Difference a 4.9 final drive makes?
Honda-Tech Member
Joined: Oct 2001
Posts: 3,310
Likes: 5
From: ILM, NC
Re: 4.9 (strepto)
i dont know how much of a difference it makes in the 1/4, but it makes a huge difference in all around driveability. i had one installed w/ a toda flywheel in my y2k itr and it made the car so much more fun to drive. acceleration was really quick, the only thing i would suggest is to install a gsr 5th gear for hwy driving. hands down the best investment i made imo. 
Honda-Tech Member
Joined: Jan 2001
Posts: 8,136
Likes: 2
From: kuidaore
Re: 4.9 (egb20)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egb20 »</TD></TR><TR><TD CLASS="quote">1/4</TD></TR></TABLE>
Not what it was designed for really but, I'm sure it would help out a whimpy R a bit on the strip.
IM rodney, he did quite well when he ran it but, then again he has a serious Diff, was on Slicks at least one pass, and runs B's...
Here's a link for ya to play with the numbers:
https://honda-tech.com/zerothread?id=698304
Not what it was designed for really but, I'm sure it would help out a whimpy R a bit on the strip.
IM rodney, he did quite well when he ran it but, then again he has a serious Diff, was on Slicks at least one pass, and runs B's...
Here's a link for ya to play with the numbers:
https://honda-tech.com/zerothread?id=698304
Honda-Tech Member
Joined: Mar 2003
Posts: 4,027
Likes: 0
From: Greenville, SC
Re: 4.9 (egb20)
I don't know how much it really helps in the 1/4, 0-60 times will actually be slower since you have to hit 3rd gear to reach 60mph. I've got the ATS 4.9 FD and it makes a BIG difference on the highway. My car seems to REALLY pull hard on the highway. I kept the stock USDM 4th & 5th gears as well.
Brad
Brad
Moderator
Joined: May 2001
Posts: 12,232
Likes: 5
From: Browns Summit, NC, USA
Re: 4.9 (strepto)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by strepto »</TD></TR><TR><TD CLASS="quote">Just a friendly tip - when making a post in here, make sure the "Topic" is straight forward.
"4.9 Final Drive / FD" or something would have been better.</TD></TR></TABLE>
why....if you don't know what 4.9 stands for by now.....then you aint been paying attention in school!
"4.9 Final Drive / FD" or something would have been better.</TD></TR></TABLE>
why....if you don't know what 4.9 stands for by now.....then you aint been paying attention in school!
H-T Order of Merit
Joined: Jan 2000
Posts: 23,478
Likes: 2
From: Chicago
Re: 4.9 (Fat Bradstard)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fat Bradstard »</TD></TR><TR><TD CLASS="quote">I don't know how much it really helps in the 1/4, 0-60 times will actually be slower since you have to hit 3rd gear to reach 60mph. I've got the ATS 4.9 FD and it makes a BIG difference on the highway. My car seems to REALLY pull hard on the highway. I kept the stock USDM 4th & 5th gears as well.</TD></TR></TABLE>
Changing the final drive gear usually makes little difference at speeds above the first upshift (around 30 mph with the stock FD). Here's why.
Using a shorter FD means that your acceleration is better within each gear but not necessarily at any speed. It improves acceleration within a gear. So when you accelerate up to ~25 mph, when you are in first gear with the stock FD or the shorter FD, you get better acceleration with the shorter FD. As soon as you upshift with the shorter FD, the car gets better acceleration above that speed (say, 25 mph) with the stock FD, because it's still in first gear, so the overall gearing above that speed is shorter. Once you have to upshift to second (at 30 mph), then the shorter FD has an advantage, but loses its advantage again when it upshifts to third and the stock FD is in second. You "flip flop" this way all the way up through the gears. Overall, the difference between the two is pretty small, because the two offset each other.
When you say that it's faster at highway speeds, I assume you are referring to the fact that the shorter FD accelerates faster in fifth gear than the stock FD in fifth gear - which is true. However, you can get the same effect at highway speeds with the stock FD, just by using a lower gear. Drive in fourth with the stock FD and you will have better acceleration than in fifth with the shorter FD. Oh, and you'll use lots more gas either way (which is a significant disadvantage of the shorter FD).
