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View Full Version : Anybody put a 4.9FD in their B16A box?



dougie_504
28-06-2013, 12:36 AM
Anybody done this and able to comment on their high-speed driveability (cruising specifically)?

Internet calculators suggest my 0.870 5th + 4.9FD = 4,000rpm @ 100km/hour.

Wondering if its worth considering sourcing a B18A 5th gear which is 0.717 and supposedly equates to 3,300rpm.


So, any personal experiences?

This isn't a daily driver and highway miles would be scarce but I don't want to rule out the possibility of jumping on the eastern freeway or doing a rural road trip...

trism
28-06-2013, 09:02 AM
my old 20v blacktop corolla sat at 3800 at 100km.

it was fcking horrible.

riruiz_88
28-06-2013, 01:05 PM
im willing to know as well...

dougie_504
28-06-2013, 01:06 PM
I'm assuming its terrible but just want some anecdotal feedback.

Probably just going to grab myself a B18A cable 5th gear anyway

lil_foy
28-06-2013, 01:21 PM
I have one in mine. B16a2 box with osgiken 4.9 final drive and mfactory lsd.
It sits at 4000 rpm @ 100kph but its not my daily so I dont care. I've done various 1h+ trips without worrys. The acceleration is fantastic though!

mocchi
28-06-2013, 02:20 PM
whats your tire profiles n8s

dougie_504
28-06-2013, 02:32 PM
I have one in mine. B16a2 box with osgiken 4.9 final drive and mfactory lsd.
It sits at 4000 rpm @ 100kph but its not my daily so I dont care. I've done various 1h+ trips without worrys. The acceleration is fantastic though!


Does the engine noise piss you off at all, or the higher workload bother you?


mocchi I'm running 195/50/15 and another setup 185/60/15

mocchi
28-06-2013, 05:27 PM
Does the engine noise piss you off at all, or the higher workload bother you?


mocchi I'm running 195/50/15 and another setup 185/60/15

that really depends on what exhaust youre running ay
4krpm is pretty much same like stock dc2r 100kph 195/50/15

chez00
28-06-2013, 06:42 PM
It'll definitely drive you mad eventually in a daily, but for a weekender a 4.9's the ****.

lil_foy
28-06-2013, 08:46 PM
Does the engine noise piss you off at all, or the higher workload bother you?


mocchi I'm running 195/50/15 and another setup 185/60/15


B18cr + 5zigen headers + fujitsubo rm01a.
It's fine for me, I don't even have a stereo either. You're only under very light load so there isn't much exhaust noise. The extra workload was just a compromise I had to live with going to it. The performance gains outweigh the downfalls for my occasional highway driving.

dougie_504
28-06-2013, 10:57 PM
Setup is JDM B16A. CAI, Rs*R header, high flow cat, Kakimoto R full cat-back, ITR TB + IM, Skunk2 Pro1 camshafts and adjustable gears, Jun oversized valves, Supertech titanium retainers and HD valve springs, enlarged intake/exhaust ports, matched manifolds and re-welded combustion chambers (smaller for higher comp/more flow).

Exhaust isn't too bad, it's a nice oval muffler, typical JDM piece good deep/throaty sound and high-pitched screaming up to 9,000rpm.

And yeah, just a hobby/weekender so I don't foresee much highway driving but I don't want to hate it too much if I drive down to say Apolo Bay and get some 110km/hour highway action.

4.9FD is ordered an definitely going in, just wondering if I should consider lengthening the 5th gear to bring the rpm down a bit at cruising speeds as I don't predict much need for 5th acceleration. By my rough calculations the longer 5th + 4.9FD should pretty much be similar to my oem setup of shorter 5th + 4.26FD.

pat88c
28-06-2013, 11:06 PM
Nice information on 4.9 Fd

I know brett off crx aus has b18a 5th gear in his ef8 worth ask him what he thoughts on the 5th gear

chez00
28-06-2013, 11:21 PM
Definitely do the LS 5th gear (.714) with the 4.9 FD - as you said, 5th is not a hard acceleration gear so the large step from 4th won't be an issue. I've got a few sets on back order out of Japan at the moment, ETA of around a week. PM if interested.

dougie_504
29-06-2013, 12:42 AM
Orders of LS 5ths? Interesting

lil_foy
29-06-2013, 12:45 AM
Depends if you track your car or not, both tracks I race on I get well into 5th (7000~rpm) so the longer gear would pull my speeds back with the loss of rpm into 5th. How would an itr 4.7 5th compare to the one you're looking at now? If you're making any trips to qld before you put it in ill take you for a drive (small chance but offer is there)

dougie_504
29-06-2013, 01:04 AM
Thanks for the offer mate. Would love to find myself in QLD randomly but I don't think I will haha.

ITR 5th is 0.787 supposedly and B16A is 0.870 so maybe it'd cruise at 100km doing roughly 3,600-3,700 with that gear.

To be honest I think with the modifications I've done I should be able to accelerate enough in 5th even if I lengthen it. The 4.9 and lightweight flywheel to come, as well as the tune down the track for the head build, should give me enough to work with. But like I said, not planning on accelerating much in 5th.

Anyway the engine revs out to 9,000 so it gives me an extra 500 odd rpm to push into 5th with

lil_foy
29-06-2013, 01:14 AM
Google mfactory gear calculator if you haven't used it already btw :)

dougie_504
29-06-2013, 02:43 AM
Yeah that's what I'm going off so far

Snoop_gee
11-07-2013, 11:07 PM
Setup is JDM B16A. CAI, Rs*R header, high flow cat, Kakimoto R full cat-back, ITR TB + IM, Skunk2 Pro1 camshafts and adjustable gears, Jun oversized valves, Supertech titanium retainers and HD valve springs, enlarged intake/exhaust ports, matched manifolds and re-welded combustion chambers (smaller for higher comp/more flow).


Wow u have been busy Andy didn't know it had that much work.

cbauto
11-07-2013, 11:30 PM
which b16a box, they're different.

have y1 cable box mated to b18c type r motor.

4000rpm @ 100km/h
4500rpm @ 120km/h
4.4 diff

cbauto
11-07-2013, 11:41 PM
b16a S1 cable
1 - 3.32
2 - 2.10
3 - 1.46
4 - 1.10
5 - 0.84
FD - 4.4

b16a Y1 cable
1 - 3.15
2 - 2.05
3 - 1.42
4 - 1.10
5 - 0.87
FD - 4.266

The Y1 with stock FD is similar to dc2r highway speed/rpm

with the 4.4 its heaps higher.

dougie_504
12-07-2013, 10:39 AM
Pretty sure Y1 mate