Greg is another racer from New Zealand that contacted me after seeing this site.
This is his 600 engined FZR400 1WG! Heres a few words from him:
Biggest improvements for racing in my opinion are having good tyres, brakes,
suspension, then engine mods in that order.
I'm racing a modified '87 1WG and my buddy Bob is on an '88 1EN and I'm
currently putting my Thundercat motor into a 3TJ frame. I did have it in the
1WG frame up until April but have now put the 400 back in so I can do the
National Champs here in NZ this summer.
With the 600 motor in the 1WG frame I was clocked at 270.3 kph at our local
track and the frame handled it easily.
I'm running the wider 17" rear rim off the later 3TJ 400's that has been turned
down on a lathe to fit the '88 swingarm. Front forks are off a '90 Suzuki
RGV-250 with race tech valving inside and rear suspension is a shortened Ohlins
YA 447 shock off the Thundercat.
I've just moved to Metzler Rennsport tyres and have to admit they're working
very well. My last race day I was lapping 4% slower than one of the top guys in
F3 in NZ wheres in the past I'm usually 7 to 10% slower.
The 400 engine I'm running is bog stock standard except for fitting ram air (my
own design) and then Arrow exhaust this required increasing main jet size to
1.2mm...you really notice the difference on high speed tracks (Yeah the 1.2mm
jets are 120's std on the engine when I bought it were 87.5 & 92.5 or
0.875mm/0.925mm, so you can richen them up a lot over std settings...we spent a
2 days at the track working up to that size and beyond before settling on the
120's.). We did the same to Bob's '88 400 and he touched 229kmph at our local
track. I haven't run mine against him there yet : )
Now when I spotted the Ohlins plug, my brain got into overdrive mode. I've
equipped my ZX6R with Ohlins front and rear and am mega impressed by the
quality and difference it's made to the handling of the bike. When I quizzed
Greg about the Ohlins mod he replied:
Ohlins don't carry a shock for the 1WG or 1EN models but for the 3TJ models you
can use the Thundercat YZF600R shock which has the Ohlins model number YA 447
(check their website). Eye to eye measurement for the YA 447 shock is 360mm
with another 12mm height adjustment but the older 400's need a much shorter
shock about 305mm. The Ohlins rep here in NZ took my YA 447 shock and shortened
by changing the lower mounting link and the spring. I think he left the
internal valving the same. It's worked extremely well ever since, so hopefully
the Ohlins people in the UK could do the same if you wanted to go down that