Aquafina

iTrader: (3)

Bought a transmission and aren't sure what the gear ratios are? Have some gears collecting dust and wondering if they'll make you faster? Read on.

Determining the gear ratios is a pretty simple task, but not everyone knows how to do it.

First of all the transmission needs to be out of the car and the case removed. Removal of the gear stacks and shift forks is not necessary except for the final drive. A paper towel to wipe oil off the gears and a Sharpie to mark your starting tooth make it easier with the gear stacks installed.

FWD Honda transmission gearing consists of two gear stacks and the differential. The gear stack that has only one shift fork located at the bottom is the countershaft, the gear stack with two shift forks located in the middle and the top is the mainshaft. I've not done a K series gearbox yet so forgive me on the shift fork locations for those. The differential is the big round flat object with a bearing on top.

To determine the gear ratio you need to count the number of teeth on both the mainshaft and countershaft gears. If you're counting 1st and 2nd gear, they are built into the mainshaft. Once you have the tooth count of both gears, divide the number for the countershaft gear by the number for the mainshaft gear. The answer is the ratio for that gear.

To determine the final drive ratio you need to count the number of teeth on the ring gear (bolts to the differential) and the countershaft (teeth on the very bottom of the countershaft). Divide the number of the ring gear by the number of the countershaft. The answer is the final drive ratio. This is the same as what domestic guys typicaklly call the "rearend" or "gear" (i.e. 4.10 usually pronounced as "four-ten").

Here are some pictures incase you don't fully understand.

MFactory D15/D16 third gear set. The finger is pointing at a gear tooth on the countershaft gear. This is what you count the number of. Mainshaft gear is on the left.


MFactory final drive. The finger is pointing at a gear tooth on the countershaft (use where the fingernail would be for reference). Ring gear is on the left.


Record the tooth count for each gear and do the math (I cheated and used my phones calculator ). Gear ratios are sometimes rounded which is why your answer might be slightly different than what the gear ratio should be.


Want to know what difference the gear ratios will make? Plug them into a calculator. Make sure to enter your tire size and RPM (use shift RPM for top speed at your shift point, use rev limit for absolute top speed). The graph was too large to screen capture so follow this link http://teammfactory.com/gearca...and+2 to see it. This is comparing a stock D16Z6 transmission to a D16Z6 transmission with the MFactory close gear set. The "Shift Pt:" is the RPM which your engine drops to after shifting into that gear.


Have fun counting or planning out your next setup!

Pippen_001

Great write up!

Silencer RPMs

excellent write up

Mista Bone

You know what I like/dislike about the gearing calc........the ratios for 5g DX/LX/VX/CX are wrong.

Just barely, not enough to be any factor, but enough to know who has used my info

ONLY one calc has the correct 5g tranny ratios

http://www.zealautowerks.com/transcalc.php

Stealing my MISinfo only proves to me my knowledge is greater widespread that I knew, which is humbling.

MFactory

I didn't "steal", I just used what was available at the time based on other calculators/spreadsheets and I certainly didn't know they were "yours". Thank you though for informing me of the correct ratios


Modified by MFactory at 9:48 PM 9/5/2008

Mista Bone

I'm not upset at all!

WAY BACK when knowledge was first stolen....to here I believe....it was info that Katman had posted on the OLD SCHOOL Hybrid forum. They linked the pics and good old Katty changed the images, nothing like gay **** that was linked to old stolen images right?????

5g ratios


DX/LX/CX/VX 1.761 or 1.762 second gear????

CX/VX .852 or .853 4th gear???

After seeing the Katman issue, I made the info page in WebTV with very minor tweaks. The numbers are not off enough to effect anything, but seeing your knowledge widespead is quite humbling.

When I created that page, I never knew it would be such a "big hit" of info, nor the fact the simple casting codes I firgured out, which I literally stumbled across because I had so many junk trannys sitting around.

insert smirk humble icon if ther is one

Evs-One

I learned a lot from your tranny page and postings from way back, MB

coolhandluke

iTrader: (2)

Very nice work, to those who have contributed, and to Aquafina. Whoopee Doo Racing and MFactory = Great work and great products.