2011 RM-Z250 MX2 Race Development

Suzuki Europe MX2 Technical Co-ordinator Jens Johansson has been
the brains and precision behind the Suzuki MX2 Grand Prix effort
since 2008. The Swede has overseen the expansion and progress of
the project at the highest level and reached a peak during 2010
when the team grabbed the red plate for the first time as series
leader and finished second in the championship itself (both rider's
and manufacturers). Here he speaks about how the RM-Z250 is
currently evolving on the MX2 GP Stage and the path for the
future.
What were your aims for development of the RM-Z250 for the
2011 season?
"Well, to be honest I think the speed of development on the bike in
2010 was unbelievable. We made a few steps throughout the year with
the help of the engineers in Japan and also our own work. The whole
package made really good progress. Both of the riders we had were
fantastic and did very well but the bike was also vastly improved
from the GP in Lommel (Limburg, round 11 of 15) onwards. I think we
ended the season with a very good motorcycle and the results, as
well as what the riders said, showed as much. When you do so much
in one year and you start from scratch - we had a new motorcycle
following the season - it is hard to find fresh stuff to keep
evolving. A stock bike these days is already a very efficient
machine so you can only make small steps anyway. Compared to last
year the improvements we can make are detail changes and slight
increases in certain areas."
So
no big forward evolution as discovered before the GP of Limburg
last summer?
"If we could do that kind of leap again it would be great but it's
not realistic. Last year before Lommel was more of a change of
philosophy and sometimes that is not always possible. For this
season the weight limit came down from 98 kilos to 95 and we
already had a light bike so now we can run something like 96kg,
which is another good step without having to do much; in fact you
could still say we have a kilo to win but that is hard to do right
now."
Does most of the work depend on the requests of the new
rider?
"If we would have kept the same riders as last year then we would
have had to do more and we would have done more. Valentin is a good
rider, young and talented, but he had no real reference point for
testing as the gap from a private team to an official bike can be
quite big and he was already happy with our machine from the
beginning. He was unlucky to have a few small injuries over the
winter that limited us in terms of testing. We found a base line
from where we wanted to start but we haven't been able to press
forward because of the injuries."
Generally
speaking what is the difference between the race-bike and the
RM-Z250
people can buy at the dealership?
"In spirit they are the same. The suspension is better and it is
set-up specifically for the rider, which is a big thing. On the
engine of any production 250 you have to do a lot of work to be
competitive here and with our engine, which means an increase of a
few horsepower and a few hundred revs. The weight is lower. Overall
our machine is a refined stock bike and we are lucky that the
Suzuki is already a very good motorcycle. If we are not talking
about GPs then with the suspension tweaked to individual
preferences it is great for regional or national races.
"Our bike is special but most parts are derived from stock. We
start from the production model and improve; an example is the
change of materials inside the engine and around the chassis to
lower weight. Where aluminium or titanium can be used then we do
so. Our service time-line is obviously much shorter and we can use
lighter materials that need changing regularly.
The camshafts are changed, the cylinder head is prepared, and
electronics are fine-tuned. The arrival of the fuel injection has
given us a great tool to change the character of the engine with
the mapping and with the support of the technicians in Japan we can
exploit its potential. If you want a top bike at world level in MX2
then you have to do these things."
Is it becoming more
difficult to find increased performance with the 250s amid all the
talk of trying to reduce the noise?
"I think everyone in the industry has to decide if they want to
reduce noise and if the answer is 'yes', then the FIM and the
federations must set new rules; even with new rules there will
always be development. There are many people who think that noise
is only to do with the exhaust and this is not the case. When you
want to reduce noise according to the 2mMax test that we now have
by, say, another 2-3 decibels, then we have to look at engine
mapping, camshafts, revs, airbox and all sorts of things. It will
be more complicated and we will have to be more precise, probably
even take some risks because if we need to reduce the noise level
again then we want to be even more on the limit for the sake of
performance. However I think we can reduce noise and still have a
strong-performing bike. It is a question of setting the rules in
stone. We might have to detune the bikes initially but then you
look forward and try to find new ways to tune."