hrd-hr30

I don't think suspension movement is an issue either. if anything, it would probalby help dampen the inertia of the trailer making it more stable. as for body roll being a problem - hardly likely on race cars as you say. I've towed a few rally cars which are much higher and softer setups than track/race cars and even a lifted 4WD a couple of times secured by unsprung components that don't move relative to the trailer so the body and suspension of the towed vehicle are free to move and I've never encountered any instability problems with my trailer.

can I get a price on 2*245/40 R18 & 2*265/35 R18 please. R888 or RE55 and please specify what compounds you have.

August is pretty good for me. The only event I have in Aug is a Lakeside Sprint on the 30th.

my old GQ Patrol 4.2 diesel averages 14l/100km towing

yep fully sprung, not unsprung as you said. so are you suggesting your 80% and 50% rule also allows for the extra strain of controlling body roll on top of just holding the weight of the load??? The only way to actually prevent suspension movement would be to pre-tension the straps so much that the suspension is on the bump stops! quite contrary to your advice of never tieing down from the axles (which you even put in bold!), best practice for securing a vehicle on a trailer is around the tyre/wheel (an unsprung component that does not move in relation to the trailer!) like this and these http://www.uscargocontrol.com/wheelnetscartiedowns-c-47.html as used by car transportes and towies. but however you tie it down, I think it would be a good idea to at least have straps rated to the weight of the car their holding, particularly if you are tieing to the fully sprung parts of the car that can and do move during transit which puts extra load on your tie downs. anyway, my advice is go overboard in your tie down ratings rather than trying to use the minimum required. it certainly can't hurt.

K frame is mounted to the body - its a fully sprung component. tieing down from fully sprung components means if the car's suspension compresses slightly when you hit a bump, the tie down goes slack and then the car's suspension rebounds and shock loads the restraint. A loosening restraint also allows the load to move. Tieing down from unsprung components which stay perfectly still in relation to the trailer keeps constant tension on the load you are trying to restrain. That has to be the best way to go. the 200% figure was just plucked out of the air. But the idea is to allow a safety margin rather than just speccing them to 8 tenths of the weight they're trying to secure. for example, my old U2L IPRA race car weighed 851kg - your 8/10s rule of thumb whould mean all I need is a single strap rated to 680kg! I use two 800kg straps to tension the front and prevent the load moving rearwards, wheras with your system all i need is two 200kg straps. may as well use Telstra rope! I don't know what kind of G force a loaded trailer/4WD combo can pull under an emergency braking situation - maybe .5 to .6G?? Passenger vehicles can do .8 to .9G if I recall the wheels/motor tests correctly, so .6G is 50% less braking force than that which is probably realistic enough. There goes 3/4 of your SWL (safe working load) just in braking alone - not much margin for safety left, is there? I'll continue to err on the side of caution. It may be uneccesary/overkill, but it just has to be safer than strap only rated to 8 tenths of the load its trying to hold. And yes, if there is a crash and parts of the trailer or car that the restraints are connected to bend, I'm fine with that - its much better than the alternative of the restraint breaking and the load flying off to cause more damage. Even if it still didn't hold, it has to absorb more energy before something breaks.

K frame is not an ideal tie down point. You really want to use unsprung components. The movement of fully sprung components will be continually slackening and then shock loading the straps as they tighten... worst case scenario for snapping a tie down, and at very least can loosen them. The only way your wheel alignment can change by tieing down to suspension members or wheels is by bending something - and that's only likely to happen in an accident. also take issue with the 80% of body weight for front movement idea. That will be fine if an accident would only pull 0.8G in a front on accident, but that's not realistic. You want gear with SWL at least 2 times the weight (200%) of the vehicle. I use a big f**koff chain on the rear with rated shackles to an unsprung component, or at least the outer end on a semi-sprung component like a suspension arm. Handily my race cars are typically Datsuns with live axle rear ends so I just loop around the diff housing. Then tension that forward with ratchet straps around the front wheels (never had any wheel alignment problems towing up to 1200km at a time interstate) and add an untensioned safety chain around the front x-member too.

4th's quieter because its not actually a gear - just links the input and output shafts.

exactly. cars typically only use about 17degrees of lock on a track, so the amount of camber gain from castor is pretty limited. Its almost always worth trading off castor for static camber if that's the choice you're faced with.