If you take your car to the dragstrip, the FD is probably going to help you a lot, because that added acceleration from 0 to 25 makes a big difference for you. If you take your car to the track, though, the FD is probably not going to make a big difference - it can help you on some tracks and hurt you on others, depending on the speeds used on each track. In addition to helping or hurting your acceleration, it may cause you do do a lot more upshifts and downshifts - or a lot fewer. To take one example, at GingerMan, most of the track is driven at speeds of 70-90 mph, aside from a couple of slow turns, due to the relatively short straights. The ITR with the stock FD can easily be driven on the entire track in third gear. If you put a 4.9 FD on it, you're going to be using fourth gear a lot more, because your shift point from third to fourth will drop from ~90 mph to ~80 mph. The car will accelerate slower in fourth with the short FD than in third with the stock FD. So at that particular track, the shorter FD will be a significant disadvantage.
Changing the final drive gear usually makes little difference at speeds above the first upshift (around 30 mph with the stock FD). Here's why.
Using a shorter FD means that your acceleration is better within each gear but not necessarily at any speed. It improves acceleration within a gear. So when you accelerate up to ~25 mph, when you are in first gear with the stock FD or the shorter FD, you get better acceleration with the shorter FD. As soon as you upshift with the shorter FD, the car gets better acceleration above that speed (say, 25 mph) with the stock FD, because it's still in first gear, so the overall gearing above that speed is shorter. Once you have to upshift to second (at 30 mph), then the shorter FD has an advantage, but loses its advantage again when it upshifts to third and the stock FD is in second. You "flip flop" this way all the way up through the gears. Overall, the difference between the two is pretty small, because the two offset each other.
When you say that it's faster at highway speeds, I assume you are referring to the fact that the shorter FD accelerates faster in fifth gear than the stock FD in fifth gear - which is true. However, you can get the same effect at highway speeds with the stock FD, just by using a lower gear. Drive in fourth with the stock FD and you will have better acceleration than in fifth with the shorter FD. Oh, and you'll use lots more gas either way (which is a significant disadvantage of the shorter FD).
If you take your car to the dragstrip, the FD is probably going to help you a lot, because that added acceleration from 0 to 25 makes a big difference for you. If you take your car to the track, though, the FD is probably not going to make a big difference - it can help you on some tracks and hurt you on others, depending on the speeds used on each track. In addition to helping or hurting your acceleration, it may cause you do do a lot more upshifts and downshifts - or a lot fewer. To take one example, at GingerMan, most of the track is driven at speeds of 70-90 mph, aside from a couple of slow turns, due to the relatively short straights. The ITR with the stock FD can easily be driven on the entire track in third gear. If you put a 4.9 FD on it, you're going to be using fourth gear a lot more, because your shift point from third to fourth will drop from ~90 mph to ~80 mph. The car will accelerate slower in fourth with the short FD than in third with the stock FD. So at that particular track, the shorter FD will be a significant disadvantage.
Trending Topics
H-T Order of Merit
Joined: Jan 2000
Posts: 23,478
Likes: 2
From: Chicago
Re: 4.9 (chad)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chad »</TD></TR><TR><TD CLASS="quote">why....if you don't know what 4.9 stands for by now.....then you aint been paying attention in school!</TD></TR></TABLE>
I agree with strepto. When I saw 4.9, I had no idea what he was talking about. I thought maybe he had a turbo and that was his 0-60 time.
If someone put "195" as a topic name, would you automatically think of the horsepower spec on the ITR? I wouldn't. I might guess that that was what he was referring to, but I also might guess that the topic was about an interstate on the east coast.
It helps to be specific enough when naming topics so that people know what you're talking about without having to guess.
strepto for mentioning it.
I agree with strepto. When I saw 4.9, I had no idea what he was talking about. I thought maybe he had a turbo and that was his 0-60 time.
If someone put "195" as a topic name, would you automatically think of the horsepower spec on the ITR? I wouldn't. I might guess that that was what he was referring to, but I also might guess that the topic was about an interstate on the east coast.
It helps to be specific enough when naming topics so that people know what you're talking about without having to guess.
strepto
for mentioning it.
Honda-Tech Member
Joined: Jan 2001
Posts: 8,136
Likes: 2
From: kuidaore
Re: 4.9 (nsxtasy)
Originally Posted by nsxtasy
Changing the final drive gear usually makes little difference at speeds above the first upshift (around 30 mph with the stock FD). Here's why.
