Notices
Tech / Misc Tech topics that don't seem to go elsewhere.

Anyone Interested in a taller d-series 1st gear?

Thread Tools
 
Search this Thread
 
Old 02-08-2007, 12:50 PM
  #1  
Go Tigers!
Thread Starter
 
Bense's Avatar
 
Join Date: Mar 2003
Location: Greenville, South Carolina
Posts: 9,782
Received 45 Likes on 33 Posts
Default Anyone Interested in a taller d-series 1st gear?

I've done some calculations trying to figure out what is needed and I've come up with a 2.75 ratio. This would provide several advantages:
1. The taller first gear brings your shifts closer to 2nd gear. Keeping you closer into the power band.
2. For cars with more power, this would make it easier to launch and maintain traction.
3. Puts less strain on 2nd gear synchro. The less the RPMs drop, the less the synchro has to work, the easier it is to shift. This is very helpful on high revving engines.
4. Less strain on the 1st/2nd gear shift fork. Again, less work on the synchros.
5. With the close ratio gears, combined with a HUGE turbo, this means you'll never fall out of boost

Aside from all that. I think that we all can agree that the most ideal gearing for a 88-00 civic would be the K20R DC5 ITR 6speed transmission with the JDM CRV 5.062 final drive. With this transmission setup combined with the smaller diameter tires, it's ideal gearing In my opinion. However there's one drawback with this setup. 1st gear becomes too short for normal use.

Here's the k20R, 5.062 FD, 205/50/15s, 8000rpm redline. Gears end at the following mph
1st = 33mph
2nd = 51mph
3rd = 72mph
4th = 89mph
5th = 112mph
6th = 139mph

80mph in top gear = 4600rpm


Think about the added power of the 2.0 liter engine, and think about the time that it takes to shift from 1-2. It becomes better to just start off in 2nd gear. Lots of people with K swaps have also said that their fastest times have come from starting off in 2nd gear. So the next question is probably something along the lines of "are you sure that that gear isn't too long to start off in for daily driving?"

That's an excellent question that deserves a good answer. Here's my take on it. On the 92-95 civic vx/cx, both being civics with the weakest engines since 1992. The vx has the d15z1 which is rated at 92 horse power, and the cx with it's d15b8 is rated at 70hp. Both of these cars share the same transmission. The first gear has a ratio of 3.25, and the final drive has a ratio of 3.25 Now lets multiply these numbers and see what the overall gearing for 1st gear is.

3.25 * 3.25 = 10.5625

The greater the number, the "shorter" the gear is. Now lets look at the 2nd gear of the K20R/5.062

2.13 * 5.062 = 10.78206

If you notice, the ratio for the K's 2nd gear is 2% shorter than the cx/vx 1st gear. Considering the fact the cx/vx have less than 100hp, and honda agreed that 1st gear wasn't too long, I think this is ample proof that starting off in 2nd gear with the k20R/5.062 isn't such a bad idea.

Also, check out the 88-91 HF with 62hp and the 2.95 final, 3.25 1st gear

3.25 * 2.95 = 9.5875 apparently this gear wasn't too long for the HF


So with the above proof, I think we can all agree that the 2nd gear ratio of 2.13 combined with the 5.062 final drive, is not too "tall" of a gear to start off in while in daily driving. With that said, the most "ideal gearing" is going to be the 2nd-6th gear of the jdm k20R with the 5.062 final drive. Notice how you never see close ratio gear kits for these k-series 6speeds, there's no point. There's final drive upgrades, like the original 5.062 that ATS made which is now rather pointless. With the $800 pricetag on the ATS 5.062, this is no way to compete with the OEM 2003+ JDM CRV final drive of the exact same ratio that is sold for less than half of the price that ATS wants. Anyways, moving on.

So now that I have shown you with adequate evidence that this tranny setup is very ideal. However there's just one catch. This K tranny is very expensive, some of the JDM gears aren't easily available in the US, and not everyone can afford K swaps. They're still to expensive for them to be worth the money. So here's where the exciting part comes in. The "D" trans.

Now I know what many of you are going to ask. Why the D trans? Well, Bisi seems to answer this question quite well in his link found here: http://bisimoto.com/wst_page4.html Also, the biggest weak point that people are experiencing are the differentials blowing apart. Many say that this is a big issue, I disagree completely. Because anyone that is considering performance in their front wheel drive car is going to have to upgrade the differential with an LSD unit. Right now the best unit to buy is the OBX LSD. There were a few issues a while back with the axles being stuck, but OBX resolved this a while ago. This is all proven in this thread https://honda-tech.com/zerothread/1752849 I actually own a quaife, but regret buying it, as the OBX LSD is been proven to be an excellent product for the price.

