I fitted an air box to cut down induction roar and lost 10 Kw at the rear wheels due to changes in ram tube length.
Cheers, Feral Errol Get Serious tm<http://www.datrats.com.au/> -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Robert Charles Scealy Sent: Wednesday, June 25, 2003 5:42 PM To: [EMAIL PROTECTED] Subject: Re: 40mm weber ram tubes Agreed. The ammount of reflection would be heavily dependant on too many factors so would change from car to car as well, as when you are getting to that level even the distance from the bellmouth to the bodywork would influence results. Also the speed of sound will be probably be different in the ram tube as the air would be cooler, and doesnt have fuel vapours mixed in. On Wed, 25 Jun 2003, David Andrews wrote: > Pick the University people. :). > > It would be possible to increase the amplitude of the compression wave I > suppose through this technique, but it may be minimal as when the > compression wave travels back from the bellmouth exit to the choke it > will be partially reflected and so only a portion of the compression will > continue back down with the original reflected compresison wave. > > I'm not going to read that to check it. Too hard. > > Dave > > >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< > > On 25/06/03, 16:26:10, Robert Charles Scealy <[EMAIL PROTECTED]> wrote > regarding Re: 40mm weber ram tubes: > > > > Maybe you could get some difference if you made the distance from the > > port to the choke equal to the tuned length from the choke to the > > bellmouth exit, then you would have some chance of setting up a harmonic > > standing wave, with a node at the choke? Like if you pick a guitar > > string, and then place your finger over the exact centre of the string, > > you still get some of the sound? > > > On Wed, 25 Jun 2003, David Andrews wrote: > > > > Guys, what you are talking about is the RAM effect which occurs as > > > follows: > > > > > > When the intake valve opens, an expansion wave travels up the intake > > > runner. When it reaches THE FIRST JUNCTION, it is reflected back as a > > > compression wave. The RAM effect is using the compression wave to > > > compress the air into the cylinder just as the intake valve closes again. > > > It is apparently possible to achieve Volumetric Efficiencies above 100% > > > (for a specific rev range obviously). > > > What Kris said was correct, longer is for low end, shorter is for top > > > end: > > > > > > http://www.grapeaperacing.com/GrapeApeRacing/tech/intaketuned.cfm > > > > > > But if you actually plus the numbers in, you're not talking 1.5 inches. > > > You're talking more like 15 inches. The link above has some formulas for > > > working it out. But the important thing to note is that it won't make > > > fuck all difference on a car with carbies because the first junction > > > (where the reflection happens) is at the `out' side of the carby, not the > > > inlet side. > > > > > > However, using bellmouth shapes does increase the airflow into the carby > > > by reducing the turbulence around the opening. But the length of this > > > will have a negilible impact on the overall VE of the engine. > > > Regards, > > > > > > Dave > > > > > > > > > >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< > > > > > > On 25/06/03, 14:31:24, Richard Webb wrote > > > regarding Re: 40mm weber ram tubes: > > > > > > > > > > I found a pic of some on that race car that someone sent to the list > > > > recently.... > > > > > > > http://www.race-cars.com/carsales/other/1054143781/1054143781ph.jpg > > > > > > > They are tiny?? and the eggcups wouldnt need any extending.. I guess > > > > they are after high end. Isnt there a stainless bowl or cup or > > > > something I can modify... :) > > > > > > > ----- Original Message ----- > > > > From: "Kristian Walsham" > > > > Date: Wednesday, June 25, 2003 2:09 pm > > > > Subject: Re: 40mm weber ram tubes > > > > > > > > A long one will better suit low to midrange torque and power while > > > > > a short > > > > > one will produce more mid to top end. > > > > > I think most short ones are about 1.5 inches long while longer > > > > > ones are > > > > > about 2-2.5 inches long. You would have to design it around engine > > > > > bay space > > > > > and the type of cam you are using. > > > > > > > > > > Kris. > > > > > ----- Original Message ----- > > > > > From: "Richard Webb" > > > > > To: > > > > > Sent: Wednesday, June 25, 2003 1:48 PM > > > > > Subject: Re: 40mm weber ram tubes > > > > > > > > > > > > > > > > I know this has been discussed before but how long (idealy) > > > > > should the > > > > > > ram tubes be? Also how the hell do you join stainless steal? The > > > > > > article says use tig welder... or hose clamp? Any ideas, because > > > > > I dont > > > > > > have a welder... > > > > > > > > > > > > ----- Original Message ----- > > > > > > From: David Andrews > > > > > > Date: