Heath, The motor currently has twin 40mm Dellorto's but will soon be getting a custom efi manifold. The motor makes over 190hp and is built to spin to 8k. A new bottom end is planned that will rev even harder. The nitrous kit, as with all nitrous kits, is adjustable and I will probably use up to 150hp of gas, maybe a bit more. I realise that gases contract as they cool but I am planning to make some big power out of this motor with a capacity increase and a supercharger. I also do not like a stepped exhaust system as it disrupts the flow especially boundary layer gases. I know the specs you list are great for a rally car style L series with a big fat midrange, but my car whilst being an everyday driver is built to rev hard and for occasional club use. Several different configurations where run through Engine Analyzer and the 4-1 system gave the most area under the curve. I will run the specs you gave me again and check the overlay of the projected power graph. Jake
--- "Cleary Signs" <[EMAIL PROTECTED]> wrote: what induction will you be running on the L20, i wouldn't call a L20 a high reving motor, i would go the 4-2-1 on a L series, esp a L20, if running N20, what size gas kit will you be running? as this will determine what size pipe you need. As the exhaust gases cool they condense, so i would be 2 1/2 to half way then, go down to 2 1/4 through the diff. on a 4-2-1 system, 4 x 1 3/4 primaries 12" long, into 2 x 2" into a 2 1/2 collector at 18" long. i think this is what Murray Coote told me. this is for a 200hp+ L series. Ring Dave Feron in Redcliffe, i'm pretty sure he'll still have the specs. Heath ----- Original Message ----- From: "Jake Andrew" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, April 28, 2004 9:10 AM Subject: Re: exhausts questions > I have just done a fair bit of research into exhaust systems as I am having a full custom system done for my 1600 at the moment. Everyone I have spoken too seems to think that anything over 2 1/4 inch on a NA 2 litre is simply overkill and will only produce more noise. For a high revving 2 litre a good 2 1/4 inch system should produce great results. An example given to me was the S2000 which runs 2 1/4 inch pipes till it splits to the twin rear mufflers. These engines are making around 170kw which is more than most L series will make in NA form. > I am getting a set of 4-1 extractors made with 1 5/8 primaries going to a full mandrel bent 2 1/2 inch exhaust with a resonator and triple pass hi flow rear muffler. This should have very good flow whilst not being overly loud. This system is for an L20 that will be running a fair bit of nitrous and will most likely end up supercharged. To run a 2 1/2 inch exhaust you will have to cut the rear crossmember as the factory crossmember exhaust hole is 2 1/2 inch. > I run a 3inch system on my FJ20et 1600 with only a truck resonator at the rear. It flows extremely well, you can drop a tennis ball in the top and it rolls straight through, but is up around 105db. > Jake > > > --- Brad <[EMAIL PROTECTED]> wrote: > > >From my experience any bigger than 3" is a waste of time, perhaps this might more apply to NA cars than turbo, but I think definitely guys go for the milo tins and cost themselves power. > > I think the rice-tosspots put on shit for the sake of it when they could choose their bits more carefully and appropriately and end up with more power and less noise. > > I know I'd always prefer a sleeper. > > A very common mistake lots of people make too is fitting race-style extractors to a road car so the thing is tuned for 5000rpm and is shit at low revs. > > We built a custom exhaust for the HQ which had nice big collectors going to a smaller diameter pipe (I think 3" down to 2.5") with a hotdog and megaphone. OK not a good indication of a road system, but our car (which was down on outright power due to no head work etc), had great drive out of the corners so you could nip up the inside of people on the short tracks. > > The exhaust was shorter overall as well (came out under the drivers door as apart from in front of the rear wheel), and the guys with longer exhausts seemed to have better top-end (but they were probably on the dyno more). > > > There is some debate about exhausts being too big & not providing enough > > back pressure. > > But i think its only the first part of your exhaust (the headers) that > > affect this. > > that why some new exhaust systems run variable exhaust manifolds as it > > affects your torque at various revs. > > > > go to about halfway down on this web page for some info. > > > > http://www.autospeed.com/cms/A_46/article.html > > > > > > I am running 4-2-1 motivator extractors into 2 1/2 with 3" tail pipe & turbo > > muffler. > > the 4-2-1 (or "y" extractors) give a slightly more spread torque range than > > 4-1 > > I think 2 1/2 inches is biggest that will fit in the rear cross member of a > > 510 > > without enlarging the hole :) > > > > When i got rid of the bit of curtain rod that was on my car i noticed not > > more power > > but that the engine felt like it could rev out further easier. > > > > BUT i could have it all wrong so ask some professionals :-) > > cheers Jeff > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] Behalf Of kla > > Sent: Sunday, April 25, 2004 12:47 AM > > To: [EMAIL PROTECTED] > > Subject: exhausts questions > > > > > > I've been wondering about sports exhausts, as i was thinking of getting a > > system installed (extractors to the back) > > and i was wandering. as a general rule. sizes. obviously too small means > > not enough flow, but what about big? > > what happens when you get too big, and what is generally the best size for > > a 1.5litre (standard, non-turbo etc.) > > if its too big do you get a dead space effect where it cant move enough of > > the air or what? > > cheers. > > > > --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]/ > > --------------------------------------------------------------------- > > > > > > > > _____________________________________________________________ > AutoSpeed - The World's Best High Performance Online Magazine > http://www.autospeed.com > > _____________________________________________________________ AutoSpeed - The World's Best High Performance Online Magazine http://www.autospeed.com --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]/ ---------------------------------------------------------------------
