avtarv

Looking at upgrading headers soon, is there much of a difference in 1 7/8's versus 2". Looking at Kook's or ARH. Currently making 764/814 with off road pipes but a cam and the 2650 is in for the next round of mods.

0Daniel@Vengeance

With the addition of the Magnuson, stepping up to the 2" would be beneficial if you plan to spin that blower.

ajrothm

Dude the cost is basically the same, why not get the biggest ones when you know you’ll be way over 800 rw..

I did the 2” Kooks this time... vs the 2” ARH on the C5Z, and the Kooks are much nicer and the stainless turns gold... not all brown and spotty looking like the ARH did.

FYREANT

I wish I did 2” on mine. At the time though I had never thought I would break 700whp much less well over 1,000

ckassen

I bet the change is <25HP.

Throw the blower on the 1 7/8" headers and see where you land. Then you can make the decision to upgrade.

Then you can communicate to the rest of us the dyno differences!

Complete Street

Anything forced induction I would run 2" all the way. No questions asked. If you need a set give us a call @ 610-628-1563!

C5-VERT

You want 2” long tubes for higher output forced induction builds. Period. It’s not even strictly about power it’s about efficiency. Engine being a big air pump especially with forced induction you want proper scavenging and flow for increased output. It matters.

robert miller

I again less pressure less LBS of boost on the motor with the 2 inch headers. In turn you can turn it up a little more & make more power at the same boost level.. Robert

SpeedyVette

I hear just that said many times that but it seems it gains efficiency. Everytime I add headers to a boosted car the boost goes up not down. The shop hooks up the boost and it shows on the dyno graph. Hard to gain power with less boost esp with the same cam and build is my thought. Other results may very just my experience from many header installs.
Yes I would run 2 inch over 1 7/8's no reason not to on a boosted car . Bigger difference with the 1 3/4. A few guys still run them but those are too small for me to use.

avtarv

Just not a fan of how close the 2" get to plugs, starter, oil lines etc,

I honestly may just cheap out and get 1 7/8's and put the money towards the diff when it brakes.

Cars been moving with just the off road pipes (9.55@143) and I recently tested a car with AR 2" over the Off road pipes and there as no difference.

SpeedyVette

No problem or issues with 2 inch header tubes starting to throw a set of 2 inch ARH on today. Plus full 2 inch headers smoke off the off road pipes by a good bit.
Have seen them back to back on dyno's.

Internets_Ninja

1 7/8's are fine for stock boost levels on Z06's and way plenty for NA LT1's. Unless you are cranking up the boost, there isn't an advantage by going 2 inch. But at the same time, there isn't a negative side by going 2 inch either.

avtarv

I don't know about that. Put a Procharger on an other wise bolt on Z06 with off road pipes and swapped to 2" AR's and it made 0 difference. 780 rwhp on the stock cam.

Higgs Boson

I run ARH 1 3/4 mid lengths with a Whipple 2.9, lol. I would expect no appreciable difference going to 2" long tubes and I am definitely not chopping up my Akrapovic to find out.

SpeedyVette

First you say you are not a fan the pipes are too big! Then it goes to they are the same ??
You will never sell that to me! I don't think that's true it sounds off from what I have seen on the dyno while they are being tuned 2 inch headers make more power than just cat delete pipes everytime . Way rather have 2 headers on my car you guys can run cat deletes all day long if you want. They produce not as good of sound either

Country Mouse

Check out this site. It may help as Popular Hot Rodding spent an afternoon dyno testing different combinations of headers.

SpeedyVette

According to this 1 3/4 headers leaves a LOT on the table to 2 inch even at 600 hp..

Higgs Boson

So if it will blow the tires off at 90MPH, do they leave a lot on the table?

If it will run a 9.50 now and 9.35-9.40 on 2" headers that might rub and require hacking up an 8k dollar exhaust system, should I worry about switching?

:-)


Maybe if I was worried about heads up racing at the track on a regular basis for money, points, and glory it might make sense, but then, I would have used a different car anyways.

robert miller

This is what I had to do on my AKRAPOVIC X pipe had to cut the pipe up at the header, But even more had to put a belt like around to two pipe up front then pull them into together, Had to have a piece of this stuff tig welded the to pipes closer together cost me 450.00 for a small piece & to have it tig to two pipes closer together so the X pipe would flow together with the LT headers . Then put the bands from the headers to the X pipe LOOKS good but the time & 450.00 cost... Robert

Silverboost

As far as the fit is concerned it might make a difference depending on the manufacture. My Arh 2" headers fit like a glove. I have never burnt a plug wire and nothing rubs, they fit well. If we are talking about switching from a 1 7/8 header you already have to a 2" header for a sub 1000 hp car I'm not sure the cost of re purchasing headers is worth the extra hp. On the flip side if we are talking about deciding between 1 7/8 vs 2" for a first time purchase then the 2" should be a no brainer.