R32 Gtr Circuit Car Build Thread

[Risking]

Inmy opinion you guys are really getting to the point of needing some basic alignment and set up equipment.

I'd be getting a basic alligner, an older type laser machine is perfect, decent set of bump steer gauges and a decent camber/castor gauge of the aligned hasn't got one.

Those rear "traction" arms should not be lengthened or shortened unless you have the chassis sitting with bump steer gauges handy to see what's happening, they are a critical arm, guessing can cause all sorts of unpredictable behavior. The hicks eliminator kit you are using is similar to the ones I build, again it needs to be tuned with the right equipement to be set up right.

Spend a few bucks on some gear and you'll start taking leaps and bounds with car setup and learn alot along the way.

[OLLIE_NZ]

Took the car out to an open day at our local track Hampton Downs on Saturday http://www.hamptondowns.com/

Here's four laps of me driving poorly (constructive criticism welcome )

Managed a 1:15.1 lap on the RaceChrono

Edited July 3, 2011 by OLLIE_NZ

[OLLIE_NZ]

Did a bit of messing around with a set of Performance Friction Pads that I was given (01 compound) they we're off an NZV8 car so were very close width wise to fitting in the factory calipers. The chap literally has shelves full of them!

They needed ~1.2mm machined off width wise, some slotted holes for the retainer pins and I had to take a few mm off the pad thickness as even second hand they are thicker than the new factory pads (15mm)

Best thing about them is that they were free ~$450 NZD for a set of fronts new

Machined the front discs down as they we're, and still are pretty shabby, plus we're changing from an Endless N35s pad to the PFC01s

Messy job, the vacuum helped my lungs

Took around .6mm off each end of the backing plate

Slotting the retainer pin holes (~8x6.5mm)

Done

Bought some slicks too!

Also bought a set of 4.3 GTS-4 diffs front and rear.

Cut the front brake backing plates off too (figure they'll be going anyhow when we upgrade to a bigger setup)

[johnbarry88]

man that looks like some awsome fun!!!

[Roy]

Be interesting to see how you go with the PFC01s. I am running PFC06s which are basically the same pad only for endurance racing so lose a little bit. I suspect they will be great in your car. In mine I have no ABS and they are VERY bitey. Too bitey for my driving and I lock fronts a lot. What rear pad are you running? You will need a pretty good rear pad I imagine to balance everything out....I suspect with the std caliper and rotors up front the pads will work better then on my car which has bigger rotors and calipers and I end up with a tad too much brakign force with such a race pad

[OLLIE_NZ]

Hi Roy, our car has no ABS also, the rear pads are Endless N35s which seem to have far less initial bite than the PFC01s but might be able to run at higher temperatures for longer?

The Endless pads seem to be quite aggressive on the rotors too so we're hoping that the Performance Frictions will be slightly less aggressive in that respect.

Have you tried any Pagid compounds?, we were going to buy some Yellow RS-29s I think which are an endurance pad but the PFC01s were free so we though we'd save ourselves $450NZD

[OLLIE_NZ]

Ended up getting an email back from the coilover spring manufacturer Merwede

This is what's written on our springs

Rear 'Merwede Progressive 250 49 98'

Front '25 250 59 118'

This is his email (I've added the conversions in red)

Good morning,

I've looked for the springs in our system, but was unable to find it. But nevertheless, I think I know the spring rates from the code on the spring.

For the rear it's progressive from 49 to 98 N/mm (280lb – 560lb), (5kg/mm - 10kg/mm)

For the front it's more difficult because that code doesn't mean much to me. But if the spring is also progressive, it will be 59 to 118 N/mm (340lb – 675lb), (6.4kg/mm - 12kg/mm)

Hop this serves you well.

Best regards,

Ramon van Dijk

Merwede Springs

Based on those figures fellas, as this is a circuit car we don't want progressive rate springs do we?

What do you guys reckon would be ideal front and rear spring rates for the car, the two circuits the car sees are pretty smooth.

[DVS JEZ]

removing the hicas ECU will make slow speed steering 50% heavier than normal. not sure about high speed never tested it.

it has speed sensitve steering

[jazzy_j]

Based on those figures fellas, as this is a circuit car we don't want progressive rate springs do we?

What do you guys reckon would be ideal front and rear spring rates for the car, the two circuits the car sees are pretty smooth.

No you don't want progressive spring rates on race car.

We run 9.8kg front springs and 7.6kg rear springs on our 32gtr and that works quite well. But we used to run it mostly at oran park which was very bumpy and it used to handle very nicely. So it maybe too soft if the circuits are smooth. Best to talk to a suspension guru who deals with race cars not road cars and has knowledge/experiance at the tracks you use. Get their advice on a ball park rate, start there and try a few different spring rates to see what your driving style responds best to.

