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Dale FZ1

R33 Gtst Track Build

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The adhesive composite sheet is good stuff. Concept probably not far removed from the gold stuff, but considerably cheaper. Downside is that because it's not paper thin (more like 1mm), it doesn't conform to the join between bonnet stiffening frame - bonnet skin. Easy fix, just run a blade along the join and then use silver refrigerant tape over the top. After a run, the section of bonnet where the sheet is applied is much cooler (less hot) than the areas directly adjacent. Should be problem solved there, so thumbs up.

The slip on sheath for the loom is thicker, probably 4mm. Easy to apply, and nothing appears to have been heat affected. Thumbs up there too.

Ceramic coating is not IMO an effective stand-alone solution to control radiant heat. It does work, but I reckon the lagged (but non ceramic coated) dump pipe contains more heat than does the turbine and manifold that have only ceramic coat. Physical barriers (ie some sort of heat shielding) can be very useful, dependent on what (if anything) actually needs protection from heat. At this point I think my setup is working and things aren't being fried.

Short run event formats should/might mean it is easier to deal with radiating temps simply because the length of exposure is shorter. I'd imagine a 20 lap race format would throw up more challenges.

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Time for a bit more suspension work.

Fairly heavy tyre wear on the front outer shoulders combined with a fair bit of mid corner understeer indicated that -4 deg camber is insufficient. A few LCA modifications should see us with a range of 5-6 degrees. Pics to come when it's reassembled and on the ground.

Rear cradle out while I inspect the tank to deal with some sort of fuel leak, and I have installed solid alloy bushes. Will confirm that removing the OEM bushes takes a fair amount of effort. I just smashed out the rubber guts with wood chisel and then used an airsaw + cold chisel to collapse the steel shell and remove it from the cradle tube. Resisted the urgings from Nigel to set fire to the rubber. :yes:

Dressed up the cradle tubes where I had left small marks, then a good smear of anti seize. Chilled the new bushes down in the freezer, then used a UNF bolt to pull them into the tubes.

Took a day to remove old stuff and prep for the install, and about an hour to install all 6 new ones.

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Nice build thread. What the overall plan for the car? General circuit events? Supersprints?

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Sprint events are the primary interest, and what it's been doing. I'd also like to give hillclimb a go.

The general costs associated with circuit racing don't make that discipline attractive. The issue of what category fits a mildly modified 2wd R33 is something that keeps a lid on that idea.

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Having raced a r33 gtst for the last 8-9 years, if you are requiring more then -4.0 camber up front then the suspension setup isn't right. I would be looking at why the car is rolling over so much and onto the outer shoulder first before trying to screw in more camber. You didn't mention what anti roll bar you are running too? what tire pressures do you run and how much caster?

Have you ever checked tire temps after you come in or are you just working from wear patterns?

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Rubber is Hankook Z221. Cold pressures 29F, 27R. It achieves 5-6 psi pressure rise during a 3-4 lap sprint. Front left is the hardest working tyre, and it rises the most.

Caster 11 degrees.

Front anti roll bar 24mm adjustable.

I have done/do temp spot tests across the face of the tyre, but tyre wear is the more reliable measure of what is going on. Temps are going to change during the cool down/in lap.

I'm going on advice from a very well credentialed suspension engineer with regards to what changes to trial. The aim is for least amount of changes for best return on effort, and 3.5-4 degrees of camber was felt to be a good starting point. It hasn't proved to be enough, so we are winding in a bit more to assess.

With luck and a lot of effort/organisation we will take it out for a test session prior to the next event in April, and should be able to form an opinion about what's working or what's not.

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Change is as simple as turning a spanner and try again. Caster figure is about as far as I want to go; inner guards have seen some adjustments via hammer to give clearance to tyres on lock and with suspension at full bump travel.

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what arms are you using to get the 11deg?

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Checking my setup notes the caster was actually 9 degrees. Pays to not rely solely on recall.

Hard Race radius rods.

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Awesome build. Keen to try get my wiring tidied up like that but ABS, TCS and electronic HICAS is making my life HELL! but will be well and truly relieved once it looks like yours keen to keep following the thread

Edited by rcs_888
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A few updates.

Fuel tank and rear cradle out. Spare wheel well cut out and replaced with a flat floor with plans to install a fuel cell and allow room for a diffuser.

