Modifications That Dont Work

[xtremeleo]

i think the driver (such as iam, lol) exert more downforce before the threshold speed compared to the spoiler / wing, lol

sum cars can go faster den dat on corners sir, these are the cars dat need all d additional help it can get, but iam holding to what i stated, after a certain speed.

side skirts, to me decreases the airflow coming from the side, to keep a steady airflow underneath the car. i wudnt worry too much about the skirts on straight line acceleration, and i wudnt take a corner crazy fast, as to exceed to limit of the vehicle. limit is the keyword

 

[EGNINE]

really good discussion, learn a lot here bout car aerodynamic, that veyron website really help alot...220kmh still in standard mode, 400kmh back to standard mode except its lowered height

 

[dabok max7]

i think the driver (such as iam, lol) exert more downforce before the threshold speed compared to the spoiler / wing, lol

sum cars can go faster den dat on corners sir, these are the cars dat need all d additional help it can get, but iam holding to what i stated, after a certain speed.

side skirts, to me decreases the airflow coming from the side, to keep a steady airflow underneath the car. i wudnt worry too much about the skirts on straight line acceleration, and i wudnt take a corner crazy fast, as to exceed to limit of the vehicle. limit is the keyword

about our road condition heheheh no comment on that.. but I try to figure out the purpose of such as rally car design in their aerodynamic purpose.. because I don't thing they always at high speed cruising and most of it tackling the corners and braking.. so why the need such big spoiler at the back and sometime u can see front splitter (is it the right name that they gave it?) as far as I concern the car max speed is around 240kmh at most.. so if this aerodynamic rolls doesn't play in handling for corner and braking than why they bother to install it which will reduce the power of acceleration of the car?... :hmmmm: and thanks for the info on side skirt and I have same opinion on that..

 

[xtremeleo]

dah nak balik, woohoo..

err, a quick question sir, is there any rally cars dat doesnt use any spoiler / wing?

 

[dabok max7]

dah nak balik, woohoo..

err, a quick question sir, is there any rally cars dat doesnt use any spoiler / wing?

all of them used it i think:hmmmm:.. why?

 

[xtremeleo]

really? okie den..

i think it wud help in high speed, since the trek is dirt an uneven. sum of the cars even fly on small hills, must be well over 200kmh tu. when its airborne and on uneven roads, the ground effect doesnt do a single thing, so it depends on the wing at high speed to keep the car stabilise when hitting the road, and help a lil when traction is an issue on the dirt. i dunno exactly what they aim to do with the wing, its not possible they are trying to sell out aerodynamic stuff, a promotion if u will.. plausible tak?

 

[dabok max7]

really? okie den..

i think it wud help in high speed, since the trek is dirt an uneven. sum of the cars even fly on small hills, must be well over 200kmh tu. when its airborne and on uneven roads, the ground effect doesnt do a single thing, so it depends on the wing at high speed to keep the car stabilise when hitting the road, and help a lil when traction is an issue on the dirt. i dunno exactly what they aim to do with the wing, its not possible they are trying to sell out aerodynamic stuff, a promotion if u will.. plausible tak?

about the calculation earlier sorry loo.. wrong value used in m/s for 36kmh...it is actually 10m/s liow... thats why the value so small heheheheeh... sorry bro.. so it suppose to be 25.83N almost equal to 2kg of force heheheh..
and for 180kmh is equal to 7176.14N drag force ~ 717.61kg liaw... sorry for simple mistake where km/h transfer to m/s is by divided with (3600s/1000m) heheheh...thats why I mention if U run around 80kmh the aerodynamic effect already taken place..
by the way...

good info on aerodynamic...

Aerodynamics Study
Aerodynamics in Car.

but still searching for the info regarding rally car aerodynamic design looo....anyone can help me...

---------- Post added at 11:32 PM ---------- 6 hour anti-bump limit - Previous post was at 11:22 PM ----------

another good explanation via books... regarding aerodynamic effect on slow speed please open page 598 to start with...
Advanced Vehicle Technology - Heisler

 

[hachiroku clan]

dah nak balik, woohoo..

err, a quick question sir, is there any rally cars dat doesnt use any spoiler / wing?

http://en.wikipedia.org/wiki/File:Markku_Alén_-_1987_RAC_Rally.jpg

;lancia delta '87 doesnt have spoiler..

 

[dabok max7]

http://en.wikipedia.org/wiki/File:Markku_Alén_-_1987_RAC_Rally.jpg

;lancia delta '87 doesnt have spoiler..

maybe not all... then again most of it la... not all.. but not sure with current design 2010... still my calculation have a little bit error in speed transfer... so if u calc. it back based on box design for 80kmh it goes to 1275.56N almost equal to 127.56kg put on your car weight. But with development of current design most probably the car design Cd can go lower than 0.35 and usually frontal area up to 3.5m^2 (assumption only) so for the new drag force can be around 75.24N for 36kmh equal to 7kg of load and for 76 kmh goes to 301.35N equal to 30.14kg of load...

 

[xtremeleo]

about the calculation earlier sorry loo.. wrong value used in m/s for 36kmh...it is actually 10m/s liow... thats why the value so small heheheheeh... sorry bro.. so it suppose to be 25.83N almost equal to 2kg of force heheheh..
and for 180kmh is equal to 7176.14N drag force ~ 717.61kg liaw... sorry for simple mistake where km/h transfer to m/s is by divided with (3600s/1000m) heheheh...thats why I mention if U run around 80kmh the aerodynamic effect already taken place..
by the way...

good info on aerodynamic...

thanx fo the correction, i tot there was sumthing wrong with the values.. wasnt in the mood the calculate properly, lol

even then, if the lift factor doesnt exceed the weight of the car, dat extra downforce still isnt needed, we need it after the lift can affect stability. i hate dragging forces

most cars on the road isnt boxy fyi, sumthing like the wira sedan has at least a sufficient amount of Cd to let it pass the 200kmh mark without affecting the stability, wud u think so sir? at least it is using similar design (seems like the same only, lol) to those of the evos, no?

