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RB20 dyno
Posted: Mon May 11, 2009 11:15 pm
by carlos fandango
I had my rb20 dynoed on friday
SPEC . std kit matched to casings and manifolds,Readspeed head, JL3, tmx35, 17deg timing and 4.8 final ratio
Whats the cause of the flat spot around 5200 rpm? is it the tmx?
I had a 30mm phbh on it before i swapped to the tmx i haven`t noticed much of a difference except in fuel consumption
it wasdoing about 75 miles per std tank
now abut 45m
so im on the look out for a 30mm flatslide.
Re: RB20 dyno
Posted: Mon May 11, 2009 11:34 pm
by sydduckett
Out of curisoty why did you go for the Jl as oppsed to the NK?
sef
Re: RB20 dyno
Posted: Mon May 11, 2009 11:43 pm
by shocky
sydduckett wrote:Out of curisoty why did you go for the Jl as oppsed to the NK?
sef
prob becouse of the 4.8 final drive the nk wouldnt have much tourqu low down and hittin a head wind would slow you down or make you change down a gear
Re: RB20 dyno
Posted: Mon May 11, 2009 11:59 pm
by carlos fandango
shocky wrote:sydduckett wrote:Out of curisoty why did you go for the Jl as oppsed to the NK?
sef
prob becouse of the 4.8 final drive the nk wouldnt have much tourqu low down and hittin a head wind would slow you down or make you change down a gear
Erm... not quite... it was because i had one
i had to modify it though
Re: RB20 dyno
Posted: Tue May 12, 2009 12:43 am
by coaster
Impressive figures though, what's it like to ride?
Re: RB20 dyno
Posted: Tue May 12, 2009 1:13 am
by drunkmunkey6969
What jetting are you running, and what was your Air/Fuel graph like? Did Readspeed discuss lean/rich spots with you or what jetting changes could be made? Top end power after the peak seems a bit rough, any further info?
Re: RB20 dyno
Posted: Tue May 12, 2009 2:00 am
by tony
Just to state that as far as I know Jerome's dyno was 'back calculated' to the crank. So if this is still the case (and it does say engine power on graph) it would be a few hp less than stated if it was run on a more conventional rear wheel reading dyno as per scootering article and comparison. But even say 16 bolt on is good from this cc.. nice one.
Re: RB20 dyno
Posted: Tue May 12, 2009 9:03 am
by RinB
Not bad out the box
One thing I query is your gear ratio 4.8 yet only get 68Mph @8600
Doesn't calc out ??
Re: RB20 dyno
Posted: Tue May 12, 2009 10:07 am
by ArKaTxU
Nice to see a Dyno with this specs, i am thinking to do something similar, but with the AF std head and a 5.0 gearbox ratio.
With 4.8 ratio at 8600rpm the speed is 90mph or not?
Re: RB20 dyno
Posted: Tue May 12, 2009 1:12 pm
by shocky
RinB wrote:Not bad out the box
One thing I query is your gear ratio 4.8 yet only get 68Mph @8600
Doesn't calc out ??
PROB A 3RD GEAR RUN