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Old 12-13-2018, 06:59 PM   #26
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Originally Posted by DrZiplok View Post
The Truetrac? If it is, then we've bought several busted ones, because they all do it.
I had the same experience with the true trac. Its fine on the street. if you start racing the car and really pushing it unloads the rear and it spins.

You would never know in a street car. For track or autox it lacks alot.
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Old 12-14-2018, 09:22 AM   #27
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I had the same experience with the true trac. Its fine on the street. if you start racing the car and really pushing it unloads the rear and it spins.
I don't know. We push our LeMons car pretty hard on 205's and very seldom have this happen. Like I said, if you're ham-fisted with it, it'll spin, but it's easy to adjust your driving style.
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Old 12-14-2018, 01:07 PM   #28
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It happens in T3 at about 30s into the video, on the downhill coming out of the Cyclone starting at 45s, over on the west side at 1m46, and again at 2m27, over the connector at 2m41, and then a big serve in T14/15 at 3m13 or so.

We'll definitely be trying some of the suggestions folks have made here, and I'll update the thread if we sort anything out.
At 2:40 it's easy to see, starts into the throttle, wheel spin, ease off, and then floor it as the steering opens back to straight ahead.

I thought it might be setup related, but I don't know....it's losing traction pretty easily and can't go full throttle til nearly pointed straight. Turn down the boost

I guess you could put a Ford 8.8 axle in it. It's just more fab work. The added unsprung weight is a downside, but a working clutch diff and a larger ring & pinion would add quite a bit to the car. Junkyard axle from an Explorer, ~$200 or less?, rebuild kit for the clutch diff $75, cutting/welding...your time.

http://forums.turbobricks.com/showpo...90&postcount=5
http://forums.turbobricks.com/showthread.php?t=274343
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Old 12-14-2018, 08:07 PM   #29
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I guess you could put a Ford 8.8 axle in it. It's just more fab work. The added unsprung weight is a downside, but a working clutch diff and a larger ring & pinion would add quite a bit to the car. Junkyard axle from an Explorer, ~$200 or less?, rebuild kit for the clutch diff $75, cutting/welding...your time.
We've been considering it, but our custom ABS setup would complicate that. None of the Ford axles seem to come with a 48t reluctor at the wheel (all seem to be diff-mounted), and it doesn't look like we'd be able to repeat the trick we played with the Volvo axle due to the way the bearing tube protrudes into the parking brake space...

It'd probably work out cheaper / quicker to talk to the Grabber folks...
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Old 12-15-2018, 09:27 AM   #30
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...and it doesn't look like we'd be able to repeat the trick we played with the Volvo axle due to the way the bearing tube protrudes into the parking brake space...
Cut the tube ends off the Volvo housing and weld them to the Ford tubes --- keep all of your existing Volvo brake/ebrake set up. There's a Timken bearing that will work with a Moser axle and the Dana housing end 0n the 8.8".
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Old 12-16-2018, 10:51 PM   #31
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HI, is this my buddy with the 240 race car at Lucky Dog Thunderhill?
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Old 12-18-2018, 08:37 PM   #32
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HI, is this my buddy with the 240 race car at Lucky Dog Thunderhill?
That would be a definite yes, yes. 8)
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Old 12-18-2018, 08:41 PM   #33
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Cut the tube ends off the Volvo housing and weld them to the Ford tubes --- keep all of your existing Volvo brake/ebrake set up. There's a Timken bearing that will work with a Moser axle and the Dana housing end 0n the 8.8".
Wow. I mean, I'm not going to say this is crazy, but the fact that you know this begs so many questions I almost don't know where to start. 8)

Is there any sort of convenient relationship between the Ford and Volvo tube diameters, or are we talking a butt joint here? Just, hypothetically speaking you understand...
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Old 12-19-2018, 06:54 AM   #34
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Wow. I mean, I'm not going to say this is crazy, but the fact that you know this begs so many questions I almost don't know where to start. 8)

Is there any sort of convenient relationship between the Ford and Volvo tube diameters, or are we talking a butt joint here? Just, hypothetically speaking you understand...
The Volvo tube is considerably smaller in diameter than the Ford, it doesn't seem easy to me as it took me several hours of finagling to just shorten one side.i didn't measure it though, the Ford does taper down a bit at the end.
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Old 12-19-2018, 09:38 AM   #35
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Could you build a new body mount for the panhard rod to get it closer to horizontal?
Edit: Sort of a rhetorical question, but you see my point.
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Old 12-19-2018, 01:01 PM   #36
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Wow. I mean, I'm not going to say this is crazy, but the fact that you know this begs so many questions I almost don't know where to start. 8)

