Garfield_

Hello!

Just started on my 2,0 Zetec Turbo (Silver top). But starting to think about the gearbox, what can it handle? Looking for 300-350bhp! The RST box is not so strong i think!? Also think i will get a lot of torque, and thats maybe harder for the box? Suggestions?

Regards Jo-Alexander

s1cab

iTrader: (1)

I have a mk1 focus rs box in mine which will be between 400-430bhp. The bc box is never that great whatever mods you do to it really. Some people use the ib5 from a ka at around the 300bhp.

Garfield_

Okay, the IB5 box is plug and play, right? And the LSD from BC goes right in?

I have figured out the spec, but not shure on the turbo choise yet! Suggestions?

Here is my engine spec:

Wňssner pistons
PEC rods
Rover inlet manifold
Std cams
Dubble valve springs
"Ramhorn" exhaust manifold
MS2 efi with coil on plug
Water to air intercooler

Going to run 98 octane pump gas. This is going to be my everyday car!

zvh

I'm running a 2045cc zvh with arrows wrc rods , arias custom pistons with wrc wrist pins . 7.5.1 compression car run from 2006 and 2012 daily !!with a p8 cossie ecu raychem wrc loom Siemens black injectors , anti lag , waisted spark etc etc With lots of mapping and rolling roads in between at 286bhp plus all the time and the standard gearbox lasted through that time 😁now between 350&360bhp with 400fbt again on a bc type box .... Not that anyone ever believes me . Lol

studabear

My fully rebuilt BC box lasted about 450 miles with my zetec turbo attached to it, every gear whining, even whined in neutral.

293bhp 311 lb ft at the flywheel.

I'm fitting a IB5 with KA gears and s2 lsd while I save up to mtx convert it, hopefully the IB5 will last a year or 2??

zvh

Didn't do well did it 😜

studabear

No its safe to say this box didn't like a severe power increase.

stuart collins

iTrader: (7)

mine shit its self in 5 miles with 350 bhp big bearing box and gripper diff

zvh

All I can say is I've been very lucky then 👍

luke19790_3

No you just drive like a girl

Garfield_

Haha, thanx for the information guys!

Think i`m going to use the IB5 with the S2 LSD then Any suggestions on turbo for my spec? What head gasket do you guys use?

russ rs

Not just normal 5 miles knowing u

studabear

Not sure regarding turbo, some sort of focus rs hybrid perhaps.

Regarding the valve springs you might want to fit devil developments springs instead of double valve springs.

Head gaskets a lot of people use focus rs multi layer steel head gaskets.

Garfield_

Okay, thanx! I will take a look at the Focus Rs hybrid

Trying to register at oddkidcreations, but there is something wrong with the site! Anyone have a mail adress to him or one of the admins there?

studabear

He is versus creations on this site, you might be able to message him on here.

zvh

Your a special kind of special xxx go play with your focus st engine and I've seen females win the summer national drag championships at the pod so thanks for the compliment . Has your car actually seen a road yet ?? Mr experienced 😘😘

jonny s2

iTrader: (12)

either go with the ib5 or spend a bit more on an mtx conversion......or you could turn the boost down

zvh

If your going to change the bc type box the only one I'd bother with is the 6 speed getrag with equal length drive shafts otherwise if stick with what you have use good gear oil mounts and clutch and the BC type is fine if it's not knackered before you fitted it !!!
Seams to me everyone with blown up BBC boxes has done something wrong along the way some where or used rubbish oil and launched the crap out of it 10 times a day !! As I said mine lasted at 335bhp @ flywheel 298@wheels with 398bft for a good 6 or 7 years !! Used daily with lots of rolling roads and mapping by tommy field (the shit kicked out of it) and was fine so I have to disagrea with all of you !that it u can't put a decent gearbox together one or the other

studabear

Your in dream world.

muz

The weakness of the BC gearbox has nothing to do with shit bearings, oils etc. It's problem is the casing itself is inherently weak, and under load the casing twists, killing the bearings. Let's also not forget about the amount of stripped gear teeth and snapped main shafts.
I have a BC gearbox and even I'll admit that they are flawed in design from the off. Let's not forget it's actually a 4 speed box that ford retro fitted a 5th gear to who's design is now 40 years old! Mine has been built with IB5 bearings, Quaife diff and Quaife gear set and I still won't be surprised when it requires a strip down.

russ rs

You gone gear set then Muz be good to see how runs

zvh

I have owned over 11 Rs turbos muz I will say no more as I said I agrea to disagrea all of which have been used regularly !! Not projects that don't see the road but cars that are used inc lots of s2 a few s1 an xr3i turbo technics and various others in 1.6 1.9 2.0 and my current 2.1 which is now at 350bhp with 400bft with a bc type box and quaife diff which funnily enough is on my drive working it gets launched well enough to pull away from my mates 2 wd cossie which is 450bhp !! So I still disagrea

mgtkr1

I suppose it depends on the integrity of the casting. I can imagine big diference between the gearbox's churned out on a Monday to ones on a Friday for example. the biggest weakness is the casing itself though. mine let go at only 200hp, the casing was cracked in various places. granted I do give it some stick so it also comes down to how its driven. a car with 180hp that's launched hard regular and frequently given 30mph to flat out in 5th will break before a 300hp cars box that gets treated with a bit more respect. in a nutshell though, its not a matter of if but when

Karlos G

iTrader: (4)

I think you have just been very lucky over the years mate, but using good oil and changing it regularly seems to help a little, Christian Major actually fitted a drain plug in the bottom of his to allow easier oil changes.

