DA100 Header Length

[TheTank]

Hey guys, what is the optimal header length for a DA100 and MTW cans? Any different header length needed with KS cans instead?

[SMOKEY]

Looking for the same info myself.
Tank...which MTW do you have and what prop are you planning to use.

Smokey

[Flyinrazrback]

I ran my DA 100 and MTWs at 9.75s, worked flawless at that length.

[SMOKEY]

What prop were you using?
Smokey

	Quote: Originally Posted by Flyinrazrback
	I ran my DA 100 and MTWs at 9.75s, worked flawless at that length.

[Flyinrazrback]

I used a mejzlik 28x10 and 3W carbon 27x11. Was in an AW 36% Katana. Prefered the mejzlik for 3D and the 3W for precision.

[Hoss]

9 3/4 with MTW 75's on with Mejzlik 28x10 and 6 3/4 with KS 1060s.

[SMOKEY]

I was going to run Menz 27x10. Would i need longer or shorter lengths.
Tank...Sorry for hijacking your thread.

Smokey

[Hoss]

I ran the same prop for beak in at the 9 3/4 header length.

[TheTank]

	Quote: Originally Posted by SMOKEY
	I was going to run Menz 27x10. Would i need longer or shorter lengths. Tank...Sorry for hijacking your thread. Smokey

No problem! I think I have got good enough information for me.

[crhammond]

DA told me 10.5" +/- 1" is optimal.

For what it's worth I modified a GP Cap 580 to take cans and ended up with very short approx 7" headers. I was warned it would have a bad mid range and be prone to surging. It is not - it works just fine and is very linear and smooth! COuld be I just got lucky...

[TheTank]

Thats good to know as well. I am currently running a 100 on some JMB cans with shorter headers, but wanted to make sure I got the correct info for a buddy of mine before he installs his. I didnt want him to give me a "tucson tuneup" if I had him cut his new headers to short right off the bat!

[DATech]

Hello

When possible, we recommend using the standard MTW header length (approx 11”). After many years, this has proven to be a good length.

If there are clearance issues, you can go shorter. The performance will generally be fine and you may even see an increase in RPM, but…. as the header length gets shorter, there is an increased chance of higher engine temps as the exhaust systems tuning envelope is pushed. This may cause problems over the life of the engine. An inch or so should be no problem. If it is much shorter than that, keep an eye out for heat related issues. Good airflow on the cylinders and correct needles settings will be a definite must.

With a lighter load/smaller prop, the header generally gets shorter, bigger load/prop, the header generally gets longer.

Optimum header lengths vary depending on the internal layout of the muffler and the prop load. “Generally” KS mufflers like the longest headers and BMB’s the shortest, with MTW in the middle. JMB’s appear to have less of a tuning effect and can work with very short headers.

Your mileage may vary....



Hope this helps.