turbopanda

Hey everyone.

Just started a new topic coz I think people are sick of seeing my "Crashed my car last night" thread and i'll probably get more response from this thread anyway.

Well, as some of you already know, I'll be getting a JDM B18C installed once the front of my car has been repaired and re-painted.

Right now all my problems are coming down to the tranny. Should I use a B18B tranny or a B18C tranny? The gears will come with LSD, I don't know whether it will be Cusco or the Honda factory LSD, but which tranny should I go for? I want drivability as this car will be a daily driver, and one day (within the next 6-12 months) it will become one of those 350+ HP beasts.. cruising speeds here are anywhere between 110-140km/h (don't know what that is in mph, u guys gonna have to work that out)

Some people are telling me to stick with the B18C tranny.. others are telling me B18B.. I really need some expert advice here! help!

Type-ARR

Im no "expert" but from talking to people I would stick with the B18c tranny.

turbopanda

ummm.. any more opinions?

something else also sprung to mind. I currently have 2.5" custom piping leading to a 2.5" HKS Hiper exhaust. No cat, straight pipe, 2.5" from the turbo to the back of the car. Is this too small for a turbo B18C?

csufweed

i know a lot of people prefer the B18B tranny for turbo and a lot are against it. As far as USDM tranny's, the B18B and B18C1 share the same 1st and 2nd gears... 3rd gear on the B18B is EXTREMELY LONG! People argue that the longer gears allow for the turbo to spool up more, but I don't know. There was also the arguement that the B18B allows for better launches cuz of the longer gears, but thats obsolete cuz the 1st and 2nd gear is the same from my experience. (correct me if i am wrong)
in my opinion, you will be able to take better advantage of your engine with the GSR tranny, so by adding a turbo, you will just enhance the power. unless you are spinning your wheels in 3rd gear also, which will make it more difficult with shorter gears. This only really applies for drag racing from a stop though... if its highway racing, thats a different story.
the longer gears in the B18B will make daily driving a little better cuz you will be able to cruise on freeways in a lower rpm. and longer 3rd gear will allow you to gain traction better if you race from a stop and spin your tires through 3rd gear.
Like I said, these are my opinions... im not 100% sure on this.

csufweed

3" piping and 3" exhaust is what you want. To reduce boost spike, it'd be good to keep a 2.5" downpipe.

Dee

My OEM Honda LSD was only used while the Mugen was being rebuilt. The Viscous diff doesn't like boost very much so you might want to look at the Cusco MZ or ATS diff. I had Mugen setup for drag when it was rebuilt a couple weeks ago.

I am going to use a Teg LS gearset because of the 4.266 final drive. 3rd, 4th and 5th gear build delicious boost so I am hoping that the LS FD will improve the performance of 1st and 2nd gear.

Turbo Laser

You don't have to get that 3 inch exhaust now. Sure, it'll be good in the future but 2.5 is fine for a turbo 1.8.

turbopanda

OK so 3" exhaust later. Got it.
Anything else that I should think about?

Bnjmn

After doing some number crunching when Drealgsr was suggesting LS gears and everyone else was saying GSR gears, I did some number crunching. The most common argument was that if you are going through the gears quicker, you must be going quicker, and GSR/Si trannies allowed you to go through gears the fastest. This is weak and short sighted. Imagine pedaling a bike- a 12 year old needs much easier gears than Lance Armstrong. By adding a big turbo, you are changing your stock engine (a peppy 12 year old) into a monster (Lance). Lance can use low gears and go much faster than the 12 year old, even though the 12 year old might be slamming through gears. Actually, Lance needs lower gears or else he'll fall off because his legs are moving too fast and he'll lose his balance. Kind of like turbo cars need lower gears to build boost

I found this site and it helps a bit- http://www.geocities.com/z_design_st..._300zx_tt.html

Just put in the gear ratios from this page- http://www.geocities.com/MotorCity/F...GearRatios.htm

I think the YS1 tranny has a 4.266 FD some sites say 4.4 others 4.266.
Anyway, you'll see that the GSR and LS gearing differ very little (in terms of rpm drop between gears)- never more than a 300 rpm or so.
Also, do some searches for gearing on cars that will have similar hp/torque figures- such as Porshe 911 turbos, 300TTs, Supra TTs, RX-7s, etc. and you'll see that the LS tranny fits in well with those.


Ben

Reid

How much boost are you planning to run on the 10.6:1 compression? I'm turboing the same motor as you.

D-SPEED

you cant directly compare GSR and LS tranny gearing because they have different FDs.

shorter gearing is going to make you accelerate faster...that is the bottom line. There is a point where going TOO tall or short gears will start making a big difference, but when the trannys are pretty similar, the one with the shorter gearing is going to let you acclerate faster.

turbopanda

thnx for the advice ben

i'll be boosting maybe 10-12psi, more probably 10psi since the engine will still be newish and running on stock internals. I will be lowering the compression to around 8.5-9:1 with a thicker head gasket and installing a blockguard to be safe. I don't have money at the moment for forged pistons and rods, so they can come later.

Bnjmn

Using the calculator you can directly compare them, just enter in the correct FD.
You point is correct about shorter gearing- up to a point. Turbo engines need load to build boost, LS trannies let them build the boost and get some traction.
I'd like to see some numbers- same car with different trannies.

Ben

Dee

A lil' more support for Ben..

I used a EG6 Y21/S21 (4.40 FD) before I went turbo and I did notice better exceleration in the first 3 gears as compared to the Y80/S80 GSR tranny. Because LS manual trannies were never available in Japan I switched back to my GSR tranny when I went turbo. After I killed my first GSR gearset I used a Y21 as a temp placement. For turbo the Y21 sucks ***! POINT BLANK! All of my FD3S friends use long ratio gearsets that are similar to the LS gearset with a 4.3 final drive. OS Giken sells a special turbo gearset for Honda's and the gear ratios are the same as the Teg LS. Top Fuel had this setup constructedbefore contracting OS Giken to make their new gearset that uses 2.500/1.800/1.250/0.957/0.733 gearing with a 4.400 or 4.785 FD. Hopefully my LS gearset will arrive sometime this weekend because I'm getting tired of driving my loanerToyota Caldina wagon. The LS gearset should build better boost in the lower gears and I will make sure that I post my findings as soon as I am rolling again!

turbopanda

drealgsr, I take it the EG6 tranny you're talking about is that of a B16A right? I kinda figured this would suck for turbo, because you'd run through the gears too quickly. B18C tranny is still too close is it? I think I can get B18B manual trannies here as there is one model Civic they sell here called the Civic 1.8 Si, which is a sedan like my civic with a B18B inside. I'm not too familiar with B18B/LS gears, but i'll take you guy's word for it - I hope the gears aren't too tall. I don't want to be able to go 190km/h in 3rd gear like I used to be able to do with one set of gears I once used on my D16Y8!

DLB1994

i think the b18b LS tranny

bigTom

doesnt matter who thinks what... just look at what is being used nowadays on the faster cars out there... i can tell u this much... they arent ls trannies for sure

Dee

If I had $2200 to waste I would get a real tranny but since LS trannies are cheap I'll stick with that alternative.

$2200 gets you any gear ratio setup that you want from OS Giken or ATS. Quaife is somewhere in that price range too.

turbopanda

umm.. so does the vote go towards a B18B/LS tranny? I gotta let the guy know tomorrow so he can get everything ready for the swap once my car comes out of the Honda service centre..

csufweed

yeah get the LS tranny... i've seen a GSR do nearly 500hp with that tranny.

csufweed

yup, they are automatics... not just on FASTER cars, ON THE FASTEST CARS!