RAISING THE LEVEL: Transmissions / Gear-Box

[Vagabond]

Link: http://img.photobucket.com/albums/v...tions/K-SeriesTransmissionTablev3-28-08re.jpg



Ok Guys, a bit of documentary & education.


I'm a bit tired of listening blindly to sales people and tuners advice, i think it's time we learn a bit about something before modding it.


Each person mods with a different goal in mind. some mods which may suit some, may not suit others.


Let's start with Transmissions / Gear Boxes.

Alot of shops keep saying: Upgrade your Final Drive ! Upgrade your final drive!

yes .... but upgrade to what?


Assuming that most of the 6 speed transmission components are inter-swappable between K-series engines,


For example, a DC5 driver may want better acceleration, he goes for a 5.1 (5.062) final drive .........


But say a DC5 driver who wants to play TOP SPEED ....... a 5.1 Final Drive will be detrimental / bad for his objective. So he should opt for the 4.389 Final Drive from the earlier american RSX's with the 0.659 6th gear from the TSX/CSX ....... that would be the formulae for the potentially maximum top speed.


Or as Terry (undermine) theorised, to get a good compromise between acceleration & top speed for a DC5, assuming that the objective is have top acceleration of up to 180 km/h (5th Gear) , and have better than stock top speed of a dc5, the DC5 owner would opt for a 5.1 (5.062) Final Drive with a 0.659 6th gear from the TSX or CSX.


There are many possible combinations, it would seem

What kind of transmission set up are you looking for? :wavey:

 

[lightningfield]

if using FD2R 5.0 final drive, at what speed the vtec will engage on 6th gear..considering that the engagement point is at 5000rpm? and will there be any significant improvement should the 6th gear of a TSX being installed?

 

[rev555]

i try my fren ep3 before he was using the final drive 5.1..std engine with k-pro..u can feel that the pick up is very good but car without grip ,(wheel spin) n the rev(rpm) very fast to redline.top speed totaly out 220km....n the engine very full..as my experian last time my e36 328..i mod to manual ..using the m3 gear box.n rear axle gear box i try using the std auto gear box...damn good pick up n fast rpm,but no more top speed at all..feel like need another gear to enter..6th..
n the day i try my fren ep3...abit same feel..but it better than my bimmer..but i think the final gear 5.1 is good for track n city use ..for me..i travel kedah to kl...2hour 45min reach toll .that will be not suit to me..the higher ratio will be more better.

 

[minivan]

Same prinsip la basically this final drive thingy. Goes back to what u want. Theres always a comprimise. Like me EK, EG frens with modded final drive, all pening when driving on da highway... 130/140kmph also VTEC bukak in 5th... and the fuel it eats up!!!

Rev, 2hrs 45mins Kedah-KL?? Damn... are we talking about Kulim Kedah or Alor Setar Kedah here??
Even if Kulim, still fast ooo....

 

[Vagabond]

Assuming we're running on stock rims + tyres, (215/45/17), and the FD ratio is 5.062 (fd2r's), and the 6th Gear Ratio of a stock dc5 tranny being 0.78, the speed the driver is travelling at at 5,000rpm would be approximately 150 KM / H

formula can be obtained from :
http://en.wikipedia.org/wiki/Gear_ratio


a 6th gear from TSX will give better top speed i guess ...... but i'm damn sure the acceleration will be bloody sluggish!!!!!

 

[rev555]

Same prinsip la basically this final drive thingy. Goes back to what u want. Theres always a comprimise. Like me EK, EG frens with modded final drive, all pening when driving on da highway... 130/140kmph also VTEC bukak in 5th... and the fuel it eats up!!!

Rev, 2hrs 45mins Kedah-KL?? Damn... are we talking about Kulim Kedah or Alor Setar Kedah here??
Even if Kulim, still fast ooo....

from alor star to kl toll...hahah..constan at 200km...1 stop kencing n feuling...haha

 

[undermine]

hehe..... thanks tim for the compliment of mentioning me regarding the TSX 6th gear.

Yes, it seems like an ideal combination of best of both worlds 5.1 final drive with the TSX 6th gear

First,
5.1 gives u better response and pickup in the earlier gears, especially in 1st 2nd 3rd. however it shortens your top speed and a slightly worse FC.