Using a shorter FD means that your acceleration is better within each gear but not necessarily at any speed. It improves acceleration within a gear. So when you accelerate up to ~25 mph, when you are in first gear with the stock FD or the shorter FD, you get better acceleration with the shorter FD. As soon as you upshift with the shorter FD, the car gets better acceleration above that speed (say, 25 mph) with the stock FD, because it's still in first gear, so the overall gearing above that speed is shorter. Once you have to upshift to second (at 30 mph), then the shorter FD has an advantage, but loses its advantage again when it upshifts to third and the stock FD is in second. You "flip flop" this way all the way up through the gears. Overall, the difference between the two is pretty small, because the two offset each other.
When you say that it's faster at highway speeds, I assume you are referring to the fact that the shorter FD accelerates faster in fifth gear than the stock FD in fifth gear - which is true. However, you can get the same effect at highway speeds with the stock FD, just by using a lower gear. Drive in fourth with the stock FD and you will have better acceleration than in fifth with the shorter FD. Oh, and you'll use lots more gas either way (which is a significant disadvantage of the shorter FD).
If you take your car to the dragstrip, the FD is probably going to help you a lot, because that added acceleration from 0 to 25 makes a big difference for you. If you take your car to the track, though, the FD is probably not going to make a big difference - it can help you on some tracks and hurt you on others, depending on the speeds used on each track. In addition to helping or hurting your acceleration, it may cause you do do a lot more upshifts and downshifts - or a lot fewer. To take one example, at GingerMan, most of the track is driven at speeds of 70-90 mph, aside from a couple of slow turns, due to the relatively short straights. The ITR with the stock FD can easily be driven on the entire track in third gear. If you put a 4.9 FD on it, you're going to be using fourth gear a lot more, because your shift point from third to fourth will drop from ~90 mph to ~80 mph. The car will accelerate slower in fourth with the short FD than in third with the stock FD. So at that particular track, the shorter FD will be a significant disadvantage.
I used to almost subscribe to the 4.93 equipped car as having some advantages on specific tracks (shorter with less lengthy straights) and disadvantages on others (where the straights are longer and upshifting one more time may yield a distinct disadvantage.)
But, as far as I can tell (and in the past all my only experience was a few years of autocross where the 4.93 rocks) The tracks that I've driven have shown NO disadvantages for the 4.93 equipped car, and in many cases the ATS 4.93 is the equalizer and or dominator especially pulling through turns, uphills and chicanes, (straight's at least for me are very close.)
I of course am not arguing with you but, just for discussions sake and since I only have a handful of tracks under my belt (Chad please speak up and elaborate.) I must convey, the Longest and fastest track I have driven thus far was Watkin's Glen full course and the 4.93 allowed me to do quite well from turn 1 up to the bus stop, down into turn 6 where the gearing just fell perfectly on up to turn 7's chicane where it totally ROCKED and either pulled on most everything that was in front of me or pulled hard enough to lose anyone behind me, (my ability is my cars only disadvantage.) Turn 9 was a great place for me to catch up again, then into turn 10 very fast (with a lift cause I'm still a bit green) and into turn 11 where it gets ahead pretty well on into the front straight.
The 4.93 is totally awesome at LimeRock as well, and felt equally at ease at Beaverun where my instructor mentioned how impressed he was with my car since it really only has the 4.93 and LWFW.
I understand the "theory" of gearing and how you may or could fall inbetween a gear in a turn, and actually have in-car video of me shifting UP (very well and smoothly I might add) at Turn 6 at Watkin's Glen. But this can even happen to a stock R at different points on different tracks, so even the mighty stock geared R is not immune.
There are and will always be 3 camps with the FD for the ITR. The OEM 4.40, the JDM 4.785. and the ATS 4.929. Each has it's own advantage and disadvantage but, for the life of me I haven't found any such disadvantage for the ITR equipped with the 4.93.
Gas mileage? Who's really looking at that anyway if your tracking your car?
And I gotta admit that the 4.93 does pull harder even a straight line but it REALLY shines on the track where the gears feel that much tighter and the damn things pulls that much harder.
I would Never go back to the stock 4.40.
Anton
Joined: Nov 2003
Posts: 2,486
Likes: 0
From: Kool Place, Y0, USA
Re: 4.9 (Dr Pooface)
i think its just preference... how much does it cost anyway. Im not sure if the $$$ and the time would justify doing this modification in the first place. I have heard many good and bad things about this mod.
I was seriously considering it but im not sure if it would be worth it. I could use the money for something else to improve my ITR.
I was seriously considering it but im not sure if it would be worth it. I could use the money for something else to improve my ITR.
