Sean Dezart

No - being lazy after a long day....certainly there are cost implications on engineering a dual exhaust - bad enough on a single one trying to get something to fit all S30s ! Well, reading through Whiteheads' description, it will fit with some machining 'perhaps' of the diff flange which would still leave it tight but exploitable.

Put 'em up lad and let's have a butchers again ! Perhaps the performance improvement was a good spin off but obviously no-one markets a product going backwards. And others too but Nissan in their wisdom sold us single pipe exhausts after twin downpipes. This is all intellectual mass-debate-ion unless someone with a Legalis system wants to try both* out on the same car, day, dyno ? *a single exhaust

Cheers - good point and not everyone wants to have to remove and refit a line once a year.

Ok, ok - the 50mm (missed off the sentence) dual-pipes that were (from Nissan) and still are (from Fujitsubo) commercially available are better suited towards the smaller cc engines (S20, L20 and L24) than larger. There probably are but you're saying that you don't know of them ? An E and D-Type have twin pipe systems (admiteddly the D(Type are VERY short) but both they have ridiculously short primary pipes compared to an L-gata and both are DOHCs. So why is it that headers and lines are so 'drag' biased ? Only motorsport competition open (read affordable) for most owners ? Thanks for the info - and so, again, a small cc, high revving engine...presumbly the pipe diameter was scaled up because : a) it'll match the combustion chambers' demands b ) it could fit under that model of car How big is 'big' basing the sandard diameter at 50mm ? I think you missed the point - Alan was talking scaling up - not me. Re importer - of course but relevant here because they were quoted AND are the N-American official importers : nice to see the extra model-specific info in there - good customer-advice. Interestingly, the RHD Legalis image shows two seperate resonator pipes as per the Spirit Garage version whereas that listed on Whiteheads' page is of the 'H' crossover design. Yes, they do work but you're comparing the incomparable : a modern '90s, DOHC, variable valve timing, high revving engine to a relatively lazy SOHC conceived in the mid-60s. I don't think that packaging is such an issue within the JDM which is for where all of these parts are destined. Do you believe that the new Fujitsubo offers more performance over the previous model or simply easier to fit around bigger diffs and with much better cround clearance which would (for me) be enough of an advantage in itself ?

What's their internal diameter pipe dimension Jason please ?

No, I'm not - I've only just seen that and quoted it as it appears to back up my theory which I've held for ages ! I'm well aware that the JDM S30s were'n't supplied OEM with anything bigger than L24s and let's be clear here, I'm NOT knocking the Fujitsubo kit !!! BTW, the North Amercian importer quotes this : Application: 1970-1973 Datsun 240Z 1974-1974.5 Datsun 260Z 1975-1978 Datsun 280Z And we've already discussed that list re diff suitability. And you sir haven't answered my question upon why Nissan offered them in the first place..... Nobody has said that a dual-pipe can't be scaled up in proportion to the engine capacity - where are you plucking these assumptions from ? I'm saying that I believe what is commercially available today for up to L24s is of the same diameter as offered by Nissan on their JDM 2.0 and 2.4ltr engines. For a reason unbeknownest to me, no-one is marketing an upscaled dual-pipe for engines bigger than 2.4ltre and certainly those which have been improved over and above the stock L24s from the early '70s.........unless you know of such a kit available today ? I was speculating that perhaps for fitting/ground-clearance reasons (and also a limited JDM because the L26s and above weren't sitted as stock ?) an upscaled dual-pipe wasn't available.... But I'll ask you Alan - why isn't one available with the plethora of larger engine swaps and strokers ?

Thanks and pretty sure you quoted twin 50mm. I didn't say they couldn't be, merely that I haven't seen any commercially available aside from theFujitsubo Legalis which I quoted because : a) we remain on topic and b ) it appears to be the only twin-pipe system available (putting aside the 'twice-pipes' kit sold my MSA) c) Fujitsubo are quoted as stating that thier twin-pipe system is only compatible with the 2.4 and under engine sizes Of course, anyone can make up a larger-diameter twin-pipe system but space IS tight under an early S30 floor - fitting larger diameter pipework is going to create fitting problems at multiple points if adequate ground clearance is to be maintained. Fujitsubo wisely re-worked theirs especially to improve this - going bigger might be going 'backwards' . To help generate low-end torque without penalising top-end power. Why else would Nissan fit them ? And Fujitsubo appear to agree : "Only For Nissan Fairlady Z S30 HS30 with L20 and L24 Engines." Are my quotes easier to read now ?

