Timbo99

iTrader: (14)

Hi,
Checkout page 338.
Cheers

Livingston

Ed, how is life down under.

This weekend gone was the second round of the BRCA Clubmans series at Eastbourne car club.
By end of Saturday practice, I had the car in a easy and consistent setup with old Sorex BRCA tires.
But on Sunday with new tires the car was good for 4-5 laps then back end started to step out.
I have attached setup I finished on.

Chris House

TryHard

iTrader: (4)

Hey Chris,

Not too bad out here
Now, regarding the setup, where is it getting loose/step-out? I'm going to make the assumption that it's mid-exit.. with the car turning in ok, then getting quite taily when you load up the rear in the middle?
I have some ideas on what to adjust (and some q's over the setup anyway, as I know eastbourne can be lowish grip), but will post those up later.

Cheers
Ed

FastPete

iTrader: (44)

I ran my box stock setup 2.0 yesterday, love the car. 32 Sorex tires at Leisure Hours in Joliet IL. High grip asphalt. Car seemed pretty good. Anyone got a setup to try? I like a fast responding car, thinking heavier springs maybe? Looks like the sides of the chassis and motor were hitting the track at times, pretty fast sweeper that was hooked. Im running 10.5 boosted.

Thanks

FastPete

iTrader: (44)

Anyone

Livingston

Ed,

Yes it is mid to corner exit, when the rear end starts to step out.
One of the things I thought it might be too much lock and ackerman.

Chris

TryHard

iTrader: (4)

One of my thoughts is that your having the rear of the car roll too much, which is effectively dumping the grip when you load the rear up. On new tyres there is the traction to handle it initially, and old Sorex's handle differently to new anyway (always tended to get looser ime).

Firstly, of raise the rear roll centre back up, this will give more forward traction, but stop the rear rolling so much. I'd also go back to a 3.0 rear block (again, IMO less rear toe is only really beneficial in stock racing on large tracks that are top speed limited..Eastbourne ain't large!), and take out some of the front arm sweep, if not all.

Personally I prefer running 1.5/1.5 front blocks at the moment, gives more initial steering than 2.0/2.0, and more stable mid to exit than 2.0/1.5. 2.0/1.0 will give a lot more middle, and take away initial.

The other suggestions I have would be to try a different motor mount setup, and play with the steering bump spacers.
I'm currently really liking the bd7 style mount, using just the front top deck screw, and a grub screw in the bottom. To lock the rear end down more, just run the normal option 2 rear end (both rear screws, no forward top deck screw).

As for bump spacers, try 3mm under the outer steering ball joint. It will smooth out the steering and give more mid/exit... Which sounds counter to what you want, but it i find it actually makes it easier to be smoother on the steering this way.

Give them a whirl and let us know
Cheers
Ed

snuvet75

iTrader: (16)

Hey Ed, Isn't it that more rolling gives more traction? If the rear end slips out during cornering, I would lower the rear roll center, give the rear soft spring/damping, take out a few screws on rear top deck, and go for the soft setting motor mount(not sure what bd7 style mount is) in order to make the rear roll more. I've set up quite a few cars based on this theory but it has not always worked. Give me your 2 cents on your "having the rear of the car roll too much, which is effectively dumping the grip when you load the rear up".

I haven't run my Eryx much yet. But it was ok with 17.5T on low to medium asphalt and the car was just un drivable with 10.5T boost due to zero traction in the rear. Everything is set up based on default set up. I lowered the rear roll center and raised the front, gave 1 degree front toe out, stood the front shocks up and laid the rear down. Didn't help much. What else would you do?
The problem I knew the car had is severe tweak although this car is new. It was like that when I checked for the first time shortly after the build. I think it's because of the ball joint being way too tight. I addressed this issue earlier but a few people say it'd be loosening up after a few races and some suggested grinding the inner link with dremel to make it wider. Well after good 100 laps, they are still pretty tight. I can't think of any other reason. I'm very sure I built everything correctly otherwise. Thanks,

ali_g

iTrader: (7)

Guys,

what springs you guys normally use for the RCM SS shocks?

gearhead_22

iTrader: (10)

just up dated to the lasted car

Livingston

Ed,

I will give these changes ago at West London on Sunday,
then let you know how it goes.
My mate's Dominick BD7 works on all tracks and all levels of grip.

Forgot to ask is that 1.5 split or solid block on the front.

TryHard

iTrader: (4)

1.5 splits on the front, 0.0 one piece on the rear. I lnow Kerswell ran that at the Cotswolds nat, gave more steering.

Now the 'dumping' theory. Basically any tire only has a finite amount of grip, with our cars, this is generated mostly by weight transfer (rather than say, aero).
As you correctly point out, generally making the car roll more will make it grip more, but only up to a point. Basically, by rolling too much, it puts too much load in the tyre, which then gives up it's grip.. This is the 'dumping' sensation I mentioned.
Bare in mind, the rate of roll also has a bearing as well as the overall amount. What I mean there is a car that rolls lots, but does so slowly (say heabily damped, or just a v.smooth driver!) would be able to hang into its grip more than say a car that rolls less, but does it quickly (lighter damping, aggressive driver).
The symptoms you mention are pretty indicative of roll too much, as the mid to exit of the turn is (usually) when the rear is most heavily loaded, and hence closer to its peak of grip.

Something else to look at would be going to a softer rear spring first, over a roll centre change.

HiH
Ed

purple haze

iTrader: (8)

thanks for the great explanation ! very helpful and much appreciated by a lurking newb , cheers .

TryHard

iTrader: (4)

All normal length springs fit, although Yokomo's can limit front height a little..
Recently been back to HPI's, although also regularly use RIDE springs as well.
Moving away from the Yok springs again, tried them out again recently, and felt ok, but I think the HPI's were faster and better balanced for the higher speed track.

HiH
Ed

Geberit

I would like to buy additional shocks #160124 for my ERYX. Somewhere I read the kit is not fully complete!? Has someone info no that?

Thanks, Lojz