Front end vibration?

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Re: Front end vibration?

Postby beck688 » Tue Nov 10, 2015 6:21 pm

I thought You can only change the camber - the caster was adjusted by shimming the torsion tubes. In the spyder the tubes are welded.
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Re: Front end vibration?

Postby DannyP » Wed Nov 11, 2015 3:14 am

Yes, technically you are right. However, if you use the aftermarket adjusters that have a much wider range of adjustment, AND end up with a reasonable amount of camber, the side benefit is a degree or two more caster, as long as you angle the spindle rearward. Pay attention to the mark or notch on the adjuster.
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Re: Front end vibration?

Postby beck688 » Wed Nov 11, 2015 4:25 am

Good to know thanks. I am going to do some gymkhana stuff this year. The car handles beautifully in the mountains but parking lot racing is a whole different animal.
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Re: Front end vibration?

Postby RVosari » Wed Nov 11, 2015 7:01 am

Beck,

Keep in mind that if you auto-cross in a serious way, you really stress the motor and need to add a dry sump or Accusump set up. You are constantly turning and accelerating forcing lots of oil into the rocker boxes which does not drain back very readily, exposing the oil pickup to froth and air. :(

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Re: Front end vibration?

Postby beck688 » Wed Nov 11, 2015 9:07 am

I think the extra sump will prevent that. I used to run a dune buggy back in the 60s with nothing special about the sumps and I would run that every other weekend.
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Re: Front end vibration?

Postby Larry Jowdy » Wed Nov 11, 2015 9:31 am

FYI, You'd need to be pulling 5 g's in a corner to empty the oil sump so usually an add on sump is sufficient for autocross or most any other motorsport.
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Re: Front end vibration?

Postby RVosari » Wed Nov 11, 2015 10:09 am

Larry, I have had a lot of experience with the old Formula V cars...and they all suffered from oiling problems at .9G let alone 5 G. The dry sump systems permitted in the new Formula First allow you to get more than a season out of the bearings!

Auto-cross is a lot harder on the motor because you are almost always accelerating out of tight turns, unlike road racing, where sweep turns or 180 degrees are harsh, but much of the time is spent on straightaways where oiling is less of as issue!

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Re: Front end vibration?

Postby beck688 » Wed Nov 11, 2015 11:26 am

Im with Larry You would have to move a lot of oil to port the tube in the sump..I would be worried more about the long sweeper - we used to put baffles in the sumps in the straight fours we used to run in B/CSR.
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Re: Front end vibration?

Postby DannyP » Wed Nov 11, 2015 11:57 am

I've been autocrossing mine for a few years now and have no oiling problems. I have a 1.5 quart CB thinline sump. I have at least 10 psi per 1000 rpm warm. My whole system carries about 6 quarts, 1 quart filter, thermostat, and 96 plate Mesa cooler. Also a Berg pressure relief cover, and obviously full-flowed.

You might pull 1 G, maybe a little more with slicks, but not 5! I'm in the process of a second set of autocross tires, I'll post it here. Because of the tube frame and over 2 liter displacement, I have to run E-mod, so it's impossible to win with the archaic suspension and street tires. Maybe slicks will help?

I'll be putting in a bigger front swaybar over the winter, among other things.

Rev, when and where did you run FV?
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Re: Front end vibration?

Postby beck688 » Wed Nov 11, 2015 11:59 am

Impossible to win, but Damned fun trying.
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Re: Front end vibration?

Postby DannyP » Wed Nov 11, 2015 12:04 pm

Yeah, it sure is fun! Addictive too. It teaches you a lot about car control. The hardest stuff as I see it? The Chicago box and the pin cone.
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Re: Front end vibration?

Postby Mark P. » Thu Jul 13, 2017 8:43 am

I know this is an old thread, but I've been having the same problem. Up to around 40,000 miles on three different sets of tires, I never had a vibration issue. I got new tires a few years back and noticed a vibration at 65 MPH. 55 is fine, 75 seemed OK, but in between it would shudder left/right, smooth, shudder, smooth, in a rhythm at around every 1.5 seconds. No vibration in the steering wheel. It is most noticeable at the top of the cowl / windshield. It is less noticeable with a full tank of fuel so adding weight up front helped. I just got the front wheels balanced (again) and the change is very subtle. Slightly better but that vibration is still there. I haven't been in to the suspension to check anything yet, hoping someone here had done all the hard expensive stuff and found it was wheel bolts or something easy!

I'm over 50,000 miles now so I've been dealing with the vibration for 10k miles or so. Front tires look brand new. I'm on another set of rears. Rears don't last long! Yokohama AVID ENVigor tires, 195/65R15 Rears, 175/65R15 Fronts. Stock steel Mangles rear rims from Beck (1998) but I replaced the fronts with 5.5" Mangles at some point.
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Re: Front end vibration?

Postby EEricson » Thu Jul 13, 2017 4:28 pm

There is a thing called (I think) "road force balancing" that one of the Speedster guys says cured this problem on his car. Apparently some high-end shops can balance wheels and tires on the car while under load, and that supposedly makes a difference.
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Re: Front end vibration?

Postby egrant5329 » Fri Jul 14, 2017 3:59 am

Mark,
I'd pull the tank and check all of the tie rod ends. It's easy to do and they are cheap. Ball joints are harder to do, but I'd look to the tie rod ends first. Of course you then need an alignment. I had a bad inner tie rod and the car acted similar. I replaced them all while I was there just so I'd know they were all good.

I pulled my tank the other day to check something out and I think found the reason my steering wheel has more play than I like. The rubber steering coupler was all cracked up and disintegrating. I'll have to pull it again when my new urethane coupler arrives. Hopefully, it will install easily. If that doesn't resolve the steering wheel floating, I'll have to adjust the steering box that I talked about doing back when this post was new.
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Re: Front end vibration?

Postby EEricson » Fri Jul 14, 2017 4:45 pm

Urethane steering couplers have a bad reputation. I use the rubber ones.
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