1 3/4 Header vs 1 7/8 Header
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
GTOdoug's test was on a stroker motor and he gained 34rwtq going to a 1 3/4 from his AR 1 7/8. He is not a tuner. Strokers, the LS3 and LS7 have no benefit with the larger primary becauser its the same rpm band theyre usedf in.
The fastest LS3 uses 1 3/4 both when it was a cam only car and then again as a h/c car. When a 1 7/8 betters that then there is proof. The car made 525rwhp and 485rwtq on a dyno and then showed a 132 trap speed. 1 3/4 seems proved there with a LS3 and Doug showed strokers benefit from the smaller primary too.
Last edited by SpinMonster; Nov 28, 2008 at 02:43 AM.
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Maybe, but these were not. No reason too, as I had 1 3/4 These are true real world comparo's
that makes solid evidence. 1 3/4 header works fine but this proof above
and the fact that George from Kook's said when I bought my headers,
the same thing. They see them every day, He said LS-2 1 3/4
LS-3 1 7/8 OR when you reach the over 500hp level the 1 7/8's perform better.
that makes solid evidence. 1 3/4 header works fine but this proof above
and the fact that George from Kook's said when I bought my headers,
the same thing. They see them every day, He said LS-2 1 3/4
LS-3 1 7/8 OR when you reach the over 500hp level the 1 7/8's perform better.
I want to see your results because you didnt change anything since your last dyno except the headers. I think your proof is most closely related to higher HP cars. I guess the kooks 1 7/8 on my car would be a good test. If they are better then I'll keep them. If they dont better my 1 3/4 then people wil say I'm biased for LG. I trust Doug 100% and he got the results showing bigger primaries arent better for low end TQ.
Team Owner
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From: salem OR
I went through all those threads and saw but one dyno sheet comparing the different primary sizes. C6dvl running 1 3/4 ran a 132 trap speed. JB's car never had the 1 3/4 and I dont see how that qualifies the 7/8 as the better primary size for the job. Cartek uses 1 3/4 exclusively and has lots of track proof. I dont care what a tuner says....they're biased.
I dont want it to turn into an argument. You and I have to have the biggest laugh on this topic since we have run the entire spectrum of header wars and now it not company, its primary size. The fastest track LS3 has 1 3/4 and the fastest C6 6 liter and 6.2 liter FI car have 1 3/4. The fastest bolt on car LS2 has 1 3/4. Track proof is still not saying anything because it isnt testing back to back runs with different primaries. I use it to illustrate the silliness in polls and dyno sheets. Since all points of view have been shown then in my eyes its a stand-off if we use that kind of data as proof.
I think anything else is just opnion by those who defend what they own. I tried once to show a back to back on header swaps on my car and ultimately bowed out when the tuner didnt want me to post dyno sheets since they saw a conflict with the header they sell even though I was just renting a dyno. Even if I posted the results, foul would have been cried by the unhappy owners of the 'other header'. One thing we have to agree on is that surgery is a bummer. Feel better Rob. Dont take the rest of it so seriously.
I have no problem when a guy shows proof with a dyno or track run. Its the peanut gallery with an opinion on things they never tested that get to me. Having a poll on whats better is simply showing which company had the best sales because people vote for what they have, not whats better for thier application.
I dont want it to turn into an argument. You and I have to have the biggest laugh on this topic since we have run the entire spectrum of header wars and now it not company, its primary size. The fastest track LS3 has 1 3/4 and the fastest C6 6 liter and 6.2 liter FI car have 1 3/4. The fastest bolt on car LS2 has 1 3/4. Track proof is still not saying anything because it isnt testing back to back runs with different primaries. I use it to illustrate the silliness in polls and dyno sheets. Since all points of view have been shown then in my eyes its a stand-off if we use that kind of data as proof.
I think anything else is just opnion by those who defend what they own. I tried once to show a back to back on header swaps on my car and ultimately bowed out when the tuner didnt want me to post dyno sheets since they saw a conflict with the header they sell even though I was just renting a dyno. Even if I posted the results, foul would have been cried by the unhappy owners of the 'other header'. One thing we have to agree on is that surgery is a bummer. Feel better Rob. Dont take the rest of it so seriously.
I have no problem when a guy shows proof with a dyno or track run. Its the peanut gallery with an opinion on things they never tested that get to me. Having a poll on whats better is simply showing which company had the best sales because people vote for what they have, not whats better for thier application.
