You will have to forgive us ignorant Americans, but what model Yamaha is
a "Thunderace"? I assume it is one of the FZR or YZF 1000 bikes as know
in the US?
I also agree that there is untapped potential in the GTS engine. The
big difference is carburetor vs. EFI. One you can change, EFI remapping
is ?? K&N doesn't make a power commander for the GTS nor plans to- I've
called and talked to them.
Just looking at the pencil thin header pipes is one area that could be
addressed.
Ram air from the chin screens under the headlight direct into the front
of the air box instead of the side scoops (which have to make 3 right
turns) would be another improvement. Usually opening up the breathing of
any constricted engine will do wonders. But even if you changed to
larger header pipes, gutted the Cat, air box/ filter changes, how would
you remap the EFI to compensate? It's current map would not suffice for
such a radical change.
Increased HP is also usually at the sacrifice of the torque curve,
typically moving them both up into a higher RPM range. The trick is to
keep it in the middle of the RPM range or "real world" power so you
don't have to rev to redline.
I had consulted with Factory Pro Tuning in San Rafael, had an
appointment to leave my bike with them for a week earlier this year to
have it dyno'd and EFI mapped with an RGA (Residual Gas Analyzer). But
their dyno broke and was down for a month. Now they are too backed up
with racing clients to get me in until the fall.
We did check the EFI box and the chips are exposed on the circuit board
so they can be removed and replaced. All in all, this type of work is
expensive - I am looking at $500-$1k just for the dyno/ EFI mapping, not
including parts for doing any of the exhaust and air box changes.
But it is intriguing and as pointed out, it is there. It will take some
engineering work to come up with something useful and demonstrated on a
dyno. I bet if a power increase kit was offered, it would sell like hot
cakes to the list.
Anybody have access to a dyno with RGA at cheaper or gratis rates?
--
Dave Biasotti // Fremont, CA
'93 Yamaha GTS-1000 // '83 Honda 650Turbo
>
> Date: Tue, 15 May 2001 20:45:51 -0700
> From: Peter Maggiacomo <[EMAIL PROTECTED]>
> Subject: Re: Learning Slowly !
>
> --- Mark C Evitts <[EMAIL PROTECTED]> wrote:
> > According to Motorcycle Consumer News the GTS was
> > produced by Yamaha from
> > 1993-1999......of course 1993-94 to the USA. I think
> > the EUs elimination of
> > the 100 hp limit sealed the GTS doom in Europe.
> > Mark Evitts
>
> Good point Mark. Just another reminder of the factory
> detunning of the YZF 1000 sportbike engine. I still
> believe, the GTS has untapped potential to increase
> it's HP/ TORQUE without sacrificing reliability.
> With 10 yrs. of technology improvement in parts,
> adapted from the Thunderace, we can have our cake
> and eat it too.
>
