Robbo's Clubbie Racer

[Ned Loh]

There is a lot of welds in that thing. How do you manage distortion? Obviously very carefully! I can see how a plan of tacking/welding in order could get you most of the way there, but do you use a jig or similar to hold critical pieces in the absolutely correct location? I suppose things could also be adjusted post welding if required?

[GR124]

There is a lot of welds in that thing. How do you manage distortion? Obviously very carefully! I can see how a plan of tacking/welding in order could get you most of the way there, but do you use a jig or similar to hold critical pieces in the absolutely correct location? I suppose things could also be adjusted post welding if required?

I was as careful as I could be managing distortion. The chassis was marked out and clamped to the flat build table. I never welded, only tacked as many parts is as I could. I then tig welded as much as I could get to whist still clamped on the table. Only then did I roll it over on the floor and complete the welding. With so many braces its straight, no distortion to speak of. As for the dimensionaly critical areas like suspension pick ups these are tabs welded on after the the chassis was completely welded. So they are within a mm. No jigs used, everything marked on the table, squared and measured.

[GR124]

Rear Brake Calipers
I am looking at rear caliper options. Currently have the standard NB8A discs and Caliper set up. I'm told I'll need larger rear caliper pistons than the 32mm. I believe the later model has larger pistons.

Can someone let me know,
which model has calipers with the larger than 32mm pistons? and if they would bolt onto my NB8A rear uprights (90mm centres caliper bolt up holes)?
Thanks

[beavis]

Who has told you this upgrade was necessary? I don't agree.
I can't imaging how the NB8A brakes would not be sufficient for a car that will weigh, around 500kg?
Not to mention, the rears don't have a lot of work to do either.

That said, the easiest upgrade, if you really want to do it, would be the larger rotor and caliper from the 6spd NB8B (2001-2005)

I have some details on it here:

[GR124]

Thanks beavis for your reply. The reason for more rear brake is the clubmans have lower centre of gravity therefore less weight transfer to the front brakes therefor the standard Nb8a set up would not quite suit. I have an adjustable brake bias with twin 5/8' master cylinders at this stage. So I either go smaller with the rear MC or larger front MC to give me a more balanced system.

I don't think I can get a bigger disc in the 13" rim so that's out. This is why I was looking at my options of a caliper with a larger piston.

What size is the piston in the NB8B?

PS. I haven't watched the video as I'm at work with no sound on my PC.

[93_Clubman]

Again, might be worth checking with JNR Clubman (Jim) on Ozclubbies, but IIRC while he used an NB8A motor the rest of the driveline was 1989-1993 NA6 (1.6), so pads & rotors smaller again for his road car. For your track car you might want different, but my initial thoughts at least are the same as Beavis.

[93_Clubman]

What size is the piston in the NB8B?

USDM specs follow (note: USDM NB8B came with either sport or non-sport brakes.ADM NB8B came with sport brakes only. USDM NB8B non-sport brakes carried over from the NB8A):

Caliper piston sizes:
non-Sport front: 2.01"
Sport front: 2.125"
non-Sport rear: 1.25"
Sport rear: 1.375"

https://forum.miata.net/vb/archive/inde ... 63284.html

[GR124]

cheers 93 clubman, I too come up with the same info on the US spec stuff. I assume its the same for OZ but I don't like to assume.
I'll do the conversion for my sake, (inches/imperial does my head in)
non sport rear (nominal) 32mm
Sport Rear 35mm

So does this mean the NB8B has a rear caliper piston of 35mm? and
Has the 90mm centres to bolt the caliper to the NB8A upright?

I was about to hit the submit button and read

(note: USDM NB8B came with either sport or non-sport brakes.ADM NB8B came with sport brakes only. USDM NB8B non-sport brakes carried over from the NB8A):

To me this means all Australian NB8B rear calipers have 35mm pistons, correct?

[93_Clubman]

To me this means all Australian NB8B rear calipers have 35mm pistons, correct?

Yes

[GR124]

To me this means all Australian NB8B rear calipers have 35mm pistons, correct?

Yes

Thank you mate

[GR124]

Who has told you this upgrade was necessary? I don't agree.
I can't imaging how the NB8A brakes would not be sufficient for a car that will weigh, around 500kg?
Not to mention, the rears don't have a lot of work to do either.

That said, the easiest upgrade, if you really want to do it, would be the larger rotor and caliper from the 6spd NB8B (2001-2005)

Finally had a look at your vid Brendan, really informative. Also had a look at your website, some nice goodies on there..
So when you were talking about the caliper bracket being all interchangeable (4.35) on the uprights you looked like you were mainly referring to the fronts.
Do all the rears have the 90mm bolt centres to the uprights so therefore interchangeable?

Thanks

[beavis]

The hub mounting points for both front and rear is the same for all NA & NB.

The comment I made in the vid around the caliper being interchangeable was between the NA6 and NA8/NB8A front caliper - the caliper bracket just needs to be swapped to the larger size, the caliper itself is the same.

[GR124]

Hi Guys, hoping I can get some help with a couple of questions on the NB8A engine. I've been felting it for the track, still standard internals.
Things done so far,
chopped 25mm off the bottom of the sump and raised the pickup.
Removed the plastic oil fill cap and welded in a Speedflow flatter style filler so it is slightly lower than the front/highest point of the cam cover.
Removed the Vics in the inlet and gutted the top half of the manifold as well as chopping the top off it so it is level with the cam cover.
All the above is to shorten the engine so the clubman bonnet is as low as possible.

anyways,,,the engine...I replaced the cam belt with a GATES RACING. The timing seems pretty straight forward. TDC, with the cams and crank all on their marks. belt fitted. The book says to "turn the crank 2 1/6 times to verify the timing marks are alined properly" the issue I have with that is the flywheel is impeded by the engine stand bolts. It's a real PITA to turn the crank. I can rock the crank, which I have done with belt tensioner tensioned and locked into place. I'm sure there will not be an issue. THOUGHTS?


The other question,,,, do I require the original oil cooler? Do I need to plumb it? If so Where? I'm doing a reroute of the water outlet.

I have removed most of the front plastic cam covers. I figure I still need the timing marks on this cover. do you see an issue in cutting along the dotted line?

[manga_blue]

Looks like it's coming along nicely.

I can't see any problems with cutting back the plastic covers until you have just enough to hold the timing scale.

That coolant outlet hole in the front of the head can be blanked off with a 30mm brass welch plug if you're doing the re-route.

I'm not sure how your NB8A throttle body is set up. Most have a hot water supply for cold running management that comes from those little hoses running from the back of the head through the cooler to the thottle body. If that's the case I'd just leave them there or else just bypass the cooler but still feed the throttle body if you have an external cooler. BTW all those little hoses are a very common point of failure on cars doing their first track days. They must be in very sound condition. You don't need moulded ones. Just bulk heater hose from Repco works fine.

[RS2000]

The book says to "turn the crank 2 1/6 times to verify the timing marks are alined properly"

That is after initially turning the crank 1-5/6 times to set the tensioner on the belt. There is a 'tensioner set mark' about 60 deg before the main timing crank mark. I remember trying to tension the belt without doing this step & it didn't tension properly.