 

[dabok max7]

thanx fo the correction, i tot there was sumthing wrong with the values.. wasnt in the mood the calculate properly, lol

even then, if the lift factor doesnt exceed the weight of the car, dat extra downforce still isnt needed, we need it after the lift can affect stability. i hate dragging forces

most cars on the road isnt boxy fyi, sumthing like the wira sedan has at least a sufficient amount of Cd to let it pass the 200kmh mark without affecting the stability, wud u think so sir? at least it is using similar design (seems like the same only, lol) to those of the evos, no?

with current car design yes the cd usually below 0.35.. and also yes current car design should give better stability for high speed cruising. the cd value usually u can get by run experiment on it and i think there is explanation in ref book that I post earlier.. most of aerodynamic aid that need to be add (based on the ref) more to contribute in high speed cornering rather than top speed because it create more drag and load to the car.. and there is something to compromise in aerodynamic factor If U want to develop a race car.. better extra aerodynamic aid will improve speed cornering but also will reduce top speed on the other hand, less aerodynamic aid gain in top speed but less effective in top speed cornering..
and thats why the Bugatti Veron (betul ke aku eja heheh) when they need extra top speed they will reduce or remove the spoiler to reduce the drag... and just now I remember about top speed of the car that can be achieve relate to the force needed to overcome by the vehicle to move...
for example If ur car have already remove speed cut and rev cut.. and ur car can clock top speed about 260kmh but cannot go much faster. it is because the force needed to overcame by vehicle that acting on ur car already exceed the power of ur engine can deliver.. so to improve ur top speed there is 2 way, which is improve ur engine h.p in high rev and second reduce car drag, load... to reduce car drag actually 1 way is the easiest which is smooth ur car skin body.. u can polish it or wax it and I believe u wira evo can go a little bit faster.. U can change final gear ratio to get more top speed if last time condition met the condition as follow: the max engine rev (for the top speed) is more that max h.p rev (based on power curve on dyno chart) for previous gear ratio. n if not ur car only get much slower in top speed.. if I not mistaken....
to think it back..do stock car need all the spoiler and extra aerodynamic effect? :hmmmmm:

 

[xtremeleo]

stock car? hehe, what do u think sir?

that wira clocked 260kmh because of the revv cut, it was still accelerating when we hit dat limiter.. speedo showed more then 180kmh, we calculated the speed ouselves by gearing ratio, and taking into consideration the tyre diameter (225/R15/60)

and its spelled weyron sir, hihi

 

[dabok max7]

stock car? hehe, what do u think sir?

that wira clocked 260kmh because of the revv cut, it was still accelerating when we hit dat limiter.. speedo showed more then 180kmh, we calculated the speed ouselves by gearing ratio, and taking into consideration the tyre diameter (225/R15/60)

and its spelled weyron sir, hihi

don't know la.. need to ask their engineers...why they need to put the extra accessory.. maybe for the aesthetic value...

Weyron aa? not veyron?... haiyaa... dont know la heheheh..

by the way U mention calc right? is this eqn same with the calc u used?...

V= wr and w = 2(phai)N/60 x Gt

where

V = speed m/s
w = angular speed x total gear ratio
r = wheel radius
N= engine speed
Gt= total gear ratio (gear ratio x final drive)

if I not mistaken... Is this the correct equation?...
I'm not so sure is it the correct equation....:hmmmm:

 

[xtremeleo]

weyron sir, iam quite sure of it, lol

a car dat shows marketing is in power nowadays can be viewed on the accent's accesories, spoiler tiang gol, air scoop laa, etc. fugly lil car with a very good handling capability imo

if u took dat formula outta the text book, then it cant be wrong sir.. we calculated the ratio between the revv and speedo, and stipulate the speedo based on the revv counter.. with dat, we calculated the ratio between the original tyre diameter with the new set, wallaaaa... this way, easier then calculation with the gearing ratios taken into calcukation. i malas maa..

 

[dabok max7]

weyron sir, iam quite sure of it, lol

a car dat shows marketing is in power nowadays can be viewed on the accent's accesories, spoiler tiang gol, air scoop laa, etc. fugly lil car with a very good handling capability imo

if u took dat formula outta the text book, then it cant be wrong sir.. we calculated the ratio between the revv and speedo, and stipulate the speedo based on the revv counter.. with dat, we calculated the ratio between the original tyre diameter with the new set, wallaaaa... this way, easier then calculation with the gearing ratios taken into calcukation. i malas maa..

the basic of the eqn...yes but maybe i miss something in the equation. I don't quite remember all the variable... maybe I miss something and maybe not...... and based on u calc.. quite practical i have to say... hehehh

yes la i think the same... current marketing for the vehicle must look more sporty or elegance so the value can go up... right?...

Actually go back to the real topic....

I want to ask U either the spark stabilizer and voltage stabilizer can actually function or not? (either ori or pirate one)... and one more thing I dont remember what they called it but It something they put or connect it at the car chassis and left it hanging and touch the road/ground (kind of rantai lebih kurang).. they said it have a function like a grounding effect for electrical something like that.. is it function?.... well to tell the truth I'm not sure it's function.. except for voltage stabilizer....