1 7/8 because Charlie @RPM tested the 2 and says the 1 7/8's is the way to go on the LS-3. He has the highest dyno of any bolt-on ls-3 on here. He has the track numbers. Also the 1 7/8 clearly kills the
1 3/4. When tuned and dyno'd and at MY tuners dyno. Tuned the same way. My car was 1 3/4 as was NWC-6 WE we made 423 or so with-in 2 hp.And around 418 rwtq Another 08 rolls in with AR 1 7/8 and made 441 and 435. Also in the thread above pg3 post 57. The debate continues
Melting Slicks
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I have a unused set of kooks 1 3/4 and the header itself is the only thing that would have to be swapped out to show the proof. Where are you? I can swap them out and see if they are right. Cartek tried this size only swap and found the 3/4 to run the fastest at the track. Please show the proof to the contrary because the manufacturer doesnt have a corvette with track runs as the reason for the reco and a tuner doing the testing is the authority. I am willing to do all the work myself. As always, if I'm wrong, I want the better header for my application on my car.
I did the swap with all Kooks parts more than once and the results for every swap showed the 3/4 to make more power under the curve every time....wait I'm repeating myself so what's the point. It isnt what people want to hear after they bought the other size.
I did the swap with all Kooks parts more than once and the results for every swap showed the 3/4 to make more power under the curve every time....wait I'm repeating myself so what's the point. It isnt what people want to hear after they bought the other size.
I may be willing to try this myself soon and can swap the headers out in about 45 minutes for a dyno run when I get my N20 tune. Im in South Florida.
Im not sure why Kooks would advise the 1 7/8's (over thier 1 3/4's) for a N/A 402/408 with 150 shot here and there but who cares, they are on the car.
Team Owner
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From: salem OR
So where is the LS3 with 1 7/8 on the track list? C6dvl is 525rwhp and is 10.66@132. Also Doug was over 500rwhp and that didnt hold true for his car; 34rwtq higher.
I want to see your results because you didnt change anything since your last dyno except the headers. I think your proof is most closely related to higher HP cars. I guess the kooks 1 7/8 on my car would be a good test. If they are better then I'll keep them. If they dont better my 1 3/4 then people wil say I'm biased for LG. I trust Doug 100% and he got the results showing bigger primaries arent better for low end TQ.
I want to see your results because you didnt change anything since your last dyno except the headers. I think your proof is most closely related to higher HP cars. I guess the kooks 1 7/8 on my car would be a good test. If they are better then I'll keep them. If they dont better my 1 3/4 then people wil say I'm biased for LG. I trust Doug 100% and he got the results showing bigger primaries arent better for low end TQ.
excluding Dennis re 1 7/8's.
So did you swap headers to 1 7/8's also with your blower?
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Jb's car is 1 7/8 and like 2nd on the bolt-on list last I looked. He has
1 7/8 because Charlie @RPM tested the 2 and says the 1 7/8's is the way to go on the LS-3. He has the highest dyno of any bolt-on ls-3 on here. He has the track numbers. Also the 1 7/8 clearly kills the
1 3/4. When tuned and dyno'd and at MY tuners dyno. Tuned the same way. My car was 1 3/4 as was NWC-6 WE we made 423 or so with-in 2 hp.And around 418 rwtq Another 08 rolls in with AR 1 7/8 and made 441 and 435. Also in the thread above pg3 post 57. The debate continues
1 7/8 because Charlie @RPM tested the 2 and says the 1 7/8's is the way to go on the LS-3. He has the highest dyno of any bolt-on ls-3 on here. He has the track numbers. Also the 1 7/8 clearly kills the
1 3/4. When tuned and dyno'd and at MY tuners dyno. Tuned the same way. My car was 1 3/4 as was NWC-6 WE we made 423 or so with-in 2 hp.And around 418 rwtq Another 08 rolls in with AR 1 7/8 and made 441 and 435. Also in the thread above pg3 post 57. The debate continues
None of these cars had one header and then swapped to the other. I'm not following your point here. An LS3 trapping 123 is proving 1 7/8 headers are better than 1 3/4? Dave at Cartek showed me their testing that shows their reasons for them using 1 3/4 exclusively, you havent produced any header swap dyno's and are saying a car trapping 123 proves something? The fastest car in each category on the track run list has 1 3/4.
