9/73-E31-260z Posted October 26, 2013 Share Posted October 26, 2013 So I'm eventually going to do a L28ET+5 speed swap in my 74 260z, so I've been doing research on the whole swap and what's involved. Now I know that the stock exhaust system for 280zx's and L28ETs are not exactly ideal for higher performance, namely the restrictive downpipe. What I'm wondering is if I were to do something like an open downpipe or straight pipe: just how loud is it? I've heard straight pipe setups that sounded like a burly V8 at idle but monstrous at WOT, I am 100% ok with that, I just would like to be able to hear myself think and not have to yell to talk to someone in the car. Is anyone here running an open exhaust of some point? I know turbos really cut down on exhaust volume but would it still be too loud realistically? And as far as the performance merit of an open setup it would be something I would like to take advantage of as my plans for this engine would be around 350hp. I need to do things like an R200+axles and the like before I put the engine in but I'm just trying to compile as much info as possible. Thanks Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 26, 2013 Share Posted October 26, 2013 An open downpipe on a stockish L28ET with a stock cam and turbo isn't godawful. It is pretty damn loud, though. Add a moderate cam and it's HELLISHLY loud...Just ask RedZedTurbo here. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 26, 2013 Author Share Posted October 26, 2013 (edited) Well in my research I found that the stock cam can actually be good for up to almost 400hp so I'll probably keep that. The build would initially be mostly stock except like ECU, exhaust, maybe injection, and probably an intercooler. I'd be using it mostly stock for a while before the more serious build elements come into play like an upgraded turbo or bigger throttle body and stuff like that. I've just heard some people say that open downpipes/exhaust are stupid loud and are totally impractical (even though they help performance quite a bit if done right) but every time I hear one it's actually not all that loud to me. Edited October 27, 2013 by 9/73-E31-260z Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted October 26, 2013 Share Posted October 26, 2013 It's loud. I'd say it's as loud as open pipes--just not quite as annoying. At idle it's bearable but anything else and it's loud. Still annoying at WOT. Plus you will have problems of fumes entering the cabin, it's still going to be loud enough to receive a citation, and emissions problems if that applies to you. Quote Link to comment Share on other sites More sharing options...
Xnke Posted October 26, 2013 Share Posted October 26, 2013 If you apply the Maximum Boost principles, then yes, a stock cam is fine. There are plenty of things to do before you change the cam; and if you plan to run more than 10lbs of stock turbo boost you really need to think about engine management before cams/boost/turbo/etc. In the state you live in, you will most likely run into a LOT of problems trying to drive with an open pipe. I'd venture a guess that you'd get a ticket within a month of driving an open pipe; out here in semi-rural Kentucky as long as you aren't bothering someone else they'll leave you alone. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 26, 2013 Author Share Posted October 26, 2013 Yeah I'll probably do Megasquirt or something when I am ready to put the engine in, and just enjoy it like 98% stock with maybe a little boost turn up, then do an intercooler, then go from there. I am exempt from emissions in CA by a year or so, and the weird thing is I never, ever see any cops around whenever I'm driving. It's just a thing. i dont drive like an idiot but with my luck it would be ridiculously easy to do some stupid crap all the time and never see a single cop. If I do see one I wouldn't say, gun it at WOT with an open downpipe. Is there any real difference between just a simple say 3'' straight pipe out the back or side eve as opposed to just an open downpipe? Both performance and sound, I assume the longer pipe would make it a bit quiter and maybe more hollow, but wouldn't change performance by much if at all. Quote Link to comment Share on other sites More sharing options...
Milenko2121 Posted October 26, 2013 Share Posted October 26, 2013 I ran an open downpipe before I got my exhaust finished. I was using the MSA Downpipe, and It did get annoying after awhile, and got me a fix it ticket. After that, I finished up my exhaust. I researched for the best muffler that would give me that nice loud WOT sound, but low growl at idle to keep me in the clear. I decided on a full 3" mandrel back with a Borla XR-1 at the end. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted October 26, 2013 Share Posted October 26, 2013 Just with a downpipe does sound pretty wicked at WOT though. I like that my car is quiet now. I rode around with straight 3 inch all the way back all this past year and recently put my muffler back on. I won't be taking it back off. That drone at 65 was horrible. In addition these cars attract enough attention both good and bad so I feel better not adding to the bad attention I might possibly attract. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 26, 2013 Author Share Posted October 26, 2013 See if I can get a good deal on piping I'd like to do 3'' turbo back to basically the most minimal muffler I can find that can cut drone some but basically be unnoticeable at WOT. And my friend has XR-1s on his 74 F250 with headers and a 360 but my 260 is louder than it (although the prvious cut out the rear muffler so all it has is that little pre-muffler thing in the middle), the exhaust shop kinda did some weird stuff like putting the x-pipe way far back and crush bending the pipes 0.o Quote Link to comment Share on other sites More sharing options...
ktm Posted October 27, 2013 Share Posted October 27, 2013 I decided on a full 3" mandrel back with a Borla XR-1 at the end. Which is what I ran for a few years and loved it, though it did drone at highway speeds. It is loud inside the car but sounded great. http://www.youtube.com/watch?v=bWMSIYn5hro Quote Link to comment Share on other sites More sharing options...
