Jump to content

Newbie Questions On Gbs Zero


nelmo
 Share

Recommended Posts

I can also +1 First Motion. I got one of their FM283 gearboxes which took about 3 weeks for them to make up. I had a good chat with them beforehand about the most appropriate ratios and type of box for what I wanted to use it for. I found them really helpful.

Link to comment
Share on other sites

£575?! This is supposed to be a budget build - isn't it?

 

Or is it now more a case of "sod the expense - just don't let the wife find out"?

 

Don't be so upset - it's not your cash :)

 

I was hoping to only spend £12 - £13k but my own desire to not do any refurb work myself means I'll probably have to spend more. GBS suggested £13k for a ' basic' Zero and i assume that means a refurbed gearbox from them, which is £800. So, if i get one for £575, i am 'doing a budget build'. Happier now? ;)

Link to comment
Share on other sites

(Should i be starting new threads in the relevant subforum?)

 

Called the place in Sevenoaks to ask about diffs and they replied in fluent 'technical' (i always feel like a pleb when talking to mechanics).

 

They basically offered to effectively build me an almost new diff with any spec i wanted but said i need to tell them certain things.

 

First off, are the drive shafts bolt or push-fit? Research says bolt are stronger in the long term but push fit should be fine - are both options easily available and cost the same? Any preference? (I might try refurb these myself - found a guide which looks pretty easy).

 

Presumably, i just want a standard 3.92 diff? Lower ratio better for cruising, i believe, but you lose acceleration, which i don't want.

 

The mechanic-alien asked me what size tyres/wheels I'd have - i have no clue right now but i assume that just helps determine what diff ratio to use. If i just want a 3.92, wheel size is irrelevant, no?

 

He also asked if i wanted 7" or 7.5". I have no idea what this measurement is of and why its important but i assume i just want a 7" (most on sale seem to be that size)?

 

Sorry for lots of questions...hope you can help.

Link to comment
Share on other sites

(Should i be starting new threads in the relevant subforum?)

 

Called the place in Sevenoaks to ask about diffs and they replied in fluent 'technical' (i always feel like a pleb when talking to mechanics).

 

They basically offered to effectively build me an almost new diff with any spec i wanted but said i need to tell them certain things.

 

First off, are the drive shafts bolt or push-fit? Research says bolt are stronger in the long term but push fit should be fine - are both options easily available and cost the same? Any preference? (I might try refurb these myself - found a guide which looks pretty easy).

 

Presumably, i just want a standard 3.92 diff? Lower ratio better for cruising, i believe, but you lose acceleration, which i don't want.

 

The mechanic-alien asked me what size tyres/wheels I'd have - i have no clue right now but i assume that just helps determine what diff ratio to use. If i just want a 3.92, wheel size is irrelevant, no?

 

He also asked if i wanted 7" or 7.5". I have no idea what this measurement is of and why its important but i assume i just want a 7" (most on sale seem to be that size)?

 

Sorry for lots of questions...hope you can help.

 

You want a 7", yes. This came with push-in (tripode joint) or bolt-on (lobro) shafts, so just pick whatever is going to match your drivetrain. I wouldn't worry about one being better than t'other, it's much of a muchness unless you're planning on fitting an LSD later on. Lobro-style is more flexible for modifications later on, but don't let it be the be-all-and-end-all and the whole matching diff/shafts/outers are a pretty easy swap if you ever need to.

 

7.5" I think only ever came in lobro style and is basically the granada/cosworth diff.

 

There was also a 6.5" diff, quite rare (I had one!). Only available in 3.6 ratio, lighter weight but ultimately not as strong. It looks very, very similar to the 7" externally but takes smaller shaft splines and if you look at the casting it's narrower - and obviously the crownwheel inside is much smaller. Avoid and if you're buying second hand, make sure someone isn't trying to palm one off on you as a 7".

Link to comment
Share on other sites

Some gear calculators online to help BUT the ford scorpio 2.0 16v came with a 7.5" 4.27 cwp ratio.... If you could locate a whole rear axle you'd be a happy boy! Then you'd have drive shafts and rear brake calipers and carriers etc etc

The zero can take a 15inch rim minimum and most run a 45/50 profile.

