. turbo kits i figured that out being such a pain in the ***. but i'm really happy with it this year thanks to slowhawk and boosntTBSS. if theres anyone out there with my kit what times have you run with stock motors. mine has done alright traps 123 with a 11.16 Et. on pump gas. all stock besides 6.0 heads and nitto drags...so it dosnt launch to well with a best 1.79 60's so far
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From: cape cod mass
No he doesnt run up here. He could easily run 10's if he ups the timing as it sits right now. He is running 15 degrees until he gets his knock sensor fixed. For an LT1 he would be fine with 24-26 degrees at that boost level. Just for reference, at his 15 degrees its like an LS1 running 8-10 degrees timing. Not bad for a lil o'l LT1 with factory top end.
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I have a single turbo with a home-built log setup. It's a 3" log with 1 3/4" primaries going into it. My best to date is 9.92 at 146 mph on a 388 cid LTx with AFR heads, 224 cam, T76GTS at 17 psi, and full stock weight+.
The cracking issues are caused by lack of flexibility. Long primaries increase flexibility of the header. Keep in mind the exhaust header metal will be running around 800 deg F (swag) while the stationary cylinder head is less than 200 deg F. The header will grow quite a bit more than the head. The short primaries of the log can't flex very much without the stresses getting very high. I actually modeled my log manifold in FEA and found that there's NO WAY that the flanges are not sliding across the head when it heats up. If the flanges were totally fixed to the head, it would split on the first heat cycle. Mine lasts because there is enough slop in the bolt holes to allow it to slide some. Solid copper gaskets are a must. If the flanges of the manifold are "linked" together, then you'll likely have cracking problems.
As far as power goes. . . I have a crazy theory about how logs could be just as good as a tubular header. A long primary on a tubular header helps build momentum to draw exhaust out of the cylinder at the end of the exhaust stroke. The short primaries of a log don't contain enough mass for this to happen. However, there is Bernoulli and the pressure effect of velocity. You see, in the log, there's high velocity gas flowing perpendicular to the gas entering the stream from the primary tube. Bernoulli's principle tells us that high velocity gas causes dynamic pressure to drop. Basically, the high velocity gas in the log is "drawing" the exhaust out of the cylinder. So, you don't get inertial tuning of the primary, but you do get low dynamic pressure.
The folks over at forcedinductions.com did a log versus tubular test a while back and found that the tubular gained alot of power. However, they were testing the TTi kit versus PTK as far as I can tell. The TTi kit has a 2.5" log and ridiculous 2.5" downpipe. My personal log system has a 3" log and 3" downpipe (which I still think is too small).
Mike
The cracking issues are caused by lack of flexibility. Long primaries increase flexibility of the header. Keep in mind the exhaust header metal will be running around 800 deg F (swag) while the stationary cylinder head is less than 200 deg F. The header will grow quite a bit more than the head. The short primaries of the log can't flex very much without the stresses getting very high. I actually modeled my log manifold in FEA and found that there's NO WAY that the flanges are not sliding across the head when it heats up. If the flanges were totally fixed to the head, it would split on the first heat cycle. Mine lasts because there is enough slop in the bolt holes to allow it to slide some. Solid copper gaskets are a must. If the flanges of the manifold are "linked" together, then you'll likely have cracking problems.
As far as power goes. . . I have a crazy theory about how logs could be just as good as a tubular header. A long primary on a tubular header helps build momentum to draw exhaust out of the cylinder at the end of the exhaust stroke. The short primaries of a log don't contain enough mass for this to happen. However, there is Bernoulli and the pressure effect of velocity. You see, in the log, there's high velocity gas flowing perpendicular to the gas entering the stream from the primary tube. Bernoulli's principle tells us that high velocity gas causes dynamic pressure to drop. Basically, the high velocity gas in the log is "drawing" the exhaust out of the cylinder. So, you don't get inertial tuning of the primary, but you do get low dynamic pressure.
The folks over at forcedinductions.com did a log versus tubular test a while back and found that the tubular gained alot of power. However, they were testing the TTi kit versus PTK as far as I can tell. The TTi kit has a 2.5" log and ridiculous 2.5" downpipe. My personal log system has a 3" log and 3" downpipe (which I still think is too small).
Mike
Last edited by engineermike; Nov 4, 2007 at 11:01 AM.
