Modded L28 - single exhaust pipe or two?

Tony 260Z

Club Member
Hi all, my 240 is "getting there" and attention is now on the exaust. At the moment there's a single 3" pipe leading to a chunky 300ZX backbox. It's quite fruity as you can imagine. The backbox has rotted out and I want to replace it and the centre pipe. The engine is an L28 with a modded head and cam, triple 45's and a NISMO 6-branch header (from MSA I think). Three cylinders go into each of two collectors and then there's a Y-piece to take it down to the single pipe. The car rides pretty low so I'm wondering about the practicalities of doing away with the single three inch pipe and putting a pair of two inchers running side-by-side under there instead. That could give me a bit of extra clearance underneath.
Does anyone have experience of the "twice pipes" setup from MSA? Or would I be better off going to someone like Pipecraft and having them make something up? I see that the twice pipes setup still comes out of a single pipe after the header - what would be the effect of running each three-header collector straight back without a y-piece? I'm guessing that y-piece and short length of single pipe smooths the gasflow which I assume is more efficent and therefore better for power but I don't know much about the physics, and that doesn't fit with what I've seen of cars running shortie headers or V engines where each bank has a side-exit exhaust.
Thoughts?
 

johnymd

Club Member
I think Sean's systems are great value but you would need someone to get it to join with your header. The twice pipes are very loud. I had a set on my rat look zed and it was a bit too loud.
 

SeanDezart

Well-Known Forum User
If you want a twin outlet exhaust, it needs twin pipe system to suit.

No, it doesn't 'need' - that may be a personal desire/choice but it doesn't 'need' it !

My first 240Z had a Twice-pipes exhaust line back in 1991 - it if effin loud !

There is no such thing as a 'Nismo' 6-1 exhaust manifold, it's just an MSA 6-1 which induces exhaust drone. Personally, I'd get rid of it - even the Pacesetter 6-2 are betetr but don't join those secondaries until way clear of the bulkhead.

" I'm guessing that y-piece and short length of single pipe smooths the gasflow which I assume is more efficent and therefore better for power "

Nope, with respect you need to read up a tadge more on exhaust mechanics and not be swayed by the armchairs on here. I'm not saying buy mine but I am saying that your guessing is wide of the mark.

ps I won't get into a slanging match here - if you would like to discuss this off forum, I'm at your disposition and maybe there are several options for you and not necessarily mine.
 

uk66fastback

Club Member
Sean, when are your pipes going to be able to join up with the standard manifold - was it next year? My current exhaust seems to run RIGHT UNDER the diff for some reason (not to one side) and I fancy a new system at some point ...
 

SeanDezart

Well-Known Forum User
Sean, when are your pipes going to be able to join up with the standard manifold - was it next year? My current exhaust seems to run RIGHT UNDER the diff for some reason (not to one side) and I fancy a new system at some point ...

Hi Mike.

It will be next year because :

I've been busy doing some fitting mods to the existing range
Producing my 'new' Fast-Road' manifold and Y-pipe
Producing my version of the stock L28ET manifold

Twin downpipes for the 240Z /260Z and a version for the 280Z should therefore be available in 12 months time.
 
Firstly - subjective

Secondly : subjective

Just think of the money BMW spent designing the system on the s50 range. That good that you got really minimal gains from any exhaust swap, still.

https://www.google.com/search?q=s50b32+exhaust+design&safe=active&client=firefox-b-ab&tbm=isch&source=iu&ictx=1&fir=qif29y7cKxdYGM%3A%2C4gE77kpFwItSIM%2C_&usg=AI4_-kR6HTzPXO353csA98wAIdbwvrDRhg&sa=X&ved=2ahUKEwig4KubxNDdAhWHJsAKHUFZChEQ9QEwBHoECAAQDA#imgrc=diq7FW6_k-UxZM:

Nissan, well I guess Prince were onto something in the 60's.
 

SeanDezart

Well-Known Forum User
Nissan offered (in Japan) the twin exhaust line system as standard on the S20 S30s and as an option on the L20. But the Lgata engines were sold in Japan and worlwide with a single exhaust pipe albeit with a smaller diameter than most single after-market lines.

Nissan don't supply exhausts anymore for our cars so aftermarket is all there is - "you pays yer money and makes yer choice" ! All I'm saying is choose wisely and informatively, every application requires a specific input, not every expensive kit is the best, not every cheap one is rubbish.
 
Nissan offered (in Japan) the twin exhaust line system as standard on the S20 S30s and as an option on the L20. But the Lgata engines were sold in Japan and worlwide with a single exhaust pipe albeit with a smaller diameter than most single after-market lines.

Nissan don't supply exhausts anymore for our cars so aftermarket is all there is - "you pays yer money and makes yer choice" ! All I'm saying is choose wisely and informatively, every application requires a specific input, not every expensive kit is the best, not every cheap one is rubbish.

Most of the time the most expensive isn't the best. My comment was nothing to do with money. I once wasted a lot of money-dyno time trying to improve/change an Il6 exhaust design from a twin pipe system.
 
Top