Honda-Tech Member
Joined: Sep 2002
Posts: 3,229
Likes: 0
Re: 4.9 (Dr Pooface)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr Pooface »</TD></TR><TR><TD CLASS="quote">I've seen a post from a HT'er here who found the 4.9 FD actually made him .1 slower in the 1/4.</TD></TR></TABLE>
I believe the post you a reffering to was a EG, with ITR swap, 4.9 FD, and shorter diameter tires(in comparision w/the ITR tire size).
The shorter diameter tires act just like a lower(in relation to speed, higher in #) geared final drive.
Therefore he geared his car too short, and was shifting too many times (into 5th I believe.) in the 1/4.
I believe the post you a reffering to was a EG, with ITR swap, 4.9 FD, and shorter diameter tires(in comparision w/the ITR tire size).
The shorter diameter tires act just like a lower(in relation to speed, higher in #) geared final drive.
Therefore he geared his car too short, and was shifting too many times (into 5th I believe.) in the 1/4.
Honda-Tech Member
Joined: Sep 2002
Posts: 3,229
Likes: 0
Re: 4.9 (type-r 01 886)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by type-r 01 886 »</TD></TR><TR><TD CLASS="quote">i think its just preference... how much does it cost anyway. Im not sure if the $$$ and the time would justify doing this modification in the first place. I have heard many good and bad things about this mod.
I was seriously considering it but im not sure if it would be worth it. I could use the money for something else to improve my ITR.</TD></TR></TABLE>
agreed, If I do anything it will most likely be the JDM FD. Although I would like to drive an ATS equipped car before making my decision..
Just looking @the #'s (4.7xx vs 4.9xx) I can't justify the cost of paying 2x as much for the ATS. Hopefully driving impressions will change all that.
I was seriously considering it but im not sure if it would be worth it. I could use the money for something else to improve my ITR.</TD></TR></TABLE>
agreed, If I do anything it will most likely be the JDM FD. Although I would like to drive an ATS equipped car before making my decision..
Just looking @the #'s (4.7xx vs 4.9xx) I can't justify the cost of paying 2x as much for the ATS. Hopefully driving impressions will change all that.
Honda-Tech Member
Joined: Sep 2002
Posts: 3,229
Likes: 0
Re: 4.9 (nsxtasy)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxtasy »</TD></TR><TR><TD CLASS="quote">
Changing the final drive gear usually makes little difference at speeds above the first upshift (around 30 mph with the stock FD). Here's why.
Using a shorter FD means that your acceleration is better within each gear but not necessarily at any speed.
</TD></TR></TABLE>
I agree here as well. You probobly made your post exaggerated to make sure we understand.. However.
The ATS FD will accelerate better from point A to B. as long as.
1.you don't top out in speed for enough time for the stock FD(theoretical car.) to catch/pass you.
2. you fall in between gears towards the end of the run. (when staying in the lower gear would have been an advantage.)
Next you have to consider how likely those 2 things are to happen...
Also consider what is important in a RR application...staying infront of your opponent. Once you out accelerate them, you can drive a defensive line. As long as your driving permits, you will pull away on the exit of nearly every the turn.
An ATS equipped car would also get the jump from standstill/roll (as long as you aren't @the top of a gear..as explained.)
This is in agreement w/what nsxstasy said....just clarification.
Changing the final drive gear usually makes little difference at speeds above the first upshift (around 30 mph with the stock FD). Here's why.
Using a shorter FD means that your acceleration is better within each gear but not necessarily at any speed.
</TD></TR></TABLE>
I agree here as well. You probobly made your post exaggerated to make sure we understand.. However.
The ATS FD will accelerate better from point A to B. as long as.
1.you don't top out in speed for enough time for the stock FD(theoretical car.) to catch/pass you.
2. you fall in between gears towards the end of the run. (when staying in the lower gear would have been an advantage.)
Next you have to consider how likely those 2 things are to happen...
Also consider what is important in a RR application...staying infront of your opponent. Once you out accelerate them, you can drive a defensive line. As long as your driving permits, you will pull away on the exit of nearly every the turn.
An ATS equipped car would also get the jump from standstill/roll (as long as you aren't @the top of a gear..as explained.)
This is in agreement w/what nsxstasy said....just clarification.
