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 ..)
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
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.
Hi Chanty .. it's not a complaining thread, the opposite in fact, I'm looking forward to getting more power from the engine ..
When I bought it a few people were very very interested in what it was making so I said I'd put the numbers up when I'd had it on the dyno .. the numbers aren't as much as I was expecting, but that's not a bad point
The numbers are post mapping, the original bhp was about 8hp shy of 324/325hp .. but I couldn't make any gains in the midrange so that retarded map wasn't actually far out.
And yep that 450hp graph was pie in the sky, I didn't realise dastek dynos over-read so far though .. if the car was wheel spinning then that would actually reduce the recorded power rather than increase it. With no wheelspin it might have read 480 lol!
The dellortos are going up for sale and an injection system going on, some playing about with intake lengths and see what happens. I will run down the compressions and if anything looks amiss it will get rebuilt, but if they are all sensible I will just play about with inlets and exhausts and see if I can improve the spread of power. At the moment it's all top end and it really should e much better throughout than it is at the moment.
All good stuff for me though, finding power from engines is what I enjoy most I'm still happy!
When I bought it a few people were very very interested in what it was making so I said I'd put the numbers up when I'd had it on the dyno .. the numbers aren't as much as I was expecting, but that's not a bad point
The numbers are post mapping, the original bhp was about 8hp shy of 324/325hp .. but I couldn't make any gains in the midrange so that retarded map wasn't actually far out.And yep that 450hp graph was pie in the sky, I didn't realise dastek dynos over-read so far though .. if the car was wheel spinning then that would actually reduce the recorded power rather than increase it. With no wheelspin it might have read 480 lol!
The dellortos are going up for sale and an injection system going on, some playing about with intake lengths and see what happens. I will run down the compressions and if anything looks amiss it will get rebuilt, but if they are all sensible I will just play about with inlets and exhausts and see if I can improve the spread of power. At the moment it's all top end and it really should e much better throughout than it is at the moment.
All good stuff for me though, finding power from engines is what I enjoy most
I'm still happy!I just wanted to add to this thread that I'm conscious that some people might see it as having a negative vibe to it, rest assured that is most definitely not the case. I never thought I'd be in a position to be able to afford to buy a tuscan racer and I'm absolutely delighted to have been able to do so. These cars will inevitably pass from hand to hand and we are custodians of them rather than owners I guess. I still can't believe I've got one 
Would be good to see the graph Perry.I'm currently welding up my new intake system for the racer (long runner lengths, straight path, small bore all to hopefully make more torque). The development intake may get trialled on a hillclimb griff I work on first though, the racer still has no exhaust either .. doh.
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