1 7/8 compared to 2" Headers

[da5deuce]

Through my research I found out that basically the bigger the diameter of the header the more hp gain with less low end torque, and the smaller diameter header will gain more low end torque and not as much horsepower. I'm currently lookin at ARH, So I have a 2 part question...

1. Is the 2" that much better than the 1 7/8" header as far as air flow?

2. Is the 2" header worth the extra $137?

Both lead into 3" O/R H pipe

Sent from my SM-G955U using Tapatalk

 

[RBB]

If by "better" you're asking if the 2" flows more air, then yes it certainly does. Whether or not that's better for your setup is another matter. If you're running a big boy KB or Whipple, 20+ lbs of boost, ported heads, etc the 2" is the best choice for you. On a more standard setup the 1 7/8" are most likely the better option for your build. What's your setup?

 

[da5deuce]

If by "better" you're asking if the 2" flows more air, then yes it certainly does. Whether or not that's better for your setup is another matter. If you're running a big boy KB or Whipple, 20+ lbs of boost, ported heads, etc the 2" is the best choice for you. On a more standard setup the 1 7/8" are most likely the better option for your build. What's your setup?

FRPP TVS(2.5 upper), 123 intake, and E85. Will add a 15% lower with the addition of exhaust. So 1 7/8 would be better?

Sent from my SM-G955U using Tapatalk

 

[sleek98]

2" would be overkill for that combo. Your looking at low to mid 700s. The 1 7/8th would be better for that.

 

[da5deuce]

2" would be overkill for that combo. Your looking at low to mid 700s. The 1 7/8th would be better for that.

Aight good lookin out...

Sent from my SM-G955U using Tapatalk

 

[RedVenom48]

You guys think 1 7/8s headers would be too restrictive for a big boy KB and JDM Cams?

 

[CD07GT500]

2" would be overkill for that combo. Your looking at low to mid 700s. The 1 7/8th would be better for that.

Based off of what?

 

[sleek98]

Mammoth Supercharged GT1000 Headers Test

Showed roughly 8-10 hp on an engine dyno at 750 hp level. Guess overkill isn’t the right word and should have used unneeded as the fitment is already super tight with 1 7/8 so I can’t imagine it’s worth going to 2 inch without being over 1,000 hp.

 

[CD07GT500]

Mammoth Supercharged GT1000 Headers Test

Showed roughly 8-10 hp on an engine dyno at 750 hp level. Guess overkill isn’t the right word and should have used unneeded as the fitment is already super tight with 1 7/8 so I can’t imagine it’s worth going to 2 inch without being over 1,000 hp.

So it was picking up 5+ whp on a ~650whp combo with a 6500 cap and both running 3.5" collectors. With the typical 3" collector on 1.875 headers and a 700+ whp combo the gains would only grow with the 2"x3.5". The fitment is not bad. For a $137 difference the big headers are well worth it.

 

[RBB]

You guys think 1 7/8s headers would be too restrictive for a big boy KB and JDM Cams?

Think you’d be fine with 1 7/8 on that setup. What blower?

 

[RedVenom48]

Most likely the 4.2LC. But for a few hundred more that 4.7....or 4.9 look mighty tempting.... Planning stage is always fun!

Reason I asked about the headers is that I still need to get my 1-7/8" Dynatech's coated and installed. Looking to have the car set to kill (at the track or Mexico) around 900+ whp, pull back timing to run about 800 on the street. This blower will come after the engine build and fuel system go in.

I think if had 1 3/4" headers Id be pulling them for 2". I should be ok with 1-7/8".

 

[RBB]

Most likely the 4.2LC. But for a few hundred more that 4.7....or 4.9 look mighty tempting.... Planning stage is always fun!

Reason I asked about the headers is that I still need to get my 1-7/8" Dynatech's coated and installed. Looking to have the car set to kill (at the track or Mexico) around 900+ whp, pull back timing to run about 800 on the street. This blower will come after the engine build and fuel system go in.

