"The Mazda" zoomzoom's NA Track toy

[MattR]

These calipers are from an R32 GTST. The Nissan calipers are all virtually the same with the major differences being that some were cast iron and some were alloy depending on what they came off, whether they were JDM vs. ADM and the length of the mounting ears also differs slightly from one model to another. There is also the difference of most of them being to suit a 30mm disc and some being to suit a 32mm disc.

These calipers being from a R32 GTST are of the alloy variety and are made to suit a 30mm disc. These were chosen due to the length of the mounts being most suitable for how I wanted to mount them. While I had them apart to rebuild them I had them modified a little so they now suit the 26mm disc. The Nissan calipers are quite thick through the piston housing so despite being alloy they are known to be quite stiff, I would hazard a guess that they would be considerably stiffer than most of the cheaper wilwoods which people are using and have a much better availability of brake pads due to them being so common in the performance car world on nissans.

So from memory should be the "other" version to what I am running, Z32 TT alloy calipers which use a different pad. If you had of hunted around for Z32 NA calipers they wouldn't have needed modifying for the 26mm rotor as that's what they were used with and the mounting holes probably would have been spot on as they are a straight swap onto S chassis like the R chassis calipers are.

In any case the Nissan stuff is plentiful and reasonably cheap if you know where to look.

And they will be quite stiff compared to Wilwood dynalites. I was very disappointed in the quality of finish in my dynalites when I had them apart to rebuild. Plus you get the advantage of not having to pull them down after every wet race event like I had to do with the wilwoods.

[zoomzoom]

From what I found they should all take the same pads, DB1170 from memory. I had a look around at various calipers but I didn't come across the 26mm calipers but that's not to say there aren't any around. The main reason I ended up with the R calipers was the availability, I went into a wrecker/importer over at Archerfield and they had a selection of R32/R33 calipers on the shelf and all at the same reasonable price so I figured it wasn't worth tearing my hair out over. Also when I first bought them I was still thinking about going with 30mm rotors which I decided against at least for the time being.

Sorry Apu, I had the brackets laser cut/machined of my own design. I may consider making them to sell as a DIY kit or something along those lines at a later date but not until I have a chance to test them out etc.

Cheers,

Tim

[MattR]

The z32 calipers wouldn't be as plentiful out here than the R calipers.

What did you do regarding the master cylinder? I would think that you would be running out of fluid using the standard mazda unit. I know that the 1" BM50 non ABS MC is the preferred unit for the R to S chassis brake swap, but you have to get the right model for the brake bias that is done internally within the cylinder. With the RX7 rears being single piston you may get away with a BM44 which is 15/16" and i'm pretty sure I have one of those doing nothing at the moment that you can have to try. I will be chasing a Z32 non ABS BM50 for my set up.

Best bet obviously is a pedal box, but that gets exxy very quickly

[zoomzoom]

Yeah I would love to do a proper dual master setup but for the time being for cost and simplicity I will be sticking with a bolt on replacement.

The NB8B should provide enough fluid at 15/16 vs the 7/8 of the NA which I was still running with the old brakes. There is also a master off a late 323 which will bolt on as well as a pejero one both at 15/16 but would require a little modification of lines to work. I will keep an eye out though, if I can get a hold of a 1" master that bolts in without too much drama I might even go that way.

Cheers,

Tim

[MattR]

You'll know pretty quick if you run out of fluid, even before hitting the track

But if you are already running a 15/16" MC you should be fine for fluid volume. It may also be worth doing a booster delete for a bit more pedal feel. I much prefer to use non boosted brakes on the track than boosted.

[zoomzoom]

I got the car out to Lakeside on the weekend for the TimeAttack round. It went fairly well, I got to have a play with the new brakes and they seemed to work well after bedding everything in and a little playing with the bias. Basically the more pressure I gave to the rear the better the car felt under braking, it got more and more stable and I could get it pulled up even sooner.

In the end I went for a 1" brake master from an early 90s subaru which takes the master cylinder to front caliper ratio back to around a std car to give a similar pedal feel and travel to stock. It had the correct bolt pattern to bolt on and the lines fit with little modification. The biggest issue was the cap just touches the bonnet. I couldn't find another shorter one that would fit on after a walk around a couple of wreckers so I decided the easiest thing was to modify it with a little heat which seemed to do the trick.


The car is still very loose through the corners and very unsettled in and out sue the the locked diff so hopefully that can be sorted out soonish.