Honda-Tech Member
Joined: Jan 2001
Posts: 8,136
Likes: 2
From: kuidaore
Re: 4.9 (type-r 01 886)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by type-r 01 886 »</TD></TR><TR><TD CLASS="quote">i think its just preference... how much does it cost anyway. Im not sure if the $$$ and the time would justify doing this modification in the first place.</TD></TR></TABLE> About $800. to $850. not including a good LW/FW and installation (if you can't do it yourself.)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by type-r 01 886 »</TD></TR><TR><TD CLASS="quote"> I have heard many good and bad things about this mod.</TD></TR></TABLE>
What exactly have you heard "Bad" about it?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by type-r 01 886 »</TD></TR><TR><TD CLASS="quote">I was seriously considering it but im not sure if it would be worth it. I could use the money for something else to improve my ITR.</TD></TR></TABLE>
Curious to know what exactly you feel needs improvement? And for what application.
Don't take this the wrong way but,
It's funny how most skeptics either have never driven a car equipped as such or don't have the mod in their car.
If it's pure dollar $$$ issue then think of all the other ways that you can spend money on your car and trust me I've spent more on other mods but, the 4.93 was the most noticeable, drastic and enjoyable change I've done.
Noone thinks twice about doing Toda B's, or spending almost $1,000. on a header or catback, or upwards of $5,000 on a JDM front end. Where the power mods actually require some tuning and finesse and or that much more money to complete the package, the FD alone and or even better with a LWFW is a; do it, enjoy it, see results immediately, and forget about it mod.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by type-r 01 886 »</TD></TR><TR><TD CLASS="quote"> I have heard many good and bad things about this mod.</TD></TR></TABLE>
What exactly have you heard "Bad" about it?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by type-r 01 886 »</TD></TR><TR><TD CLASS="quote">I was seriously considering it but im not sure if it would be worth it. I could use the money for something else to improve my ITR.</TD></TR></TABLE>
Curious to know what exactly you feel needs improvement? And for what application.
Don't take this the wrong way but,
It's funny how most skeptics either have never driven a car equipped as such or don't have the mod in their car.
If it's pure dollar $$$ issue then think of all the other ways that you can spend money on your car and trust me I've spent more on other mods but, the 4.93 was the most noticeable, drastic and enjoyable change I've done.
Noone thinks twice about doing Toda B's, or spending almost $1,000. on a header or catback, or upwards of $5,000 on a JDM front end. Where the power mods actually require some tuning and finesse and or that much more money to complete the package, the FD alone and or even better with a LWFW is a; do it, enjoy it, see results immediately, and forget about it mod.
Honda-Tech Member
Joined: Apr 2000
Posts: 12,949
Likes: 8
From: Atlantis
Re: 4.9 (nsxtasy)
I agree with nsxtasy's post more than I disagree.
Thank you, nsxtasy; and thank you 1greyteg; because I don't like typing that much anymore.....
Everything they said is right on the money.
My suggestion is to raise the rev limiter to 9200-10000.
And don't go with a 4.9 final drive. Go with a jdm final + ats 3,4,5 gearset.
Now THERE's some acceleration! 
Thank you, nsxtasy; and thank you 1greyteg; because I don't like typing that much anymore.....
Everything they said is right on the money.
My suggestion is to raise the rev limiter to 9200-10000.
And don't go with a 4.9 final drive. Go with a jdm final + ats 3,4,5 gearset.
Now THERE's some acceleration!
H-T Order of Merit
Joined: Jan 2000
Posts: 23,478
Likes: 2
From: Chicago
Re: 4.9 (Black R)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr Pooface »</TD></TR><TR><TD CLASS="quote">I've seen a post from a HT'er here who found the 4.9 FD actually made him .1 slower in the 1/4.</TD></TR></TABLE>
As noted above, the particular instance recalled here was slower for other reasons; the shorter FD was not the only change in the car, and it was not an ITR.
As I mentioned, the primary benefit is in first gear - which tends to help 1/4 mile times. And it's not like the shorter FD is going to make you need an extra upshift in the 1/4 mile. I'm quite confident that the shorter FD will improve 1/4 mile times. However, it's possible that it might make 0-60 slightly slower by requiring an extra upshift (to third).
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1GreyTeg »</TD></TR><TR><TD CLASS="quote">It's funny how most skeptics either have never driven a car equipped as such or don't have the mod in their car.</TD></TR></TABLE>
And it's equally funny how most diehards have the mod and seem to be struggling to justify it as much to themselves as to others.