I think if had 1 3/4" headers Id be pulling them for 2". I should be ok with 1-7/8".

With that beast on there I’d swap out to 2” when I pulled the motor for the build. You can offload your current headers and offset a good chunk of the cost.

 

[biminiLX]

It's always subjective.
2" are a tight fit and to really benefit from them; should have 3.5" collectors and a 3.5 to 3" mid pipe.
Unless building for over 800rwhp, I don't see the 2" being necessary or worth the fitment ussues.
And yes, I took off perfectly good 1 7/8" for 2".
You're build goals sound like staying 1 7/8" sounds easier.
-J

 

[VNMOUS1]

Think you’d be fine with 1 7/8 on that setup. What blower?

I make 1,000+ rwhp on 1 7/8.

Sent from my SM-N950U using Tapatalk

 

[4VandHemiKiller]

I make 1,000+ rwhp on 1 7/8.

Sent from my SM-N950U using Tapatalk

Lol, and you would have made another ~30RW with 2” primaries.

One could make 1000+ rw with 1-5/8” headers on a 1100+ rw combo, I fail to see how that would make 1-5/8” primaries optimal.

1-7/8” headers are undersized on 1000+ rwhp combo, get on Pipemax some time.

 

[sono]

Also what bends and work to get them in. The 2" sometimes are hard to fit if I'm not mistaken.

 

[VNMOUS1]

Lol, and you would have made another ~30RW with 2” primaries.

One could make 1000+ rw with 1-5/8” headers on a 1100+ rw combo, I fail to see how that would make 1-5/8” primaries optimal.

1-7/8” headers are undersized on 1000+ rwhp combo, get on Pipemax some time.

Missed the point. I'm not saying it is the optimal size for my specific powertrain. Simply saying that for ease of install, clearances, etc, 17/8 will work and they'll support a lot of power.

I've used Pipemax. Not the end-all but a decent tool.

Sent from my SM-N950U using the svtperformance.com mobile app

 

[4VandHemiKiller]

Missed the point. I'm not saying it is the optimal size for my specific powertrain. Simply saying that for ease of install, clearances, etc, 17/8 will work and they'll support a lot of power.

I've used Pipemax. Not the end-all but a decent tool.

Sent from my SM-N950U using the svtperformance.com mobile app

Stock manifolds will also support “a lot of power”.

You should select parts that best compliment a combo, at 1000+ rw a 1-7/8” primary is not optimal and is sacrificing power.

Pipemax is pretty decent, nothing is the “end all be all”.

 

[RedVenom48]

Mammoth Supercharged GT1000 Headers Test

Ignore the Mopar Challenge pics, I guess even Kenne bell gets a wrong coding with their website.

If Im making near 1K hp and torque, Im not worrying about 30hp average less on 1 7/8" primaries. You are right, less is less... but its such a small differential is it even worth scrapping perfectly good headers for 30hp?

My wallet says no. Oher wallets may spread open at the thought of more power, regardless of how small that gain is. To each their own.

 

[4VandHemiKiller]

Mammoth Supercharged GT1000 Headers Test

Ignore the Mopar Challenge pics, I guess even Kenne bell gets a wrong coding with their website.

If Im making near 1K hp and torque, Im not worrying about 30hp average less on 1 7/8" primaries. You are right, less is less... but its such a small differential is it even worth scrapping perfectly good headers for 30hp?

My wallet says no. Oher wallets may spread open at the thought of more power, regardless of how small that gain is. To each their own.

The header test on a 650 rwhp combo isn't ideal. The 2" header still gained at that power level, and the gap will grow as power increases.
30 rwhp is a "average" gain, some guys have picked up 50-60 rwhp going to 2" or 2-1/8" headers at 1000+ rwhp.

The problem with the mentality of "I'm making 1000+, what difference does 30 rwhp mean?" is that mentality leads to similar conclusions for various choices, 30 rwhp here, 30 rwhp oftens leads to 100+ rwhp left on the table. That's the right way to build a very average combination.