Underfloor bracing with some C section channel, and used 0.55mm panel steel with a few spot welds and plenty of Sikaflex to finish the job. Coat of paint and it's all tidy again. Big advantage is easier access to make rear toe changes.

While things were apart I also cut a larger access hole so that I can get to the fuel pump without the usual hand injuries. Good value for as long as the OEM tank stays in the car. Made a new cover to suit and after painting it's looking good to me.

Replaced the OEM rubber bushes in the cradle with solid alloy units. All the comments about them being difficult to remove aren't too far off the mark, but I think a few blokes might be pushing it up a bit. Installation of the new ones was a piece of cake. Cradle baking in the sun, bushes in the freezer, liberally apply some anti-seize and then just pull them in using a fine-thread bolt.

Coat of black paint and it looks like new.

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Edited by Dale FZ1
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Alignment work is something that lots of people apparently see as a bit of witchcraft. It doesn't need to be that way, and with a few basic and cheap tools it's possible to get decent results.

Pictures below show a stringline setup on the car while it's on stands. Using a couple of jacks and blocks I set camber and toe both front and rear, and check/adjust the rear for bump steer. Achieved zero toe change between 60mm bump and 50mm droop travel.

This is done with the shocks removed from the car, and sway bars front and rear disconnected.

Tools involved are the measuring rods, a couple of simple jigs to locate/hold them, two light fishing lines, an engineers ruler, and a builder's level. Car stands and a couple of hydraulic jacks.

It takes a bit of time, but is possible to achieve very good setup with the added benefit of knowing how your suspension is working.

Caster is checked/set with the car on its wheels on the ground, using equally high tech gear as for camber/toe.

No laser setups, wheel jigs, or bearing-plate turntables. (not that I wouldn't like some of that gear, just this is within budget)

I'm 100% confident there will be a few old blokes around who know all about this gear and used it back in their day.

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So have you been modifying locating points or just changing settings? Wonder how much i can transfer to the 34

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Currently there is no need to change pickup points. There may be some technical merit in doing so, but there's quite a bit of improvement available from the changes to date.

I will wait until the driver improves and catches up to the car before taking that step.

It's very likely that the R33 and R34 run the same geometry and suspension components (lower shock mount at the rear is different) so it's probably not going to be very hard to use the same methods and parts.

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This is a great build so far mate, the interior work is really nice! keep it up!

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Continuing the chase for best acceptable front end geometry.

The stringline jigs are easy and low cost, here's the rest of my gear.

1.2mm sheetmetal squares about 400x400. Apply a smear of grease between two, and roll the tyre contact patch onto them. Low friction, low cost bearing plates to help when doing toe and caster work.

Another piece of sheet metal approx. 1000 long, with the measured/marked angles being 20 / 20 degrees. Laid on the ground beside the wheel, and attach a straight edge low across the wheel. This makes it pretty easy to swing the wheel either way and check that the line and the straight edge are parallel before taking the camber measurements. Caster is all about the amount of camber change across a given arc, and the 20 / 20 arc is most commonly used. Low cost, simple and effective because it's very hard to not get the arc right.

A camber/caster gauge would be nice, but I already had a builder's spirit level and engineer's ruler so just check the measurements and use a bit of maths to get the angle.

Adjustments to the LCA have yielded -5.5 degrees camber and 8.5 degrees of caster. It's got to the point of being difficult to achieve satisfactory clearances between the rubber and bodywork, so caster now backed off to 7.5 and I'll give it a run like that.

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Edited by Dale FZ1
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Running the geometry as per above posts, at last weekend's sprint meeting it seems that the car can change direction well and make a reasonable fist of holding a tight line. However it's still got a big long heavy donk sitting a long way out in front, so it's no MX5 or RX7, or Z car. But it is very satisfactory.

Rear end mostly does what it's supposed to but we will play with rear ride height to address a slightly oversteery attitude.

Good outcomes considering the setup has really only cost time and it's still using the original pivot points.

Would be doubly good if the driver was up to the car :wacko:

Edited by Dale FZ1
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Thats interesting. We are running very different setups and im having the opposite issue im chasing understeer into corner. Definatley keen to catchup and have a look over the car sometime buddy

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