chief63

Hey guys,

I was thinking the other day about long tube headers but after being borderline on certain tracks (sound check), I'm reconsidering. Some tracks have a 92dB maximum but then again the distance it's taken from varies. For example I was at 91dB at Calabogie at 5000RPM, which is pretty close to the limit, with a fully stock setup.

Anybody here has tested it? If you can give us your setup, the distance taken from and your DB level it would be great. If you haven't done it yet, a good thing would be to test it from 10 feet, 20 feet and 30 feet to cover most tracks. I don't have an iphone but supposively there is an app for it that can read it up to 100db. Again bringing it to 5000RPM should be a good standard to compare (and usually 2/3 max RPM is the standard).

It's also a good way to know how loud these setups are!

thanks!

superlubricity

I measured two cars at our last dyno day. Both had Long Tube Headers.

nrgy (w/ cats) and avengerboater (catless) exceeded 125db on the meter while on the dyno @ WOT. Nothing really scientific, just me standing behind the car with the meter in my hand as they made their pulls. Thank God for hearing protection.

Catless Long Tube Headers on a C63 = the loudest street car I have ever heard at cold start and wide open throttle.

JM

I want long tubes

But my car would be way too loud. haha

chief63

thanks. 125 dB at very close range, that's like a jet engine LOL

I pretty much have my answer, even from 30 feet away, this is way too loud to take on most tracks, except 1/4 mile ones...

Anyone knows where the Kleemann K2 shorties stand?

superlubricity

It was likely louder than 125db. The meter was pegged and couldn't go any higher.

If you are looking for a power increase from the exhaust, I would avoid any header/manifold system that uses high-flow cats or retains the stock cats. Every system I've tested or analyzed has shown minimal HP/TQ gains. They just aren't worth the money, especially when you include labor.

BerBer63

What about Bhamg car? ~50hp with HF cats and LTs?

chief63

I understand your point. If you had to list the mods that bring the best bang for the buck, all around performance wise, what would they be (with HP for power upgrades)?

I'm not saying this is the right order:

1. K1 or tune -> 50-60 HP
2. Better tires -> better grip
3. LSD -> put the power down
4. Coil overs -> handling upgrade
5. Light rotors -> weight saving of rotating mass
6. Light wheels -> weight saving of rotating mass
7. ??
8. ??
9. ??
10. ??

superlubricity

I don't think you read his post/charts correctly. Take a look at again and note the "all runs done with no primary cats." If you read the chart, you'll see the catless LTs gave him 35-40RWHP. This is the same gain I've witnessed with other LT headers.

He then mentioned he was down 20HP from when the cats were installed. That's the same 20HP decline I've witnessed with other Long Tube headers w/ cats compared to catless.

BerBer63

Got it superlub. I nominate you as a moderator.

superlubricity

My recipe from the beginning has been:

Tune, sticky tires, lightweight rotors, lightweight wheels, LSD.

The rotors are pricey, but nothing else will give you that kind of unsprung weight reduction.

superlubricity

I like that idea.

hhughes1

Roebling Road has a 103db limit taken just past the tower on the main straight. Dad's and I have both been black flagged more than once.

chief63

Yep the more I think about it, the more I can't get headers.

That makes a lot of sense, my objective is to track it without any traction control. Not that easy!