Wednesday, June 25, 2003 1:21 pm > > > > > > Subject: Re: 40mm weber ram tubes > > > > > > > > > > > > > If twas me: i'd be going from 47 (45 by moi) down to the 40 > > > > > with a > > > > > > > nice > > > > > > > cone rolled up by your local stainless shop. I'm doing the same > > > > > > > thing, > > > > > > > albeit longer, for my custom intake manifold. > > > > > > > > > > > > > > Dave > > > > > > > > > > > > > > >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< > > > > > > > > > > > > > > On 25/06/03, 15:36:55, Richard Webb wrote > > > > > > > regarding Re: 40mm weber ram tubes: > > > > > > > > > > > > > > > > > > > > > > Yeah just got the article, 47mm diamater isnt going to work too > > > > > > > well on > > > > > > > 40mm > > > > > > > > webbers. I'll have a look with one of them see what I can make. > > > > > > > > > > > > > > > I dunno how that Jullian Edgar guy comes up with 1/2 that > > > > > > > stuff.... hes a > > > > > > > > total car nerd :) > > > > > > > > ----- Original Message ----- > > > > > > > > From: "E Smith" > > > > > > > > To: > > > > > > > > Sent: Tuesday, June 24, 2003 5:11 AM > > > > > > > > Subject: RE: 40mm weber ram tubes > > > > > > > > > > > > > > > > > > > > > > Dave, > > > > > > > > Youve been reading Autospeed :-) > > > > > > > > > > > > > > > Cheers, > > > > > > > > Feral Errol > > > > > > > > Get Serious tm<" target="l">" > > > > > target="l">http://www.datrats.com.au/>> > > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > > > > > > > From: [EMAIL PROTECTED] > > > > > > > > [mailto:[EMAIL PROTECTED] Behalf Of David > > > > > > > Andrews> Sent: Tuesday, June 24, 2003 2:42 PM > > > > > > > > To: [EMAIL PROTECTED] > > > > > > > > Subject: Re: 40mm weber ram tubes > > > > > > > > > > > > > > > > > > > > > > You may be able to make your own out of some egg holders from > > > > > > > > Safeway/Woolworths. They're $1.85 each here, perfect bellmouth > > > > > > > shape. ID > > > > > > > > of 44mm. Regards, > > > > > > > > > > > > > > > Dave > > > > > > > > > > > > > > > >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< > > > > > > > > > > > > > > > On 24/06/03, 14:01:59, "Kristian Walsham" wrote > > > > > > > > regarding Re: 40mm weber ram tubes: > > > > > > > > > > > > > > > > > > > > > > > You could try Four Plus Performance in Brisbane ( i don`t > > > > > have the > > > > > > > > number) , > > > > > > > > > or Autosport in Vermont, Datrally in Cheltenam. > > > > > > > > > > > > > > > > I know i had a few spare somewhere, i will have to look. > > > > > > > > > > > > > > > > Kris. > > > > > > > > > ----- Original Message ----- > > > > > > > > > From: "Richard Webb" > > > > > > > > > To: > > > > > > > > > Sent: Tuesday, June 24, 2003 1:39 PM > > > > > > > > > Subject: 40mm weber ram tubes > > > > > > > > > > > > > > > > > > > > > > > > Hi guys, > > > > > > > > > > > > > > > > > > > > Can anyone tell me where abouts I might be able to get some > > > > > > > weber ram > > > > > > > > > > tubes/pods/trumpets (whatever you call them). The guy at > > > > > > > unifilter> > > thaught he had some but doesnt anymore! Now I've > > > > > > > rang up a few places > > > > > > > > > > and they are telling me no one makes them anymore??? > > > > > > > > > > > > > > > > > > > > Im in melbourne and would be interested in any info on > > > > > where to > > > > > > > > > > purchase them. > > > > > > > > > > > > > > > > > > > > Thanks in advance, > > > > > > > > > > > > > > > > > > > > Richard > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > --membersozdat------------------------------------------------- > > > > > ---- > > > > > > > -- > > > > > > > OZDAT Mailing List Please Note:- > > > > > > > Send (un)subscribe requests to [EMAIL PROTECTED] > > > > > > > Send submissions to [EMAIL PROTECTED] > > > > > > > No unauthorised redistribution of this email > > > > > > > http://www.ozdat.com/ozdatonline/index.htm > > > > > > > http://www.ozdat.com/ozdatonline/listindex.html > > > > > > > http://www.mail-archive.com/[EMAIL PROTECTED]/ > > > > > > > --------------------------------------------------------------- > > > > > ---- > > > > > > > -- > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > --membersozdat----------------------------------------------------- > > > > > -- > > > > > OZDAT Mailing List Please Note:- > > > > > Send (un)subscribe requests to [EMAIL PROTECTED] > > > > > Send submissions to [EMAIL PROTECTED] > > > > > No unauthorised redistribution of this email > > > > > http://www.ozdat.com/ozdatonline/index.htm > > > > > http://www.ozdat.com/ozdatonline/listindex.html > > > > > http://www.mail-archive.com/[EMAIL PROTECTED]/ > > > > > ------------------------------------------------------------------- > > > > > -- > > > > > > > > > > > > > > > > > > > > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[EMAIL PROTECTED]/ ---------------------------------------------------------------------
