2 vs. 1 7/8 Header
12-30-2017, 08:46 AM
#21
Le Mans Master
I mean no not really, if you have a 10s car and add a mod that makes 5 more hp will you see a change? Nope def not, doesnt change the fact its still a better mod though.Its weird how many people can stare point blank evidence i the face and then ignore it based on their own formed opinions lmao
Dave
The following users liked this post:
jim2092 (12-30-2017)
12-30-2017, 09:19 AM
#22
In the test shown above where did they lose power with late headers? They didnt, anywhere, so essentially the 5hp up top was free...did you look at the link even?To what dan said above obviously collector design and tube length are important design factors but thats not pertinent to the conversation at this point. The op asked about tube size meaning I would assume hes looking at the same headers design and in that case the evidence suggests larger tubes make more powerbwith no negative effects. If you want to start talking about different brands with different design then Id agree tube dia becomes more of a moot point. However thankfully for us most of the major header companies have a very similar design. This test showed that given the same design the larger id will be betterTake a look at LG for example, they always claim that their 1-3/4 makes more power than 1-7/8 and theyre not wrong. However the 1-3/4 is a completely different designed header. Are they wrong? No....does that mean given the same design the 1-7/8 wouldnt be better? Nope.....
12-30-2017, 09:21 AM
#23
Thanks for that Dano. I think we both know there are several more factors to be considered when choosing exhaust systems than just primary tube size. The only thing that dyno test did, was to show differences by the same manufacturer on a car with no supporting mods. Dynos are only a stationary tuning tool anyway. Timeslips tell a more accurate story of real performance.
See my above reply....but also curious how would addin more mods that helps the car breathe better help it make more power with 1-7/8
12-30-2017, 11:59 AM
#24
Team Owner
Yet all the test and graphs show zero loss down low, so why not take the extra 5-7hp up top?
The following 2 users liked this post by Unreal:
HC Mechanic (12-30-2017),
Innovate (12-31-2017)
12-30-2017, 01:32 PM
#25
Le Mans Master
Regarding the LS3 and LS7 engines, it certainly appears to me there's no downside to having 2 inch headers in every application. However I've often wondered about Dyno results, even though they show Power at all RPMs, they do not show them at partial throttle settings, and I can't help but wonder if you're giving up significant part throttle response with the 2-inch headers. But I don't know.
12-30-2017, 01:57 PM
#26
We had a member here that passed a couple of years back name New Jersey Dennis, he dynoed and ran the quarter-mile back-to-back 1 and 3/4 verses 1 and 7/8 inch headers on a LS2, and the one in three quarter inch headers were significantly faster in both situations. It's because the head design on the LS2 is pretty inefficient, so I would say if you're going to swap out heads on an LS2, go to the bigger headers. So I believe it is you that are incorrect.
Regarding the LS3 and LS7 engines, it certainly appears to me there's no downside to having 2 inch headers in every application. However I've often wondered about Dyno results, even though they show Power at all RPMs, they do not show them at partial throttle settings, and I can't help but wonder if you're giving up significant part throttle response with the 2-inch headers. But I don't know.
Regarding the LS3 and LS7 engines, it certainly appears to me there's no downside to having 2 inch headers in every application. However I've often wondered about Dyno results, even though they show Power at all RPMs, they do not show them at partial throttle settings, and I can't help but wonder if you're giving up significant part throttle response with the 2-inch headers. But I don't know.
There are always exceptions to every rule. I dont doubt his results but others including me who have performed similar tests have not seen those results. I have seen a cam only car swap on a fast intake and lose trap speed over the ls6 intake. Would you want to argue that is the norm and therefore the fast is not a worthwhile swap? I doubt his tests were all done same day same track and same weather. All of those things can have a significant effect on the end result and have 0 to do with the mods
Last edited by redbird555; 12-30-2017 at 01:59 PM.
12-30-2017, 04:16 PM
#27
Race Director
Member Since: Sep 2007
Location: Peoria/Phoenix AZ
Posts: 16,555
Received 2,061 Likes
on
1,505 Posts
C6 of Year Finalist (performance mods) 2019
There are always exceptions to every rule. I dont doubt his results but others including me who have performed similar tests have not seen those results. I have seen a cam only car swap on a fast intake and lose trap speed over the ls6 intake. Would you want to argue that is the norm and therefore the fast is not a worthwhile swap? I doubt his tests were all done same day same track and same weather. All of those things can have a significant effect on the end result and have 0 to do with the mods
So what did we know that you haven't learned yet?
BTW, I've looked on the fast lists and don't see your name anywhere. Are you only a dyno sheet racer or just too ashamed to post times?
The following users liked this post:
Dcasole (12-30-2017)
12-30-2017, 04:26 PM
#28
It's still strange that Dennis and myself (the quickest boltons, LS2 and LS3) are the "exception to the rule" and those who are not exceptions tend to run slower.
So what did we know that you haven't learned yet?
BTW, I've looked on the fast lists and don't see your name anywhere. Are you only a dyno sheet racer or just too ashamed to post times?
So what did we know that you haven't learned yet?
BTW, I've looked on the fast lists and don't see your name anywhere. Are you only a dyno sheet racer or just too ashamed to post times?
Im not discrediting anyone...no need to get upset because someone else has a different opinion than you man. The fastest bolt on fbodys run 1-7/8 and 2 headers. So do ls2 cars like smaller headers or are they exceptions. If you did a mod that gained 5hp would you see itvat the track? I just would assume someone with your car and record would have a much more open mind but maybe not man?
The following users liked this post:
Innovate (12-31-2017)
12-31-2017, 02:21 AM
#29
Drifting
12-31-2017, 10:24 PM
#30
Race Director
Member Since: Sep 2007
Location: Peoria/Phoenix AZ
Posts: 16,555
Received 2,061 Likes
on
1,505 Posts
C6 of Year Finalist (performance mods) 2019
Im not discrediting anyone...no need to get upset because someone else has a different opinion than you man. The fastest bolt on fbodys run 1-7/8 and 2 headers. So do ls2 cars like smaller headers or are they exceptions. If you did a mod that gained 5hp would you see itvat the track? I just would assume someone with your car and record would have a much more open mind but maybe not man?
You fail to understand that it's not the size of the primaries that produce the most power, but how the entire exhaust system works with all the other components, whether they are stock or modified. There is far more to creating a quick car than just sourcing parts that worked in some dyno test.
AFAIK, Dennis and I only had one non-stock mod (Vararam) in common. He also had several more mods than I. We shared header tube size, but not brand. He had a LS2 with a A4 trans and 3.90 gears and I have a LS3 with a A6 and 2.56 gears. He learned what worked for him and I for me, because we both were willing to fail during the process of finding the right combination. I still have several things yet to try, but 2" headers are not on that list at this time.
Post up your car with the mods and your best timeslip, we are all willing to help.
Try filling out your profile too. You've been here 8 years and you're way overdue.