So Im currently running a best of 12.6 @ 109 with 1.7 60ft.
I dyno at 228 whp and redline at 9100 currently and willing to go higher.
Running on 23" slicks.

I currently have a jdm ys1 with the stock LSD.

I want to know what kind of a change putting a 4.7 or 4.9 final drive would do
to the car in the 1/4 mile. And maybe any suggestions you can give.

 

Stock Final Drive (4.400):

1st gear - 42.8 mph
2nd gear - 67.2 mph
3rd gear - 97.0 mph
4th gear - 127.9 mph

4.785 Final Drive:

1st gear - 39.3 mph
2nd gear - 61.8 mph
3rd gear - 89.2 mph
4th gear - 117.6 mph

4.900~ Final Drive: (forget the exact numerical value of the 4.9)

1st gear - 38.4 mph
2nd gear - 60.4 mph
3rd gear - 87.1 mph
4th gear - 114.8 mph

That's at your 9100 rpm rev limit. So you may spin a bit more going into 2nd. But those final drives will tighten up the gears and maximize the power you're making right now. So I'm sure they'd help. Just a matter of how much.

 

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

That's at your 9100 rpm rev limit. So you may spin a bit more going into 2nd. But those final drives will tighten up the gears and maximize the power you're making right now. So I'm sure they'd help. Just a matter of how much.

</TD></TR></TABLE>

One way to fix the the spin into 2nd gear is to also utilize a longer (3.070) 1st gear. is this a daily driver?

 

This is not daily driven. Mainly track and weekend car.

 

use the ats 4.9 fd with ats 3.077 1st gear i have that in my daily gsr turbo, it's great

 

^^ a 4.9 final drive in a turbo car.. i always was under the impression thats its way better to run a lower final drive with turbo setups... anyway to the op i dropped a jdm type r 4.7 in my b16 trans and it improved about a .2 or .3 better in the 1/4 from the stock b16 final drive. as for mph i dont think it moved much.

 

It will be worth your while to play with this for a while

http://www.teammfactory.com/gearcalculator.php


Just a hint, the 98 spec type r tranny is pretty close to what you want to be running... but it's incompatability with alot of aftermarket parts and other B-tranny;s make it a bad place to start if you want to build a hybrid

 

incompatibility? I had no problem installing a gsr 2nd gear, itr 4th, and ls 5th in mine, along with a Quaife lsd. now gears 2,3,4 are nice and close, and I get ~40mpg en route to the track at ~80mph (4K rpm). The bell housing is that of the typical hydro B trans, as is clutch compatibility, the VSS and linkage are the same; I don't see what you mean.

 

Wait, what's your 1,3 gear ratio's slofu? Is this a turbo car?


Modified by FST GSR 1 at 8:04 AM 10/2/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by logg_frogg &raquo;</TD></TR><TR><TD CLASS="quote">It will be worth your while to play with this for a while

http://www.teammfactory.com/gearcalculator.php

</TD></TR></TABLE>

you can also use this to calculate your RPM drops. it's very helpful when you're trying to determine gearing and where you want your shift points to be.

http://www.wallaceracing.com/R...r.php

Good Luck!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slofu &raquo;</TD></TR><TR><TD CLASS="quote">incompatibility? I had no problem installing a gsr 2nd gear, itr 4th, and ls 5th in mine, along with a Quaife lsd. now gears 2,3,4 are nice and close, and I get ~40mpg en route to the track at ~80mph (4K rpm). The bell housing is that of the typical hydro B trans, as is clutch compatibility, the VSS and linkage are the same; I don't see what you mean. </TD></TR></TABLE>

The 98 spec type-r cases are slightly more heavily reinforced which causes some minor incompatabilities with *some* parts (ie the mfactory 3.070 1st gear). It's nothing that you can't fix by removing a little material, but some ppl are not comfortable with that. I may have exagerated that a little bit.

 

no FI (all motor forum). stock 1st; wheelspin is wheelspin. gsr 2nd, itr 3rd & 4th, ls 5th. 4.78FD. It's daily-driven, tracked on weekends.

it'd actually be better for track using gsr 2nd & 3rd, itr 4th & 5th, keeping the 4.78FD; I mostly use 3rd & 4th on the track. On the street, though, having 3rd closer to 2nd is more useful (though I don't streetrace).

 

Is your tranny for a road racing application slofu?? ("I mostly use 3rd & 4th on the track")

Another great source of info if you can digest it all:


http://bensebuilt.livejournal.com/2006/01/08/

 

I disagree. You loose more time in the RPM loss on the 1-2 then you can make up with even lower ratios on the 3-4 in the 1/4.

Front half numbers with the 2.1 is the better choice IMO. Front half numbers on a NA car is key to getting that weight moving.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FST GSR 1 &raquo;</TD></TR><TR><TD CLASS="quote">I disagree. You loose more time in the RPM loss on the 1-2 then you can make up with even lower ratios on the 3-4 in the 1/4.

Front half numbers with the 2.1 is the better choice IMO. Front half numbers on a NA car is key to getting that weight moving.</TD></TR></TABLE>



IMO, calculating rpm drops vs peak tq and shift points will net better et's at the end of the day.

 

what do you think of these??



