WELD/SUTTON DIRT MISSILE build - Page 33 - Lateral-g Forums

CJD Automotive · #**321** 06-15-2018, 07:42 AM

I have a question on weight placement. On some of the heavier objects mounted, if given a choice, is it beneficial to mount them closer to the COG at a higher height, or further away at a lower installed height?

Ron Sutton · #**322** 06-15-2018, 08:23 AM

Quote:

Originally Posted by CJD Automotive

I have a question on weight placement. On some of the heavier objects mounted, if given a choice, is it beneficial to mount them closer to the COG at a higher height, or further away at a lower installed height?

Hey Craig!

That's a good question. It depends on "how far" we're talking.

Meaning, if we have the choice of mounting 30# battery 10" above the bottom of the chassis behind the passenger seat ... or ... 3" above the bottom of the chassis but 20" behind the rear axle ... for sure we'd go with the first option.

On the other hand, if we had the choice to mount our 160# fuel cell 20" above the above the bottom of the chassis behind the roll cage ... or ... 1" above the bottom of the chassis but 10" behind the rear axle ... for sure we'd go with the latter option. So if definitely depends on "how much" up or away from the COG we're considering.

I try to keep all the mass possible inside the wheelbase. As things past either axle centerline add to the pendulum effect. The realities of packaging occasionally prevent that and we end up with the fuel tank behind the rear axle & the engine & radiator ahead of the axle. I suggest you do your best, but it's not always practical to make these cars perfect.

**GregWeld** · #**323** 06-15-2018, 09:05 AM

Quote:

Originally Posted by Ron Sutton

it's not always practical to make these cars perfect.

Not what you told me when I was ordering !!!

++++++++++ Kidding folks ++++++++++

CJD Automotive · #**324** 06-15-2018, 09:14 AM

Quote:

Originally Posted by Ron Sutton

Hey Craig!
I try to keep all the mass possible inside the wheelbase. As things past either axle centerline add to the pendulum effect. The realities of packaging occasionally prevent that and we end up with the fuel tank behind the rear axle & the engine & radiator ahead of the axle. I suggest you do your best, but it's not always practical to make these cars perfect.

Thanks, not sure for the advice or reassurance!

SSLance · #**325** 06-15-2018, 10:06 AM

Quote:

Originally Posted by GregWeld

Not what you told me when I was ordering !!!

++++++++++ Kidding folks ++++++++++

lol...

Ron, did not know you were working with Ron Ver Mulm on his Camaro. I've known and watched him for years as he was "close by". That car is special for sure and I'm betting it's even better now.

Ron Sutton · #**326** 06-15-2018, 10:18 AM

Quote:

Originally Posted by GregWeld

Not what you told me when I was ordering !!!

++++++++++ Kidding folks ++++++++++

I think I told you the car would be perfect ... for hauling azz.

Ron Sutton · #**327** 06-15-2018, 10:21 AM

Quote:

Originally Posted by SSLance

lol...

Ron, did not know you were working with Ron Ver Mulm on his Camaro. I've known and watched him for years as he was "close by". That car is special for sure and I'm betting it's even better now.

Yeah, he emailed me the link to the video to watch after his first day out with it. He said it has WAY more rear grip on entry & exit, which is exactly what a decoupled 3-link does.

The accel side of his is spot on. The decel side needs stiffer dampening & spring rate. I do not know how much he picked up, but he said it was quicker than ever.

mfain · #**328** 06-15-2018, 11:07 AM

Quote:

Originally Posted by Ron Sutton

Yeah, he emailed me the link to the video to watch after his first day out with it. He said it has WAY more rear grip on entry & exit, which is exactly what a decoupled 3-link does.

The accel side of his is spot on. The decel side needs stiffer dampening & spring rate. I do not know how much he picked up, but he said it was quicker than ever.

Ron,

I see the upper link is offset inboard of the differential (which itself is offset well to the right), but the upper link still appears to be offset to the right (passenger side) of the center of the axle housing. How did you calculate the left/right lateral offset of the upper link with this oddball configuration?

Thanks

Pappy

Ron Sutton · #**329** 06-15-2018, 01:32 PM

Quote:

Originally Posted by mfain

Ron,

I see the upper link is offset inboard of the differential (which itself is offset well to the right), but the upper link still appears to be offset to the right (passenger side) of the center of the axle housing. How did you calculate the left/right lateral offset of the upper link with this oddball configuration?

Thanks

Pappy

Hey Pappy !

The pinion offset (or 3rd member offset) does not play a calculation in the determination of top link offset. The track width & friction (or power loss) from the specifics of the rear end are used to calculate the optimum top link offset.

While I don't share my formula, I will say the more power loss a specific rear end creates, the more it is unevenly loading the left rear tire & the more we're going to move top link to the passenger side to neutralize this.

For folks that don't know this, all symmetrical rear suspensions experience "torque steer" ... meaning the left rear tire gets loaded more than the right rear tire. The amount (or degree) is directly related to how much friction a given rear end has, from it's hub bearings, carrier & pinion bearings & R&P gear teeth meshing.

CJD Automotive · #**330** 06-17-2018, 04:55 PM

I have a question on the steering shaft. I looked at the Sweet and Woodward universal joints, and they state to keep them under 20*. It looks like your angle after the firewall kicks over at about 45*. Is it okay to run that much angle? I’m going to be close to the same angle and thought I would need a double to half the angles, but if they can run that much, would make life easier.