Is there any sort of convenient relationship between the Ford and Volvo tube diameters, or are we talking a butt joint here? Just, hypothetically speaking you understand...
The ends of the volvo axle (bearing flange) have to be machined to slip inside the Ford tubes.
STS Machining is doing that with an axle right now.
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Old 12-20-2018, 12:23 AM   #37
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Could you build a new body mount for the panhard rod to get it closer to horizontal?
Edit: Sort of a rhetorical question, but you see my point.
Actually considering an extender to lower the attachment point on the axle, as looking at e.g. the GrpA 240 rear ends suggests they shifted the mount on the axle rather than at the body end.
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Old 12-20-2018, 01:14 PM   #38
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Actually considering an extender to lower the attachment point on the axle, as looking at e.g. the GrpA 240 rear ends suggests they shifted the mount on the axle rather than at the body end.
Yes, thats better. lowers the rear roll center.

Been wanting to release product for a while now that does that.

BTW.. since you have that fancy ass ABS, why not rig up a traction control strategy? If you can get the rear to slightly drag in the inside rear caliper... the truetrac can work.
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Old 12-20-2018, 09:26 PM   #39
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If you can get the rear to slightly drag in the inside rear caliper... the truetrac can work.
Hence the left-foot-brake experiment -- which ended up working quite well in a friend's car; but with electronics could be even more effective.

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Wow. I mean, I'm not going to say this is crazy, but the fact that you know this begs so many questions I almost don't know where to start. 8)

Is there any sort of convenient relationship between the Ford and Volvo tube diameters, or are we talking a butt joint here? Just, hypothetically speaking you understand...
It's how we did the Ford 8.8" rearend in mine -- that's in year 9 of it's "beta" test. All stock Volvo rear brakes/ebrake/Volvo bolt circle -- I wanted to keep my wheels and for my needs, the stock rear brakes were sufficient. Yes, the Volvo tube is slightly smaller than the Ford tube - but not so much smaller that it poses a problem. Properly aligned/welded/beveled - butt welding axle tubes isn't a problem at all. In fact, the VAST majority of rearend narrowing is done this way.

BTW - not suggesting this is the way to go - just that if you decide you wanna move to something stouter, with lots of gear/LSD/locker options and you have to cut/paste to make it fit anyway, it's pretty easy to keep your braking set up.

Last edited by M.H. Yount; 12-20-2018 at 09:36 PM..
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Old 12-21-2018, 07:07 PM   #40
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An old drag racing trick was to put an air bag/lift in the R/R spring coil or over the leaf spring to preload that side due to the torque reaction.
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Old 12-22-2018, 06:21 PM   #41
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This probably has way more detail than you want.

https://www.collectionscanada.gc.ca/...11/MQ39983.pdf

Its primarily the development of a mathematical model describing a beam axle with panhard rod system. The model also includes spring rates, damping rates and lots of other stuff. The interesting part is around page 48 where the author starts getting into the effect of lateral forces (going around corners) and the load transfers that occurs across the vehicle centerline just because of the panhard geometry.

So the short of it is that the panhard geometry can contribute to a difference in left - right side loading that might make your problem worse. That is not to imply that it is the sole cause of your problem.

Since the vehicle seems to like the left hand turns, perhaps you should switch to stock car racing? From my extremely limited knowledge the stock car dudes treat the panhard rod angle as a desirable component of chassis tuning. If you insist on turning left and right, the geometry lesson in the paper says the longer the panhard rod and the smaller the mounting angle, the less the difference between left and right hand turns. The Watts linkage does seem to be the go to solution for turning right and left at high speed if you have a fair amount of suspension travel (I have never bothered to check the linkage motions to confirm that it really does eliminate the panhard rod problems). If you have limited suspension travel and can get the rod angle small and the rod long enough the panhard rod's undesirable behaviour might not be significant.

I can't remember what the 240 was like; but, on my 140 optimizing the panhard geometry to minimize left - right differences did not seem to be uppermost on Volvo's design file.
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Old 12-25-2018, 12:54 AM   #42
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Yes, thats better. lowers the rear roll center.

Been wanting to release product for a while now that does that.

BTW.. since you have that fancy ass ABS, why not rig up a traction control strategy? If you can get the rear to slightly drag in the inside rear caliper... the truetrac can work.
Honestly, I haven't looked to see if the e-differential stuff can be coded in and whether it will work without the steering angle sensor. It's not a terrible idea, and probably less work than most of the alternatives. 8)
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Old 05-21-2019, 12:45 PM   #43
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Your situation is way too extreme in my opinion to just be the panhard rod mounting. Watching the video of Pobst driving the car makes me cringe, I would be so annoyed!