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
The fastest H/C LS3 uses 1 3/4 trapping 132 with 525rwhp.
The fastest cam only LS3 used 1 3/4. The fastest LS2 uses 1 3/4....FI, head/cam, and bolt-on. The fastest bolt-on LS2 with 1 3/4 is faster than the fastest bolt-on LS3 with 1 7/8.
Engine size aside: trap speed is the best dyno.
I dont want to argue and since you will only go by the tuners you like, you will never concede the point and it eventually becomes personal to you. I dont want a fight.
No disrespect, I respect your position. Defending the opinions of your tuner is admirable.
Anyway Happy Thanksgiving everyone. I'm happy I'm alive and own this awesome car.
Last edited by SpinMonster; Nov 28, 2008 at 05:03 AM.
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Yes, excluding the fastest car because the fastest car doesnt make your point. Usually the fastest car serves to be the proof.
As for digging, there shouldnt be a need. The fastest car is the top one on the list. No need to dig. The authority on whats better is the company that built it. Cartek's dyno sheets showed a loss in low end TQ for the bigger primary.
The fastest H/C LS3 uses 1 3/4 trapping 132 with 525rwhp.
The fatest cam only LS3 used 1 3/4. The fastest LS2 uses 1 3/4....FI, head/cam, and bolt-on.
If 1 7/8 were superior they would be faster than the 1 3/4 cars. Since the 1 3/4 has these spots...the 1 7/8 is either ineffective or it doesnt matter. End point: no 1 7/8 header is on any of the first place class categories. Engine size alone: trap speed is the best dyno.
But they should be ingnored because they dont prove your point. Makes no sense.
I dont want to argue and since you only go by the tuners you like, you will never concede the point nor would you go by the winning car. The 2nd place winner makes your point.
No disrespect, I respect your position. Defending the opinions of your tuner is admirable.
Anyway Happy Thanksgiving everyone. I'm happy I'm alive and own this awesome car.
As for digging, there shouldnt be a need. The fastest car is the top one on the list. No need to dig. The authority on whats better is the company that built it. Cartek's dyno sheets showed a loss in low end TQ for the bigger primary.
The fastest H/C LS3 uses 1 3/4 trapping 132 with 525rwhp.
The fatest cam only LS3 used 1 3/4. The fastest LS2 uses 1 3/4....FI, head/cam, and bolt-on.
If 1 7/8 were superior they would be faster than the 1 3/4 cars. Since the 1 3/4 has these spots...the 1 7/8 is either ineffective or it doesnt matter. End point: no 1 7/8 header is on any of the first place class categories. Engine size alone: trap speed is the best dyno.
But they should be ingnored because they dont prove your point. Makes no sense.
I dont want to argue and since you only go by the tuners you like, you will never concede the point nor would you go by the winning car. The 2nd place winner makes your point.
No disrespect, I respect your position. Defending the opinions of your tuner is admirable.
Anyway Happy Thanksgiving everyone. I'm happy I'm alive and own this awesome car.
on the Ls-2. Lets see one dyno sheet on a stock ls-3 that makes as much as the top 2, being with 1 7/8's.I am still in the 1 3/4 camp on ls-2's excluding Dennis the bolt-on list
top 08's contains other headers than 1 3/4. All the top cars are 08's (again exclue Dennis) plus if you compare tracks and JB's newest run
I think he beats Dennis or is real close on the Same track. More cars out there with 1 3/4 too. I have to get Andy to send me a new BOV then I'll have some results next week.
Last edited by 3 Z06ZR1; Nov 28, 2008 at 05:11 AM.
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Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Your going up the wrong tree cause if you look I said I like the 1 3/4
on the Ls-2. Lets see one dyno sheet on a stock ls-3 that makes as much as the top 2, being 1 7/8's.I am still in the 1 3/4 camp on ls-2's excluding Dennis the bolt-on list
top 08's contains other headers than 1 3/4. More cars out there with 1 3/4 too. I have to get Andy to send me a new BOV then I'll have some results next week.
on the Ls-2. Lets see one dyno sheet on a stock ls-3 that makes as much as the top 2, being 1 7/8's.I am still in the 1 3/4 camp on ls-2's excluding Dennis the bolt-on list
top 08's contains other headers than 1 3/4. More cars out there with 1 3/4 too. I have to get Andy to send me a new BOV then I'll have some results next week.