The thing to realize, about shorter gearing in general, is that it creates the perception of faster acceleration, well beyond the actual difference in acceleration. This is because you will reach redline a whole lot faster with the shorter gearing. You're shifting sooner, so it seems like you're accelerating faster. But you reach redline at a lower road speed, so to the extent that you are simply shifting at a lower speed, the acceleration seems quicker even though it is not. Not for that reason, anyway. As I mentioned, there is an increase in acceleration, but there is a perception that the increase is greater than it actually is. And this added perception may be enjoyable for its own sake, beyond actual performance improvement; there's nothing wrong with that.
Hope this all makes sense.
As noted above, the particular instance recalled here was slower for other reasons; the shorter FD was not the only change in the car, and it was not an ITR.
As I mentioned, the primary benefit is in first gear - which tends to help 1/4 mile times. And it's not like the shorter FD is going to make you need an extra upshift in the 1/4 mile. I'm quite confident that the shorter FD will improve 1/4 mile times. However, it's possible that it might make 0-60 slightly slower by requiring an extra upshift (to third).
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1GreyTeg »</TD></TR><TR><TD CLASS="quote">It's funny how most skeptics either have never driven a car equipped as such or don't have the mod in their car.</TD></TR></TABLE>
And it's equally funny how most diehards have the mod and seem to be struggling to justify it as much to themselves as to others.
The thing to realize, about shorter gearing in general, is that it creates the perception of faster acceleration, well beyond the actual difference in acceleration. This is because you will reach redline a whole lot faster with the shorter gearing. You're shifting sooner, so it seems like you're accelerating faster. But you reach redline at a lower road speed, so to the extent that you are simply shifting at a lower speed, the acceleration seems quicker even though it is not. Not for that reason, anyway. As I mentioned, there is an increase in acceleration, but there is a perception that the increase is greater than it actually is. And this added perception may be enjoyable for its own sake, beyond actual performance improvement; there's nothing wrong with that.
Hope this all makes sense.
Honda-Tech Member
Joined: Jan 2001
Posts: 8,136
Likes: 2
From: kuidaore
Re: 4.9 (nsxtasy)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxtasy »</TD></TR><TR><TD CLASS="quote">
And it's equally funny how most diehards have the mod and seem to be struggling to justify it as much to themselves as to others.
</TD></TR></TABLE>
C'mon, you obviously knew that wasn't aimed towards you. Backatcha 
Without further adieu and without any more redundant verbiage. If you are interested in ANY FD, do your homework. We're just rehashing the same debates that have been ongoing since the FD's were available for the car.
It's obvious I'm a proponent of the ATS 4.93. But, as I said before I would Not go back to a stock 4.40 for any reason, and I can't see stepping down to a JDM/FD either. The car is just so much more fun to drive, it's like it just Woke up after the FD and FW combo was added.
And it's equally funny how most diehards have the mod and seem to be struggling to justify it as much to themselves as to others.
</TD></TR></TABLE>
C'mon, you obviously knew that wasn't aimed towards you.
Backatcha Without further adieu and without any more redundant verbiage. If you are interested in ANY FD, do your homework. We're just rehashing the same debates that have been ongoing since the FD's were available for the car.
It's obvious I'm a proponent of the ATS 4.93. But, as I said before I would Not go back to a stock 4.40 for any reason, and I can't see stepping down to a JDM/FD either. The car is just so much more fun to drive, it's like it just Woke up after the FD and FW combo was added.
Honda-Tech Member
Joined: Sep 2002
Posts: 3,229
Likes: 0
Re: 4.9 (1GreyTeg)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1GreyTeg »</TD></TR><TR><TD CLASS="quote">
Without further adieu and without any more redundant verbiage. If you are interested in ANY FD, do your homework. We're just rehashing the same debates that have been ongoing since the FD's were available for the car.
</TD></TR></TABLE>
Without further adieu and without any more redundant verbiage. If you are interested in ANY FD, do your homework. We're just rehashing the same debates that have been ongoing since the FD's were available for the car.
</TD></TR></TABLE>
H-T Order of Merit
Joined: Jan 2000
Posts: 23,478
Likes: 2
From: Chicago
Re: 4.9 (nsxtasy)
Via PM (thanks!), I was passed along a link to this nifty gearing calculator which does the computation of speeds and gearing based on inputting the ratios. Let's use it to do a little analysis here of the effect of the 4.93 FD.