First question, have you lowered the rear yet or is it still jacked way up? If the ride height is anything like the pictures of the bus on your page that was linked to in another thread I came across, it looks like you need to lower the rear an inch or more! That is and should've been step one a LONG time ago(so maybe you've already addressed it, but this video makes me think not). I would either get scales and corner weight the car, or measure at the pinch seam behind the front wheel wells and in front of the rear wells and make them more even. You can't use the wheel well openings as a judge for the car being level as the rear ones are so much smaller than the fronts. On the General Leif, we have a 51.5/48.5% weight balance front to rear and you should be able to get this even closer to 50/50 considering you're in a wagon.

If the problem still occurs after doing that, I would cut some more off the right front spring to put more weight on the left front and right rear as I assume your corner weights are not near even. Or you can cut some more off the left rear. Or if you don't want to lower the car any more, you can put a spacer in between the upper spring perch and the chassis in the right rear to raise that corner and put more weight on that and the left front wheel. Our cross weight in the General Leif last time it was measured with me in it was 50.7%, so that's 50.7 percent of the vehicle's weight was on the right front and left rear wheels. If that gets closer to 50% of the weight, the car will behave closer to the same in left turns as it does in right turns. It hasn't been enough of a priority for us to dial that in more as there's always something else that's going on and it's been "close enough".

Also, yes, your springs are super soft and not ideal for racing, but if you have the rest of the car balanced out well enough, it should be fine, as it is in shoestring's car(140+rwhp B230F on cut stock springs with nothing special for shocks/struts). I suspect they don't even have roll correction spacers. Do you, shoestring?

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Thanks for the data & suggestions. We have tried the welded rear end, loved the traction, did not like the grenade aspect. Looking for someone to make a spool, but probably not going to be cost-effective.
[...]
https://i.imgur.com/9E8FKRwh.jpg
I was going to mention the roll correction stuff up front until I saw this picture. We ran a welded differential in the General Leif for years with no problems having it come apart. I assume it needed more welding?

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Originally Posted by blkaplan View Post
Yes, thats better. lowers the rear roll center.

Been wanting to release product for a while now that does that.

BTW.. since you have that fancy ass ABS, why not rig up a traction control strategy? If you can get the rear to slightly drag in the inside rear caliper... the truetrac can work.
Get on with making that product, then! You have a perfect tester here to verify the fix, it seems(however, I don't think the panhard rod is the main problem).

Also, getting the ABS to drag this wheel is still just a band-aid for something that shouldn't be nearly as bad as it is, so I would suggest trying the basics of chassis setup before doing something that fancy.

Last edited by klr142; 05-21-2019 at 05:43 PM..
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Old 05-21-2019, 01:10 PM   #44
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Also, yes, your springs are super soft and not ideal for racing, but if you have the rest of the car balanced out well enough, it should be closer fine, as in shoestring's car(140+rwhp B230F on cut stock springs with nothing special for shocks/struts). I suspect they don't even have roll correction spacers. Do you, shoestring?
Um no.

I think I mentioned earlier in this thread that one or two of my teammates can spin the RH inside tire in extreme circumstances, maybe a handful of times in a 2.5 hr stint. I never do. I am maybe a second a lap slower than them, at most, on tracks that have an average lap of between 1:40-1:50. I cut my teeth roadracing in a '69 Camaro with a 361whp small block, and I always fed it throttle, never used it as a throttle "switch". That habit has carried over into my style in this car. I'm pretty sure that these differentials need to see load before they'll work correctly, and I have to think that's the difference.

Last edited by shoestring; 05-21-2019 at 01:19 PM..
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Old 08-22-2019, 06:15 PM   #45
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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.
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Old 08-23-2019, 08:34 AM   #46
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Still watching to see what happens.
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Old 09-30-2019, 07:11 PM   #47
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We ran a day at Buttonwillow (lots of RH corners) with the front right lowered ~3" more than the left. That made it better, but it gives a wicked initial pull to the right when braking hard.

https://www.youtube.com/watch?v=pfzQ3_o2w-0

Then we ran a day with the front jacked 'way up (about 1" down from full top on Ben's coilovers)... that took it back to bad again.

https://www.youtube.com/watch?v=18w4w2s01RM

Next outing will be ~thanksgiving. Going to try a milder version of the RH front drop to see if that helps any...
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Old 12-16-2019, 09:25 PM   #48
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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.
I missed this earlier but just had to go find this thread after watching the continued wheelspin and general rear looseness of the fast lap video just posted.

That's a large chunk of weight on the LF/RR already indeed! I can't explain your issues, 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.

Have you tried lowering the rear of the car more? Like, an inch? And leaving the front where it is?

So crazy.
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Old 12-16-2019, 10:03 PM   #49
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Has anyone built a watts link yet?
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Old 12-16-2019, 10:16 PM   #50
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Has anyone built a watts link yet?
Why build when you can buy????
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