Exhaust Primary - Secondary Length and configuration

Exhaust Primary - Secondary Length and configuration

Author
Discussion

Inline__engine

Original Poster:

195 posts

137 months

Monday 23rd April 2018
quotequote all
What method are people using to estimate the "best" primary and secondary length for a naturally aspirated engine.

no need to stick to 6-2 configuration, 6-3 and 6-1 would also physically fit

lets say for example its a 6 cylinder 3,152 cc making peak hp 330 at approx 6750 rpm 4V per cylinder, Camshaft is 250*@ 1 mm

the aim is not most peak hp but good area under the curve for the track and being able to come out of corners.



Inline__engine

Original Poster:

195 posts

137 months

Monday 23rd April 2018
quotequote all
it was my understanding that benfits of a 6-3 over a 6-2 are quite small and unlikely to be found without signicant testing (something i dont have the stomach for). the reason being stated was the 6-2 is still equal firing and seperated far enough for most camshafts, even though not a full 360.

what ever design produces the highest average torque is ideal

lets assume peak torque say 5000-5500rpm.

Edited by Inline__engine on Monday 23 April 22:34

Inline__engine

Original Poster:

195 posts

137 months

Tuesday 24th April 2018
quotequote all
I have that software but I'm after other people's experiences, thoughts, opinions, results from testing etc

Inline__engine

Original Poster:

195 posts

137 months

Wednesday 25th April 2018
quotequote all
How many 4v per cylinder Inline 6's do you think Larry does? And how many for non drag applications.....probably slightly difference between getting a 2nd opionion and ignoring

Edited by Inline__engine on Wednesday 25th April 21:55

Inline__engine

Original Poster:

195 posts

137 months

Wednesday 25th April 2018
quotequote all
The program is largely empirical therefore the test mules do matter . If you speak to Larry it doesn't explicitly differentiate between 6-3 6-2 or 6-1 as that's not until the newer version he's been working on which also works more like a simulator You only can use tri-y somewhat approximate 6-3. I was hoping others had experience trying different things and could comment

I've done my own testing on a full exhaust system (as opposed to open headers) on a different spec Inline engine but haven't been able to test the primary influence ( only collector Length was varied ) . My Findings were that you can't just blindly use the recommended lengths when using a full exhaust system. Some of the best lengths recommended are short but with full exhaust without a large termination box this does not work best. With a termination perhaps the recommended lengths may actually be the best due to acting like open headers but have yet tested this



Edited by Inline__engine on Wednesday 25th April 23:41


Edited by Inline__engine on Wednesday 25th April 23:56