Where's my power? Dyno T34 & 55lb's
#1
Where's my power? Dyno T34 & 55lb's
Been on a rolling road day today, and the car was run with disappointing results.
Spec: T34.48, 55lb siemens, Pace cooler, 4x4 inlet plenum, bosch 044 fuel pump.
On motorway car pulls well, peak of 30psi, holding 25-26psi through most of the revs, not sure over 6,000 rpm though (need to check), wideband AFR gauge indicates approx 11.5-12 on boost.
Anyway was expecting bhp 340+ish
Results of runs 2 & 3: 290's clutch bhp, 270's bhp at wheels (average transmission loss = 17 bhp), 360's lb/ft torque.
I can't understand why if the car is holding boost (significantly more than a T3 can), how it is under 300bhp ? And why the bhp doesn't raise even slowly after the inital boost spike.
RR was at AwesomeGTI, cooling fan on for runs, other Saphs gave reasonable results for there spec.
My intercooler practically touches my radiator, but would be supprised if the heat sink from that caused the issue.
Spec: T34.48, 55lb siemens, Pace cooler, 4x4 inlet plenum, bosch 044 fuel pump.
On motorway car pulls well, peak of 30psi, holding 25-26psi through most of the revs, not sure over 6,000 rpm though (need to check), wideband AFR gauge indicates approx 11.5-12 on boost.
Anyway was expecting bhp 340+ish
Results of runs 2 & 3: 290's clutch bhp, 270's bhp at wheels (average transmission loss = 17 bhp), 360's lb/ft torque.
I can't understand why if the car is holding boost (significantly more than a T3 can), how it is under 300bhp ? And why the bhp doesn't raise even slowly after the inital boost spike.
RR was at AwesomeGTI, cooling fan on for runs, other Saphs gave reasonable results for there spec.
My intercooler practically touches my radiator, but would be supprised if the heat sink from that caused the issue.
Last edited by Ridgey; 19-05-2012 at 08:34 PM.
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#10
PassionFord Post Whore!!
Some RR graphs do not cross at 5252 rpm as they are on different scales.
If the rpm pick ups are not spot on you might as well ignore the results.
Good old dynos...
If the rpm pick ups are not spot on you might as well ignore the results.
Good old dynos...
Last edited by GVK.; 19-05-2012 at 09:34 PM.
#12
Not entirely sane
The scales on the graphs are aligned and use bhp & lb ft so the power and torque curves should cross at 5252 rpm. Also 17 bhp transmission losses sounds low, even for two wheel drive.
#14
Super Moderator
iTrader: (5)
what was the problem with your run compared with some of the other cosworth that were run
fraser made the numbers so what problems were they having with yours to his
If you are happy with the on road power and performance stop worrying about the rr figures
and they should have been monitoring afr on every car and every run
fraser made the numbers so what problems were they having with yours to his
If you are happy with the on road power and performance stop worrying about the rr figures
and they should have been monitoring afr on every car and every run
#15
10K+ Poster!!
iTrader: (4)
what was the problem with your run compared with some of the other cosworth that were run
fraser made the numbers so what problems were they having with yours to his
If you are happy with the on road power and performance stop worrying about the rr figures
and they should have been monitoring afr on every car and every run
fraser made the numbers so what problems were they having with yours to his
If you are happy with the on road power and performance stop worrying about the rr figures
and they should have been monitoring afr on every car and every run
nail on head there tony, opps second fuel pump relay has failed didnt realise and melted engine !
#17
Super Moderator
iTrader: (5)
it really does shock me the number of these RR shoot out run what you brung type days where they do not monitor AFR it is as simple as sticking the sampler up the exhaust
AFR and boost should be plotted along with your power
I also think they should measure ACT and plot that too considering it is the key to power on a turbo charged high boost car
AFR and boost should be plotted along with your power
I also think they should measure ACT and plot that too considering it is the key to power on a turbo charged high boost car
#30
Zee Germans are coming
if the cooler and rad are back to back then you should get a high on air pressure all the way through
i think your problem is down to a shit old cooler
they have come on a little since the pace one
and what rad are you using
Last edited by v man; 22-05-2012 at 10:01 AM.
#31
20K+ Super Poster.
iTrader: (4)
it really does shock me the number of these RR shoot out run what you brung type days where they do not monitor AFR it is as simple as sticking the sampler up the exhaust
AFR and boost should be plotted along with your power
I also think they should measure ACT and plot that too considering it is the key to power on a turbo charged high boost car
AFR and boost should be plotted along with your power
I also think they should measure ACT and plot that too considering it is the key to power on a turbo charged high boost car
Dave, your car is quick...enjoy it. I would give AWESOME GTI a wide birth & find another Rolling Road to try & for the club to use.
#32
Testing the future
better would be to have you intercooler spaced forward of your radiator but with both of them enclosed in a cowl so that the air has to pass through both
#33
Zee Germans are coming
low air pressure on the rad can only result in 1 thing
hight water temps
think about it
the act will not heat up from the rad as both will be getting good high air pressure passing through giving good cooling
but if you have a shite cooler and rad your fucked from the start lol
Last edited by v man; 22-05-2012 at 10:43 AM.
#36
Zee Germans are coming
think your problem is the quality of the cooler in the first place
what you need to do is back to back the cooler and rad and still fit some kind of air dam so the air on cant escape off the sides
#37
A great place to try this is Santa Pod.
The air passing through an intercooler is NOT supposed to be trying to cool the intercooler down to ambient from 90C...