b18c

[MRDEANOS]

sorry i feel like im askin the same question but i need to kno :/
when i get the b18c will i need to get a new gearbox? and will i need to get new ecu or anything else ??

Cheers once more have had alot of pm's and you guys are very helpfull :D:thumbsup:

[Chi]

What car are you putting it in and what engine does the car have atm?

[ACTI0NMAN-1]

if your car already has a b series engine in it you can use that. if your car has any other engine inside, then you will require a gearbox and have to make the decision of wether to go a cable or hydro gear box.
-with hydro it reduces the chances of slipping into a lower gear at high revs.
-with a cable gearbox there is no protection from accidental changing to lower gears.

[Zilli]

assuming you have a B series motor already in your car, swapping over to the B18c, you will also need to consider the gearing to accompany the motor. As VTEC is like a "powerband" so to speak, you would need to consider the fact that you may drop out of said powerband given the different gearsets of another motor. This will affect the way your car accelerates

Assuming you have a B18b, im not sure if there is a difference in the gearing between that motor and the B18c

[ACTI0NMAN-1]

assuming you have a B series motor already in your car, swapping over to the B18c, you will also need to consider the gearing to accompany the motor. As VTEC is like a "powerband" so to speak, you would need to consider the fact that you may drop out of said powerband given the different gearsets of another motor. This will affect the way your car accelerates

Assuming you have a B18b, im not sure if there is a difference in the gearing between that motor and the B18c

only problems you would have is a b18(a,b,c) gearbox with a b16a motor.
a b18(a,b,c) gearbox would still be fine with the b18c vtec motor, you dont actually drop out of vtec enough to make a difference.
the vtec powerband isnt like some nitrous surge and wouldnt be felt anyways. reading dyno graphs show that when vtec engages the power range stays relativly even.

[Zilli]

only problems you would have is a b18(a,b,c) gearbox with a b16a motor.
a b18(a,b,c) gearbox would still be fine with the b18c vtec motor, you dont actually drop out of vtec enough to make a difference.
the vtec powerband isnt like some nitrous surge and wouldnt be felt anyways. reading dyno graphs show that when vtec engages the power range stays relativly even.

i disagree with you

and i never stated it's a nitrous purge, ive own an ITR since new so i have a pretty solid understanding of how these things work:wave:

There is NOTHING more frustrating for me as when i accidentally short shift and the motor falls below cutover point. Even if it is just for a second, it's very frustrating, and could potentially cost you a race ( at the drag strip) or seconds (at a circuit).

I recognise that the B18c1 cutover isnt as pronounced as the c7, but if your serious about your driving "you dont actually drop out of vtec enough to make a difference" is just not good enough.

I don't profess to know anything about the different gearsets in different gearboxes, i'm just a real particular bastard and thought i'd let the OP know that there may be other considerations than just being able to bolt the box up to the motor.

Can you maybe educate us because your talking ballpark stuff, and that means nothing to me. Maybe you can provide us with your dynosheets? this is interesting stuff and i'd like to learn more

[string]

The second and third ratios on the B18A/B gearboxes are frustratingly short. Even driving around the street, changing gears at low 3000's you fall back to very low rpm in the next gear and it's a pain in the arse. You get the same feeling at high rpm.

Get the B18C gearbox, you will definately regret it otherwise - especially driving around town. The vtec motors have a pathetic ammount of torque down low.

To answer the question though, no you don't NEED it. Any b-series transmission will bolt up, but you'll need to get the right clutch plate for the gearbox you're using as there are some variances in input shaft spline diameter over the years (you havn't told us much information...).

Also, I don't see how a hydro clutch gives you more protection from slipping it into a low gear at high speed, that's all up to your syncros and your left hand. Hydro = less feel but less pedal pressure - Cable = more feel but harder pedal and arguably less things to break.

[Zilli]

good post, thanks mate

[string]

Just to add a bit more.

Acceleration is all about how much power you are generating versus how fast you are going.

A car going 60kph making 70kW will accelerate faster than a car going 60kph making 60kW.

When you start to shorten gear ratios you are mechanically increasing torque when speed is the constant, thus increasing acceleration at that speed. The trade-off is then more frequent gear changes, higher cruising rpm and limited top speed.

Here's a graph to describe what I mean.
The lines roughtly describe a B18C mated to a B18A/B gearbox compared to a B18C gearbox. I didn't know the exact figures so I just got them off a random site and picked what looked right.

http://img148.imageshack.us/img148/3945/powervspeedrj0.jpg

You can see that when you change gears, you just drop straight down to the next line and you see that the shorter geared transmission will be allowing the motor to rev a bit higher at the given speed and thus generating more power. It also shows why it's pretty much never a good idea for pure speed purposes to shift before your maximum revs. You will only be faster if your power output drops below what you'd be producing in the next gear, which is very unlikely with a vtec motor which holds torque very well at high rpm.

[Spunkymonkey]

lol...just lost half my post....but anyway....

good post string...

also other trade off...is slightly less fuel economy.

I have a b16a box set up with my b18c2. Compared to the stock b18c (vtir) box the ratios are shorter...

b18c2 box when changing gear at the top of the rev limit will drop down below secondary intake butterflies engagement.

with the b16a box which has ratios closer to a type r box than the standard b18c vtir box when changing gear at the top of the rev limit will drop down and be in a rev range where seconday intake butterflies engage

I would probably not recommend a b18b (gsi) box as its got one of the longest gear ratios in the honda range.

[string]

b18c2 box when changing gear at the top of the rev limit will drop down below vtec engagement.

Are you sure you're not confusing the VTEC crossover with the secondary intake butterflies? The B18C2 vtec engagement is at 44xx rpm which you would fall back to even with a non-vtec box let alone a close ratio vtec box.

[Spunkymonkey]

Are you sure you're not confusing the VTEC crossover with the secondary intake butterflies? The B18C2 vtec engagement is at 44xx rpm which you would fall back to even with a non-vtec box let alone a close ratio vtec box.

oh yeah sorry mate I meant second intake butterflies lol....

very noticeable compared to an ITR shifting at the same time.

[MRDEANOS]

sorry i forgot its a 99 Civic and ive been told i have a EK1 in there atm and no the engine isnt in there atm but im on the look for 1 and what i need to pretty much drop and drive as i need the car to get to work !!

[fatboyz39]

You need to find a Ek4 halfcut (b16a equipped), will save you alot of headache.

I've just completed a conversion in 8hrs, b16a into EJ8.

[MRDEANOS]

b16a whats the diff ??

[Spunkymonkey]

1.6litre 118KW compared to b18c (vtir) 125kw

[string]

Unfortunately it also has less (relative to capacity) torque so will be a bit more sluggish around town.

[Spunkymonkey]

Yes thats true. The ek4 civic vtir which has the b16a you need to step on the gas more to get it going compared to stock integra vtir with the b18c....

hey mate think you either want a b16a or a b18c....u need to update ur signature lol