But ultimately what Muz says I have also found to be correct in my own experience, I've never had bearings fail but have had teeth striped and shafts snap...







This always happens in a higher gear when the engine makes peak torque (usually 3rd for me), hard launches are fine as your in the lowest possible gear and of course wheel spin too... all of this takes strain off the gearbox comparatively as the power isn't being put down and you are no where near peak torque.

jonny s2

iTrader: (12)

i agree with using the correct gear oils etc.... but a standard bc box wont go past 300hp maybe a modified one. also depends on the driving styles. if you ran without an atb diff i reckon it would last a while. as also grip will break the box.

Karlos G

iTrader: (4)

I found the same thing Jonny, fitted an ATB and within a week I snapped the shaft you see above, very harsh diff! Went with a Racing Puma viscous LSD after that.

Fiesta_Jed

It has nothing to do with oil its just that bc boxes are shit. If you cant repeatedly do 2nd gear launches and 2nd/3rd gear burnouts then your gearbox simply is not strong enough.

Please prove us all wrong and show us a video your unique indestructible bc box doing 3rd burnouts and 2nd gear launches ? then maybe if its still in one piece people will believe you.

essexRSTSouthend

Standard box is like 170ft of torque rated i think, so using this for higher power will go in the end. Trouble is if you want to stick with the bc box, build it correctly in the first place. Yes the case is the weak point,, so why fit a bigger bearing, that weakens the case even more. Fit decent high grade bearing, super finish the internals etc and you should be laughing. As they say you pay what you get.. Also the option of ib5 is a great choice if you wanting a stronger case but again if you willing to change boxes, you might as well go mtx...

Also depends if you drive like you stole it and from what i've seen most owners do drive like they have stole it and wonder why the 1st and second gears destroy them selfs. Then you looking into straight cut gears. How deep are your pockets hey.

boost monster

I've had 3 rebuilds and sheared a shaft like in Karlos' pics and mine has only 190bhp and I have lots of mechanical sympathy. I must be really unlucky or bc boxes are shit?

stuart collins

iTrader: (7)

my mate tommy has a s1 300bhp 1.9cvh and 300lbft it get fucked around track all year he runs a bc box and does 2 or 3 boxes a year he rebuilds him them him self so they are built right, it runs a standard diff , if it was to has a proper diff in it , it would snap the teeth straight off in the 1st lap

GVK.

Even when the RSTs were 'fairly' new in the late 80s/early 90s when they still came into main dealers, even st1 chipped cars would wreck gearboxes, usually the crappy stock main shaft bearing would fail first, as it's not a full bearing.

I went through a few standard 'boxes in mine back in the day.

Adam.

Im 215bhp/260lbft, first box siezedi n gear and stripped teeth after whining properly, new box has uprated bearings and has been good as gold so far, but i dont gun 1st gear and rarely 2nd as theres no point due to wheelspin lol

luke19790_3

Why didn't you tell ford they could of saved cash instead of designing the mtx which is a waste of time when your super Bc box can take the power


How many miles you done in the last 6 or 7 years? It's used daily so what 60-70k?

russ rs

Driver builder clutch diff parts quality all can make them shat themselves like everything on a. Car. But u way up change to mtx with a diff against the rebuilds and decide

Karlos G

iTrader: (4)

To be fair there's no need to slate the guy, maybe the dyno he uses is way off with what power it shows? Or maybe it's a really close ratio box? (closer ratios put less strain on the internals), or runs 13" wheels? Or the car only weighs 600kg? Or something?! Always drives downhill?! There must be a reason?! lol

studabear

Or he could be trolling?

zvh

il say no more !!! Luke you are a hythe of knowledge this forum should be called passion luke . As I said I've owned 11 Rs turbos all of which have been used . You bore me and I'm no longer intrested in your opinion on anything . Here's 50p phone someone who gives a ,,,, good night

zvh

Any idea what the datapost s1 gearbox was ?? @ 300bhp good night

russ rs

Hewland with custom clutch set up . Ask Gus sure he has one?

Sure it didn't require a clutch after starting so stop lazy foot crunching through gears as prob some do

muz

It used a special 909 gear set with closer ratios. I used to have one. Whether it was any stronger than the original, though, I have no idea.