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From: cape cod mass
sounds like a nice set up and realy goo times. i have the same size log and primaries also and 3in down pipe. we had some tunning issues because of the cross over going into the log. so then the O2's didnt realy have a bank1 and bank 2 reading they were in the cross over. they had to be made to think it was reading them seperate. i was realy thinking about doing another log on the other side next year. same size 3in log and 1 /24 primaries so and 3in down pipe so there will be no worry about flow.
i know theres not much talk about log man. turbo kits i figured that out being such a pain in the ***. but i'm really happy with it this year thanks to slowhawk and boosntTBSS. if theres anyone out there with my kit what times have you run with stock motors. mine has done alright traps 123 with a 11.16 Et. on pump gas. all stock besides 6.0 heads and nitto drags...so it dosnt launch to well with a best 1.79 60's so far
I have a single turbo with a home-built log setup. It's a 3" log with 1 3/4" primaries going into it. My best to date is 9.92 at 146 mph on a 388 cid LTx with AFR heads, 224 cam, T76GTS at 17 psi, and full stock weight+.
The cracking issues are caused by lack of flexibility. Long primaries increase flexibility of the header. Keep in mind the exhaust header metal will be running around 800 deg F (swag) while the stationary cylinder head is less than 200 deg F. The header will grow quite a bit more than the head. The short primaries of the log can't flex very much without the stresses getting very high. I actually modeled my log manifold in FEA and found that there's NO WAY that the flanges are not sliding across the head when it heats up. If the flanges were totally fixed to the head, it would split on the first heat cycle. Mine lasts because there is enough slop in the bolt holes to allow it to slide some. Solid copper gaskets are a must. If the flanges of the manifold are "linked" together, then you'll likely have cracking problems.
As far as power goes. . . I have a crazy theory about how logs could be just as good as a tubular header. A long primary on a tubular header helps build momentum to draw exhaust out of the cylinder at the end of the exhaust stroke. The short primaries of a log don't contain enough mass for this to happen. However, there is Bernoulli and the pressure effect of velocity. You see, in the log, there's high velocity gas flowing perpendicular to the gas entering the stream from the primary tube. Bernoulli's principle tells us that high velocity gas causes dynamic pressure to drop. Basically, the high velocity gas in the log is "drawing" the exhaust out of the cylinder. So, you don't get inertial tuning of the primary, but you do get low dynamic pressure.
The folks over at forcedinductions.com did a log versus tubular test a while back and found that the tubular gained alot of power. However, they were testing the TTi kit versus PTK as far as I can tell. The TTi kit has a 2.5" log and ridiculous 2.5" downpipe. My personal log system has a 3" log and 3" downpipe (which I still think is too small).
Mike
The cracking issues are caused by lack of flexibility. Long primaries increase flexibility of the header. Keep in mind the exhaust header metal will be running around 800 deg F (swag) while the stationary cylinder head is less than 200 deg F. The header will grow quite a bit more than the head. The short primaries of the log can't flex very much without the stresses getting very high. I actually modeled my log manifold in FEA and found that there's NO WAY that the flanges are not sliding across the head when it heats up. If the flanges were totally fixed to the head, it would split on the first heat cycle. Mine lasts because there is enough slop in the bolt holes to allow it to slide some. Solid copper gaskets are a must. If the flanges of the manifold are "linked" together, then you'll likely have cracking problems.
As far as power goes. . . I have a crazy theory about how logs could be just as good as a tubular header. A long primary on a tubular header helps build momentum to draw exhaust out of the cylinder at the end of the exhaust stroke. The short primaries of a log don't contain enough mass for this to happen. However, there is Bernoulli and the pressure effect of velocity. You see, in the log, there's high velocity gas flowing perpendicular to the gas entering the stream from the primary tube. Bernoulli's principle tells us that high velocity gas causes dynamic pressure to drop. Basically, the high velocity gas in the log is "drawing" the exhaust out of the cylinder. So, you don't get inertial tuning of the primary, but you do get low dynamic pressure.
The folks over at forcedinductions.com did a log versus tubular test a while back and found that the tubular gained alot of power. However, they were testing the TTi kit versus PTK as far as I can tell. The TTi kit has a 2.5" log and ridiculous 2.5" downpipe. My personal log system has a 3" log and 3" downpipe (which I still think is too small).
Mike
I have built Cast manifolds. Log, and tube haeder setups. IMO Logs make for a great cost effective setup. I plan to do a dual Log setup for a front mount single turbo. I am building a street car this time around.
There is no doubt that cast manifolds are stronger. Tube headers make more power. Log manifolds are simple. I have made stupid power with them all.
11.21 at 121 with a 1.56 60ft my first time to the track with this setup on pump gas, 15 degrees timing, and a nitrous converter(not good for the turbo). That is with completely STOCK lt1 heads, stock cam, stock intake, stock tb, stock 3.42 10 bolt, a stock th400(broke my built one a few weeks ago), and 6lbs in 1st and 2nd and 8 in 3rd.
