HELP! choosing header size is becoming a nightmare!
02-21-2014, 03:43 PM
#1
HELP! choosing header size is becoming a nightmare! 1 3/4, 1 7/8, stepped, straight...so many options and so many conflicting information...its frustrating!
Just started researching on what size headers to go with and everyone on here and everywhere else is saying something different.
Car is bone stock LS1 GTO. This is its first mod. Starting with OTR CAI mafless tune and a complete exhaust system.
Motor will definitely be modded more in the future so building for the future. Although that doesn't mean that since we are modding for the future the absolute most we can gain now is not required...cz it is.
Car is a DD that will be used for street racing...think 1/4 mile type races off stop lights.
Looking to go 408 in the future. So yeah, it would be nice if the headers now could be used later for ultimate performance and not have to get new ones.
So what's the deal? What size exhaust system should we go for? Like what size headers, collectors, cat back, stepped, straight?
Realize you are talking to a beginner that just started researching exhaust systems...but is having a hard time finding the correct info.
Just started researching on what size headers to go with and everyone on here and everywhere else is saying something different.
Car is bone stock LS1 GTO. This is its first mod. Starting with OTR CAI mafless tune and a complete exhaust system.
Motor will definitely be modded more in the future so building for the future. Although that doesn't mean that since we are modding for the future the absolute most we can gain now is not required...cz it is.
Car is a DD that will be used for street racing...think 1/4 mile type races off stop lights.
Looking to go 408 in the future. So yeah, it would be nice if the headers now could be used later for ultimate performance and not have to get new ones.
So what's the deal? What size exhaust system should we go for? Like what size headers, collectors, cat back, stepped, straight?
Realize you are talking to a beginner that just started researching exhaust systems...but is having a hard time finding the correct info.
02-21-2014, 04:57 PM
#7
Here is my dyno after swapping 1 3/4" to 1 7/8" headers...both were Kooks and on the same dyno. I had H/C/I with true duals already done, stock cubes. There's not a lot (or any) of info on 2" headers for ls1's I have seen, but if your going big cubes you might consider them. I know they (2") make more power on LS3's than 1 7/8"....one of the mags did a comparison on them. One thing for certain is to cross 1 3/4" off your list.
I researched stepped headers a lot and was never sold on them completely. Here is a good thread about them http://www.camaro5.com/forums/showth...=182653&page=3
I researched stepped headers a lot and was never sold on them completely. Here is a good thread about them http://www.camaro5.com/forums/showth...=182653&page=3
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02-21-2014, 06:03 PM
#8
Thank for the replies guys!
Ok so you guys are saying 1 7/8.
But i hear a lot say that bigger is not always better. And that 1 7/8 would be good on 400+ CID engines. And that it becomes counterproductive on smaller engines.
I remember reading this post on here where this guy actually lost power going from 1 3/4 to 1 7/8. What's the deal on that?
Ok so you guys are saying 1 7/8.
But i hear a lot say that bigger is not always better. And that 1 7/8 would be good on 400+ CID engines. And that it becomes counterproductive on smaller engines.
I remember reading this post on here where this guy actually lost power going from 1 3/4 to 1 7/8. What's the deal on that?
02-21-2014, 06:11 PM
#9
On a setup like that you are not going to sacrifice anything with 1 3/4 and they will still sustain plenty of power. Either way you want to go though we can set you up with any of them.
02-21-2014, 08:14 PM
#10
Yeah, 1 3/4 would be plenty for your car now but the question is...
Do you plan on heads cam intake? If so then just get the 1 7/8 now instead of doing it twice.
Also, I see a possible 408 in future so, get the 1 7/8 right now so you will have them later.
Unless you want to go 1 3/4 now and take the chance of kicking yourself in the *** later on for not doing 1 7/8 now. You like to avoid doing things twice? I sure as hell do.
Do you plan on heads cam intake? If so then just get the 1 7/8 now instead of doing it twice.
Also, I see a possible 408 in future so, get the 1 7/8 right now so you will have them later.
Unless you want to go 1 3/4 now and take the chance of kicking yourself in the *** later on for not doing 1 7/8 now. You like to avoid doing things twice? I sure as hell do.
02-21-2014, 09:41 PM
#11
On an ls3 427 I have personally seen gains of 15 on an fbody. Slp 1 3/4 vs kooks 1 7/8. But the 1 3/4 still made 580...so I am not sure the comparison is up to the internet hype.
02-21-2014, 10:17 PM
#12
Thank for the replies guys!
