[SierraDan]

Old info there bud

[tanshi]

Just having a look through the TT rules, Does any one know of any rules that say you can't run Dual wheels ??

ie two tyres side by side on each corner?

[SierraDan]

Not in the rules no.
They are a guide anyway, find the loop holes

[SierraDan]

You want to stay under 2m wide and 110" long in my opinion.

We came 20th on well flogged out 37's last year. And it did hinder a little not because of diff clearance but diameter for climbing. (skateboard wheel v bmx wheel up a gutter)

[tanshi]

SierraDan wrote:

We came 20th on well flogged out 37's last year. And it did hinder a little not because of diff clearance but diameter for climbing. (skateboard wheel v bmx wheel up a gutter)

See this is what i dont get. 40 vs 37 = 3 inches

so 1.5 inches difference in radius. I find no difference at all between 31s and 33s when it comes to climbing.

The difference i do find is diff clearance. and seeing as i can gain the equvalent of 2 inches in tyre size with a violently shaved diff,\

not to mention that a rock even 6inches across will ad more advantage than any extra tyre size.
Does stacking penalise heavily or is it just the stigma attached to stacking that stops people from doing it that way.

[SierraDan]

The tyres were more like 35's once aired down. It may sound stupid on paper but every bit counts.

Rock stacking bears no penalty.

[tanshi]

what would you say is the shortest vehicle that competed in the last few years?

[SierraDan]

90" i think. Doesn't mean it was any good.
The Green Hornet is 109" i think. If it were my car it would be 105"

[tanshi]

90" is way short! what type of truck was that?

[SierraDan]

That Hazzard thing.

[tanshi]

Just saw a vid of it on devils marbles in 2011.

didnt look like the length of it was the reason it was struggling.

[SierraDan]

I didn't mean to imply he struggled because of wheelbase, or struggled at all. I just don't think its practical.

[tanshi]

yeah cool, fair enough

[SierraDan]

IM sure you would social wheel and use the tuff truck build in Tough tracks etc for the rest of the year too.
Building for that should come into it too if its not going to just sit in the shed 362days a year

[tanshi]

yeah it would be for alot of things. if it could manage TT, it would get used for tough tracks.
if i built it right it would work for aust4 and superior short course aswell.

so thats 10 comps a year and social wheeling too.

[canberramav]

Gwagensteve wrote:

The thing is, on the TT course diff clearance is irrelevant except that the wider the car gets, the less line choice you have, so the more diff clearance required. So the giant car thing becomes self perpetuating.

The car I saw have the most problem with diff clearance was the proclaimer- running the biggest tyres. Not because it lacked diff clearance- because it has zero line choice.

Steve.

There is a happy medium between too big and too small. 37 is too small. 54 is too big. I suffered alot on 37s with diff clearance. Have you actually driven any of the tracks?

[canberramav]

Gwagensteve wrote:

But that's just a missed opportunity. If a cromo axle housing is stronger at the same thickness as a mild steel housing, then that's a missed opportunity to loose weight in a lightweight/ low power car.

TT is full of cars that are built because their builders think they are cool, they're a copy of something that has done well, or it's something the builder thinks the crowd will like.

If you started with zero preconceptions and purely complied with the rules I don't think cars would look the way they do. What's the minimum weight? Why is anyone building a car that's heavier than the minimum weight?

Next is to analyse the terrain. The minimum torque required to do the job will mean the driveline will last and the running gear can be lighter.

I'm not telling people how to suck eggs but look at the cars that succeed at TT and there is no correlation to power, tyres or width. Dan (a1vit) has made it on the podium with 60 series diffs and a g16b- but he's a super smart driver who understands what is required to podium. He is never spectacular- he doesn't play to the crowd.

If you look at what does well it has nothing to do with tyre size, rear steer, or what's doing the springing. Simple, low, reliable cars driven by experienced drivers with lots of seat time win TT.

Those pirate guys a1 vit have driven that property more times than most people have ever wheeled. They have a strong advantage there. They are an exeption to your tyre size, rear steer is irrelevant theory.

[SierraDan]

I don't think 37's are TOO small. But they do leave a bit to be desired.

[11_evl]

Good read.
All cars, any code, are determined on tyre choice. As started there are too big and too small. A big tyre say 42"+ is not needed. I'd say smaller than 40 is struggling as well.
Motor choice is more of a personal choice. I have competed with a g16-3speed and a v6, and next weekend with a v8. All has been acceptable, I can break as much with the g16 as I could with the v6. That's the down side on running sticky Tyres and small diffs. I can make it last but could break if I got a bit carried away. Had to really be gentle. That's with no expense spared lux diffs. With sticky Tyres bigger hopefully will be better. My new build I'm running dana60 rear and 68 front.
Wheel base- I have run at 105 and 110", 110" seemed very good all round with a 500mm belly height and rear steer. NO rear steer I'd stay 104-106". My new build is up to 116" but not built as a strictly crawling ttc car. Built more for speed.
Width wise my lux diff with 3" spacers but 0 offset rims to me was just too narrow. My new setup is wider so will not be able to comment till end of April.

