[240] Right rear spins turning right, left rear does not spin turning left. Wut?

[redblockpowered]

Originally Posted by DrZiplok

Necro'ing this thread; got the car on some scales:



So, already quite a bit of LF/RR preload. Another good idea shot to hell.

Is this with driver/gas? Seems pretty heavy. I think our 245 was almost dead on 2500 lbs with no driver and half a tank of gas. 53% on the front axle and almost 50/50 cross weights. I think the stubby nose of the 140 helps more than having the wagon rear end with regard to weight distribution.

I guess that's a little beside the point though...

[klr142]

Originally Posted by redblockpowered

Is this with driver/gas? Seems pretty heavy. I think our 245 was almost dead on 2500 lbs with no driver and half a tank of gas. 53% on the front axle and almost 50/50 cross weights. I think the stubby nose of the 140 helps more than having the wagon rear end with regard to weight distribution.

I guess that's a little beside the point though...

That is with driver, I am sure. One of the team asked how much we weighed on FB recently before the LDRL Thunderhill race last month.

[blkaplan]

Originally Posted by klr142

That is with driver, I am sure. One of the team asked how much we weighed on FB recently before the LDRL Thunderhill race last month.

2500 for a 245 is pretty good. That is damn well stripped down.

[klr142]

Originally Posted by DrZiplok

Necro'ing this thread; got the car on some scales:



So, already quite a bit of LF/RR preload. Another good idea shot to hell.

Do you remember what the ride heights were for this trip to the scale? I really want to know if you have the pinch weld in front of the rear wheels even with or lower than the pinch weld that is just behind the front wheels. If you don't have it level or some slope down to the rear, get some!

[mck1117]

Originally Posted by klr142

Do you remember what the ride heights were for this trip to the scale? I really want to know if you have the pinch weld in front of the rear wheels even with or lower than the pinch weld that is just behind the front wheels. If you don't have it level or some slope down to the rear, get some!

Slamming the rear compared to the front will help with the pissing-dog-cornering problem, but not change the weight distribution, by the way.

For comparison, here's my LDRL '91 240 sedan's weights with most of a tank of gas, and no driver:



2489 total, 54/46 front rear, and within 0.5% on the diagonals and L-R. Slightly biased left with a person in the car, but diagonals stay good.

It does the same thing that DrZiplok's car does, but not as bad (though it's hard to tell, as we make less power than their BMW engine).

[mck1117]

Originally Posted by klr142

but I think you should be able to do better than 45% weight on the rear wheels. I would think the wagon would have a lot more weight back there than our 142 that had 49% weight back there previously and 48% currently with our revised fuel cell location being closer to the rear diff.

Remember that they're running a BMW M52 up front. Total ~200lb heavier than my B230 sedan, with the same F/R distribution.

[klr142]

Originally Posted by mck1117

Slamming the rear compared to the front will help with the pissing-dog-cornering problem, but not change the weight distribution, by the way.

For comparison, here's my LDRL '91 240 sedan's weights with most of a tank of gas, and no driver:

https://imgur.com/XBsqEiV.jpg

2489 total, 54/46 front rear, and within 0.5% on the diagonals and L-R. Slightly biased left with a person in the car, but diagonals stay good.

It does the same thing that DrZiplok's car does, but not as bad (though it's hard to tell, as we make less power than their BMW engine).

Yes, but I still really, really, want to know because I don't remember getting an answer and it is the easiest thing to try.

Originally Posted by mck1117

Remember that they're running a BMW M52 up front. Total ~200lb heavier than my B230 sedan, with the same F/R distribution.

I didn't know if their engine was all aluminum or not. Their weights I am sure are with a driver. The weights without a driver don't matter too much as it isn't what's being represented on the track.

[DrZiplok]

Necro'ing my old thread, but the answer we've reached is a Gripper and a 60" wing off an old Radical. No more RR wheelspin.

Our engine's the regular cast M52. Nothing special there. Rake is essentially zero (pinch welds level with the ground, given that neither the welds nor my shop floor are particularly "straight").

[culberro]

Originally Posted by DrZiplok

Necro'ing my old thread, but the answer we've reached is a Gripper and a 60" wing off an old Radical. No more RR wheelspin.

Our engine's the regular cast M52. Nothing special there. Rake is essentially zero (pinch welds level with the ground, given that neither the welds nor my shop floor are particularly "straight").

What ramps and preload did you go with for the Gripper, more curious than anything

[DrZiplok]

Originally Posted by culberro

What ramps and preload did you go with for the Gripper, more curious than anything

The "tarmac race" spec (40/65, 120Nm).

[blkaplan]

Gripper has been excellent in our 850 lemons car as well.

[klr142]

Originally Posted by DrZiplok

Necro'ing my old thread, but the answer we've reached is a Gripper and a 60" wing off an old Radical. No more RR wheelspin.

Our engine's the regular cast M52. Nothing special there. Rake is essentially zero (pinch welds level with the ground, given that neither the welds nor my shop floor are particularly "straight").

Congrats on the diff and wing! Did you add a splitter up front, as well? That has to be so much more fun to drive now!

[DrZiplok]

Originally Posted by klr142

Congrats on the diff and wing! Did you add a splitter up front, as well? That has to be so much more fun to drive now!

We have not added a splitter; several of our drivers are a bit too keen when it comes to off-roading, and we'd be needing a collection of spares every weekend.

I did take a late-model plastic bumper cover and bolt it to the bottom of the Commando we run up front. It's ugly as sin, but maybe helps? Latest addition is some brake ducts in the bumper, but even before they've had their first outing one of the above-mentioned farmers put the nose into the hillside up here "testing" and I had to spend half an hour digging the dirt out of the duct...

Someone asked a while back about the corner weight numbers and how the car was loaded; I'm pretty sure it was full of fuel & 4x50# bags of cement in the driver's seat.

Here's an "after" video; it's not so great quality-wise because this was cropped from the PiP view after the VBox's main camera crapped itself, and (excuses) we were down on power because we had to bodge a Supertrapp after getting black-flagged for blowing sound. Total BS, but it does seem like most of the contents of the Flowmaster we've been using are curiously missing. Also last stint for the weekend, and RS4s are not our favorite tire. But, you will notice, no RR nonsense. Gripper noises are the nasty grinding sound you hear in some corners. Mostly you don't notice them, but the VBox audio setup is weirdly sensitive.


https://www.youtube.com/watch?v=ecpqiCsLsb0