The next question that comes into place is "what about the gearing?" Well Mfactory is currently offering close ratio gearsets for the D trans. They sell the 3/5 kit which uses the stock EX 3rd gear as 4th, giving your eX trans a close 2/3/4/5. Which provides excellent gearing. Except that 1-2 is still stock. The solution to this is a longer first gear

With a 2.75 1st gear, the ex 2nd gear, mfactory 3rd gear, ex 3rd gear as 4th, mfactory 5th gear. Combined with a 3.888 dx final drive, let's compare this 1-5 to the k-series 2-6



As you can see, the 1-5 of this D trans is nearly identical to the K gearing that we all agreed on earlier Ready for the fun part?
The following OEM D final drives are available:
2.95, 3.25, 3.722, 3.888, 4.058, 4.25, 4.4375

The following D aftermarket final drives are available:
4.53, 4.73, 4.928

With the 2.75 1st gear, this is the last gear that we need to make the "perfect" transmission to suit our needs.

2.75 1st gear, y8 2nd gear, mfactory 3rd, ex 3rd as 4th, mfactory 5th, dx 3.888 final drive, 8000rpm redline, 205/50/15s
1st = 51mph
2nd = 74mph
3rd = 90mph
4th = 112mph
5th = 141mph

80mph in top gear = 4550rpm


Next anticipated question/concern: "I don't want to fork out this much money on my transmission" Completely understandable. Although the above is "ideal" in my opinion, it also comes with more money spent on my trans than others are willing to put forth. If you take a look here http://bensebuilt.livejournal.com/2006/11/11 Towards the bottom I talk about the "SCHardbody" trans. It is a fairly simple setup with a "budget" in mind.

Originally Posted by BenseBuilt.Livejournal.com
And last but not least, the SCHardbody Trans. I built this trans for my buddy Lee.

SCHardbody Trans:
1st = 3.250
2nd = 1.762
3rd = 1.250
4th = 1.033
5th = 0.702
FNL = 4.250

He started off with a d15z1 trans and we placed an ex final drive in it, ex 3rd gear, and a hf 3rd gear as 4th.

gears end at following mph
1st = 37.28
2nd = 68.77
3rd = 96.93
4th = 117.30
5th = 172.60

70mph in 5th = ~3050rpm
80mph in 5th = ~3450rpm

Driving impressions: First thing I'm going to say is that this trans isn't "perfect" There are better gearing options available. This is a complete budget setup with parts that I had left over. The only thing is we had to spend $25 for the hf 3rd gear as 4th. Lee had a d15z1 trans which is insanely long gearing. Anything is better than stock cx/vx gearing. Anything. So rather than getting ahead of ourselves and spending too much money on gearing, I came up with this cheap setup. It's better than a stock ex trans from a roll, because the taller 2nd gear takes him further into the shorter ex 3rd. The shorter 4th gear also helps out. If I were to make one change to this trans I would have thrown in a 88-91 civic dx/si 5th gear of 0.771 in it to help out with the gap
from 4th to 5th. But who cares, it's not like lee will need to be accelerating past 117.3 mph
The main problem with the above trans with the 3.25 1st gear, is that 1st - 2nd shift is gappy.
when you take 1st gear to 7500rpms and shift to 2nd, the rpms fall to 4066rpm

7500 * 0.542 = 4066

With the 2.75 1st gear to the 1.762 2nd gear

7500 * 0.641 = 4805

Lets take that trans, and put in a 2.75 1st gear instead of the 3.25 1st gear. gears end at following mph
1st = 44mph
2nd = 69mph
3rd = 97mph
4th = 117mph
5th = 173mph

That's an 18% decrease of rpm drop. Which may sound insignificant at first (no pun intended ), but I guarantee you that you'd feel the difference. See that 0.641 number that I mentioned before? Think about how a b16/itr trans feels from 1st - 2nd. Well the b16 1st -> 2nd = 0.651 This 2.75 1st gear will make your dx 1-2 shift feel like an itr/b16 1-2 shift

here's some more 1-2 shifts for comparison
0.542 = 92-95 dx/cx/lx/vx
0.548 = 96-00 dx/hx/lx/cx
0.585 = 92-95 ex/si
0.587 = 96-00 ex
0.588 = 94-01 gsr/ls
0.641 = 92-95 dx/cx/lx/vx with 2.75 1st gear
0.648 = 96-00 dx/hx/cx with 2.75 1st gear
0.652 = 94-01 b16/itr
0.691 = 92-95 ex/si with 2.75 1st gear
0.694 = 96-00 ex with 2.75 1st gear


I've spoken with MFactory, they have agreed that if enough people show interest, they will start making them. They've also stated that the cost of the gear will not be more than the current b-series 3.0777 gear which goes for $249

I realize that this is probably more info than you guys want to read, however I think it's important for you guys to know my reasons why for wanting this. Who knows, maybe you'll agree with me.

