nice to meet you and glad you are enjoying your 156.
BTW Hope that wasnt your hand holding the camera
I understand why you are saying what you are, and please don't take my post as impuning your integrity in any way - sincerely its not my intent.
What you are saying amounts to the fact that you reckon a standard 1.6 156 with 120 bhp is about 1.5 seconds or so slower to 100 mph than a 2.5v6 156 - even though the v6 should already be ahead by just under 3 seconds at 60mph with the gap widening ever more quickly.
I suspect that in the cold light of day you might admit that this would be "suprising" if it were true, but if you do believe it then you really should never sell that car!
Seriously though speedo readings for timing runs are so inaccurate as to be worthless.
I have personally calibrated a number of different Alfa 156 speedos on standard rims/tyres with Race Technology GPS+accelerometer timing gear and found the speedo error can be up 10 miles out at 100 mph.
Never mind me though - the two sets of quoted figures I gave you were from professional testers using high quality GPS timing gear.
Autocar in particular use incredibly accurate RaceLogic VBOX ultra high precision GPS receiver timing gear costing many thousands of euro.
If you were basing your speed readings off a GPS sat nav system then forget it - the primitive gps in these systems are not anywhere near accurate enough to be useful for timing runs.
Dyno runs on rollers are also notoriously inaccurate for calibration due to unavoidable wheel slippage.
The problem is that speedometers are just so low tech, for example they can't cope with the fact that sand or other slippy surfaces may cause the wheel to slip more and thus give a falsely high speed reading due to an increase in wheel slippage.
Even changes in tyre pressure and tyre wear make a difference to the error in the indicated speed - low tyre pressure, and cold worn tyres falsely increase the indicated speed.
Also changing to smaller diameter tyres will make a huge difference.
a) A small difference because it will actually slightly increase acceleration due to the fact less energy is required to rotate smaller wheels.
b) plus a big difference if your speedo isn't calibrated to exactly the rim/tyre combination you have then your figures would be way out anyway.
None of the above changes the fact that the 1.6 is still a nice car!
Originally Posted by Paulo Mendes
I do not agree!
The 1.6 T-Spark (120bhp) makes a lot less than 32 seconds from 0 to 100mph (+- 160km/h)!
I did a test almost one year ago with my “bella” almost stock, in a road with sand and some up hills, with damage MAF and lambda sensors and with a bigger tire (225/45-17’’)….. I did something like 20 seconds from 0 to 100mph!
If someone doesn’t believe, here’s the movie:
Now with smaller tire (215/40-17’’), new clutch, new MAF, etc…I think my “bella” does a little less than 20 seconds… but haven't had the time to test yet!
When possible, I will make a new movie with the new mods and no engine problem.
BTW, with my old tires 225/45-17’’ I almost had no velocity error in the dials, I’ve tested with a GPS and in a Dyno…