A car that dyno's 470rwhp and traps 123 means nothing about comparing primary sizes unless it has tested both sizes on the same car. So JB ran a 123 trap speed. Whats the point? Does there exist a LS3--1 3/4 run that was slower with the same mods? It isnt comparing anything. A stroker is more displacement than the LS3 and a 1 3/4 beat the 1 7/8 header by 34rwtq on that motor. Why doesnt that matter?
Last edited by SpinMonster; Nov 28, 2008 at 05:18 AM.
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From: salem OR
besides your head is just as hard as mine, You are clearly disreguarding my statement on two ls-3 with 1 3/4
different brands made 423-424 418-419. Then bone stock with 1 7/8's same dyno same tuner some MO, pulled an unreal 441 435 this backs up Jb's and another one on here with 1 7/8's All clearly making more than any 1 3/4 on here and I have personally seen a lot! Yes I'll find it! clearly shows to me the 1 7/8's
may be the choice where I agree with 1 3/4 on the ls-2. I testing the F/I myself If I don't better my old numbers They will come off trust me on that! Plus Anyone can say what they want but the true HP test is the roll start
1/4 is all 60ft dependtant. If the faster car can't get it down he loses to a car with less power Roll'em at 40-50 on good road and the Faster car with the real power wins! Thats the real test! Some/Most so called 10 second cars ARE toast on the road againest an S/C'd C-6.
Last edited by 3 Z06ZR1; Nov 28, 2008 at 05:32 AM.
Tech Contributor
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St. Jude Donor '08-'09-'10-'11
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From: Los Alamitos California
St. Jude Donor '09
Rock-n Blue,
I think it would be prudent to wait until you have done a comparable dyno pull on your 1 7/8s to compare against your 1 3/4s (all other things being equal) so you could provide real data for comparison. I realize you've been injured and hope you recover soon. I'd like to see your new dyno plot against the old one.
I realize there are some very reputable header manufacturers making LSx headers that provide 1 3/4 and 1 7/8 sizes. I find it interesting that LG only makes 1 3/4 headers and Cartek seems to prefer them as well. Both are very reputable.
I'd like to see some tuners chime in here that aren't bound by the products they carry, but I realize that is asking a lot.
I think that Spin did an objective swap between the two different sizes and stuck with what he saw as the better product for his application. I also think that if Lou tested the 1 7/8 on his 427 and preferred the results with the 1 3/4, that is probably the route I'll take, as I doubt I'll ever need more displacement.
One last thing, I'm more concerned with power under the curve than peak numbers. Another reason an overlay of both dyno plots would be nice to see.
San
I think it would be prudent to wait until you have done a comparable dyno pull on your 1 7/8s to compare against your 1 3/4s (all other things being equal) so you could provide real data for comparison. I realize you've been injured and hope you recover soon. I'd like to see your new dyno plot against the old one.
I realize there are some very reputable header manufacturers making LSx headers that provide 1 3/4 and 1 7/8 sizes. I find it interesting that LG only makes 1 3/4 headers and Cartek seems to prefer them as well. Both are very reputable.
I'd like to see some tuners chime in here that aren't bound by the products they carry, but I realize that is asking a lot.
I think that Spin did an objective swap between the two different sizes and stuck with what he saw as the better product for his application. I also think that if Lou tested the 1 7/8 on his 427 and preferred the results with the 1 3/4, that is probably the route I'll take, as I doubt I'll ever need more displacement.
One last thing, I'm more concerned with power under the curve than peak numbers. Another reason an overlay of both dyno plots would be nice to see.
San
Last edited by oldmansan; Nov 28, 2008 at 05:36 AM.
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St. Jude Donor '08-'09-'10-'11
Plus Anyone can say what they want but the true HP test is the roll start
1/4 is all 60ft dependtant. If the faster car can't get it down he loses to a car with less power Roll'em at 40-50 on good road and the Faster car with the real power wins! Thats the real test! Some/Most so called 10 second cars ARE toast on the road againest an S/C'd C-6.
1/4 is all 60ft dependtant. If the faster car can't get it down he loses to a car with less power Roll'em at 40-50 on good road and the Faster car with the real power wins! Thats the real test! Some/Most so called 10 second cars ARE toast on the road againest an S/C'd C-6.
Trap speed indicates power output regardless of traction.
The 123 trap speed is an indicator or JB's power output. Runflats or drag radials make no difference. The trap speed will not change.