I put a crappy video from the weekend up on youtube if you are interested. This was my quickest lap of the day after, about a tenth off my best but still not a bad time of 57.47s.


Cheers,

Tim

[plohl]

Good stuff dude.

You need to get some telemetry on the videos though so we can all see how crazy fast you're going haha.

Are you pulling the brakes apart to see how the adapters went?

[zoomzoom]

So it's been a while since the last update, we have had a pretty decent break since the last round of the Lakeside TimeAttack series and the next event is still not till the 11th of October so I have started to slowly get a couple of things done.

The car has pretty well just been sitting since the last round, I did have a look at the brakes and pull the brake pads to inspect them and the calipers. They all look OK except for the new dust boots I installed on the front calipers which are already toast! Going off the colour changing paint on the DBA 4000 series rotors it looks like they are just reaching about 550*C which is pretty close to optimal, it would be interesting to see what QR National would do to them though!

I have been on the lookout for a while for a real wing, then finally the week before last I came across a wing at a reasonable price. The wing came off a GT3 car so I know it is a serious unit! Previously I was temporarily running an ebay special of some sort which I am sure made some downforce but was definitely a little more fooli sik than absolutely performance!

This wing looks to be quite a modest profile until you get to the last third where it gets very aggressive with a lot more camber. It has a 300mm total chord length and also has a small gurney flap bonded to it. Here is an image of it mounted to the temporary alloy uprights I had knocked up for the previous wing.


I decided to make up some new wing stands for the extra downforce I am expecting. After a little consideration I opted to make them from steel tube, they work out to a similar weight to using alloy flat bar but are much stiffer and stronger and cost very little but time. I also chose to bring the wing up a touch, about 75mm or so which would bring the top up level with the top of the rood when at the highest AOA just in the case the local TimeAttack rules decide to go the way of the World TimeAttack.

The uprights


A bit of diagonal support


Wing mounted


Next thing is to do some work on the bootlid to accommodate the change in spacing of the wing stands.

Cheers,

Tim

[gslender]

Looks serious

[corners]

Looks good

Coming out Monday?

[Lokiel]

Are the wing stand's base-bolts just bolted into the boot floor using rivnuts or do the bolts go through a matching DIY steel strip on the underside of the boot floor and fasten via a nut?

The 2nd option ensures that the load is distributed over a greater area (ie. less likely to tear up the boot floor at the bolt points).

[zoomzoom]

Looks serious

It is a pretty serious looking wing, I am pretty confident it will make some downforce, the hard bit will be setting a suitable angle. Since I don't know the manufacturer I might need to get my hands on some CFD software to at least get some reference data to begin with if I get the time.

Looks good

Coming out Monday?

I won't be coming out monday unfortunately, I made a decision earlier this year to reduce costs for the time being so just running the Lakeside timeattack series this year and a couple of special events. It was tempting to come out though being that there was about a 2 month break in the timeattack series, but then I would have had to rush these sort of things rather than doing it at a leisurely pace being every minute of my spare time!

Are the wing stand's base-bolts just bolted into the boot floor using rivnuts or do the bolts go through a matching DIY steel strip on the underside of the boot floor and fasten via a nut?

The 2nd option ensures that the load is distributed over a greater area (ie. less likely to tear up the boot floor at the bolt points).

The stands bolt through with a backing plate and nuts on the underside which help to distribute the load and prevent the nuts from pulling through, should they be loaded excessively. The mounts also happen to be right between the chassis rail and the vertical face of the spare tyre well which is about the best place I could find to mount it short of mounting directly to the top of the chassis rail which is further out and thus does not line up with the wing mounts.

Cheers,

Tim

[zoomzoom]

Through the week I got a started on the boot lid. The slots have to be relocated slightly for the new wing stands so I got started on covering up the old slots. I am currently getting it ready for paint again now .

Old slots


Some resin and cloth


Slots gone... well sorta, body filler yet to go on the outside!


I also fitted a window net through the week so I can run with the window down when summer comes around again


Cheers,

Tim

[plohl]

Pretty cool man! Can't wait to see the new wing in the flesh again!

[MattR]

Tim, if you are interested in lighter weight panels than fibreglass without the expense of carbon fibre I should have my plastic panels in a month or so for the S14.

I am looking at going from 20+kg for the bonnet down to 1-2kg and the same 1-2kg weight for the front guards and bootlid. They come in white so don't even need painting and have a few other advantages for repais over 'glass and carbon as well.