A similiar thread on d-series.org
http://www.d-series.org/forums...58631

My original journal entry from 9/22/06
http://bensebuilt.livejournal.com/2006/09/22/

So....WHO WANTS ONE?


Modified by Bense at 2:59 AM 2/9/2007
Old 02-08-2007, 12:55 PM
  #2  
Honda-Tech Member
 
Soccerking3000's Avatar
 
Join Date: Oct 2003
Location: Catching Rivers on Fire TWICE
Posts: 6,281
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (Bense)

weirdo... but good work
Old 02-08-2007, 12:57 PM
  #3  
Go Tigers!
Thread Starter
 
Bense's Avatar
 
Join Date: Mar 2003
Location: Greenville, South Carolina
Posts: 9,782
Received 45 Likes on 33 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (Soccerking3000)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Soccerking3000 &raquo;</TD></TR><TR><TD CLASS="quote">weirdo... but good work </TD></TR></TABLE>

HAH! And they say that being single doesn't have it's perks!
Old 02-08-2007, 01:14 PM
  #4  
Honda-Tech Member
 
Soccerking3000's Avatar
 
Join Date: Oct 2003
Location: Catching Rivers on Fire TWICE
Posts: 6,281
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (Bense)

i hope to not be single much longer
Old 02-08-2007, 03:25 PM
  #5  
z6
Honda-Tech Member
 
z6's Avatar
 
Join Date: Dec 2003
Location: Winnipeg, manitoba, Canada
Posts: 592
Likes: 0
Received 0 Likes on 0 Posts
Default

Can you imagine how peaky you can let your powerband be with gearing like that.....that tranny is a big turbo's best friend
Old 02-08-2007, 03:48 PM
  #6  
Honda-Tech Member
 
Soccerking3000's Avatar
 
Join Date: Oct 2003
Location: Catching Rivers on Fire TWICE
Posts: 6,281
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (rota92)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rota92 &raquo;</TD></TR><TR><TD CLASS="quote">

Are you the one on the news scoping out elementary schools?

nice info! If I go D-again in a daily I will look into this!</TD></TR></TABLE>

**** they got a pic of my face?? i thought the ski mask covered it enough
Old 02-08-2007, 07:42 PM
  #7  
Honda-Tech Member
 
SovXietday's Avatar
 
Join Date: Jan 2005
Location: Lower Right Hand Corner, PA
Posts: 5,643
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (Soccerking3000)

I WANT ONE!!!

Stupid really short 1st gear really big turbo really big gap between 3.25 and 1.762.

Bense and I have talked a lot about building a tranny for a high whp Dseries engine. So far all of my gears have cost me ~100 plus the OBX LSD and a few bearings that need replacing. Kickass eh?

Final: 4.25

1st: 3.25
2nd: 1.762
3rd: 1.25
4th: 1.033
5th: .771

It was pretty clear that using the MFactory gearing would be too short for anything above a 110mph trap speed. All the above are gears that you can get from production Honda's, and for cheap at that. This gearing setup will cover 130mph traps pretty much on the dot, and will keep rev drop to a minimum with each shift.

This is your MPH and gear graph with a stock EX tranny in green and my tranny in the red. 24.5" slick size and revving out to 8250 (just about any 400whp Honda out there should be doing this...)

http://www.fatboyraceworks.com...are=1

All I need, is that goddamn 1st gear!
Old 02-08-2007, 08:15 PM
  #8  
 
EJgsr's Avatar
 
Join Date: Jan 2006
Location: vtec, us
Posts: 1,551
Likes: 0
Received 2 Likes on 2 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (SovXietday)

bense, you are one crazy bastard.
Old 02-08-2007, 10:59 PM
  #9  
Go Tigers!
Thread Starter
 
Bense's Avatar
 
Join Date: Mar 2003
Location: Greenville, South Carolina
Posts: 9,782
Received 45 Likes on 33 Posts
Default

Old 02-09-2007, 09:49 AM
  #10  
Honda-Tech Member
 
Justin Jones's Avatar
 
Join Date: Jul 2002
Location: Peg City, 204
Posts: 812
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (Bense)

Wasn't there another thread about this months ago?

God, please make this first gear! This is the answer to our prayers. We should phone Mfactory everyday until they make this bad boi. I'll buy one right now. Gimme the paypal address. now.
Old 02-09-2007, 10:58 AM
  #11  
Honda-Tech Member
 
s_18's Avatar
 
Join Date: Sep 2003
Location: Norway
Posts: 135
Likes: 0
Received 0 Likes on 0 Posts
Default

I would love one of those for my trans!
Old 02-10-2007, 02:14 PM
  #12  
Go Tigers!
Thread Starter
 
Bense's Avatar
 
Join Date: Mar 2003
Location: Greenville, South Carolina
Posts: 9,782
Received 45 Likes on 33 Posts
Default Re: (Justin Jones)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin Jones &raquo;</TD></TR><TR><TD CLASS="quote">Wasn't there another thread about this months ago?