Milenko2121 Posted October 27, 2013 Share Posted October 27, 2013 Which is what I ran for a few years and loved it, though it did drone at highway speeds. It is loud inside the car but sounded great. http://www.youtube.com/watch?v=bWMSIYn5hro Your video is the reason I chose the XR-1 It just makes the L28ET sound so mean. There is a slight drone, but It hasn't bothered me too much. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 27, 2013 Author Share Posted October 27, 2013 That's pretty much what I'll run eventually, but probably not Borlas, my friend has an L28 240z with headers straight to a Magnaflow racing muffler that sounds sinply ungodly... by far one of the best exhaust setups I've ever heard. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 27, 2013 Author Share Posted October 27, 2013 I'd looove to replicate something like this. Scare some ricers for sure... But like I was saying it doesn't really seem all that crazy loud to me, even though the guy was like right in front of it filming, it wasn't that loud when the guy was sliding away further either Quote Link to comment Share on other sites More sharing options...
roger280zx Posted October 27, 2013 Share Posted October 27, 2013 (edited) Why is the question either down pipe only, or 3'' all the way out back to a muffler. There is all kinds of middle ground in between. Keep the muffler but do side exit fore rear wheel is one example, this way you have the sound elimination, but don't have to add the weight (and bends) to carry it around the axles and out the rear. I have seen guys run a turn down just in front of the rear suspension. My car is currently on jack stands receiving 3" dp in SS carrying into the tunnel, then v band to 3" aluminum splitting into a y pipe and dual 2.5" exiting at about 45* in front of the rear wheel. The incentive for this system came when my 2.5" dp to 3" all the way out back to a magnaflow straight through came in at something like 38lbs iirc, new system is less than ten Edited October 27, 2013 by roger280zx Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 27, 2013 Author Share Posted October 27, 2013 I was actually thinking about something like that as well^ My friend's truck has the same kind of exits before the rear wheels. I just wasn't sure about if there was enough room out the sides of if that would cause any heat issues for the underside. My friend's truck is a heck of a lot higher than my 260 obviously so that's not an issue for him, and I haven't really seen many people running side exits on S30s if at all. I love side exits though, would the Y pipe effect the flow at all as opposed to just out the back? And what about the fumes issue? Quote Link to comment Share on other sites More sharing options...
redzedturbo Posted October 27, 2013 Share Posted October 27, 2013 I have ran a open 2.5'' dp for almost a year on my daily zx-t. And for some time it was fun but after a few months it becomes old and annoying. Take it from me run a 3'' all the way out the rear of the car with no muffler and its still loud as hell on boost but tolerable to drive daily. My car is pretty mild stock longblock 60mm throttle body, comp cam to4e 50 trim on 8 psi for now and megasquirt ms1 v3. I still return 24-26 mpg and runs 13.s on street tires at 102 mph. I will soon be going to a full 3'' for its long over due. A turbocharger in my county is a legal muffler lol I feel for you guys in cali with emission laws and crap no smog checks here THANKS Ernie fletcher. Bottom line is put the longest free flowing exhaust you can manage and still get the sound you want and can live with everyday. Best of luck!!!! Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted October 27, 2013 Author Share Posted October 27, 2013 I should look up what California considers as a muffler haha It'd be sweet if I could just not have any muffler, be lighter and cheaper haha I can't wait til I can at least drive my car even as it sits... xP Quote Link to comment Share on other sites More sharing options...
spiff Posted October 27, 2013 Share Posted October 27, 2013 Just a downpipe would become pretty annoying pretty fast, at least in my experience... I'm running a 2.5" exhaust from the turbo and back with only a muffler, isn't loud at all... Pretty sure I could remove the muffler without being to bothered about it, at least since this isn't my daily driver... Quote Link to comment Share on other sites More sharing options...
redzedturbo Posted October 30, 2013 Share Posted October 30, 2013 I know guys in cali that have got a ticket for illegal exhaust modifications for having a chrome tip on! Now way you will get away with no muffler if its not stock there they will kill you lmao. Best of luck. Quote Link to comment Share on other sites More sharing options...
tyson Posted October 30, 2013 Share Posted October 30, 2013 (edited) Ran a 3" downpipe on my internally stock 280ZXT. At idle it sounded nice At WOT it sounded nice At higher RPM it sounded nice. Revving it sounded nice. At lower RPM and most cruising, it was annoying as hell and sounded like complete ass, like a shitty car without a muffler. The drone and sometimes resonance during freeway driving was hellish over time. I'd never choose to run a car like that again, it was more annoying than anything. Edited October 30, 2013 by tyson Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.