 

To fit a 4.1 or 4.4 cwp to a 7" diff is going to cost you £550+ (not that I'm researching that), I'm personally not bothered about cruising rpm and mpg stats-mine is usually having it's neck wrung! The higher the numerical number the faster the acceleration but the lower the top speed-all ratios will still produce over 100mph and you will always be limited by aerodynamics.

 

Mine is running a 3.6 diff and is quick but only because mine is exceptionally light.

Link to comment
Share on other sites

"GBS suggested £13k for a ' basic' Zero and i assume that means a refurbed gearbox"

 

I'd be very surprised if it did!

 

Wheel size is 15" for the Zero.

 

Either a 3.92 or 3.62 diff will be fine

 

My drivetrain is an MT75 box, push-in shafts to a 3.92 diff & 15" rims with 195x50 tyres

Link to comment
Share on other sites

My engine, ecu, gear box, 3.92 diff, drive shafts, hubs, brakes steering column, wiring loom, master cylinder, iva steering wheel and fuel sender cost £325. With a free sierra!

  • Like 1
Link to comment
Share on other sites

"GBS suggested £13k for a ' basic' Zero and i assume that means a refurbed gearbox"

 

I'd be very surprised if it did!

 

 

I think you're right and i have the feeling i have been a tad mislead by the sales guy but my own fault for not clarifying. Ah well, it's only the kids inheritance :)

Link to comment
Share on other sites

I was assured a budget of £7.5k would easily mean a Zero on the road. I haven't added it up but it definitely broke the £10k mark....and I would class mine as fairly basic (stripped mx5 myself, no recon parts, mx5 loom/ecu, mx5 dash)....but could have been a fair amount cheaper - seats, prop/drive shaft modifications, lights etc

 

Some bits would save a few quid, others possibly could have saved a few hundred, for example, could probably have used the MX5 seats saving £200 (but I sold them for £100 to lessen the blow lol) Eitherway, I neutralised a cost of the running gear buying a car and selling bits I didn't need....and thats a lot of the car/cost if you look at it that way.

Link to comment
Share on other sites

I was told to budget for £9K for a new reg (this was 4 yrs ago). The build came in at £11.5K.

Donor parts & a DIY refurb came to £500 for hubs, drive shafts, steering column, diff & gearbox.

I only bought from GBS things that were car-specific, or that I couldn’t get a lot cheaper elsewhere.

The stuff that didn’t come from them included such things as brakes, fuel system, cooling system, electrics, instruments & seats. (All new, except for the seats.)

As I’m not going racing, I went for a plenum, plus the standard Ford ECU & wiring loom, rather than go for an aftermarket ECU & throttle bodies.

Chopped the sump rather than fit the Raceline one, & didn’t bother with a water rail.

I don’t dare work out how much I would have ended up costing if I hadn’t done that little lot... though of course I suppose I could have offset it by selling one of the kids to medical science. Now why didn’t I think of that at the time? :mellow:

Link to comment
Share on other sites

Gawd, so much to learn...sump next - has anyone simply raised the engine, rather than fitting (or hacking) a lower sump?

 

I guess you'd need a bonnet hump (although i like them) or are there more fundamental issues with doing that (maybe prop shaft angle?)?

 

Prompted by the cost of the Raceline sump... :o

Link to comment
Share on other sites

Raising the engine has several problems.

1) some things will interfere with parts of the body.

2) Gear lever may hit top of tunnel.

3) rear of gearbox will be lower hitting that part of the tunnel

4) (as you said) poor prop shaft direction

5) Higher centre of gravity of the whole car

6) rather large bonnet hump

 

7) no room left for the supercharger ....

 

I fitted the raceline sump even though it's expensive as it is flush with the bottom of the car.

You will also need to cut off the lower part of the gearbox so that it is flush with the sump bottom. Do this off the car - it's easier (How do I know this? I had to cut this off by hand with a hacksaw after the engine was fitted - took hours but built muscles I didn't know existed !)

 

Simon.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...