Author Topic: 4x4 Explanation Please!  (Read 1990 times)

0 Members and 1 Guest are viewing this topic.

Offline .:Mondo:.

  • Trade Count: (9)
  • Calibra Expert
  • Posts: 1857
  • Respect 0
  • Gender: Male
    • Past owner
4x4 Explanation Please!
« on: January 16, 2009, 12:29:34 PM »
Without wanting to open a huge can of worms here, would somebody be able to explain how the drive is transmitted to the rear wheels please? Specifically, I'm interested in the role of the transfer box and how it couples to the F28 gearbox.

Cheers!
Hide'N'Seat Interiors - bespoke leather design!

[quote author=Black Arts Carbon

vexorg

  • Guest
  • Trade Count: (0)
Re: 4x4 Explanation Please!
« Reply #1 on: January 16, 2009, 12:41:50 PM »
Read here: http://www.members.lycos.co.uk/maxboost/htms/4x4description.htm

Front wheels as a normal car. The front diff has a second output for the TX box. The TX box has a clutch to switch the power to the rear off and on, then a vc to allow small speed differences, then out to the rear diff.

Offline .:Mondo:.

  • Trade Count: (9)
  • Calibra Expert
  • Posts: 1857
  • Respect 0
  • Gender: Male
    • Past owner
Re: 4x4 Explanation Please!
« Reply #2 on: January 16, 2009, 12:45:40 PM »
So, theoretically, would it be possible to remove the TX box altogether and just fit a prop between the F28 rear output and the rear diff...?
Hide'N'Seat Interiors - bespoke leather design!

[quote author=Black Arts Carbon

vexorg

  • Guest
  • Trade Count: (0)
Re: 4x4 Explanation Please!
« Reply #3 on: January 16, 2009, 13:06:16 PM »
Yes, if you uprated the tx box gears as they are known to fail.

Offline Bad Kid

  • Trade Count: (17)
  • Calibra Pro
  • Posts: 613
  • Respect 10
  • Gender: Male
    • Calibra B204 Turbo
Re: 4x4 Explanation Please!
« Reply #4 on: January 16, 2009, 13:06:38 PM »
So, theoretically, would it be possible to remove the TX box altogether and just fit a prop between the F28 rear output and the rear diff...?

Nope.

In simple terms...

On a Cali Turbo, the transfer box turns the drive through 90 degrees (pointing it towards the rear of the car) and transmits it down the propshaft.

If you're thinking of making a RWD Calibra without turning the engine round, it's not really possible without compromising longevity.
NURBURGRING CHALLENGE :-D

Offline Bad Kid

  • Trade Count: (17)
  • Calibra Pro
  • Posts: 613
  • Respect 10
  • Gender: Male
    • Calibra B204 Turbo
Re: 4x4 Explanation Please!
« Reply #5 on: January 16, 2009, 13:08:21 PM »
Vexorg just read through the question and your answer again...

So, theoretically, would it be possible to remove the TX box altogether and just fit a prop between the F28 rear output and the rear diff...?

Yes, if you uprated the tx box gears as they are known to fail.

It wouldn't be possible, as without the TXB the drive would still be transverse.
NURBURGRING CHALLENGE :-D

Offline .:Mondo:.

  • Trade Count: (9)
  • Calibra Expert
  • Posts: 1857
  • Respect 0
  • Gender: Male
    • Past owner
Re: 4x4 Explanation Please!
« Reply #6 on: January 16, 2009, 13:10:05 PM »
I was just curious to know if a 4x4 Calibra could be altered to run without the transfer box, as this seems to be a weak link in the chain. This would keep it 4WD but remove that inherent weakness.

If I was going to build a RWD Calibra, I'd just stick the engine in the boot...!
Hide'N'Seat Interiors - bespoke leather design!

[quote author=Black Arts Carbon

Offline Bad Kid

  • Trade Count: (17)
  • Calibra Pro
  • Posts: 613
  • Respect 10
  • Gender: Male
    • Calibra B204 Turbo
Re: 4x4 Explanation Please!
« Reply #7 on: January 16, 2009, 13:13:42 PM »
I was just curious to know if a 4x4 Calibra could be altered to run without the transfer box, as this seems to be a weak link in the chain. This would keep it 4WD but remove that inherent weakness.

Some sort of transfer box is needed mate, as said before it's what "turns" the drive through 90 degrees so it can go down the propshaft to the rear.

Evo's, Pulsars, GT-4s and VW's use transfer boxes too.

A lot of the hype surrounding the transfer box is a myth don't forget. They actually do their job quite well, anyone who's driven a Calibra Turbo in 4WD then 2WD will tell you that. The people that tend to slate the boxes are people who've backed the wrong horse and put the LET in a crappy Corsa or something, they then have to justify driving a crap car and they do this by blaming the TXB.

Remember, a well-looked after TXB can do more miles than most Vauxhall engines without attention ;)
NURBURGRING CHALLENGE :-D

Offline .:Mondo:.