Last edited by SpinMonster; Nov 28, 2008 at 05:37 AM.
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St. Jude Donor '07-'08-'09-'11-'12
Ok...to throw another log onto the fire.....
In Spin's swap from 1 3/4 Kooks to 1 3/4 LG, there was a significant rise in the mid range torque, and we thought a lot of it had to do with the collector design. I think Kooks has since tweaked the design to improve the mid band torque. Does anyone know if this is true, and if so, have a before/after comparison of the two?
In Spin's swap from 1 3/4 Kooks to 1 3/4 LG, there was a significant rise in the mid range torque, and we thought a lot of it had to do with the collector design. I think Kooks has since tweaked the design to improve the mid band torque. Does anyone know if this is true, and if so, have a before/after comparison of the two?
Le Mans Master
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From: NJ
We have seen great results on c5's with 1 7/8 inch headers for anyone interested in results.
I don't have controlled studies like Spin does
I don't even know if the 1 3/4 headers would dyno better but I don't believe we lost anything running them on the strip.
heads/cam c5z= 9.98et
bolt on c5Z= 10.99et
The headers used are American Racing Headers
I don't have controlled studies like Spin does
I don't even know if the 1 3/4 headers would dyno better but I don't believe we lost anything running them on the strip.
heads/cam c5z= 9.98et
bolt on c5Z= 10.99et
The headers used are American Racing Headers
Melting Slicks
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C6's are light cars in general (they are not GTO's or Cobras) so " IF " they lost a hair of rwtq (5-20) where it may actually help on the street (a bit less spinning when WOT from 2500-3500) but you gain a few peak rwhp 6K + rpm where traction is usually attained, the car could be quicker.
If not, usually it wont even be noticable.
Either way, I am an N20 guy and N20 always favors a 1 7/8, so for me its a no-brainer. Besides, my car will spin the tires at will with 1/2 throttle (Kooks 1 7/8 w/ 3" offroad X) form a slow roll, so " IF " I had an extra 10rwtq now, it would be even worse.
How about flip a coin with an edge going to LG if you are not planning on FI.
Last edited by JayplaySS2; Nov 28, 2008 at 02:09 PM.
Tech Contributor
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
We have seen great results on c5's with 1 7/8 inch headers for anyone interested in results.
I don't have controlled studies like Spin does
I don't even know if the 1 3/4 headers would dyno better but I don't believe we lost anything running them on the strip.
heads/cam c5z= 9.98et
bolt on c5Z= 10.99et
The headers used are American Racing Headers
I don't have controlled studies like Spin does
I don't even know if the 1 3/4 headers would dyno better but I don't believe we lost anything running them on the strip.
heads/cam c5z= 9.98et
bolt on c5Z= 10.99et
The headers used are American Racing Headers
The point? You may have run 9.97 with the 1 3/4.
Tech Contributor
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St. Jude Donor '08-'09-'10-'11
Here is how I see it and God knows this will add another 3 pages to the thread,
C6's are light cars in general (they are not GTO's or Cobras) so " IF " they lost a hair of rwtq (5-20) where it may actually help on the street (a bit less spinning when WOT from 2500-3500) but you gain a few peak rwhp 6K + rpm where traction is usually attained, the car could be quicker.
If not, usually it wont even be noticable.
Either way, I am an N20 guy and N20 always favors a 1 7/8, so for me its a no-brainer. Besides, my car will spin the tires at will with 1/2 throttle (Kooks 1 7/8 w/ 3" offroad X) form a slow roll, so " IF " I had an extra 10rwtq now, it would be even worse.
How about flip a coin with an edge going to LG if you are not planning on FI.
C6's are light cars in general (they are not GTO's or Cobras) so " IF " they lost a hair of rwtq (5-20) where it may actually help on the street (a bit less spinning when WOT from 2500-3500) but you gain a few peak rwhp 6K + rpm where traction is usually attained, the car could be quicker.
If not, usually it wont even be noticable.
Either way, I am an N20 guy and N20 always favors a 1 7/8, so for me its a no-brainer. Besides, my car will spin the tires at will with 1/2 throttle (Kooks 1 7/8 w/ 3" offroad X) form a slow roll, so " IF " I had an extra 10rwtq now, it would be even worse.
How about flip a coin with an edge going to LG if you are not planning on FI.
Intermediate
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