I'm using it as an excuse to justify replacing the standard swaybars with adjustable Whiteline bars. It only hits when you've got it all loaded up in the middle of a corner and you hit a decent bump. I'm hoping the sway bars will increase roll resistance enough to stop it happening. Doesn't happen at QR or on the road, just those 2 spots at Lakeside - both have decent bumps in them when the car is all loaded up on that side. If that doesn't work I'll look at other options. but I don't fancy relocating the loom...

talking it up like that is kinda asking for a breakdown, but I've driven it to a Wakefield track day as well as Superlap last year, and half a dozen local events without any issues. Stock Supras don't breakdown. As long as I can stop the tyre rubbing through the main wiring loom (so far its only taken out the ABS and traction control, so its no biggie) I'll be alright I think! the bumps in the midlle of the kink and one in the downhill left hander after the bridge at Lakeside make the front right rub on the wiring loom diretly above it... I've already raised it up 10mm at the front, but it still rubs. I'm hoping a pair of swaybars will stop it - I don't want to go any higher.

no wussy transporter for me. real cars drive to and from interstate track days!

Its got Brembo replacement front rotors and TRW Lucas pads all round. The rear discs are probably still OEM. I did go back to QR too - got a 1:01.46. So 2.5sec improvement from tyres and the change from sequential to TTC. It was a 34 degree day so it could probably go a little quicker yet in cooler conditions.

http://autosports.com.au/events/view/16 you'll need to register on the site to sign up to the event. Only 18 positions remaining currently so get onto it now!

exactly what I'm doing. Signed up for Autosport's EC track day last week as soon as I saw the date for Superlap.

you should come and do Lakeside! Its the best track up here - hell its better than Oran Park GP! Its a great driver's track. There's heaps of dates next year too - I just got a calendar inthe mail yesterday, but can't find it on their website - still only has the provisional calendar...

they get better (on the track) as they wear down. They do have a very soft sidewall for a semi slick and a different 'feel' as a result. But I've only used them on a very light car so I can't say what that soft sidewall would be like on a Skyline...

the S2000 that ran 17.1 on road rubber? If that doesn't go sub 15 on decent semis with you at the wheel I'll eat my shoes!

I don't think there's a problem with cages in Clubsprint. The guidelines say convertibles must have either a full cage or a hardtop fitted. If they must surely other cars can... and there was something about being allowed to remove the rear seat if you have a cage too.

always tempted to ditch work for a run around a track somewhere! but its too late for me to organise the day off have fun out there

that's only because of the RX7 oil down in your group. That's unfortunate that it cost you track time, but the organisers had no control over that. Sure the Open class got slightly longer sessions and the opportunity to get a handful more laps in, but they are paying almost double the Clubsprint entry fee afterall. But Superlap isn't a "track day" about getting maximum time on the track anyway, is a competition where you are just trying to get the best single lap time possible. 18 laps is heaps for that purpose (most of Clubsprint got just under 20 laps in), particularly when you consider most tracks are at their fastest early in the day so that's the best time to put your fastest lap down. Just because they're having 3 Classes doesn't mean there will neccesarily be more cars or even more groups than last time.

the 888 doesn't need buffing for dry use, just the superseeded RA1.

cool. I think it was temporary insanity??? I sold it for the 230rwkw Datsun 1200 coupe, but I always regretted it. I may have another Skyline very soon anyway and if that comes through I'll join SAU now that they've got CAMS affiliation. yeah the noise isn't too much of an issue at Mt Cotton. I think they say 95dB, but my CA18DET Datsun 1200 just ran an open side pipe and never got pinged for noise there! I'll second wrxkilla's Morgan Park suggestion too, but having been involved in runing events there in the past with SPARC you find alot of people think its a bit far to go. Its definitely worth driving the extra hour past QR IMO. They have a pretty full calendar though so that would pretty much have to be a weekday thing I'd say.

slapper, did you have them buffed? full depth RA1 is only recommended for use as a wet. Hornibrook Motorsport can buff them for you - its not that expensive. They'll go at least a couple of laps longer after buffing and you'll probably get more life out of them too.

225/50*16 is the control tyre size for the older Saloon cars. They use Kumho V70As now. If you hunt around you may be able to get one of those guys to buy some tyres for you at their discounted price, or get some of their old tyres cheap. Otherwise, try Hornibrook Motorsport the QLD distributor forKumho Motorsport tyres. They may be cheaper anyway due to the higher volume they'd sell compared to other brands.