930 CV angle

tkr

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Ok, so with ground out 930's you're supposed to be able to get at least 29 degrees before they start to bind...right? How can you tell when they do start to bind. On our car, after about 24 degrees, the axles stop moving in and out and they don't turn smooth anymore. Is this nothing to worry about or are they exceeding their angle?

Matt Nelson
Team Kwik Racing
 

jim_moulton

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Sounds like the axles are to short. The axle should have about 1/4" play at full drop.
 

tkr

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We actually had to shorten them because when they were level, they were bottoming out against the transmission. How do you get around that problem?

Thanks for the help.

Matt Nelson
Team Kwik Racing
 

desertracer

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As a point of reference on our class 1 car we are getting like 21-22 with 935 cv's and no bind.

MDR #112
 

FABRICATOR

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Without knowing anything else about your situation such as what type of car, suspension, etc., etc., the problem is most likely the outer CV being too close or too far from the inner CV. Looking at them with the boots off should tell you which. You also have to make sure the ends of axle are not binding against anything, such as the stub axle flanges at the wheel or trans. If one person slowly cycles the suspension while the other moves the axle around (in and out too) it should reveal where it is binding.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>
 

tkr

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It's a Chenowth DR-2 beam car...not that that tells you much. When we first put it together, the axle would hit the center of the flange on the transmission when it was level.
so we shortened the axles...actually twice to get the length right. But then we found that the axles stopped moving in and out at about 24 degrees. So we limited the travel to keep it at 22 degrees. I was told once that if the cv mounting points on the arms isn't far enough behind the mounting points on the trans, it will limit the angle on the cv's. Is this true? If so, what is the optimum angle? I've always thought it was strange that the axle length would limit our travel, and not the cv angle, but couldn't figure out why. Our axles are now 23" long. Any suggestions?

Thanks again for the help

Matt Nelson
Team Kwik Racing
 

jim_moulton

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If your axles are hitting in the middle of your suspension cycle you must be running a stub/micro stub assy. Moving the transaxle forward 1"t0 2" will eliminate the axles hitting in the middle. The added set back angle has to be added to your drop angle. So your probably not going to get much more travel. For more travel go to a differ'nt outer hub. I,m building a 2 seat 12 car that has kreger hubs and it gets 21" of travel with 25 degrees of c.v. angle. A typical summers hub gets about the same travel. If I can help any way give me a call jim moulton @ MOULTON RACE CARS 661-295-0253
 

FABRICATOR

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Matt,
This is where the homework comes in. One of the biggest challenges to obtaining long travel is steering at the front of the car and axle plunge at the rear for IRS. For long travel in the rear, the outer CV's must be a few inches behind the inners when the axle is level. When the best set back is found, the variance of distance between the inner and outer CV will be minimized throughout the entire suspension travel. It is never perfect, but you should be able to get fairly close to a constant distance. If the distance between the CV's becomes lesser or greater than the axle length, parts will fail quickly. There should be at least 1/4" to 1/2" extra "breathing" room for the axle plunge at all angles, to take care of the unexpected. This procedure cannot be ignored. If it is, you will likely end up with too much in and out movement (plunge). This is especially true for VW style rear suspension using a single control arm. The arm can be moved back or lengthened. Or the transaxle can be moved forward.

This is why longer axles are better, in that they require less CV angle for a given amount of wheel travel. Outboard mounted CV's do nothing more than lengthen the axles. Time spent here will save many hours of heartache in the dezert.

<font color=orange>The best ideas are the ones that look obvious to the casual observer.</font color=orange>
 

tkr

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Thank you guys very much for your help. New arms aren't in the budget right now...dammitt. So we're gonna try moving the engine/transaxle forward and see if we can get
a little more travel out of it.
Thanks again.

Matt Nelson
Team Kwik Racing
 

01_el_tiburon

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graat info on the 930, just out of curiosity, how much travel does a bus cv have ?

thx

omar
 

tkr

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I've been told no more than 24 degrees.

Matt Nelson
Team Kwik Racing
 

rdc

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Which CVs?

I have a 2000 Tacoma and plan on doing the Camburg LT kit when I get enough money. I want to retain my 4x4 so what would I be better off doing? Putting in the 930's or just having camburg lengthen my existing cv's?

BTW These are the Porche cv's right? Pardon my ignorance, but what makes them special, I'm guessing they're beefier than stock cv's?
-Chris

2000 v6 4x4 TRD 5-Speed Tacoma
 
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