I'm going to post the "speed bands", i.e. ranges of speed and gears for each gearing setup for an ITR with stock sized tires. This assumes that you shift exactly at redline (reasonable assumption). I will show the "total gearing" for each setup ("Stock" = 4.40 FD, "Short" = 4.93 FD). Remember, the higher the number for total gearing, the better the acceleration, assuming that the torque curve is totally flat (close enough that it's a reasonable assumption also).
0-35.6 mph Stock first 14.2, Short first 15.9 (Short 12 percent better)
35.6-39.9 mph Stock first 14.2, Short second 10.4 (Stock 27 percent better)
39.9-54.7 mph Stock second 9.3, Short second 10.4 (Short 12 percent better)
54.7-61.2 mph Stock second 9.3, Short third 7.2 (Stock 23 percent better)
61.2-78.9 mph Stock third 6.4, Short third 7.2 (Short 12 percent better)
78.9-88.4 mph Stock third 6.4, Short fourth 5.5 (Stock 14 percent better)
88.4-103.9 mph Stock fourth 4.9, Short fourth 5.5 (Short 12 percent better)
103.9-116.5 mph Stock fourth 4.9, Short fifth 4.2 (Stock 14 percent better)
116.5-135.7 mph Stock fifth 3.7, Short fifth 4.2 (Short 12 percent better)
135.7 mph is the maximum top speed at redline in fifth with the 4.93 FD; you can continue to 152 mph, power and drag permitting, with the stock FD.
As you can see from these numbers, what this means is that whenever the two gearing setups are in the same gear, the gearing will be slightly better with the short 4.93 FD, by about 12 percent. And whenever the two gearing setups are not in the same gear, the gearing will be significantly better with the stock 4.40 FD, by as much as 27 percent in 1st/2nd gear, and decreasing percentages at higher gears. So you have shorter bands with a bigger benefit for the stock FD, and wider bands with a smaller benefit for the short FD. As the speeds and gears go up, the size of the bands evens out, but the benefit of one gearing setup over another shrinks. Overall, the short FD will give you slightly better acceleration, but - at least, above 35 mph - it's fairly minor, and certainly not as dramatic as some would like to imply.
If you're on a track where one setup creates the need for a lot of shifting, and the other setup keeps you in the upper end of the revband in a particular gear, the latter setup will be better... and that could be either one, depending on the track. Oh wait, I think I already said that.
I'm going to post the "speed bands", i.e. ranges of speed and gears for each gearing setup for an ITR with stock sized tires. This assumes that you shift exactly at redline (reasonable assumption). I will show the "total gearing" for each setup ("Stock" = 4.40 FD, "Short" = 4.93 FD). Remember, the higher the number for total gearing, the better the acceleration, assuming that the torque curve is totally flat (close enough that it's a reasonable assumption also).
0-35.6 mph Stock first 14.2, Short first 15.9 (Short 12 percent better)
35.6-39.9 mph Stock first 14.2, Short second 10.4 (Stock 27 percent better)
39.9-54.7 mph Stock second 9.3, Short second 10.4 (Short 12 percent better)
54.7-61.2 mph Stock second 9.3, Short third 7.2 (Stock 23 percent better)
61.2-78.9 mph Stock third 6.4, Short third 7.2 (Short 12 percent better)
78.9-88.4 mph Stock third 6.4, Short fourth 5.5 (Stock 14 percent better)
88.4-103.9 mph Stock fourth 4.9, Short fourth 5.5 (Short 12 percent better)
103.9-116.5 mph Stock fourth 4.9, Short fifth 4.2 (Stock 14 percent better)
116.5-135.7 mph Stock fifth 3.7, Short fifth 4.2 (Short 12 percent better)
135.7 mph is the maximum top speed at redline in fifth with the 4.93 FD; you can continue to 152 mph, power and drag permitting, with the stock FD.
As you can see from these numbers, what this means is that whenever the two gearing setups are in the same gear, the gearing will be slightly better with the short 4.93 FD, by about 12 percent. And whenever the two gearing setups are not in the same gear, the gearing will be significantly better with the stock 4.40 FD, by as much as 27 percent in 1st/2nd gear, and decreasing percentages at higher gears. So you have shorter bands with a bigger benefit for the stock FD, and wider bands with a smaller benefit for the short FD. As the speeds and gears go up, the size of the bands evens out, but the benefit of one gearing setup over another shrinks. Overall, the short FD will give you slightly better acceleration, but - at least, above 35 mph - it's fairly minor, and certainly not as dramatic as some would like to imply.
