Bigtickets

Fellas, it's time for headers and I would like opinions. I take the car to the track so cooling is always an issue. I know shorties will give more torque and long tubes will give more top end. Do shorties help with heat as much as Lt's? Would it be better to go with the shorties for the extra torque to pull the car through the corners? What brand etc?

99lightning

you will gain everywhere with longtubes even without adding pulley

DVC

If you were N/A you'd may need to worry more about primary length and how it will effect torque at corner exit, but for the 55K go MBH/ARH.

cal1

I am running a Kleemann style shortie. Should have done LTs.

vikingdiesel

Mids= IMO

shardul

iTrader: (1)

Kleemann mids

Sir-Boost-a-Lot

iTrader: (1)

Shorties aren't going to give you much if any gains in torque over a hood set of longtubes with merge collectors like the ARH/MBH sets. It just seems that way due to the top end losses. That being said, the more economical shorties/mids are a better value hp/$$ wise but they're also Chinese. The ARH get my vote without hesitation. Fast build time, great communication and manufactured in Long Island NY of all places. The perfect fit, one piece 1 7/8 primary tubes and top end charge are a nice tough as well

AMGPilot

MBH Longtubes are the ONLY way to go, HUGE gains with that mod only

kponti

Any difference between MBH and ARH?

After getting and installing the Kleemann mids, I feel the primaries are too small for this size engine coupled with a positive displacement supercharger

DVC

MBH= 1 3/4" primaries
ARH= 1 7/8" primaries

Both are 304 SS. The ARH are longer and have a little less ground clearance. They also sometimes have clearance issues with the steering column. Seem to have really good customer service.

MBH uses super spendy 321 SS flanges and are dyno/track proven time and again. I just did motor mounts, and gotta say, the MBH headers may be too pretty to keep under the car ha.

Hammer Down

+1

BC928

They are beautiful. No Doubt.

They have a higher perceived gain because you most remove the primary catalytic converters.

You Do not do this with "Shorties", and so you do not gain as much flow and reduction in backpressure.

A good compromise between the insane cost (but well crafted nature) of the long tubes is a properly assembled set of shorter headers attached to high flow cats (as high as you can find) in the primary location (or near it), and secondary cats also replaced with high flow, and a nice X-pipe. Add in some C63 muffs, and you would probably have a very nice sounding, and perfectly (federally) legal exhaust system.

That said - the cost of what I suggested may be very near the mbh now!

Just a note - because I have read some very strange **** on this forum about exhaust science, most of it wrong:

With independent understanding of collector length/shape, as well as tuning of where the primaries exist into the collector in firing order:

1) Primary length determines powerband position on a rev range: longer header primary-tube lengths usually add low-end torque, while shorter lengths should move the powerband up into a higher-rpm range.

2) Primary-tube diameter establishes the velocity of the exhaust-gas as it travels down the pipe. In simple terms, you want the tubes big enough so they don't form a restriction but not so large that the inertia of the incoming gas becomes insufficient to scavenge the cylinder of all exhaust gases. There is also something called "Tilt" as you look at a Dyno Chart. Larger Primary tubes will "Tilt" the power line so that its lower on the left lower rev side, and higher on the right, higer rev side.

On our engines, once you move from the log-style manifold we have stock, you are speaking of 15-25hp/tq variations in either direction when tuning the above physical dimensions. Of course if you found the perfect setup, it may be more. Again - I am not speaking of the total change from OEM to headers - that is quite large when you remove the logs and take out the VERY small (relative) transition from exhaust manifold to primary cats.

AMG E Power

if money is not a problem go MBH. if so go kleemann, had mine for almost 3 years no problems

DVC

Good stuff, BC928.

There's a post on the "other" forum where the Kleemann shorty headers are disassembled. Really a poor design. That they show any improvement demonstrates how restrictive the stock manifolds are.

AMG E Power

well ppl can say what they want about the design but me and others have all gained 35WHP from them so IM not complaining.

DVC

There you go. I love Kleemann and wish I lived closer so I could get a dyno tune.

AMG E Power

ya me to. the box tune isnt bad tho. been running it for almost 3 years.

BC928

That is indeed the point. The work for what they are there to do - but we have to be realistic as to why they are able to - the removal of the primary catalyst - which if someone wants to get really nasty in certain states - can cause some problems. No knock on the makers.

The MBH is a work of art as many have stated - but the gains past a set of (almost any) headers and removing the primaries is essentially the collector length and some tube tuning.

BC928

Yes. The real deal, in some minds, on a street machine is the collector shape and length. Make some headers, open that up - great - but focus on the collector length and shape to really gain the power. You can calculate the best primary length for this size engine/power level on a spreadsheet or some software like "pipemax" - but to get the nth - you need some dyno tuning.

boosted305

Bump for great info