They are

Mfactory 1st,
B16 2nd / 3rd
GSR 4th (or type r 2-4)
and LS 5th


/w 2 options for final drive and tire sizes

any opinions on these??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FST GSR 1 &raquo;</TD></TR><TR><TD CLASS="quote">
I disagree. You loose more time in the RPM loss on the 1-2 then you can make up with even lower ratios on the 3-4 in the 1/4.

Front half numbers with the 2.1 is the better choice IMO. Front half numbers on a NA car is key to getting that weight moving.</TD></TR></TABLE>

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



IMO, calculating rpm drops vs peak tq and shift points will net better et's at the end of the day.</TD></TR></TABLE>

You mean that when the tires spin going into 2nd because tq&gt;traction, as is, I'd be faster dropping into 2nd at yet a higher rpm with more power output? I'll take the extra rpm/power at higher loads, when I've traction to fight the wind drag.

Yes, I track the car on road courses. I don't drag race.

To the OP, what about trying the 4.266 LS FD, stock gsr gears 1-3, and shifting at 9500rpm? You could hold 112mph in 3rd.

To reduce wheelspin for drag, can't you use an EMS to pull ign timing at lower engine loads to reduce power output until you gain traction?


Modified by slofu at 9:46 PM 10/2/2008

 

In drag racing it's hardly ever an advantage to take your foot out of the pedal.

I have tried many many time to gain traction by bogging or shifting early and have always ended up with worse 60' and 1/8thmile times (on slicks)


making suspension adjustments and tire pressure changes as well as adjusting launch rpm's have always yeilded me better results..

 

who said anything about lifting? I recommended using load-based ignition timing to aid traction for a better launch, and trying to trap at the top of 3rd to abate shift time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slofu &raquo;</TD></TR><TR><TD CLASS="quote">
I don't drag race.

To the OP, what about trying the 4.266 LS FD, stock gsr gears 1-3, and shifting at 9500rpm? You could hold 112mph in 3rd.
Modified by slofu at 9:46 PM 10/2/2008</TD></TR></TABLE>
That second statement is by far one of the worst recomendations I have seen in a month on HT. Since you don't drag race, maybe you should stop giving advice on it.

 

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

To the OP, what about trying the 4.266 LS FD, stock gsr gears 1-3, and shifting at 9500rpm? You could hold 112mph in 3rd.

To reduce wheelspin for drag, can't you use an EMS to pull ign timing at lower engine loads to reduce power output until you gain traction?


Modified by slofu at 9:46 PM 10/2/2008</TD></TR></TABLE>


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FST GSR 1 &raquo;</TD></TR><TR><TD CLASS="quote">
That second statement is by far one of the worst recomendations I have seen in a month on HT. Since you don't drag race, maybe you should stop giving advice on it.


</TD></TR></TABLE>


Yeah.... we're comparing apples to oranges here as gearing for both types of racing is completely different.

 

The Difference at 9k!

Gearbox:- Standard B18C
Tire: 23

Top Speed in 1 gear = 43.310 MPH

And changes into 2 gear at 5294 RPM dropping 3706 RPM
Top Speed in 2 gear = 73.626 MPH

And changes into 3 gear at 6442 RPM dropping 2558 RPM
Top Speed in 3 gear = 102.860 MPH

And changes into 4 gear at 6843 RPM dropping 2157 RPM
Top Speed in 4 gear = 135.290 MPH
________________________________________________

Gearbox:- Standard B16
Tire: 23

Top Speed in 1 gear = 43.310 MPH

And changes into 2 gear at 5865 RPM dropping 3135 RPM
Top Speed in 2 gear = 66.456 MPH

And changes into 3 gear at 6234 RPM dropping 2766 RPM
Top Speed in 3 gear = 95.946 MPH

And changes into 4 gear at 6833 RPM dropping 2167 RPM
Top Speed in 4 gear = 126.368 MPH
________________________________________________

Gearbox:- Standard B16 w/ 4.785
Tire: 23”

Top Speed in 1 gear = 39.825 MPH

And changes into 2 gear at 5865 RPM dropping 3135 RPM
Top Speed in 2 gear = 61.109 MPH

And changes into 3 gear at 6234 RPM dropping 2766 RPM
Top Speed in 3 gear = 88.227 MPH

And changes into 4 gear at 6833 RPM dropping 2167 RPM
Top Speed in 4 gear = 116.201 MPH




Modified by FST GSR 1 at 9:17 AM 10/3/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FST GSR 1 &raquo;</TD></TR><TR><TD CLASS="quote">
That second statement is by far one of the worst recomendations I have seen in a month on HT. Since you don't drag race, maybe you should stop giving advice on it. </TD></TR></TABLE>

I'm just here to learn, much of which entails trying new things. I don't drag race, so it's not something I'd try, but has anyone tried it? I'd be interested to learn why it doesn't work.

 

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

I'm just here to learn, much of which entails trying new things. I don't drag race, so it's not something I'd try, but has anyone tried it? I'd be interested to learn why it doesn't work. </TD></TR></TABLE>

I think its more of running out of real estate to make it work. remember, we're only dealing with 1,320 feet here

 

You can't go faster in a fixed distance with less mechanical advantage (Gear).
Look at the gear charts I posted, it's all in the numbers.