Ok so you guys are saying 1 7/8.
But i hear a lot say that bigger is not always better. And that 1 7/8 would be good on 400+ CID engines. And that it becomes counterproductive on smaller engines.
I remember reading this post on here where this guy actually lost power going from 1 3/4 to 1 7/8. What's the deal on that?
Ok so you guys are saying 1 7/8.
But i hear a lot say that bigger is not always better. And that 1 7/8 would be good on 400+ CID engines. And that it becomes counterproductive on smaller engines.
I remember reading this post on here where this guy actually lost power going from 1 3/4 to 1 7/8. What's the deal on that?
Just get 1 7/8" and be done.
02-22-2014, 06:17 AM
#13
1 7/8" and be done.
I love it when folks, especially on a particular sister forum, say, "well the 1 3/4" made 6xx rwhp so obviously they support it and make power"
Sure, they'll "support" that power. Your car will run, and run well at that.
But you're STILL leaving power on the table. Why leave power on the table? Do it once, do it right.
I love it when folks, especially on a particular sister forum, say, "well the 1 3/4" made 6xx rwhp so obviously they support it and make power"
Sure, they'll "support" that power. Your car will run, and run well at that.
But you're STILL leaving power on the table. Why leave power on the table? Do it once, do it right.
02-22-2014, 07:59 AM
#14
I have kooks 1 3/4 on my 04 GTO. I only planned headers, catback, tune and SVEDE CAI. Now im getting ready for heads, cam, fast etc and kinda wish I would have went 1 7/8. Im not going to change it at this point though. With your intentions, just get the 1 7/8.
02-22-2014, 01:04 PM
#17
The cost difference between a 1-3/4 and 1-7/8 (if cross-shopping within a brand like Kooks or ARH) is negligible. Why leave 10-15rwhp on the table for $10? People spend $1000+ on FAST intakes for that much power.
Do 1-7/8" headers.
Hell, look in this thread. Someone posted back-to-back dynos with the same combo and 1-3/4 and 1-7/8" headers. That's a sizeable difference. Will you notice it? Maybe not, but the Kooks headers are within $10 of each other.
Why is this still being discussed?
Do 1-7/8" headers.
Hell, look in this thread. Someone posted back-to-back dynos with the same combo and 1-3/4 and 1-7/8" headers. That's a sizeable difference. Will you notice it? Maybe not, but the Kooks headers are within $10 of each other.
Why is this still being discussed?
02-23-2014, 07:35 PM
#18
TECH Fanatic
I don't think every setup is going to be the same, i honestly would say 1-7/8" because will give room to grow for a larger engine and will make the same or more top end.
The stepped are gonna cost more. Something i think I read one time was that a more efficient exhaust port will not benefit from a larger header like going from 1-3/4 to 1-7/8. But i think that was basically a stock head maybe cnc'd vs something like a trickflow 215. Thats just something to think about, i have not been able to find any info out there to really say what exactly is needed.
Here is a good dyno to post on big blocks that you can read just showing super big is not always best.
http://www.hotrod.com/techarticles/e...s/viewall.html
here is another on a 03 kenne bell cobra where the larger was not good.
http://www.musclemustangfastfords.co.../photo_34.html
The stepped are gonna cost more. Something i think I read one time was that a more efficient exhaust port will not benefit from a larger header like going from 1-3/4 to 1-7/8. But i think that was basically a stock head maybe cnc'd vs something like a trickflow 215. Thats just something to think about, i have not been able to find any info out there to really say what exactly is needed.
Here is a good dyno to post on big blocks that you can read just showing super big is not always best.
http://www.hotrod.com/techarticles/e...s/viewall.html
here is another on a 03 kenne bell cobra where the larger was not good.
http://www.musclemustangfastfords.co.../photo_34.html
03-19-2014, 04:37 PM
#19
The street racing comment - really? Building a badass car with 500+ horse should not be raced on the street. You sound young (based on your other comments). Take the car to the track and learn how to handle 500+ horse before racing on the street and potentially killing someone and/or yourself. Street racing is illegal, stupid and deadly. It takes self control and maturity to not race on the street.
OK - end of old man speech.
03-19-2014, 04:51 PM
#20
This doesn't need to be a debate anymore. If you can get 1 7/8" headers, get them. If for some reason you can't due to price, availability, etc get 1 3/4". There is no honest downside to the bigger headers as far as performance whether it be a stock or modded application.
It's that simple.
It's that simple.
