A nisi ravno ti govoril v tej temi nekaj strani nazaj, da je inercija zakon in zavora nepotrebna? Kako to, da si potem zdaj ubodel valje z zavoro?

Tile so inercijski in z zavoro. Da pa stranke dobijo kar zahtevajo, smo izbrali oboje.

Torej si ugotovil, da zavora le ni tam brez veze... Lepo to...

A mi prosim razložiš "valje samo z zavoro".
Namreč ne predstavljam si, da bi bil valj brez mase ob mehanski trdnosti, ki jo mora imeti.

Do koliko KM pri določeni hitrosti lahko merite samo inercijsko? In do koliko km/h?

Nekateri valji ne omogocajo inercijskega mejenja. Zmeraj merijo samo z zavoro.
Tako so narejeni.
Tile ponujajo obe moznosti. Do 1600HP v obeh primerih. Do 350km/h.

kok pa kasiras. a zelo niski avti z 13 col nisko+ napeto gumo lahko merio.... ker dosedaj je avto povsod nasedel.

b3ybo ... lahko bi en dino day naredil... pa mal pomerili...

@Pro_Tuning, koliko colski so ti valji?

mito155 je napisal/-a:b3ybo ... lahko bi en dino day naredil... pa mal pomerili...

jas sem za.... treba zmerit od punce avto. Me zanima kak je prirastek

pro_tuning
lahko bi nas iz avtomobilizma povabil na kakšen dan odprtih vrat in nam zainteresiranim promocijsko izmeril malo moč..
sam sicer čutim povečano moč po čipanju ampak tako se vozim že kar nekaj časa in me zanima če se je po 100.000km kaj spremenilo

Jest sem tudi za to idejo. Da vidim, koliko so tovarniski podatki podcenjeni

Seveda bo promocijski dyno day. Edino moderatorji foruma naj javijo, ce to lahko omenim. Kdaj in kje bo.

Tudi nizki avti naj bi sli gor. Valji se kaksen mesec ali dva ne bodo postavljeni, ker se pripravlja nova delavnica.

Dimenzije valjev in ostale znacilnosti bodo predstavljene na dyno dayu. Omogocajo tudi meritve najvecje hitrosti. Ce vneseno, koeficient zracnega upora ter precni presek avta, valji avtomobila ne bodo spustili prek dolocene hitrosti.

Kako je rešeno hlajenje eddyjev; namreč pri 1600KM je to ~1200kW oz. 1,2MW

What wheel Hp can I dyno?

We usually get this from someone wanting to run 1,000 Hp on 8� rolls! Foolish? No, it is just inexperience regarding these four factors:

1) Roller diameter is the major power limiter for chassis dynamometers. Tires are engineered for running on the (relatively) flat earth. On a chassis dynamometer, as the roll (or tire) diameter decreases, the tire's effective contact patch shrinks. The smaller the area, the higher the shearing loads on the remaining tread contact. Worse still, small rolls apply more contact PSI − per pound of vehicle weight. These are running forces that continuously deform the tire�s sidewalls during testing. Combine high Hp and high speed with small rolls and this deformation can overheat and destroy tire integrity!

As an approximate rule of thumb, downgrade a tire's speed rating (while on small dynamometer rollers) using this formula:

MPH = (186sr / 2.8"^.5deform)

Where "sr" is the tire's factory speed rating
Where "deform" is the tire's roll-diameter-induced deformation (indentation)

Examples:
8�" tandem rolls (speedo tester) = 95 MPH (186sr / 3.8"^.5deform)
12" tandem rolls (linked) = 112 MPH (186sr / 2.8"^.5deform)
13" tandem quad rolls (linked) = 113 MPH (186sr / 2.7"^.5deform)
20" wide roll = 125 MPH (186sr / 2.2"^.5deform)
24" wide roll or 24" twin rolls = 132 MPH (186sr / 2.0"^.5deform)
30" wide roll = 137 MPH (186sr / 1.5"^.5deform)
44" twin rolls =166 MPH (186sr / 1.2"^.5deform)
60" twin rolls = 186 MPH (186sr / 1.0"^.5deform)

Do you doubt that tire deformation is a significant source of power loss (heat energy drain) during high powered testing when testing on too small a diameter roll ? If so, take a look at this high-speed film clip we were e-mailed. It captured what happens when trying to handle a few hundred horsepower on less than 12" diameter rolls. Also, notice that the (uncoupled) rear roll is loosing contact with the tire and doing virtually nothing for support and traction - plus any inertial compensation for that (uncoupled) roll's mass will be overstated.



Dynamometer rolls vary in size from 8-5/8-inch to 50-inches. The smaller rolls have a greater potential for damaging the tires.

During a dynamometer check, there is little weight on the tires and only a small area of the tread face (usually the center rib or center portion of the tread) is in contact with the roll. Excessive heat builds up in this small area. If the test runs too long, the excessive heat can damage the tire to the point where it could fail later on the highway.

The maximum safe time for running tires on a dynamometer roll varies with the roll diameter, speed, the power or torque transmitted from the tire to the roll, and, to some extent, the load and inflation.

Figure 12.1 shows general rules for limiting the time for maximum power testing.

hemingway je napisal/-a:

Tale slika meni pove več kot tisoč besed. Take zadeve pomoje niso dobre niti za gumo niti za točnost meritve.

Ah bejš no

a ni to k pr dragsterjih

Ne, pri "dragsterjih" se platišče prej zavrti kot pnevmatika in tako vidiš nagubano pnevmatiko na notranji strani, ne zunaj.

Pri uporabi dveh tekalnih površin je pač omejitev kako veliki so valji.
Moje mnenje je, da je definitivno idealno uporabiti čim večji radij tekalne površine in posledično samo ene, ampak iz stališča varnosti nebi upal ob meritvi biti v istem prostoru, ko je edina stvar, ki avto drži na mestu najlonski pas ali dva...
Kaj šele, da bi take meritve ponujal dnevno vsakdanjim strankam.

Iz stališča varnosti in praktičnosti, valji z eno tekalno površino sigurno odpadejo....

Pro_Tuning je napisal/-a: Ce vneseno, koeficient zracnega upora ter precni presek avta, valji avtomobila ne bodo spustili prek dolocene hitrosti.

Fino!