I can only really comment on what I have or general idea on cars I drive with.

To me a setup vehicle is good but a driver with plenty experience and knows their car will go further than any open cheque book build.

[tanshi]

Thank michael. Was hoping you would have some input.

[Gwagensteve]

No Canberramav, I haven't driven any of the tracks, but as I photographed the event for Dirtcomp last year, I got a pretty good look and how the various cars were performing from all over the course - including the night stage - from the "right side of the bunting" so to speak, so I reckon I have a pretty good handle on what is working. I also spectated at the first two TT's, when there was a much greater range of cars competing.

The big thing is definitely driver experience. So many of the drivers look to have limited seat time in their cars, either because they are new or because there are few other places with comparable terrain to drive them. I think the QLD guys have an advantage in this as they have lots of parks to drive - we don't have access to that level of terrain, so victorians will always be at a disadvantage.

The other factor is that there's no point building a car specifically for Tuff Truck, and that's a problem because you'll always have to comply with some other rule set (or type of terrain) that will compromise the car for TT. Add in that there's precious little seat time to be gained at an actual TT event.

an LJ makes the perfect starting point IMHO because it ha the narrowest body, smallest, narrowest chassis, and lightest weight of anything available. As cool as a high HP 2 stroke would be, I don't think its practical or advantageous. beyond that, I don't think the motor is all that relevant. HP is required in the "mud" run but so long as the engine runs properly in deep water, you're most likely going to make it to the tyres, and then it's a bit of a luck and a big bump as to whether you'll make it over them or not.

I reckon I'd agree with 11_evl - 104" WB with no rear steer looks to be about right. Id' say steering angle and maybe fiddle brakes would be as effective as rear steer is as long as you were familiar with them and had seat time. 500mm belly clearance sounds a bit tall for me. I'm pretty sure the Bond Racing 40 series is well under this - it's CRAZY low and didn't have obvious disadvantages to taller cars from what I saw. IMHO a shorter/narrower car can have a lower belly height because it's not spanning as much of the track at any one time.

Mismatched duals would be cool - maybe a 39" krawler outer and a 9/34 swamper inner, but again, with no ruts except in the "mud" it's a lot of fab and weight for little advantage I reckon. Matched duals would suck, especially on a light car.

I read the rules and see there's no minimum weight. Getting sub 1000kg would have to be a huge advantage - some of those cars would be crazy heavy.

Air shocks, sway bars and suckdown winches for sure for TT, and this is where the issue of building for multiple events is an issue.

I had a bit of a dubious idea a couple of years ago. Hydraulic suspension doesn't seem to offer any real advantage, but I wonder if it would be possible to plumb airshocks to a manifold and tank permanently. With many of the TT stages pretty much just relying on a belly-out scenario to stop the cars, being able to force the airshocks to full droop even if it was just once on a stage, would be an advantage over the fixed suspension guys but avoid the complexity and weight of hydraulics. anyway, just an idea. I can see a heap of potential problems, but you see so many cars bellied out with inadequate ground pressure to drive because their suspension is fully unloaded, even if the tyres are on the ground.

Has anyone else (other than the dobbin 40 series which were offset) run planetary hubs? They would allow much smaller diff centres and take the torque off the axles. Small planetary hubs from an old EWP or something could be an option. Obviously adapting brakes could be a hassle, but I can see advantages especially being able to run less reduction upstream of the hub and a small housing.

Anyways… some ideas.

[got_bar_work]

Cap51z was only around 99. We pushed the front forward a bit for the 39.
The bundy rear axles were the weak point. It twisted the splines on the night stage and broke both on another stage taking out the air locker and c&p. Pete kept bending main leafs in the custom hd Sierra front packs.

[31zook]

Correct me if im wrong dan, buy is OKE's entry around the 800kg mark?

[Gwagensteve]

Wow, that's super light and will be an excellent test to see what can be achieved with a more compact build.

Steve

[tanshi]

is OCE running 40s?

[tanshi]

I was talking to JRzook on the weekend and he sugested a setup a mate of his has in Cairns, Its active airbag suspension, self leveling, self flexing.

Might be worth looking more into.

[Zook_Fan]

tanshi wrote:

is OCE running 40s?

37" Pitbulls according to their entry information. It will be an interesting car to watch for sure

[tanshi]

just checked their facebook page. 37 inch iroks.

[SierraDan]

31zook wrote:

Correct me if im wrong dan, buy is OKE's entry around the 800kg mark?

Haha, nah.
But it is light. More like 1000-1100 id say.

[SierraDan]

tanshi wrote:

I was talking to JRzook on the weekend and he sugested a setup a mate of his has in Cairns, Its active airbag suspension, self leveling, self flexing.

Might be worth looking more into.

GRAVITRON!!!!!