blue99si
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I currently own a 99 SI (absolutely love this car) and am contemplating changing the transmission in it by swapping it out with another Honda product tranny or by changing the gearing. I do a majority of my driving on the highway (35,000 per year) and am wordering about the longevity of my B16 as it is turning 5,000 rpm (doing 90mph). I had a 95 EX before this car and it was turning just over 4,000 rpm doing the same type of driving. Has anyone out there done this type of change? I would imagine a change to the EX tranny or gearing would also push me that much further away from my beloved v-tech cam lobe change.....Are there any other tranny's that might be better suited for this engine? Any gearing ideas would also be a big help as well.
Also has anyone added a limited slip differential to their car? If I am going to tear into the tranny, I would think this would also be something that I sould be considering? Any thoughts? Ideally, I would like to be around 3500 rpm at 80mph.
Thanks,
Former Lurker turned POSTER
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dc2
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My GSR is at about 4K at 80mph and if you got an Ls tranny the gears are taller than both the GSR and Si. But if you want more accl. get the Type R tranny it has a lot closer gearing and LSD. It's an S80 casing, with a 4.785 final gear.
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jkw99si
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I have to agree with dc2 - I just helped a friend of mine install a GSR tranny on his B16A in a hatch back, the different gearing is noticeable - if you want to go balls out get the Type R tranny!
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Clarence
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Most ppl upgrade in the opposite direction: they want tighter ratios for better acceleration.
Given Hondas need close ratios for spirited driving, you'd probably want to keep the factory 1-4 ratios but change the 5th to a lower ratio. This is provided by the LS B18A/B18C gearbox.
The GSR gearbox gives poorer acceleration than the B16A gearbox; the gears are spaced wider but this is usually compensated by the B18's extra torque. However, I wouldn't think it's the best upgrade for a B16A.
The US ITR's gearbox has identical ratios to the B16A so the only change you'd get from changing to this box is the addition of the Torsen helical LSD. The Japanese 98 Spec ITR gearbox, on the other hand, has the higher 4.785 final drive and lower 4th and 5th (providing better 1st, 2nd and 3rd gear response but negligible difference in 4th and 5th).
http://www.bseries.net/html/specs/btrannyspecs.php
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blue99si
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What are your thoughts on a LSD and winter driving? I currently live in Michigan and I am kind of wondering if adding a LSD would be good or bad in the way of staying in or out of the ditch. Last year I did the Blizzaks and steel wheels thing, to stay out of the ditch but, I am kind of wondering what I might be in for by changing to a LSD. Anyone have any ideas as to whether a LSD would be benefit or hinderance in the way of winter driving? When I think of a LSD my first thought is possi traction. Are the two one in the same or am I just ignorant......
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blue99si
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Many thanks to everyone for their posts. Anyone have any idea's to how I could get my hands on a 98 ITR gear box or would I be better suited to just ordering the new gears/syncros from Honda and having someone else crack open and replace the current gears and syncros?
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jkw99si
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First place to start would be your locally Honda wrecking yard, however; in most cases if the get a totaled ITR your not going to convince them to break the tranny from that motor and sell it to you seperate - they make more money selling it as a whole. 2 other opitions - order it from Honda or find an aftermarket company who specializes in gear sets for Honda tranny's. A good place to start: http://www.quaifeusa.com - here's what they have
GEAR RATIOS
gear input output ratio rev drop @ 8000 rpm shift
(teeth) (teeth)
1 13 teeth 32 teeth 2.462 -
2 16 teeth 29 teeth 1.813 2109 rpm
3 18 teeth 27 teeth 1.500 1381 rpm
4 20 teeth 25 teeth 1.250 1333 rpm
5 22 teeth 23 teeth 1.045 1312 rpm
FINAL DRIVE RATIOS
3.786 4.154 4.500 4.750
Hope this helps out - I looked into this myself for my '99 Si but decided on only using their LSD for now - I don't have $3K to drop on a new gear ratio set for my tranny! I would recomend the LSD from Quaife because it is actuated via gears instead of a clutch mechanism in most LSD's including the ITR LSD. Anything with a clutch (especially if you drive your car hard) is prone to go out before a geared setup - plus it comes with a lifetime warranty!
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Clarence
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jkw99si wrote:
I would recomend the LSD from Quaife because it is actuated via gears instead of a clutch mechanism in most LSD's including the ITR LSD. Anything with a clutch (especially if you drive your car hard) is prone to go out before a geared setup - plus it comes with a lifetime warranty!
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Actually, the ITR factory LSD is a helical LSD and I believe it's made by Torsen and it uses helical gears (I have no idea how that works but not too differently in theory to Quaife). It doesn't have the expected wear like a clutch-type system would. The other option is a viscous-type system, which isn't really popular anymore but was offered on earlier model Hondas. The reason why ppl often prefer the clutch-type systems is their quick response and their different action e.g. 1-way, 1.5-way, 2-way (the LSD will affect your line on acceleration and deceleration differently). The LSD clutch setups can be customised to driving style.
Of course this is too hardcore for most ppl and usually too expensive if you're living outside Japan (where most of the clutch-type LSDs are made for Hondas).
If you're looking for the entire 98Spec ITR gearbox, you must remember it's a Japanese market item, so you probably have to find a used one. I'd imagine they're pretty expensive in the US since there's a premium placed on "JDM".
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