Mickeyduck's machines

[mickeyduck]

Thanks for the hint Simon, I hadn't thought about that. very good point. Might find I need to raise the height of the rear a wee bit more yet eh? Not that it would matter, just make it tend towards oversteer slightly more which is fine by me cos at the moment it understeers if anything.

Sorry Alex I didn't pull the steering column out of that AW wreck mate. In fact it was Jared (Born Disturbed) did most of the work pulling that thing apart so I do hope he's happy with the interior stuff I gave him for his AW. He can always hit me up if he needs more bits too of course...

Here's a wee vid of the red beastie getting onto the motorway. About 4 seconds to 100kmh with road tyres on and the rev limiter turned down half a grand, plus my launches need practice. But you'll see the arse wants to kick around under power so tomorrow I might have a wee play with those coil-overs, balance them up cos the springs are set with a different pre-load side to side. Might even them up and see what comes of it.

[85AW20v]

There could be a reason for the different preload as coilovers allow you to corner weight the car and get the balance from side to side and front to back correct. The preloads could be allowing for one person sitting in the car or it could be one side of the car is heavier than the other e.g. engine side could be hevier than the gearbox side so to get even weights on all four wheels, preload is added in to the coilover setup.

[EssDub]

Those coilovers are probably set up for drag racing... since thats all that car really did in anger.

[85AW20v]

So he probably got the weights set evenly over the back at least.

[EssDub]

Not necessarily.

Think about it.

If the driver weighs 100kg, then thats an extra 100kg of weight off to one side. that can in turn affect how the car behaves apon launch. Hence the slightly higher damper rates on the drivers side. Also taking into consideration the static weight balance of the engine/gearbox as well, putting even more weight over on the drivers side of the car.

[Grrrrrrr!]

Here's a wee vid of the red beastie getting onto the motorway. About 4 seconds to 100kmh with road tyres on and the rev limiter turned down half a grand, plus my launches need practice. But you'll see the arse wants to kick around under power so tomorrow I might have a wee play with those coil-overs, balance them up cos the springs are set with a different pre-load side to side. Might even them up and see what comes of it.

Do those coilovers have independent height adjustment or not? If they do then the preload should basically just be enough to stop the springs rattling about. Contact + 5-8mm of preload is normal, then use the height adjustment to set either rideheight or weight distribution. Be wary about using preload to set ride height, it can limit droop travel resulting in strange handling if set too high.

[mickeyduck]

Do those coilovers have independent height adjustment or not? If they do then the preload should basically just be enough to stop the springs rattling about. Contact + 5-8mm of preload is normal, then use the height adjustment to set either rideheight or weight distribution. Be wary about using preload to set ride height, it can limit droop travel resulting in strange handling if set too high.

Pretty-much what I'm thinking of trying Lee.

Simon I get your point too mate, and Mel had suggested (when he spotted the odd preload setup of the coilovers) that the car may have been weighed on each corner and set up accordingly.

But I think what I'll do is record the settings of each corner, then alter them so they are pretty-much as Lee has proposed, even on either side as well, and see how it ends up.

At the moment it kicks around a bit under power with the tail trying to go to the right. It's behaving like my AW does if one rear tyre has more pressure than the other. So I believe it's either the different preload on the rear springs or something to do with the large camber on the rear... Or perhaps just a wheel alignment issue?

BTW Graham that thing handles amazingly well around a track, low profile tyres and all, even if Scott mainly did drags (actually I don't know). Never even got close to losing it in a corner, even with road tyres, though I did lock up once as the brakes are huge. But for open road stuff I need a softer ride, for sure. Hence I'm thinking of pretty-much removing preload from the springs and extracting all the travel I can out of them until I can replace them with longer softer ones one day.

I very much appreciate everyone's advice and won't ignore any of it. But I will be experimenting...

This weekend has largely been spent removing a large privet tree so I'm a bit behind schedule but I'll post the results of my experiments as things evolve.

Thanks guys.

[EssDub]

At the moment it kicks around a bit under power with the tail trying to go to the right.

BTW Graham that thing handles amazingly well around a track, low profile tyres and all

Okay, so first up, you're saying the car squirms and torque steers around when you flatten your foot, causing you to go chasing the reasons from a safety point of view.... Then you go and say it was perfectly fine at the track??? That doesn't make sense!

Taking all your preload out will do two things:

1) Remove any captivity on the spring altogether, which will in turn cause the spring to pivot around and essentially 'bounce' on the lower collar, making for some REALLY unstable movements and noises.
DANGEROUS on bumpy roads!

