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Re: B Series Trans for DD duties
Posted: Sun Jul 28, 2019 7:51 pm
by noahf
i actually do think it has aftermarket (so im assuming firm) motor and trans mounts. i was wondering if that would increase in cabin noise. maybe ill switch those out to stock before switching trans. thanks RTW
Re: B Series Trans for DD duties
Posted: Sun Jul 28, 2019 9:40 pm
by aklackner
If firm rubber additional noise will very likely be marginal. Poly mounts will pretty quickly add to vibration, specifically the rear motor mount. If all original stick with OEM mounts. If looking for small “upgrades” re-enforced rubber might be worthwhile but could mean reduced life (depending on brand?).
Re: B Series Trans for DD duties
Posted: Sun Jul 28, 2019 9:42 pm
by aw614
Im surprised no one has made a custom six speed B series transmission, usinf the JDM 4.7 and with the stock ITR exhaust and cat, it is barely tolerable at 70 to 80 mph. I'd probably hate life if I had something like a buddy club spec 2 or something lol. I'd gladly keep the stock 1-5 ratios with another gear. As it is, I get an annoying shifter vibration at those speeds with the Spoon shift knob. If I run the the JDM Itr weighed knob, it goes away. I think it has to do with the mfactory shift bushings causing the vibrations though...
Rarely go faster now, but due to the loss of the main autocross site that was 30 minutes away, most of my events require highway driving.
Re: B Series Trans for DD duties
Posted: Sun Jul 28, 2019 10:00 pm
by Dave7CDMTYPER
Could go with mugen trans mounts?
Sometimes shifter vibration noise is just the round plastic piece of the shift boot vibrating against the shift knob. That's how it is in my gs-r.
Re: B Series Trans for DD duties
Posted: Mon Jul 29, 2019 11:35 am
by 3pedalJohn
noahf wrote: ↑Sun Jul 28, 2019 5:06 pm
thanks for the feedback. its what i needed to hear about the LS 5th gear. looking for a jdm gsr lsd trans for now, as that meets most of requirements.
stin1: i am waiting on a hytech twin loop cat back.
Hytech Twin Loop very nice
I have this exhaust on my GSR with a 98-01 JDM ITR trans and it's pretty quiet. You could also up size the tire a little bit to drop the revs a little more but that GSR should be the best of both worlds.
Re: B Series Trans for DD duties
Posted: Thu Aug 01, 2019 11:23 am
by Aquafina
CTR/ITR trans with 205/45/16's is 4,300 RPM at 80mph. RPM drop from 4-5 upshift at 4,000 RPM is 928 RPM.
GSR 5th is 4,000 RPM at 80 and RPM drop is 1,149 RPM.
LS 5th is too long to use, you'll need to wind 4th out and downshift to 4th to accelerate.
Honda engines are designed to cruise at a high RPM. The only ones designed for low RPM cruising have lean burn. Lowering your cruising RPM can actually hurt your fuel economy.
The absolute lowest you can go using off the shelf parts is 2,850 RPM using an LS 5th and MFactory 3.47 final drive. Your acceleration will be slower than a stock Civic DX and your fuel economy will plummet.
The JDM GSR LSD is not the same as the CTR/ITR. It is a viscous type and isn't really optimal for anything other than saying you have an LSD. It uses a special ring gear so the final drive ratio can never be changed and if the ring gear or countershaft break then it's a paperweight as replacements are very hard to find. It's also a paperweight if it overheats (easy to do on track) as it will either lock up, break, or revert to an open diff function. When any of those happen it is no reversible and it must be replaced. It also has weak splined gears (what the axles mesh with) and it can shear off inside the LSD (the gear itself, not the axle).
I recommend keeping your trans as-is.
Re: B Series Trans for DD duties
Posted: Thu Aug 01, 2019 12:43 pm
by coolhandluke
I don't see a thread mapping out transmission gear ratios. I will work on that.
Re: B Series Trans for DD duties
Posted: Thu Aug 01, 2019 3:50 pm
by DC231
Aquafina wrote: ↑Thu Aug 01, 2019 11:23 am
CTR/ITR trans with 205/45/16's is 4,300 RPM at 80mph. RPM drop from 4-5 upshift at 4,000 RPM is 928 RPM.
GSR 5th is 4,000 RPM at 80 and RPM drop is 1,149 RPM.
LS 5th is too long to use, you'll need to wind 4th out and downshift to 4th to accelerate.
Honda engines are designed to cruise at a high RPM. The only ones designed for low RPM cruising have lean burn. Lowering your cruising RPM can actually hurt your fuel economy.
The absolute lowest you can go using off the shelf parts is 2,850 RPM using an LS 5th and MFactory 3.47 final drive. Your acceleration will be slower than a stock Civic DX and your fuel economy will plummet.
The JDM GSR LSD is not the same as the CTR/ITR. It is a viscous type and isn't really optimal for anything other than saying you have an LSD. It uses a special ring gear so the final drive ratio can never be changed and if the ring gear or countershaft break then it's a paperweight as replacements are very hard to find. It's also a paperweight if it overheats (easy to do on track) as it will either lock up, break, or revert to an open diff function. When any of those happen it is no reversible and it must be replaced. It also has weak splined gears (what the axles mesh with) and it can shear off inside the LSD (the gear itself, not the axle).
I recommend keeping your trans as-is.
Very good info here. Thanks Aquafina. I was honestly hoping to hear you chime in as I've seen your name here and I've read many many posts from you in the past about Honda Transmissions. You know your shit for sure.
Re: B Series Trans for DD duties
Posted: Thu Aug 01, 2019 6:24 pm
by Aquafina
You're welcome. If you have any questions and want to ask me directly you can reach me at Chris (at) wd-r.com