God, please make this first gear! This is the answer to our prayers. We should phone Mfactory everyday until they make this bad boi. I'll buy one right now. Gimme the paypal address. now.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by s_18 &raquo;</TD></TR><TR><TD CLASS="quote">I would love one of those for my trans!</TD></TR></TABLE>

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

MORE MORE MORE
Old 02-11-2007, 07:09 AM
  #13  
EG8
Honda-Tech Member
 
EG8's Avatar
 
Join Date: Nov 2005
Location: Phoenix AZ, USA
Posts: 173
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (Bense)

I would be very intrested!
Old 02-11-2007, 08:35 AM
  #14  
Honda-Tech Member
iTrader: (1)
 
PA MATT's Avatar
 
Join Date: Feb 2003
Location: somewhere in..., pa, usa
Posts: 3,923
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (EG8)

nice! assuming I get my lsd, I'm planning on changing the gears around, so Id definetly be interested in this
Old 02-11-2007, 10:21 AM
  #15  
Honda-Tech Member
 
SLowCrx's Avatar
 
Join Date: Jun 2002
Location: Roanoke, VA, USA
Posts: 1,239
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (Bense)

Interested !!!!
Old 02-11-2007, 02:47 PM
  #16  
Honda-Tech Member
 
Justin Jones's Avatar
 
Join Date: Jul 2002
Location: Peg City, 204
Posts: 812
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (Bense)

spam this ****. mass illegal email.


or maybe try http://www.petitiononline.com ?


we the undersigned: demand mfactory, inc to begin production on a taller first gear for D series
Old 02-11-2007, 03:22 PM
  #17  
Honda-Tech Member
iTrader: (3)
 
Aquafina's Avatar
 
Join Date: Jan 2003
Location: Johnson City TN
Posts: 11,928
Received 37 Likes on 37 Posts
Default

I'm in. Maybe for 2-3
Old 02-12-2007, 06:46 PM
  #18  
Honda-Tech Member
 
Justin Jones's Avatar
 
Join Date: Jul 2002
Location: Peg City, 204
Posts: 812
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (Aquafina)

can/should this be made a sticky?
Old 02-12-2007, 07:07 PM
  #19  
Go Tigers!
Thread Starter
 
Bense's Avatar
 
Join Date: Mar 2003
Location: Greenville, South Carolina
Posts: 9,782
Received 45 Likes on 33 Posts
Default

pm a mod and ask them
Old 02-12-2007, 07:21 PM
  #20  
Honda-Tech Member
 
Justin Jones's Avatar
 
Join Date: Jul 2002
Location: Peg City, 204
Posts: 812
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (Bense)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bense &raquo;</TD></TR><TR><TD CLASS="quote">pm a mod and ask them </TD></TR></TABLE>

like your homie george knighton?
Old 02-12-2007, 08:53 PM
  #21  
Honda-Tech Member
 
HatchEh2's Avatar
 
Join Date: Sep 2004
Location: Windchestertonfieldville, NJ, USA
Posts: 1,555
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (Bense)

here goes the mad scientist at it again
Old 02-13-2007, 12:50 AM
  #22  
Honda-Tech Member
 
redex04's Avatar
 
Join Date: Feb 2006
Location: montoursville, pa, usa
Posts: 996
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Anyone Interested in a taller d-series 1st gear? (HatchEh2)

interested
Old 02-14-2007, 10:00 AM
  #23  
Honda-Tech Member
 
69NOSAJ's Avatar
 
Join Date: Aug 2006
Location: LackLand, TX, USA
Posts: 192
Likes: 0
Received 0 Likes on 0 Posts
Default

Put me down for two

one for me and another one for a buddy w/ high hp D
Old 02-15-2007, 04:05 PM
  #24  
Member
 
743power's Avatar
 
Join Date: Feb 2002
Location: at the track
Posts: 5,962
Likes: 0
Received 0 Likes on 0 Posts
Default Re: (69NOSAJ)

I would be interested. This is something that is definitely missing on the market.
Old 02-20-2007, 05:44 AM
  #25  
Honda-Tech Member
 
ELSpool's Avatar
 
Join Date: Apr 2003
Location: Ottawa, ON
Posts: 1,364
Likes: 0
Received 0 Likes on 0 Posts
Default

sign me up!


Quick Reply: Anyone Interested in a taller d-series 1st gear?



All times are GMT -8. The time now is 10:48 PM.