guess the power
Discussion
Well the tuscan finally made it onto the dyno today for a few runs to see just what it makes before taking the induction off and changing to injection.
Chanty said the map in the omex (used for the ignition only) was a safe retarded map, but after a bit of tweaking it made next to no difference, only benefiting the very top end power with a bit extra advance in there .. no gains to the midrange.
Significant fuel stand-off from the bell mouths during the power runs suggests there's a bad inbalance between inlet length, cam and exhaust which needs addressing as part of the winter upgrades..
anyway anyone care to guess what it made on the dyno ? (flywheel figures or wheels figures ..)
Chanty said the map in the omex (used for the ignition only) was a safe retarded map, but after a bit of tweaking it made next to no difference, only benefiting the very top end power with a bit extra advance in there .. no gains to the midrange.
Significant fuel stand-off from the bell mouths during the power runs suggests there's a bad inbalance between inlet length, cam and exhaust which needs addressing as part of the winter upgrades..
anyway anyone care to guess what it made on the dyno ? (flywheel figures or wheels figures ..)
Class B Cars between 176 and 325 BHP per ton measured at the wheels. All cars other than those running
a normally aspirated Rover V8 engine between 3 and 4 litres in capacity must run data logger.
Forced induction allowed up to class Bhp/Ton limits. All cars with forced induction must run a data
logger
cant be any more than the above can it
a normally aspirated Rover V8 engine between 3 and 4 litres in capacity must run data logger.
Forced induction allowed up to class Bhp/Ton limits. All cars with forced induction must run a data
logger
cant be any more than the above can it
t!
Well ..
I've got a graph in the history file from another rolling road showing 450plus hp flywheel so I was expecting great things ..
I ran the car without the filter arrangement as that was expected to be robbing some power, so I had a cold air feed to the carb trumpets as this was going to be the best the engine was going to give in hp terms, a base line figure from which to work from.
Sadly for me there's some work to be done. I was secretly hoping this engine was way above class b power limits from what people had said about it's straight line speed but the reality is far from that, 324hp at the wheels peak is just about bang on power to weight with chanty in the car, and it's a very short peak. With the air filter back on in the trim it's been racing in the hp at the top would be even less. Definitely a safe class b car then!
The midrange that everyone thought was going to be so strong is really very poor right now
195hp at 4000rpm wasn't what I was expecting to see at all. The engine makes a peak of 355lb.ft at around 5k rpm, but a pitiful 290lb.ft at 3k rpm. From there on it meanders around 320lb.ft gradually climbing to that peak high up the rev range. It's not the gut-wrenching engine I was expecting and it looks like I'm going to be pulling it apart to see what's going on. It possibly might have been a more powerful engine at one point, but in the current state of tune it's certainly not happy as it is.
Run it above 5k rpm all the time and it makes decent though not sparkling power. Let it drop down the rev range though and it's a different story.
I've got a graph in the history file from another rolling road showing 450plus hp flywheel so I was expecting great things ..
I ran the car without the filter arrangement as that was expected to be robbing some power, so I had a cold air feed to the carb trumpets as this was going to be the best the engine was going to give in hp terms, a base line figure from which to work from.
Sadly for me there's some work to be done. I was secretly hoping this engine was way above class b power limits from what people had said about it's straight line speed but the reality is far from that, 324hp at the wheels peak is just about bang on power to weight with chanty in the car, and it's a very short peak. With the air filter back on in the trim it's been racing in the hp at the top would be even less. Definitely a safe class b car then!
The midrange that everyone thought was going to be so strong is really very poor right now
195hp at 4000rpm wasn't what I was expecting to see at all. The engine makes a peak of 355lb.ft at around 5k rpm, but a pitiful 290lb.ft at 3k rpm. From there on it meanders around 320lb.ft gradually climbing to that peak high up the rev range. It's not the gut-wrenching engine I was expecting and it looks like I'm going to be pulling it apart to see what's going on. It possibly might have been a more powerful engine at one point, but in the current state of tune it's certainly not happy as it is.
Run it above 5k rpm all the time and it makes decent though not sparkling power. Let it drop down the rev range though and it's a different story.
Edited by spitfire4v8 on Thursday 15th October 09:24
Something not right there either with Rolling Road or engine itself. I know roughly what it made when it was rebuilt by ACR as mine makes similar (a little less but thats down to cr mainly!). It was I imagine only just a B class car as mine equates to around 320rwhp/tonne... Oh and the torque on mine is up around 400lbft apparently on engine dyno. Unless there are serious tranny losses there not being accountes for (or mega wheelspin!).
All imho of course...
All imho of course...
my lowley 4.5 makes more than that, some think odd going on there me thinks. A couple of B cars in the past could have done with that graph. Do I get a prize as I was the closest 
Joolz as you had petrol pissing out before it went on the rollers I would have a stab in the dark and guess that the float level is wrong on one of the carbs and not fuelling properly. What do I know about it though to be honest.
Joolz as you had petrol pissing out before it went on the rollers I would have a stab in the dark and guess that the float level is wrong on one of the carbs and not fuelling properly. What do I know about it though to be honest.
Hi Perry it wasn't the carb in the end but the braided fuel hose feeding the offside carbs .. it's split inside and fuel was running down the "U" shape of the hose and filling the valley gasket .. it looked like a carb leak but was the hose in the end. I'm replacing all hoses anyway when it gets put on injection, potential fire hazard right now.
Fuelling is quite rich in the mid range, but back to lambda 0.8 / 0.85 at the to end so top end power and fuelling are about right I think, the midrange lacks airflow which would account for the rich running in that area and the low power figures midrange, all that does seem to fit the picture.
Dave .. yep i imagine the engine was once stronger than it is now .. from paddock talk it seems the car has been very fast in the past so it looks like some horses have since gone AWOL.
Fuelling is quite rich in the mid range, but back to lambda 0.8 / 0.85 at the to end so top end power and fuelling are about right I think, the midrange lacks airflow which would account for the rich running in that area and the low power figures midrange, all that does seem to fit the picture.
Dave .. yep i imagine the engine was once stronger than it is now .. from paddock talk it seems the car has been very fast in the past so it looks like some horses have since gone AWOL.
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