Why wouldn't it be scaleable ? Well, yes why not ? But are they available so commercially today ? What were the internal diamter pipes offered by Nissan as OEM on PS30s and options on S30s please ? Whitehead quotes : Featuring dual 2” stainless pipes and RHDJapan for the Legalis system : Pipe Diameter: 50.8mm but also : COMPATIBILITY NOTES - Only For Nissan Fairlady Z S30 HS30 with L20 and L24 Engines. I'm not sure packaging IS a big issue as these twin pipes are long and the overall package heavy at (source RHD) : Muffler Weight: Fujitsubo: 15.9kg whereas Ix I know well weighs in at 13.5kgs (2-1 Y-pipe included) I suspect but you can confirm this Alan that the OEM JDM twin-pipe system was of dual 50mm pipes then as now so any upscaling just hasn't happened. Maybe something to do with fitting confortably underneath the cars too......?

I'm tempted to believe that dual pipes on an S30 are better suited towards the smaller cc engines (S20 and L20) than for larger.

Thanks for the input - all is appreciated. I'll have a word with he who's helping me re mobile application. I'm doing a blog which might work better ? "Also, you might want to have page for complete systems, header to exhaust. Choose a header, line and exhaust for a combined price etc. Auto calculating the combined items etc." Hmm, the point is I don't want people to buy direct off the site - I'd rather discuss with people their real needs and maybe mine isn't even what they need ! The combined price is easy to calculate : any 2x or more products bought together attract a discount of 7%

So, finally up and running but still some great content to follow and more parts later. Thanks for your support.

Hi Matthew. As you say, it'll be better to have a 'list' compiled info and that's just what I've nearly finished and you'll find soon posted up on my new website under 'Tech-Talk'. Like engine heads, there is no 'best' - each works well and can be adapted to suit various applications, we tend to work on what is handy, easy and cheap to obtain. Exhausts and headers are similar, there is a fair amount of choice out there at quite diverse price levels, people need to choose what is best for them and their car and to do so, they need to understand how and why the various different parts work and then choose the right parts that work TOGETHER. A little patience please and I'll post up when it's online.

Thanks - I will update when I have some solid news.

That is the considered opinion but I have yet to see one fitted and dyno-ed.

No R200s fitted as stock equipment on Japanese market S30/S31-series Z cars. Seriously honestly, truly ? Not even on 2by2s ? Why then were R200s specified for all export S30s , both 2x seaters and 2+2s ('cepting automatics) from 1974 ?

Working on them currently to fit with all S30s and S130s. I'd have said below the Street because of the short primary pipes but funnily enough, a rather knowledgeable man actually prefers them for a friends' L28, tripled engine build.

Passing the rhetorical question, I'd have said 2by2 JDM Zs. A question back to you - what percentage of 'improved' JDM Zs improved sufficuently to require the investment of such a quality header) have had R200 fitted since they left the factory - is it a common 'upgrade' ?

I guess if it's made to fit S31s up 'til '78 is should fit and also LHD cars.

Just the basics really but more content to follow soon.

I was off on a tangent and thinking of Datsun Spirit.....! So, do they fit around R200 diffs Alan ?

I would contact SG directly but there is a bit of a communication barrier...hmmm.. Considering the cost etc, I'd expect them to be very helpful. But are you buying from RHD or SG (thinking of shipping and customs) ?

Yes, I see that (which is in front of the diff) but as an R200 is wider at the rear, I'm curious to know it was conceived to split around that or an R180 (as per stock 240Zs) ?

Thanks - is that designed to pass around an R200 diff ?

Not sure I've seen further than their header - any images to share please of the line ?

Hi. Isn't the Spirit Garage header a cut and welded primary pipe system too ?