180 degree headers?

[c131fdave]

Has anyone tried using 180 degree headers instead of those that come with the kit? It seems using them is the best way to get that "exotic" sound typical of Ferraris and Lamborghinis.

[LCD Gauges]

I don't think you want to try that on LS engines due to the arrangement of the firing order.

On older Gen 1 SBC engines, it would sound good, and increase power. On the LS engines, you would probably end up cutting power
because of the interference of the exhaust pulses in the cross-over collector design.

You would essentially be undoing the benefits of the improved firing order of the Gen III/IV over Gen I/II engines.

[Presto51]

Has anyone tried using 180 degree headers instead of those that come with the kit? It seems using them is the best way to get that "exotic" sound typical of Ferraris and Lamborghinis.

Not sure why you want Farrari\Lambo exotic when you can have American sexy



Ron

[CHOTIS BILL]

I you want a really cool sound go to a flat crank which will make the 180 degree headers very simple and will make sounds that send shivers up and down your spine. At least they do that to me.

YMMV

Bill Lomenick

[tirod]

Sexy is what we thought was incredibly awesome the first times we heard a truly impressive car fire up.

The 180 header concept has been around a long time, the sixties saw them sold for drag cars, and the "bag of snakes" was common on the GT40's and Formula/Indy cars. Panteras and other mid engine designs tolerate getting the exhaust to match up as the tubing can be connected over the bellhousing to even out the pulses.

What needed to be corrected was getting the exhaust pulses exactly 180 at the collector - which meant crossing over the center cylinders to the other side on most American V8's. That allowed having the four pipes in the collector always passing a pulse of gas in equal timing, rather that some at less or more, disturbing the cadence. When equal timing is accomplished, the collector can resonate without an off-paced pulse disturbing the frequency. It's amplified to a higher degree to match the designed rpm and helps pull the intake charge in better when a reflected low pressure wave enters the chamber.

With "sexy American" tuning, the reflected waves are out of sync and the pull is less. Because there is a difference in the quality of sound, some prefer one or the other, but theoretically we are throwing horsepower away not designing 180 headers. NASCAR was poised to move to them - in a front engined car - just a few years back but the typical rules wrangling shelved them just before the season opened. Working headers were relegated to historical photo shots on web pages.

The LT1 doesn't have a flat crank, any alteration in the firing order of a 90 degree crank would create an imbalance in the firing order, making things worse. That's the inherent problem with V8 motors with 90 degree cranks that forces running the exhaust to the other side. What most generally decide is that the expense to make a convoluted set of headers doesn't justify the potential unless there is a lot of development to get the hp increase - like in NASCAR.

The result is a higher pitched sound with no lumpiness - it refines the tone and loses the harley-like out of sync rumble so many grew up with here in the States. Which isn't necessarily a bad thing when you are trying to stand out from the crowd. 180 headers ARE the "professional" level of sound emitted from actual race motors designed as such. Unlike cheap commuter motors pressed into service in hobby class racing.

[c131fdave]

I don't really want "American Sexy" because I've had it for the last 28 years and I'm frankly looking for something different. Ever since I was on the New Jersey Turnpike and pulled off to get gas next to a Porsche Carrera GT- and it took off at full song back onto the highway- I've always said that if I were to ever build an "exotic" car like the GTM, it would sound something like that Porsche. I realize a lot of it has to do with the 8000-9000 rpm those euro-exotics turn. I love both the American rumble and the Euro scream, and would like a car with the Euro Scream this time around.

That video posted above is very cool- but it sounds just like my Corvette.

[Presto51]

You want it to sound like this?



Maybe these folks can help you out
http://www.burnsstainless.com/BundleofSnakes-2.aspx

Hope it works out for you

Ron

[tirod]

Definitely Burns.

Something to feed the fever: GT40's at Spa on youtube: http://www.youtube.com/results?searc...T40%27s+at+spa

[c131fdave]

That's more like it, Presto. I don't like the resonators (assuming they are resonator tips that I am hearing) much, but the sound is what I'm after. The resonators make it sound like a teenager with a giant can tip on the back of his Honda sticking out and scraping the road.. lol The GT40 sound Tirod linked is perfect- but they have 180 degree headers.. lol

[Fraser D]

If after you install the 180 deg and you don't get the sound that you are looking for there is this...........

https://www.youtube.com/watch?featur...&v=FmNolu_ZUpk

[KeithBoden]

Personally, I'd rather go through the endless headaches of going with a non-LS motor to achieve the sound than have to fab 180 degree headers and deal with the added exhaust surface area. How many days have I thought of pulling the M275 (5.5L V12 twin A2W intercooler / twin turbo) from my S600 and using it for my GTM build. Stock form is 500 hp / 590 ft-lb 1800-3500, but can be tuned to 650 hp / 745 ft-lbs on the same turbos. 4 extra cylinders helps the sound in my opinion!

M275.jpg
28" long with accessories, 29" wide with turbos, intercoolers and air filters. They can be had for $9000 or less with a car, hah!

[c131fdave]

I had an S600 also, 2004 model, and I've had the same thought- but I'd have to install a completely different induction system so somebody couldn't walk up and say "Hey, that's a Merc engine". Same things goes with the LS engine personally, but there's lots of stuff out there to disguise them. But a good idea. Turbos kind of muffle the noise though...

[Presto51]

If after you install the 180 deg and you don't get the sound that you are looking for there is this...........

https://www.youtube.com/watch?featur...&v=FmNolu_ZUpk

OMG Dave that is down right funny. So........

When you going to do that mod to your GTM

Ron

[VD2021]

If after you install the 180 deg and you don't get the sound that you are looking for there is this...........

https://www.youtube.com/watch?featur...&v=FmNolu_ZUpk

OMG Dave that is down right funny. So........

When you going to do that mod to your GTM

Ron

Funny!

I'm going to have to try that on my commuter. LOL.

[Roger Reid]

Continuing the you tube search I found this one. It's pretty good.

https://www.youtube.com/watch?v=m40ZAfJb4f8

The blip on downshift near the end is great.

[KeithBoden]

Lambo drivers should try to model their driving after his sounds...they might learn a few things about shifting! The simulation of driveline loading/unloading at 6:12 by jumping up and down, cracked me up, that is some attention to detail. Should we ask for an E-Gear sound as well?

[kabacj]

I personally think the GTM with the kooks and individual throttle bodies sounds a lot like the gt40 at spa



But maybe I am biased.

John

[claybags]

That's pretty AWESOME John!!! Gave me goose bumps. We need MORE!!!!
Cheers, Jeff

[Artois]

I really have been trying to research this. hard information to get