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anyone struggle for traction? (BEC)
jimmyjonga - 12/1/06 at 06:58 PM

hi,
i have a zx9r engined vortx. i have a 3.92 open diff and 195 tyres on 15 rims. when i give the car some stick i end up having to wind on a load of opposite lock as i feel as one of the driven wheels is just not getting enough grip.
what should i do (apart from less throttle!)
lsd diff?
any suggestions very welcome as i would like to give the car full throttle and stay relatively straight. its frustrating not been able to use the power available.

james

Jon Ison - 12/1/06 at 07:02 PM

maybe you could look at your suspension set up ? soften the rear a little, what trye pressures you running ?
I ran an open diff on the isonblade with no probs.

Mad Dave - 12/1/06 at 07:02 PM

I've got a zx9 Indy. I went out yesterday and it spins up so easy, the only difference is that both my tyres are spinning not just one. It still tries to go sideways so you have to be careful

[Edited on 12/1/06 by Mad Dave]

froggy - 12/1/06 at 07:06 PM

how about a course of intensive pie eating

britishtrident - 12/1/06 at 08:06 PM

Corner weights need set up

smart51 - 12/1/06 at 08:08 PM

My R1 vortx only loses traction if you boot it hard out of side roads in 1st gear. I am running 195 50 15s at about 18psi. I have the dampers set at 1 click from zero at the back. 0 clicks makes the ride nice and soft but a bit bouncy. 1 click seems about right for road use. I do have an LSD mind you.

Check the rear geometry as well. both Toe and camber affect oversteer.

My vortx has more grip than I have courage, certainly on public roads lined with trees, and I have ordinary road tyres fitted at the moment.

Give Marc a ring. I'm sure he'll tell you what settings work best. that or arange to go up there in it and get him to set it up. I doub't you'll do better than that.

Lightning - 12/1/06 at 08:25 PM

I have trouble getting traction, however that might be due to having no tread left and a damp road. Must invest in new tyres soon before plod notices.

JoelP - 12/1/06 at 10:42 PM

i found today in particular to be a very greasy day, i was wheelspinning all day just driving round in a rush! and that was in a 1.8 estate! But my locost seems to have excellent grip most days.

DarrenW - 18/1/06 at 10:56 AM

Fit a car engine

smart51 - 18/1/06 at 11:45 AM

quote:
Originally posted by DarrenW
Fit a car engine


That would only make it worse. The high torque / low rev nature of a car engine is more likely to spin the wheels than the lower torque higher rev range of a bike engine.

Not only that but car engines being heavier, you have to use more torque still to get the same accelerateion. Also, that extra weight is biased towards the front wheels and so you don't get the increase in traction to match the increase in torque.

Dale - 20/1/06 at 02:07 PM

Eat more pie and get some weight on the rear wheels? I cant see the difference between hight torque low revs vs low torque hi revs as the gearing will put you at the same rear wheel rpm when taking off.
Dale

smart51 - 20/1/06 at 09:03 PM

quote:
Originally posted by Dale
I cant see the difference between high torque low revs vs low torque hi revs as the gearing will put you at the same rear wheel rpm when taking off.
Dale


Not so. You will probably gear your car for between 4 and 5 mph per 1000 revs in 1st gear regardless of using a bike or car engine. Your 100 Nm bike engine will generate half the torque at the wheels as your 200 Nm car engine as the gearing for 1st will be the same. The difference is that your car engine will run out of revs at about 30 MPH whereas the bike engine will pull all the way to 60.

Beacuse the car engine has more torque, both at the flywheel and at the road wheel because of the same gearing, there is more chance of that higher torque overcoming the maximum traction that the tyre can provide, causing wheel spin.

[Edited on 20-1-2006 by smart51]

richijenkin - 23/1/06 at 12:15 PM

LSD is the way to go!!!!

smart51 - 23/1/06 at 12:31 PM

quote:
Originally posted by richijenkin
LSD is the way to go!!!!


How much difference does an LSD make? I've never driven a seven without one. on slipery roads I can struggle to get the power down in 1st gear but it never gets out of hand. I guess without an LSD I'd be sliding about the whole time.