I built a set of cans today. I used about 7 feet of 3/8" air hose. The shiny hard stuff, thinking it would transmit high frequency sound better. I used a brass barbed T and 3/8" vac line leading up to a pair of ear protectors that I drilled holes in the bottom of. The line was pressed tightly through the holes about 1.5".

The engine end of this deal was the regular 1/4" NPT fitting so I took a male quick disconnect and welded it to the upper jaw of a small pair of vice-grips. The weld sealed up the end of fitting.

I tapped the vice grips on a metal bench and the tapping was very nicely transmitted. So i went over to a car on in the shop and clamped it to the only easy accessible part of the block, a head bolt on cyl #2, about 4" from the center fo the combustion chamber. I have to say that I was very disappointed and could not hear the engine at all through them (you would think a stone cold v10 with forged pistons would be loud). I have a chassis ear so I probably wont experiment with the cans tomorrow, but I hope to make use of them soon and compare them to their electronic cousins.

 

I think part of your problem is that you used vacuum line after the T.. I don't see how vacuum line can transmit sound very well at all.

 

yup maybe that is it. it was pretty thick walled but relatively soft. something a little more pliable than the air hose would be nice though. Maybe that clear plastic stuff that is reinforced with fiberglass woudl work...I was under $10 total. might have to go all out and spend $15

 

yea something aint right. You should be able to hear very clearly.

 

might be where I clamped too. I only spent about 10min on the whole thing except for buying the vicegrips. I'll post pics and more info i get them working.

 

 

anymore feedback on this? i'm really starting to second guess myself on this. Shouldnt an enginge have more power with knock eliminated? Because ever since I retarded my timing to eliminate knock(which was about 4-5* throughout the high cam) I can definately feel a loss in power.

What kind of sound is everyone else hearing for detonation? does it sound like a bunch of rice hitting foil? or just a little amount of rice? Mine was just a small amount, not like a rainstorm of rice. Do you think it would be safe to run the car like that? because it definately pulled harder that way.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by See Are X &raquo;</TD></TR><TR><TD CLASS="quote">anymore feedback on this? i'm really starting to second guess myself on this. Shouldnt an enginge have more power with knock eliminated? Because ever since I retarded my timing to eliminate knock(which was about 4-5* throughout the high cam) I can definately feel a loss in power.

What kind of sound is everyone else hearing for detonation? does it sound like a bunch of rice hitting foil? or just a little amount of rice? Mine was just a small amount, not like a rainstorm of rice. Do you think it would be safe to run the car like that? because it definately pulled harder that way.</TD></TR></TABLE>

sounds like your just "pulled" 4-5 * threw the whole high cam, maybe you pulled "more" timing than peak HP and started droppin power. Add a degree or 2 back in and see what kinda differnce it makes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMs1eeper &raquo;</TD></TR><TR><TD CLASS="quote">sounds like your just "pulled" 4-5 * threw the whole high cam, maybe you pulled "more" timing than peak HP and started droppin power. Add a degree or 2 back in and see what kinda differnce it makes. </TD></TR></TABLE>

I didnt just pull 4-5* throughout the whole high cam. I made pass after pass up to 5k rpm, then 6k rpm, then 7k rpm, then 8k rpm, and retarded the timing where it needed it....maybe I should just turn up the boost to compensate? right now im running only 9psi w/ total timing at 15*. If I turn it up to 11psi, i'll probably be running around 13* total timing, which seems kind of low.

 

Well you have to think, you’re going to make more power at the ragged edge. But for longevity you want to keep ALL detonation at bay. Slight detonation over a long period of time might not be enough to crack a piston but imagine what your bearings and other vital parts are going threw.

I say play it safe and if you lost a tad of power then up the boost 1-2psi to make up for it.

 

Honestly, Ive heard the sound you are talking about, b/c it happens on my car. Right now I am running 16.75* total timing @ 7.5 psi, putting me at 1*/psi total retard. It seems almost IMPOSSIBLE that the car is detonating at this amt of timing, but I still hear that noise. My plugs are perfect!

Now low rpm detonation I can tell you what that sounds like. It really does sound like a sharp, metallic noise, very distinctive. Like some have said, sounds like steel ***** knocking around in a tin can. Im sure you've heard it before too. Havent you ever been in an older car that pings on acceleration? That is detonation!

 

the common practice of tuning timing on a dyno is to add timing after peak torque until the power begins to drop, then pull out like 2-3 degrees.

this thread makes me seriously doubt the reliability of that practice.

 

If it's knocking at 16.75* total timing @ 7.5 psi, then ECU and cam/crank timing are probably not synch or you have very high CR.

You will gain hp when the engine is not knocking. Most tuners have seen the results on a dyno.

 

SOHC's dont like timing! I just tuned another sohc today and on 9psi it didn't want anymore than about 15* total timing and again I had to pull out a good couple degrees around vtec crossover. Thats 3 sohc's i've tuned recently and all of them needed to run nice and low timing.

 

in any of them, did the ignition timing slope down like mine?

 

nope none of them had to slope down. I didn't really have to touch the timing much before vtec.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">SOHC's dont like timing! I just tuned another sohc today and on 9psi it didn't want anymore than about 15* total timing and again I had to pull out a good couple degrees around vtec crossover. Thats 3 sohc's i've tuned recently and all of them needed to run nice and low timing. </TD></TR></TABLE>

that was a nice car

 

Heck yea. Clean *** EK

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">nope none of them had to slope down. I didn't really have to touch the timing much before vtec.</TD></TR></TABLE>

damnit...i wonder what makes mine so much different than everyone else...when you retarded ignition on any of those sohc, did you feel any loss of power on the butt dyno?

 

i honestly cant tell if there is much loss in power or not. Def doesn't feel like 5* were pulled out on my own car. Some days i feel like i lost power and other days i feel like it gained power lol. I guess i'll just have to break down and pay for a dyno of my own car

 

BTW here is a goofy vid of me using the Det Cans. I'm not really that short...my seat bracket just sits extremely low
http://media.putfile.com/SOHC_Mshue-Det-Cans


Modified by SOHC_MShue at 3:02 PM 3/26/2006

 

LOL @ you mr Shoe! lol.

 

hahaha i knew you guys would get a kick out of that

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">
</TD></TR></TABLE>

Why do you have this one here? Checking for knock on the radiator support? Do you have pix of the "headphones"?

 

is that my old tial 38?