2) Ride comfort won't change significantly enough for you to notice it. Adding extra preload basically just adds some weight onto the spring, meaning it'd take more weight to compress the spring any further.

If you wanted a softer ride, raise the car, drop the damper force off substantially and then it won't break backs when you're on the highway. The springs on coilovers are of a set rate (from factory) and the only way to change them significantly is to purchase specifically weighted springs ( = $$$$$$$$$$$$)

You may also be finding that under acceleration, the rear tyres are toeing out too much, causing them to scuff and not sit straight. Alignment will probably be 80% of your issue and can be fixed relatively cheaply with a laser-style alignment machine and a competent operator. Best thing to do there, assuming you don't know much about how suspension geometry works, is to get the car aligned using a totally OEM setup. Make changes from there, based on your driving style and power delivery.

Having huge wheels wont make it any easier either, because with the super-thin sidewalls, there is no flex in them to deal with the torque that they're subjected to when you open it up, so basically what is transferred through the diff gets put straight to the ground, imbalance, (due to one driveshaft being longer than the other) weight balance (more weight on RHS of the car) and all.

[mickeyduck]

Hmmm... OK.

Nice graphic and big red letters Graham. Thanks for not giving me the face-palm just yet.

I would like to try the coilovers with an even setup side to side and just see what it does. As I said, I do understand that the car may have been weighed and the preload set accordingly, and I do intend to note its setup so I can put it back later if necessary. But I am curious to see what effect an even setup (read "even preload side to side") yields.

And no I don't intend to set them with NO preload. Just (as Lee suggested) a little - enough to stop the springs from rotating etc but mainly to set them up evenly from side to side to see how it handles.

Shocks - actually I have tried every setting available. On softest setting the car bounces like a mad thing. I'm running on 2 now and it's pretty reasonable - soft as possible but enough damping to reduce the mad bounciness. Though yes Graham I will need to inve$t in different springs for the coilovers to really make it work on bumpy roads. Hence it's in the plan but can wait.

And yes it handled lovely on track (under minimum boost at 14 lb), whereas it's a bit squirmy on the road (under full boost at 23 lb). I guess Taupo raceway is a lot smoother than the streets around here... Plus there is a HUGE difference in the power delivered at 14 lb and 23 lb and it's only at full boost that she gets a bit squirmy on a smooth flat surface. Heck it used to get all sideways at full boost but my new tyres seem to allow me to keep her pretty straight as long as I don't hit a bump.

Toe in (and wheel alignment generally) may well be a very big factor, agreed. Maybe even the biggest. A simple wheel alignment might sort out the worst of the squirminess under throttle. It might be a bit too much toe in on one side and not enough on the other... My old Kawasaki triple used to need a rear wheel alignment with string every month or less else she'd become equally mental under full throttle (they had a power band just as nuts as any turbo eh). But I won't worry about toe in and wheel alignment until I have had a go at setting the rear up with less camber. Need them special bolts first for knuckle to strut.

The bump-steer (not to be confused with squirminess under full boost on a smooth surface) is a suspension thing and not just an alignment thing in my estimation. If for example one of the rear wheels hits a bump, the car will want to naff off sideways with one wheel having good purchase and the other having a lot less (if any) as there is not enough give in the suspension for a bumpy road. Heck if I jack up one wheel a couple of inches the opposite one will come off the ground. No problem on Taupo but it's pretty interesting around home. When I turned the dampers up to 3/4 I found the rebound was slowed too much and one rear wheel would lose traction altogether on bad bumps causing the other to light up. Under full boost she really does need both wheels on the ground, with the best rubber you can afford. Otherwise yeah you're going sideways in a cloud of smoke.

Big camber (or excess toe in for that matter) could only serve to aggravate that, as the road is presented with a wheel that seems to be trying to roll off to one side, by way of how it presents itself to the road. So when only one of them is in proper contact with the road cos of a bump, of course it's going to want to kick the arse sideways eh. I find it interesting that race cars like the V8's or the F1 cars all run with almost no apparent camber on the rear but quite a bit at the front, and I think it might not hurt to try to take that hint.

So having listened to everyone and driven this thing and thought about it I reckon:

Less camber on the rear wheels may reduce bump-steer under full boost by helping the wheel that's in contact with the road to go straight ahead instead of trying to turn a corner. And I'll take the hint from the pros on this one anyway. Relatively cheap to do with the bolts from twos-r-us and needs doing before looking at toe in and wheel alignment as it affects these.

