260DET

Great work, Steve. How about bringing her up here next year for the Z Nationals? Try her out around Queensland Raceway. You will have some opposition though, including a RB30ET 260 with MoTeC management and 15psi boost which reaches 230 kph down the back straight

Thanks all, the idea is to improve turn in and to reduce loading (and wear) on the the outer edge of the outside tyre in a corner, without using more than around 1.5 degrees negative camber. We have patented eccentric camber adjusters, which instal on the inner suspension arm pivot in the Xmember. No-one slots the strut towers around here that I know of. Like your kit Mikelly but freight to here would be a killer. 1.25" forwards eh Terry to get around 7 degrees pos caster. Thanks for that info.

From a discussion some time ago, some people for road/track were using up to 7 degrees caster. Now mine with 3 degrees results in the tyre running close to the front part of the guard (fender). So it looks like to increase caster more, the front edge of the guards will have to be cut out. Is this everyone's experience? Anyway, I'm looking at fabricating a new Xmember mounted further forward, incorporating vertically adjustable steering rack brackets for bump steer adjustment purposes. Not sure that the stock rubber top strut mounts will allow the struts to be inclined forward that much. And the steering shaft from the rack to the flexible coupling may be too short, although the coupling itself could possibly be extended in length. Any other problems or comments?

Yes, its pretty difficult to diagnose a fault without being there. Your 'wierd rattling sound' could be pre-ignition, then again it could be something mechanical.

Sounds like a fuel supply problem to me, but I've been wrong before

The following info is from a magazine, the Bosch part # is first. 0580 254 942 ... 390 bhp max 0580 254 975 ... 455 0580 254 984 ... 520 B580 152 460 ... 600 The 460 is the Bosch Motorsport pump, and is huge, and very expensive I use the 984 pump on my 320 approx bhp engine which is probably overkill but as advised by someone who should know you should have a BIG safety margin. To give you an idea, the 984 was used with the Porsche K-Jetronic system. There is another German brand ? around which is supposed to be pretty good, and cheaper than Bosch.

The '77 when I got it was an auto with a R180 diff but it has a stronger Xmember. It's an 8/77 to be precise.

Thanks Mike and ScaryFast for your suggestions, the Ferodo pads have a centre groove and still screamed, but all suggestions are truly appreciated. Anyone tried EBC Kevlar pads? I can get those. Anyway, the Outlaw 2800 calipers with 290 x 28mm grooved rotors worked really well on the track, even if the Bendix pads started squarking on the way home. Much better retardation than the previous Toyota 4 spots with vented rotor setup, and no sign of overheating. In fact the fronts with sticky tyres will now tend to lock up at slower speeds. All the car needs now is a good driver

I'm raising this problem again because it is costing me and the answer may help others. So far, Bendix Metal King Plus pads seem to be the answer. But I'm wary about using them on the track because with the previous Toyota 4 spot setup they tended to disintegrate. Tried a set of Ferodo Excel pads but they scream just as much as the Hawk's Not a squeal that can be tolerated, a high pitched, near deafening scream! Any Aussies who can suggest another brand available here? I'll report back after the coming weekend anyway, it's Saturday track time again

What blueovalz said about solid front/flexible rear diff mounts. Agree, it's a no no. My '77 had a stronger diff front Xmember than earlier 240's I've seen BTW.

No, no no, it's BIMBO

For anyone that runs across this problem, I cut up a used set of road type pads off the old Toyota 4 spots to try. They still squeal a bit, but nothing like it was before. In fact it sounds sort of cool. Now these pads didn't squeal at all on the Toyota's so maybe those big heavy lumps of metal dampen the squeal causing vibration.

Not a good idea to cut a hole in the strut tower IMHO. I've run my 75mm (3") ducting outside the inner guard, fairly high up so the tyre doesn't hit it on full lock.

A bloke here who has extensive experience with building and navigating road rally Z's agrees that the heavier 260 on axle is the solution. In his experience 240 axles are a weak point that should be attended to on any competition Z.

One thing to consider is that the 260 incorporates quite a few improvements that make it heavier. Eg, I think, stronger frame rails, front struts, rear axles. So the 260 IMHO is a better car if you are thinking of improving its performance, except perhaps for drag racing where the chassis improvements may not be important. One way to significantly reduce weight without reducing structural integrity is to use fibreglass panels eg bonnet (hood) and rear hatch, the latter incorporating a perspex (plexiglass) 'glass'. All the side glass can be replaced with perspex too.

Yes, the local brake expert says that racing brake pads don't work properly until they are up to the required operating operating temp, hence the squeal when cold. So the calipers are not the problem, good, those Outlaws are too pretty to discard. As well as ordering a custom made set of pads, I'm looking at adapting a set of premium quality road pads from another vehicle by simply cutting bits off them so they fit. This may sound a bit rough but its the end result that counts.

Took the Z out to test the new brake setup (Outlaw 2800 front calipers, Hawk black pads on the front) and it screams when the brakes are applied. Brought her back and bevelled the leading and trailing edges of the pads, plus put anti-squeal goo on the back of the pads. No improvement. So it looks like the pads are incompatible with the rotor face finish, all new. The rears are OK, same brand rotors but Ferodo Excel pads. Any suggestions before I try to find some different pads, or else throw a tantrum?

Through the firewall sounds good, Douglas. My guess is that the front flexing results from the firewall itself flexing where the various structural components attach. Only those mickey mouse under chassis channels are continuous. And they tend to get damaged over time. Best of luck with your house

Hmmm, the in progress 260 brake mods will give me virtually the same size rotors as a 90 model Jaguar XJ40 ie 291mm dia x 28mm thick front, 294x10 rear. Some others are Honda NSX early 282x28, 282x21, late 298x28, 303x23; Mazda RX7 92 294x22, 294x20; Nissan 300ZX Z32 280x30, 297x18; Porsche 911 3.6 298x28, 299x24; Subaru 99 WRX 294x24, 266x18.

Thanks all for your input, much food for thought there. Douglas, like your idea, providing the trans tunnel bracing is tied strongly forward towards the front suspension so as to counter the hinging tendancy mentioned by John and blueovalz. Maybe onto the tension rod's chassis brackets?

You can get more powerful bulbs, from memory go up 1/2 a watt but use the small glass bulbs, not he big ones. Removing the green plastic bulb surrounds helps a lot. But if you want to keep the green light feature then just clean the surrounds. Don't use too powerful bulbs, the extra heat may cause damage.

When driving diagonally over a low kerb gutter, the 260 creaks so I'm guessing that torsional rigidity is not all it should be. Has anyone succeeded in improving the situation? Perhaps by using something that doesn't involve an extensive rework? I was thinking of bolting a rigid plate underneath, across the transmission tunnel just behind the gearbox.

That JTR manual recommendation is puzzling. The finned aluminium part of the Z drum is designed to improve heat dissapation. My bet is that the factory knew what they were doing. When I replaced my Z drums with discs, a hot 510 owner bought the aluminium drums.

Going to a 15/16" master cylinder helps keep the pedal up when converting to 4 spot fronts. Off a 280Z or ZX, not sure what years. You may need to duct some air in to help cool the rotors if you use your brakes hard.

Lots of good advice above, here is mine. Unless you are going to upgrade your front rotors to vented, around 290mm dia or larger, plus 4 spot calipers like Outlaws, I'd keep the stock drums at the rear. From a performance balance perspective that is, maint. is another issue.