Total effect of boring throttle body and changing final drive ratio?

[Viostan]

I got frd doing BBTB Too

 

Better find a Good service Shop to Do

 

As my frd got Clone at GE n Done in less then 40mins jobs " $150 "

 

Doing this Light MOd

 

Got any more Feedback

 

Plan to Do this light Mod for my Vios

 

Gain ?

[Icetrap]

Do check around in your VIOS club to see if there are any side effects.

 

Theoretically speaking, having a bigger throttle body will allow more air into the engine.

 

A rough idea is picture your engine throttle body like a straw, sucking up air. Picture now getting a Straw that is 1cm bigger. Does it enables you to suck up more air?

 

To summarise (as layman's term) As you all know more air + more fuel = better combustion, thus more powerful

 

However, the your car ECU may be a closed loop system which might detect more Air and may offset this with lesser fuel even!

 

Anyway boring the throttle body is only a minimum gain. Don't expect your car to be more powerful like a turbo system. In the worst case it might even damage your throttle body sensor!

Edited May 28, 2007 by Icetrap

[Milgram]

  Quote

do u have any idea how much does it cost to change FD?

 

The TRD one availabe for Yaris is about $980 (FDR= 3.7, original is 4.3).

[Seanboi]

Still using 5MT i suppose? $980 abit on the high side. Includes labour?

Btw are there any 6MT available?

[Icekitten]

Bro, I just add on to your post for TS's info.

 

  Quote

if we compare two same cars one with a lower FD and the other with a higher FD,the one with the higher FD(bigger number) will reach 0-100km/hr in a shorter time though their power are the same.

 

This is due to the gears having a closer ratio, thus less power loss between shifting of gears ie. the rpm drops lesser between shifting of gears that's why it takes a shorter time to reach a certain speed as compared to the one with a higher FD, thus making it a smoother drive as well.

 

  Quote

but for a longer drive of max speed,the one with the lower FD will win because it can reach higher top speed.

 

As above, because the rpm drops lesser between gearshifts, it means that at the same speed, the car with a higher FD will be moving at a higher rpm as compared to one with a lower FD eg. higher FD car will be doing 100km/h at 3200 rpm while lower FD car will be doing 100km/h at 3000 rpm. In other words, the rev cut will kick in at a lower speed for the car with a higher FD as compared to the one with a lower FD. Thus the car with a lower FD can achieve a higher max speed.

[EventH]

Will altering the FD affect Speedo and Odometer reading?

[Icekitten]

I'm not totally sure but I guess not, because FD is a gearbox issue, shouldn't affect speedo and odo readings. Wheels ie. rims and tyres should be the things which affect speedo and odo readings.

Edited June 6, 2007 by Icekitten

[EventH]

[inline Clipboard01.jpg]I though so too ... but the TRD WPC Final Gear set comes with speedometer calibration line

Edited June 6, 2007 by EventH

[Icekitten]

Hmmm....then I wouldn't know...

 

Hopefully some gurus can enlighten us regarding this?

[Dynaway]

this BBTB u mentioned, do they change the butterfly plate to bigger size or still retain the original plate????

[Milgram]

  Quote

Still using 5MT i suppose? $980 abit on the high side. Includes labour?

Btw are there any 6MT available?

 

$980 all in. I don't think that's a 6MT yet bro...

[Milgram]

  Quote

Bro, I just add on to your post for TS's info.

 

[reply]if we compare two same cars one with a lower FD and the other with a higher FD,the one with the higher FD(bigger number) will reach 0-100km/hr in a shorter time though their power are the same.

 

This is due to the gears having a closer ratio, thus less power loss between shifting of gears ie. the rpm drops lesser between shifting of gears that's why it takes a shorter time to reach a certain speed as compared to the one with a higher FD, thus making it a smoother drive as well.

 

Bro, I'm confused...according to Turbo bro, he says higher FD will reach 0-100km/h in a shorter time. From your write-up, you appear to be saying that a lower FD will reach 0-100km/h first. Could you clarify please? Thank you lots!

[Seanboi]

U changing bro?

 

If FDR is 3.7, wads the speed of e engine @ 100kmh?

[Milgram]

Haven't changed it yet...not too sure I want to...must wait till all my doubts cleared up and I know exactly the effects of the FD...then I'll think about changing it.. Btw, I'm not sure what's the rpm at 100km/h...

Edited June 7, 2007 by Milgram

[Seanboi]

Bro u have ani idea wads the FDR of the AT version?

 

U changed liao muz let me noe hor... Can consider.

[Icekitten]

Sorry, my mistake.

 

The one with a higher FD takes a shorter time to reach a certain speed as compared to one with a lower FD. Hand faster than brain.

[Suxelis]

Done both. Makes big diff, esp to German cars, which are so often way overgeared. To my mind best bang for the mod!

[EventH]

overgeared meaning ... gear ratio too long so that car can reach 220+km/h on autobahn.