TypeSLO

what kind of difference is expected if i went from making 400 whp with an LS trans to a b16 trans? no change to motor or anything. just swapping transmissions. i'm guessing with shorter gear ratios, there will be less load so the turbo might spool a little later? i'm not 100% sure.

Mugencrxsir1

Here's a good trans calculator that should answer all of your questions....

http://www.fatboyraceworks.com/gears/

TypeSLO

that's a good site to compare speed, etc. but not power. it doesn't answer my question. anybody?

boostedcivicsir

there has always been the argument, longer gears better for turbo. all i know is i want to be goin through the traps at my engines peak power. i am hoping for 700whp, on a b16 trans with a gsr 4th.

TypeSLO

i need to research this a little more but i think what i may need to do is change the final drive on the b16. somewhere between 4.1 and 4.2. i need to find a place where they make custom final drives. any inputs? thanks.

boostedcivicsir

yup and they arent cheap. liberty. mess with tire size and gear combos. it is easier to change a gear than a whole final.

TypeSLO

wow, you're not kidding with the 'not cheap'. i'll have to look into changing a gear maybe. thanks for the tip.

TheShodan

iTrader: (14)

B18B/B20B 4.2 Final Drive
B18C1 USDM 4.4
B18C5 USDM 4.4
B18C5 JDM 4.785
B16A USDM 4.4
B16B 4.685
F20C 4.1 (6 speed)

The final drive doesn't change Power, but is more of a torque mulitplier, which can act in a way as a power adder, because the car between gears stays within its peak rev range. The drawback for some is that top end is sacrificed due to the shorter gearing, but in circuit racing top speed is not the focus. It does bring your rpms up by a few hundred in the highway but DOES NOT sacrifice fuel economy unless you actually put the car under load.

I currently have a GSR with ATS LSD, 4.785 final drive and LS 5th gear. kinda crazy, but works great for my particular goals.

TypeSLO

i think what i'd like to do is use the b16 trans and an LS final drive. (4.266) that puts me where i want to be at at the top of 4th with the right tire size and whatnot. can you just swap the final drives or is there more involved? i've never worked on transmissions other than my dirt bike but that was easy. i have both the b16 and LS trans so it works for me.

boostedcivicsir

final drive is the whole countershaft and the ring gear. to swap the ring it is easy. take diff out, swap ring, bolts are left hand thread.

to swap the counter, i just took mine apart, on its way to racer stev, you need to completely strip it. i think you have to press a gear or 2 off. they arent tight but they take a little effort to do so. mysetup is a b16 with a gsr 4th. i hope i dont run out of gear because 5th is gone in favor of a liberty cuff.

SovXietday

IMO, the perfect gearing for a boosted car is this.

Long first, long second, medium 3rd, short 4th.

Obviously the transmission you have and trap speed goals is going to dictate what is long/short. But the longer (within reason of course) 1-2 gears are the less likely you are to break the tires loose, and as we all know high whp honda's are late spoolers, so if you can keep the revs from falling below full spool points and have room with 4 gears to run the entire track and cross the beams at just after the peak of your power curve you've got a good gearing setup.

TypeSLO

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostedcivicsir &raquo;</TD></TR><TR><TD CLASS="quote">final drive is the whole countershaft and the ring gear. to swap the ring it is easy. take diff out, swap ring, bolts are left hand thread.

to swap the counter, i just took mine apart, on its way to racer stev, you need to completely strip it. i think you have to press a gear or 2 off. they arent tight but they take a little effort to do so. mysetup is a b16 with a gsr 4th. i hope i dont run out of gear because 5th is gone in favor of a liberty cuff.</TD></TR></TABLE>

ok, when you say the countershaft, i'm thinking the output shaft. i'm sure i'll figure it all out when i get my honda manual. i understand what you're saying though. just take all the gears off my LS countershaft and put the b16 gears on it and install in the case. i hope that's correct. thanks for all your help.

Mugencrxsir1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TypeSLO &raquo;</TD></TR><TR><TD CLASS="quote">that's a good site to compare speed, etc. but not power. it doesn't answer my question. anybody?</TD></TR></TABLE>

We are not comparing HP, your HP is the same, so HP is out of the equation....... You wanted gear ratios, trap speeds, what tranny is right for you? Well start messing around with this calcualtor and most of your questions should be answered. It has a drop down menu with most of the popular honda trannies, or just input your specific gears manually.....

TypeSLO

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mugencrxsir1 &raquo;</TD></TR><TR><TD CLASS="quote">

We are not comparing HP, your HP is the same, so HP is out of the equation....... You wanted gear ratios, trap speeds, what tranny is right for you? Well start messing around with this calcualtor and most of your questions should be answered. It has a drop down menu with most of the popular honda trannies, or just input your specific gears manually..... </TD></TR></TABLE>

what i meant by power is how it will affect the turbo. with shorter gearing, there will be less load on the engine so my guess is that it will not spool as fast as a trans with longer gearing. it may not be much of a difference but i'd like to find out.