If you're on a track where one setup creates the need for a lot of shifting, and the other setup keeps you in the upper end of the revband in a particular gear, the latter setup will be better... and that could be either one, depending on the track. Oh wait, I think I already said that.
Honda-Tech Member
Joined: Jan 2001
Posts: 8,136
Likes: 2
From: kuidaore
Re: 4.9 (nsxtasy)
Wonder if this will work, because I am a total visual person, (just ask my wife )
With the 4.93, 8500 RPM revlimit/shift point and 205/50/15 tires
JDM 4.785 FD with same sized tires and same shift point.
Stock USDM 4.40 FD with same size tires and shift point.
Great link BTW nsxtasy, who'd you get it from again?
And since I run the 4.93 with 205/50/15 tires, my top speed is 139.6, not that I have or most likely will get that close. Just FYI, in the top straight before the bus stop at Watkin's Glen I was hitting between 122 and 124 MPH pretty consistantly and depending upon traffic would either stay in 4th gear through the bus stop or go down to 3rd, but when I was behind someone and went down to 3rd, the recovery was quick. Short of it all is that I didn't see the revlimit in 5th gear like many had warned of and regardless of if you are a much better driver than I, in my car in it's current form the motor just doesn't have enough power to go far over 130MPH in that section even with a clear shot and no traffic. So top speed is not any type of issue for me.
)Great link BTW nsxtasy, who'd you get it from again?
And since I run the 4.93 with 205/50/15 tires, my top speed is 139.6, not that I have or most likely will get that close. Just FYI, in the top straight before the bus stop at Watkin's Glen I was hitting between 122 and 124 MPH pretty consistantly and depending upon traffic would either stay in 4th gear through the bus stop or go down to 3rd, but when I was behind someone and went down to 3rd, the recovery was quick. Short of it all is that I didn't see the revlimit in 5th gear like many had warned of and regardless of if you are a much better driver than I, in my car in it's current form the motor just doesn't have enough power to go far over 130MPH in that section even with a clear shot and no traffic. So top speed is not any type of issue for me.
H-T Order of Merit
Joined: Jan 2000
Posts: 23,478
Likes: 2
From: Chicago
Re: 4.9 (1GreyTeg)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1GreyTeg »</TD></TR><TR><TD CLASS="quote">since I run the 4.93 with 205/50/15 tires, my top speed is 139.6</TD></TR></TABLE>
Actually, with 205/50-15, your top speed drops from 135.7 mph to 133.7 mph, assuming you only go to 8400 RPM. Even if you go to 8500 RPM (I wouldn't, but hey, it's your car), it only gets to 135.3 mph. (I think you failed to check the box to factor in tire deflection, which makes it the numbers more realistic and accurate.)
Actually, with 205/50-15, your top speed drops from 135.7 mph to 133.7 mph, assuming you only go to 8400 RPM. Even if you go to 8500 RPM (I wouldn't, but hey, it's your car), it only gets to 135.3 mph. (I think you failed to check the box to factor in tire deflection, which makes it the numbers more realistic and accurate.)
H-T Order of Merit
Joined: Jan 2000
Posts: 23,478
Likes: 2
From: Chicago
Re: 4.9 (1GreyTeg)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1GreyTeg »</TD></TR><TR><TD CLASS="quote">Great link BTW nsxtasy, who'd you get it from again?</TD></TR></TABLE>
Thanks, DsR!
Thanks, DsR!
Moderator
Joined: May 2001
Posts: 12,232
Likes: 5
From: Browns Summit, NC, USA
Re: 4.9 (DsR)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DsR »</TD></TR><TR><TD CLASS="quote">
I believe the post you a reffering to was a EG, with ITR swap, 4.9 FD, and shorter diameter tires(in comparision w/the ITR tire size).
The shorter diameter tires act just like a lower(in relation to speed, higher in #) geared final drive.
Therefore he geared his car too short, and was shifting too many times (into 5th I believe.) in the 1/4. </TD></TR></TABLE>
with 4.785 final drive and 8300 rpms i was shifting into fifth in 1/4
I believe the post you a reffering to was a EG, with ITR swap, 4.9 FD, and shorter diameter tires(in comparision w/the ITR tire size).
The shorter diameter tires act just like a lower(in relation to speed, higher in #) geared final drive.
Therefore he geared his car too short, and was shifting too many times (into 5th I believe.) in the 1/4. </TD></TR></TABLE>
with 4.785 final drive and 8300 rpms i was shifting into fifth in 1/4