2 hours ago, Sean Dezart said:

I have no data  - you said that you'd check the OEM Nissan twin-pipe diameters and I'm hoping someone on here with a Legalis system will come forward and volunteer the current pipe diameters. Until then, one can only speculate upon where the improvements originated but it was mentioned by someone else that an H-crossover wasn't ideal for inline engines....I didn't say that !

 

Fujitsubo quote the current pipe diameter - several times in several different places - as 50.8mm x 2.

Volume 13 of NOSTALGIC SPEED magazine - published July 2017 - carried an 'Advertorial' feature on the new Fujitsubo Legalis R system for the S30-series Z. See scans below:

Old design on the right, new design on the left:

Box on the bottom right gives data for an L28 engine in the tested car.

Apparently their improvements have been realised through various changes, notably the exhaust manifold and the resonator box re-design.

Thanks Alan.  Looks like the whole thing is new.

Thanks Alan - the scans are low resolution though so I can't make out the L28 references.

Looks to me that some of the primary pipes have been lengthened to equalise better the length differences, obviously the resonator has been seperated into two (most probably there was gas flow and velocity interference creating multiple influences on engine performance) and the rear end has been divided into very probably for the cheaper packaging mentioned earlier (shorter parts make for smaller boxes).

What's interesting is that around the diff the twin pipes are almost at 90° whereas before they were angled closer to 45 and those elbows haven't adversely afected performance.

Some intelligent mods.

Jeremy is running a Fujitsubo header on his L35.

15 minutes ago, Sean Dezart said:

Thanks Alan - the scans are low resolution though so I can't make out the L28 references.

Looks to me that some of the primary pipes have been lengthened to equalise better the length differences, obviously the resonator has been seperated into two (most probably there was gas flow and velocity interference creating multiple influences on engine performance) and the rear end has been divided into very probably for the cheaper packaging mentioned earlier (shorter parts make for smaller boxes).

What's interesting is that around the diff the twin pipes are almost at 90° whereas before they were angled closer to 45 and those elbows haven't adversely afected performance.

Some intelligent mods.

Jeremy is running a Fujitsubo header on his L35.

The old ‘low power’ one.

5 minutes ago, Jason240z said:

The old ‘low power’ one.

Not low, lower and probably quite minimal loss considering that he hasn't the Legalis line.

11 hours ago, Sean Dezart said:

Not low, lower and probably quite minimal loss considering that he hasn't the Legalis line.

Looking at comparison graphs, it’s a lot lower, percentage wise. Designed as a full system. 

Most power comes from a manifold and Center section

Sadly they are back ordered for at least a month. 

6 hours ago, Jason240z said:

Looking at comparison graphs, it’s a lot lower, percentage wise. Designed as a full system. 

Most power comes from a manifold and Center section

I was referring to Jeremys' engine for which I have no graphs. Agreed on what primarily affects power and torque.

1 hour ago, duffymahoney said:

Sadly they are back ordered for at least a month. 

Couldn't he wait for such a vital part?

I think you're missing the thread Jason - Jeremy fitted his months ago !

15 minutes ago, Jason240z said:

Couldn't he wait for such a vital part?

I am trying to get my series 1 ready for a local car show.  The only thing left really is exhaust.  Sadly my stock is shot, so I can't use that.  

Surely your inlet manifold too as it'll be 'difficult' fitting that after the exhaust.