  • Trade Count: (9)
  • Calibra Expert
  • Posts: 1857
  • Respect 0
  • Gender: Male
    • Past owner
Re: 4x4 Explanation Please!
« Reply #8 on: January 16, 2009, 13:15:16 PM »
That was the bit I was unsure about - how the drive is altered from transverse to longtitudinal.

Engine in the boot it is then!
Hide'N'Seat Interiors - bespoke leather design!

[quote author=Black Arts Carbon

vexorg

  • Guest
  • Trade Count: (0)
Re: 4x4 Explanation Please!
« Reply #9 on: January 16, 2009, 13:36:52 PM »
It wouldn't be possible, as without the TXB the drive would still be transverse.

Yeah, misread the question, I was meaning the clutch and vc, but you'd still need something to change the direction of the shaft.

Offline carl

  • Trade Count: (0)
  • Calibra Mentor
  • Posts: 11731
  • Respect 1
  • Gender: Male
    • Cally 16v Redtop
Re: 4x4 Explanation Please!
« Reply #10 on: January 16, 2009, 13:43:49 PM »
That was the bit I was unsure about - how the drive is altered from transverse to longtitudinal.

Engine in the boot it is then!
why? are you starting a project?
bodybuilding thread! the thread for winners!
http://www.clubcalibra.com/index.php?topic=34651.msg449718#msg449718
**Carl's calibra project**
http://www.clubcalibra.com/index.php?topic=34701.msg450951#msg450951
You argued with an idiot, I brought you down to my level and I beat you with experience.

Offline Bad Kid

  • Trade Count: (17)
  • Calibra Pro
  • Posts: 613
  • Respect 10
  • Gender: Male
    • Calibra B204 Turbo
Re: 4x4 Explanation Please!
« Reply #11 on: January 16, 2009, 14:43:01 PM »
Engine in the boot it is then!

After realising a V8 wasn't going to fit in my Calibra, a mid-engined LET was my next idea (just behind the front seats)

I can tell you now, there is a LOT more to it than you'd think.

For example:

How are you going to change gear?
How are you going to change the entire rear suspension?
How are you going to spaceframe or box-out the rear?

Tell us more about this project as it does sound interesting! I'm not trying to put you off, just point out the hurdles you have to overcome.
NURBURGRING CHALLENGE :-D

Offline .:Mondo:.

  • Trade Count: (9)
  • Calibra Expert
  • Posts: 1857
  • Respect 0
  • Gender: Male
    • Past owner
Re: 4x4 Explanation Please!
« Reply #12 on: January 16, 2009, 14:50:30 PM »
As this is only an idea at the moment, I can pretty much answer only one of your questions...

How am I going to change gear? By mounting the engine transversely so the gear linkage (extended, obviously) operates in exactly the same manner and direction as it does with the engine under the bonnet.

After that, I'm just drawing on napkins!!!
Hide'N'Seat Interiors - bespoke leather design!

[quote author=Black Arts Carbon

Offline Bad Kid

  • Trade Count: (17)
  • Calibra Pro
  • Posts: 613
  • Respect 10
  • Gender: Male
    • Calibra B204 Turbo
Re: 4x4 Explanation Please!
« Reply #13 on: January 16, 2009, 15:00:42 PM »
The linkage is going to be pointing the wrong way though, your gear stick linkage is pointing towards the bonnet... and the linkage on the gearbox will be pointing towards the boot. You'll either need an elaborate linkage going through the car, or a cable shifter

The suspension will have to be totally changed, it's too bulky to allow an engine and gearbox to hang down in the rear to drive the wheels. You'll need to do something like Chip has done in his Nova (damn, tried to do a whole post without mentioning him, LOL) - ie Astra Mk4 front suspension mounted on the rear. This has it's own issues of bump-steer, something that's beyond my knowledge but worth pointing out.

The chassis itself will need strengthening too, at a minimum you'll need loads of box section and make a ladder type chassis at the rear. Better still you need a proper spaceframe.

So to summarise - sh*tload of work.

Love Chav xxxx
NURBURGRING CHALLENGE :-D

Offline .:Mondo:.

  • Trade Count: (9)
  • Calibra Expert
  • Posts: 1857
  • Respect 0
  • Gender: Male
    • Past owner
Re: 4x4 Explanation Please!
« Reply #14 on: January 16, 2009, 15:10:04 PM »
I'm quite glad I haven't just cut the back end of the car out now then!
Hide'N'Seat Interiors - bespoke leather design!

[quote author=Black Arts Carbon

Offline Bad Kid

  • Trade Count: (17)
  • Calibra Pro
  • Posts: 613
  • Respect 10
  • Gender: Male
    • Calibra B204 Turbo
Re: 4x4 Explanation Please!
« Reply #15 on: January 16, 2009, 15:45:07 PM »
I'm quite glad I haven't just cut the back end of the car out now then!

Mate I was stood there with the car on the ramps, with the angle grinder powered up when I realised :D

I would upload a pic but my PC is being gay right now.

Still, there is hope for a good project car. What do you want from a Calibra? How much have you got to spend over the course of the project? How good are you with spanners? Can you weld? Do you have workshop space or are you willing to pay someone else to fabricate?
NURBURGRING CHALLENGE :-D