Checking toe in and wheel alignment is the most likely solution to the "squirminess under full boost on a flat surface" thing, and needs doing. It won't eliminate bump steer cos that calls for different springs followed by further damper adjustment. But it will sure help.

Softer springs with longer travel to increase each wheel's traction on bumpy roads will reduce bump-steer and be a huge improvement on the road, though it's not necessary for the track. But this will have to wait for obvious rea$ons.

Evening up of the preload on the coilovers...? Hey only an experiment will say whether it was a good idea or a bad one. Easy to revert if a bad idea so whatever...

And the tyres? Hey they grip something amazing and even give me confidence driving this beast in the rain under full boost (like when coming back from Taupo where we passed a few cars eh). I mean how many tyres can allow you to throw 500 horse at the rear wheels of a 1200kg car in the rain, with no traction control, and actually stick? Yes tyres with higher sidewalls would hide a lot of the suspension's little idiosyncracies, but these ones are staying firmly planted cos it's what they do best. Having invested 2 grand in those tyres and being more than pleased with their grip I'll gradually try to iron out those other wee bugs instead.

Gotta say (thinking about my blue AW) I can't help wondering what this car would be like to drive with standard suspension and heavier sway bars... Just a random thought.

Graham, I'd have imagined that different length axles should make no difference if the wheel is held firmly from moving forward or backward because the tyre on the ground moves in relation to the central point of rotation of the axle, and not forward or backward relative to the joint with the gearbox (as an oar might in a boat). Unless the suspension bushes are shot of course.... Which Mel tells me does tend to happen a bit faster when this kind of grunt is involved, so yeah maybe you're right and maybe it's a factor.

Thanks for the thoughts eh Graham. Good food for thought mate. It's all good eh. I'm enjoying having a whole new level of stuff to play with and think through. Good fun, new challenges.

[mickeyduck]

Well this weekend was another case of chipping away at things...

Dismantled the steering column area cos I wanted to get the windscreen washer working. Tested a control cluster from a gen 2 and everything worked ok. That's after removing a funny wee electronic something that had been soldered into the wiring of it, and bandaging it all up again.

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Thought pretty hard about swapping out the entire steering column so as to end up with the gen 2 forward-back steering wheel adjustment, but after looking very carefully at all those wires and where they were going I decided that wouldn't be the wiser choice. Don't need to end up with an ECU that's gone ga-ga or anything eh...

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So the gen 2 column will have to wait until I have more free time. One day perhaps...

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The gen 2 has that extra adjustment, plus the lower column plastic surround is different accordingly, and there are subtle differences with the construction of the control cluster. Though the obvious difference is that the gen 2 cluster has a white plastic thing with the loom coiled inside it to accommodate that push-pull adjustment. Whereas the gen 3 cluster has a simple short loom.

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Other things I did this weekend: fitted some urethane under the battery tie-down so it's properly secured.

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Bought a power steering pump etc from spyderballer (Hayden). Good couple of young fellas, him and his brother. Looking forward to seeing them on some runs. They have yet another V6 SW in the works too... Cool. The next 4's n Rotas show will be a lot of fun.

And I thought I'd see if any kind of standard SW wheel would fit the front end with its big brakes. Nope. Not a hope. So much for a spare wheel... Goodness knows what I'll do for a spare set of track-day rims too... There'll be something out there but as yet I dunno what will fit. All in good time.

Maybe next weekend I might get around to pulling out some bolts and try to suss that camber...

Kaiaua next Sunday. Alright!

[Mattaw11]

be carfull playing with the camber charlie u could end up destroying those tyres on the guards

[mickeyduck]

Yeah but the camber is destroying the inner tread anyway - you should have seen the tyres I pulled off there. A couple of mm tread on the outside but to the canvas on the inside. If I have to raise the suspension a wee bit more, so be it.

[Mattaw11]

yer mine wear out on the inside bit quicker so i just get the rears swaped on the rims so then the inner is now the outer

[mickeyduck]

Can't do that with these tyres Matt. Their outer sidewall is different to their inner one. It would destroy the handling characteristics of the tyres.

[JasonFriday13]

Correct, you can only swap tyres side to side if they are symmetric ie Toyo T1R, R1R, and R888. Mickeyduck has a-symmetric tires, which means the tread pattern is meant for one side of the car and the opposite pattern is for the other side. Add stagger into the mix and you have 4 unique tires, unlike symmetric which gives 2 fronts which are the same and 2 backs which are the same.