Originally Posted by Trailbraker
Yup, get some timing gear and then you will have some facts
Have a look at the 2.0 TS performance thread, don't want to post all the details again, but essentially speedo derived times are useless except for making people feel good.
Hmm I must be feeling like the Grinch today
BTW simple accellerometer based timing gear isn't very expensive.
Race Technnology have a budget version without GPS and G-Tech spring to mind. If you want links I can try and root them out for you.
They won't be anywhere near as accurate as a GPS /accelerometer combo system, (or even better but way more expensive) a high frequency GPS Race timing system but you might be amused at how inaccurate speedos are.
Or just go to a drag strip for really accurate times.
I know and I think everyone knows that speedos are inaccurate, but one thing it’s the velocity that they show and we drive and another is the time that we can go from one specific velocity to another, like for example from 80km/h to 120km/h!
Maybe when I take times from 0-100km/h it gives inaccurate value because I could go at 98km/h or 95km/h…but if I go from 80-120km/h in one specific gear I have to make always 40km/h indifferently the car I drive!
Maybe in some cars I could do from 78-118km/h real speed or from 72-122km/h real speed…but I still do 40km/h in acceleration!
I know is not a precise science to measure because 40km/h in speedo could be only 35km/h or 45km/h on a simple accelerometer, but it gives some kind of comparison to one car to another because I don’t believe that there is such much difference on acceleration from speedo manufactures!
Anyway, official values are official values and they have certain rule to make their test, like specific weight, tires, etc, etc…and real accurate machines to take time…
I don’t have that and I don’t know the rules…I only do like everyone does…on the road with a stopwatch or movie, I take average times because it could be some road inclination…and I compare!
Normally I take times on same road (when possible), to compare times from previous mods…and to see if I win or lose something…that way I know that I have solid base that it’s the same car with same speedo reading error…and if there is a different time, I know if I have win or lose performance…not only to feel good!
I already have “played” some time ago with different GPS devices…and I’ve found that they are not accurate as people think, sometimes on a uphill or downhill they give strange readings…also dyno’s same thing we cannot trust them…that’s why I think…what do we believe!?
We cannot believe in nothing in concrete…in my point of view!
But with inaccurate speedo or not…here is another movie I’ve found over the net from another Alfa147 1.6TS, making 80-120km/h in 3º and 4º gear:
To me a real test is with two cars of same model, engine, weight, tires, etc…side by side…first to finish it’s the best prepared!