[OLLIE_NZ]

Small update,

Made some headway into the 'missing' coming out of certain corners at Hampton Downs.

It's pretty basic but should be good for another year or two.

Single Bosch 044 external pump, spare outlet on the surge tank for another external fuel pump in the future.

Apologies for the cellphone pics, will post some higher res images soon.

Surge tank

Tow Hook, looks wonky but it's just the camera angle.

[CrimsonLey]

subscribed.

[OLLIE_NZ]

Rightio chaps,

Not a lot of news on the car front since July.

Bought a set of near new Michelin slicks (only done 12 laps at Taupo). They were used for a back to back test on a NZV8 car to see if the car would be quicker on the Michelins than the current regulation Dunlops. Apparently they were 2-3 seconds per lap quicker than the Dunlops.

We also bought a used brake package from an NZV8 race car for a very good price and got a few sets of brand new Performance Friction pads 01, 03 and 97 compounds, also a few spare sets of Performance friction front discs and Wilwood rears.

In an ideal world we would have splashed out for a set of used V8 Supercar Alcons but currently can't justify spending that kind of coin and were so sick of the factory R32 GTR brakes that we think this will be a good mid-way brake setup.

We have to design and make new brake hats and caliper brackets to get them to work with the GTR.

Front disc dummied up using washers to space out the NZV8 hat to get some measurements.

Front caliper brackets were whipped up at work on the water jet cutter out of 12mm plate

Rear dummied up, I think the easiest thing to do with the rear calipers is to re-drill them from the 135mm Wilwood bolt hole spacing down to 115mm Nissan spacing and we wont have to worry about a caliper bracket which looks pretty tricky for the rear.

Still not convinced there is enough free space to re-drill the caliper down from 135mm to 115mm.

Has anyone been down this path before?

Very very loose mock-up with the wheel on to check clearance.

Also bought a set of 17x9" Et20 BBS LMs

Here's our current front brake hat design, pretty confident it will work. Still not 100% certain on what diameter the centre bore should be and also what size to make the stud holes (we're aware the studs are M12).

The hats will be turned up on the CNC mill and lathe at work.

If anyone has been down this path before and sees any errors with our design or would like to add anything please let us know

[Sub Boy32]

Hi Ollie, Unfortunately the guy that made the hats for me is nowhere to be found, I think he has moved overseas after the earthquakes, I needed to get a set of rear brakes done for another guy keen on a set, Otherwise I might have been able to find out for you.

We redrilled the holes for the rear ones, And yes it does get within a mill or two to the old holes, We put a loctite a Grub Screw in the old holes to help with the strength of it.

One piece of advice when making hats for the front, Make sure there are fairly shallow dished, The first set I got made looked like they would clear easily....But when the front suspension comes up the lower king pins rub on the rotor.

What size are the Michelin's?

Edited September 29, 2011 by Sub Boy32

[OLLIE_NZ]

Small update, hot off the tools comes some new hats

From this

To this (still needs a bit of finishing)

[OLLIE_NZ]

Well back from the wilderness that is filming on location and back to reality

Not a lot has happened since the last update but we're hoping to have the car back together for some January trackdays.

Decided to finish the rears in a month or so and are hanging out to get the car on the track so have unfortunately put the stock brakes back on the rear.

Ended up getting a good deal on a set of new discs.

Made an extra set of caliper brackets on the water jet cutter and then milled a step in them. The new sets bolt holes are 2mm wider to push the caliper further to the edge of the disc.

Garage clutter

Hats are done and anodised black

[SHOWOFFR32]

Wow mate, I just had a read of your whole thread... That's one hell of a nice race GTR...

I'm going to continue to follow the progress and hopefully turn my R34 GTR into something similar haha

Nice roll cage too by the way, whoever made it was a genius!

[OLLIE_NZ]

Very small update chaps.

Today I replaced the springs with some linear Eibach springs as the car had some progressive ones in it.

I ended up going for some 800 Ib front and 500 Ib rears after much head scratching.

I got some helper springs to keep the rear springs captive as when the car is up off the ground there was about 50mm of slop with the spring.

Also purchased and installed a Cusco rear sway bar.

On the way from Japan is an Ikeya tie rod end set.

Made a cardboard mockup of the centre console, maily to hide the dash bars. Will probably make the final thing up tomorrow from aluminium.

Rear sway bar

Rear springs in

Fronts done

[bigmikespec]

Probably too heavy at the front.

[SHOWOFFR32]

Brakes looks great mate!!

[bellis_GTR]

Gorgeous gorgeous car ! I love all the detail. Love the cage, brakes, brake duct, gauge panel and the whole car!!!

Love the build