Enter TSX 6th gear. Ask yourself, what gear do u engage on average most of the time? yes, it is 6th gear. You might engage 1st gear or 2nd gear the most, but thats for a mere 3 seconds before u switch to another gear. the 6th gear is where u spend the most minute and hours in it. the TSX 6th gear has lower ratio, hence gaining back the lost top speed caused by the 5.1 final drive as well as improving fuel consumption since it is lower, your engine operate at a lower rpm at the same speed.

So there you go =)

 

[papagoines]

sorry to butt in... not a honda user... just like to read about ur guys theory on gear ratio

i think this software might help...
http://www.locost7.info/gearcalc.php

sorry again

 

[122]

saw that graph few months back b4 i installed my 5.1FD. Initially wanted to install the FD with 4,5,6 gear from FD2R to get the best of both pick up and also top speed, but after an advise from singapore dc5 guys who just use the FD w/o the longer gearing, they still could obtain a top speed of roughly 10 km/h lower than stock dc5 gearing. So i decided to try it out. verdict , the acceleration from 1-6 is much stronger compared to normal FD and also throughout the gear we can feel the shorter ratio.......very very good feeling, i will never go back to 4.7 FD, small sacrifice of fuel consumption for better acceleration. if u just put the tsx 6 gear, you will experience a power loss when shifting from 5-6.
just my preference.......

 

[NFS]

i'm using FD2R Final drive too and the top speed loss is acceptable comparing to the pick up ... my highest top speed is 239km/h with few k's of rpm to go ...

for me its good enough ... :)

 

[slick]

Had this discussion about gear ratios late last year with a friend (FD2R owner) and he wrote this excel file to help us calculate speeds at each gears, taking into account all factors including final drive.

You can change parameters such as final drive, gear, RPM, tyre profile, wheel diameter, etc and see the speed you can get.
It also shows a comparison between DC5R and FD2R gear ratios.

Just sharing in case someone finds it useful.

 

[rev555]

guy..acculy the std gear ratio can go max...km..?

cos evertime i push to the limit just can see the rpm at 8xxx only..don have time to see my speed meter..cos my speed meter at the right hand side too small to see it..haha...

 

[slick]

guy..acculy the std gear ratio can go max...km..?

cos evertime i push to the limit just can see the rpm at 8xxx only..don have time to see my speed meter..cos my speed meter at the right hand side too small to see it..haha...

If you refer to the spreadsheet i attached earlier, for a DC5 with stock gears and stock final drive(4.764), 17" rims, 45 series tyre, at 8,400RPM, speed will be 266.44 km/h

 

[Vagabond]

slick:

yup, it's somewhere around there.

one crazy fukker lunatic tried this on a dyno in penang,

stock dc5 with rev cut removed, stock gear ratio, 6th gear maxed out REACHED 276KM/H.

recorded on the rsm, so +/- 5%

I wonder which dumb-ass was that?

 

[slick]

slick:

yup, it's somewhere around there.

one crazy fukker lunatic tried this on a dyno in penang,

stock dc5 with rev cut removed, stock gear ratio, 6th gear maxed out REACHED 276KM/H.

recorded on the rsm, so +/- 5%

I wonder which dumb-ass was that?

That's crazy, don't wanna be anywhere near that dyno!

 

[rev555]

if i can doing my car break at 300kmh..that will be more fun...i think give me some time to doing..haha..cos i realy like this staff..maybe have to doing the bottom end..n remove the rev cut to 9500rpm...huhu...got target...umhh world faster dc5 running how fast....???hahha..lot of quition..haha

 

[undermine]

well yeah you ll have a power loss when shifting from 5th to 6th using tsx gear but you will never reach 6th gear when you are racing or in need of the power. 6th is always the cruising mode and hence the purpose of it.

 

[dcloo]

guys stock DC 5 gearbox was most close ratio ever in among all Honda model
If u think swap tsx 6 speed into stock gearbox u will regreat
The best idea was your must proper calculate your rpm power vs tire
I was complete swap from 1-6 speed ratio & final to reach my goal
FD 2 R 6th gear was the best among for crusing from 200-240 whp DC 5
With k-pro low load 6 k rpm Vtec I could get 190 km/h in 6 speed and what do you guys think rev cut at 9500 what the the top speed ended at

 

[Vagabond]

Loo:

real world top speed (needs balls)

or

theory top speed (need calculator) ???

 

[rev555]

Loo:

real world top speed (needs balls)

or

theory top speed (need calculator) ???

real world top speed i think need ball.

n need $$$$$.....hihihih