throwit

So I'm in the market for some headers to go on a ~600whp 427 track only engine, and after reading a TON of posts, I had my mind pretty much set on 1 7/8 until I came across this thread...

http://www.camaro5.com/forums/showth...ghlight=header

Seems like it is legit, but it is the only one I have ever seen that does NOT show ANY loss of anything anywhere with the 2" headers.

Thoughts?

mgarfias

Your url is busted.

throwit

Thank you sir...try now

C5 Hardtop

That graph is as clear as mud. 4 lines of the same color intersecting frequently throughout the power band, each line has the same width and there are no labels for the lines that are running into each-other. We need to look at the area under the curve.

Where is the baseline to compare that shows no loss? I guess if I can't read or trust the graph I wouldn't see it

Have you tried LG Motorsports? Lou runs a tight ship and stands by his products.

throwit

Although I agree the colors could have been changed, I can read the graph pretty well. Not sure what baseline your looking for...there are 4 distinct pulls: stock header system, 1 3/4, 1 7/8, 2".

Thanks for the unprompted LG pitch, but just so you know I have been running LG headers for over 10 years

RX-Ben

The gains are pretty minimal and I can't imagine how tight fitment is with a 2" setup. Space is already at a premium with a 1 3/4" setup.

throwit

Whats up Ben! Hope 2nd day of Chin was better for you, and best of luck at the Nationals!

Installation PIA aside, looking at the numbers, its 10hp and 5 ft/lb over the 1 3/4, and that's on a 400 whp motor. I would expect those gains to be about 15 and 10 respectively on a ~600 whp motor. With that said, the price difference is a couple hundred bucks. I cant think of anyone who would not spend $200 for 15 horses.

Regardless of that though, the biggest point here is that 2" was better everywhere (even if minimal). That is a HUGE shock to me since everything I had ever read previous to this was insistent on losing low end.

troyguitar

Who cares about low end on a track only car anyway? You should always be well over 4000 on the track. If you can have more power in your racing class then 2" headers is a good cheap way to add it IMO.

throwit

My thoughts exactly

bdanyluk

I basically have a stock LS2 with 1-7/8 headers....

from what I have read on the forum over the years, 1-7/8 is good for up to about 800 RWHP......

So 2" would only be beneficial at 1000rwhp+ or more.

throwit

Yup, this is definitely popular belief

breecher_7

Go 2" from the get go and be done with it. People complain about how "tight" the fitment is and thats absolute crap. The ARH 2" units fit better than most companies 1.75" units.

RX-Ben

I have seen a number of dynos to back up the "bigger is better" idea on headers but I would be wary unless you can see the fitment with the headers installed. Not saying it can't be done, but there is barely enough room as it is to fit some heat shielding between the starter motor and the primaries. If there is still room for heat shielding, the collector clearance is still acceptable and they aren't a huge pain to install...

Pumba

I have a 248/252/118 degree LSA/.730" lift solid roller lifter camshaft, 12.0:1 compression ratio, ALL PRO LSW-12-1 heads, Tony Mamo 102 F.A.S.T. intake, Mamo-ported throttle body, 7.4L LS engine in my Z06. My engine makes 675 SAE HP and 706 STP HP on pump gas.

2-inch headers lost power at the peak (6,500 rpms) and everywhere else under the curve, compared to my L.G. Motorsports 1 7/8-inch Super Long Pro headers. 2-inch headers are a packaging nightmare and a waste of money.

C5 Hardtop

It would be interesting to hear why he doesn't offer a 2".

throwit

Great video.

Pumba

I will start out by stating that I spent 7 years as an engine dynamometer operator at the beginning of my Automotive Engineering career.

What I would have like to have seen in the testing is two changes:

• First, I would have insisted on all corrections to the power runs be done to SAE Horsepower, not STP Horsepower. The correction factors used for STP were abandoned in 1980 by the worldwide automotive industry. Engine builders, engine dyno shops, or chassis dyno shops that use STP correction factors are lying to their customers!

• Second, I would have insisted that the dyno operator start the power runs at 2,000 rpms, instead of the 3,000 rpms where he started. That would have shown those of us who drive our cars on the street what the low-end torque differences were between the various header combinations.

Other than that is was a good video to watch.


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