dynojet or not

opinions welcome. been recommended not after talking to a few friends I've
been warned to stay away.
wots your opinion on your dynojet kit , how hard was it to setup correctly
and has anyone fitted it to a Y2K R1 (been told I need a power commander
too, but I thought they were only for fuel injected bikes).

Robin

 

I've just had a dynojet removed from my 7R, and it (along with the
setup) has made the power curve smoother than a baby's bum. And more
linear than Mr Linear of Lineartown, Nebraska. (for Blaney)

 

I've been reading reviews for the FZR, and people say that the dynojet kits
give you more power top end, but you loose the more road usable power lower
down. On a bike like an R1, I'm guessing you can't keep it pinned on the
road, so unless it's mainly for track use, it would most likely just make
your bike less user friendly.

May be different on the R1 mind?

--

 

ogden says...

That can't be taken as a condemnation of the Dynojet kit. It may well
have been fitted to correct the fuelling on your bike when it was fitted
with a non-standard exhaust. The Dynojet kit on my bike has filled the
hole in the power at 5K revs and it carburates beautifully throughout
the whole rev range.

 

I had a stage 1 dynojet kit put on the GPX600R, I was asked whether I
wanted it for mid-range power or top-end power [1] on set-up, I chose
the mid-range power and it performed very well. I haven't had it done
to another bike that I've owned, but that's because the guy I went to
stopped doing it, and I've not had any recommendations for anyone with
a clue about setting up bikes with dynojet kits.

So, in essence I would be prepared to have a dynojet kit fitted to the
CBR, but only on recommendation from someone who's had it done and is
satisfied with the end result.

[1] I was told that if I chose the top-end set-up then the mid-range
power would be compromised, and it was down to personal choice.

--
Lesley
CBR600FW
SBS#11 (with oak-leaf cluster)
BOTAFOT#101A UKRMHRC#12
BONY#54P BOB#18
Real burds don't take hormones, they rage naturally

 

http://www.pre.org/image003.gif

The Red lines are with the kit, the green ones are with stock parts
put back on.

 

Ok, just to clarify, the "duff power" curve is with the full race system and
the dynojet kit set up for that race system, or with a dynojet kit with a
stock exhaust system?

 

Just because a dynojet kit is fitted doesn't mean the carbs are set up
properly. Looking at your power curve it seems the bottom end fueling
was mostly what was screwed up, which is as much down to float height as
anything.

The 5K flat spot would have been due to needle height..

Someone with a bit of nouse (and an air/fuel meter stuck in the exhaust)
could probably have got the dynojetted setup just as smooth, given a bit
of dyno time..

 

Having a bike put on a dyno and the fuelling sorted is worth it on *every*
bike as long as the dyno operator knows what they are doing.

A dynojet kit can make this process easier.

Fitting a dynojet kit without access to a rolling road dyno and someone who
knows what they are doing is probably not worth doing as its a lottery as to
whether it'll be better or worse when the 'kit' is fitted.

My own opinion is to have it done and find the time and money to get the
bike to a dyno and, maybe, change the gearing.

After having the R6 dynojetted it was worse.

Having the fuelling sorted by Sam Ermolenko (twice world speedway champion,
now a dyno-fella in Derbys) at Sam's Dyno it was loads better.

Letting him drop the gearbox sprocket one tooth after that made it
accellerate harder & faster than my 955i from 70 in top (as I found out to
my horror shortly afterwards[1]).......

Dave

[1] It didn't before[2]
[2] Not just it didn't accellerate harder. It didn't accellerate at all
when you opened the throttle. Now it'll go for the redline in top. Well I
think it will. It'll indicate 180mph (wrong, I know, by at least7%) and
still be accellerating when I bottle out.....

 

Ahh you've used him... and he's good, yes?

Might throw the ZRX at him once I get a Quill T3, K&N, etc..

 

Good, yes. Worrying that he didn't realise that th R6 had the speedo driven
by the gearbox sprocket and so was now een more wildly optomistic. But
adamn nice chap and got the fuelling sorted lovely-like (hardly any change
in peak power (up by 0.1bhp) but soooomuch better you wouldn't believe it)

If you've got the cash why not throw him the bike and see what he can
do/recommend. If it's owt like the R6 it may be better without the K&N....

Dave

PS. Yes, he will be getting a visit from the NS once it is run in (and
hopefully before the BOSM)

 

Sounds like what RMD in Heanor did for my old R6.. No flat spot at all,
popped the front wheel up off the power way too easily.

Having read up on ZRXes the K&N is a good idea over the cheap stock Kwak
paper filter... there are alternatives, but not many unless you ****
about with the airbox any more than removing the restrictive plastic
snorkel.. I don't want to go too extreme.

Mmmm. Petroley.

 

The duff one is with the dynojet kit set up for K&Ns and the race
system - I've got the dyno charts from when it was all done and
it looks much better than it was when I had it tested in November.

The good curve is stock carb parts, K&Ns and OE exhaust as set up
by PDQ.

 

ogden says...

Someone either chose the wrong combination of tuning parts/jets or
didn't spend the necessary time needed to set the fuelling up on a dyno
once they'd fitted them. Your experience of Dynojet kits is not the
norm.

You can't just lob a race exhaust system and K+N air filter on the bike
and think that fitting a Dynojet kit straight from the box will sort the
fuelling all through the rev range. They need careful setting up on a
dyno, which yours obviously hadn't had.

 

Cool, that's nearly as much power as an R6

 

Not far off (111.9)

 

Damn. You see, it's that 0.1 that makes *all* the difference.

 

Namedropper.

 

Oh no, that's you and porl now - a split is developing in the hitherto
unshakeable unity in shamurai bike choice - what /am/ I going to do?

 

simonk says...

Do what you normally do, and buy something totally unsuitable.