You have to look at the cost-to-benefit. The cost is weight. The benefit is more control over your car. Having more control over your car can shave a few more seconds off your times than having just a couple more pounds that the engine has to carry.
Mumford Suspension
#31
Posted 08 December 2006 - 11:51 PM
You have to look at the cost-to-benefit. The cost is weight. The benefit is more control over your car. Having more control over your car can shave a few more seconds off your times than having just a couple more pounds that the engine has to carry.
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#32
Posted 09 December 2006 - 06:03 AM
Thanks for the bigger info and better explanation sometimes writing large shunks of english tech can be difficult for me i know what it is but to explain it can be hard in a other language.
And like Greg and I told the weight is low down in the car and adds allot of control to the rear suspension. So it is something i can live with. but thats a thing everbody has to decide for him self.
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive
#33
Posted 09 December 2006 - 09:12 AM
Panhard bars work very well, and are simple and can be made to be adjustable (to a point). Really, the only advantage that the Mumford linkage has is that it can be designed to place the roll center at a location that is not physically possible with a Panhard bar. This may be a huge advantage for certain applications, but for others, it may have limited usefullness. It all depends on where the optimum location of the roll center really is, and how much room you have to work with.
Often times, panhard bars are built with curved shapes to clear other parts, thus allowing the virtual line that connects the two mounting points to go through something. Another feature (or disadvantage) of a Panhard bar is that you can get slightly different rear tire loading by controlling the angle of the bar. NASCAR uses this as the primary tuning tool for adjusting handling - they raise or lower the 'track link', which is the height of the connection of the Panhard bar to the axle.
The Mumford linkage has a lot more moving parts, bearings, links, etc. It is also generating much higher reaction forces due to the leverage of the linkage, so it requires a more sturdy mount to the chassis. In most race cars, that added weight really isn't an issue, because you have weight minimums anyway.
-Chris
#34
Posted 09 December 2006 - 09:47 AM
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#35
Posted 09 December 2006 - 04:15 PM
whe are all here to learn something so no problem. im sure most of the guys over here all needed to have someone to learn them stuff in the beginning
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive
#36
Posted 09 December 2006 - 10:40 PM
Panhard bars work very well, and are simple and can be made to be adjustable (to a point). Really, the only advantage that the Mumford linkage has is that it can be designed to place the roll center at a location that is not physically possible with a Panhard bar. This may be a huge advantage for certain applications, but for others, it may have limited usefullness. It all depends on where the optimum location of the roll center really is, and how much room you have to work with.
Exactly...I agree.
The Mumford link may be useful if you know where the rear roll center should be relative to the front on these cars...I, for one, haven't a clue where that is. I'm sure I could figure it out, but, I not sure the gains are worth the time and hassle spent to do that and the fabrication necessary to install one that works properly.
I think that with the small amount of rear suspension travel these cars have when properly set up for track events, a height adjustable phb is more value added. To that end, I have another HF axle that I'll probably modify for an adjustable (height) phb mount.
Here's what I'm wondering: Does the Mumford link allow you to place the rear roll center such that it prevents the 1/3g cars from "three wheeling" (lifting their inside rear wheel)? If it does not, then, when the car lifts it's inside rear wheel, what does it matter where Mumford link defined rear roll center is? Wouldn't you of acheived the same result with an adj phb without the time/weight/cost associated with designing, fabbing and installing a Mumford link?
#37
Posted 10 December 2006 - 06:25 AM
#38
Posted 10 December 2006 - 08:03 AM
And because my car kept three wheeling true corners and i could not get the roll center to the point where i would like to have it i decided to go for the mumford setup, and ill keep the mounts for the panhard on the chassis and axle so i can always go back when needed.
But i would like something wich is better adjustable then the panhardbar with its stock mounts. because my car was lowered -4cm and the panhardbar was parralel to the axle and i could not do annything else! because i made a flat bottom car and a real diffusor out of carbon for my car ( made a belly pan out of carbon sheets ) i need to lower my car some more and if im going to weld what is a thing that needs to be done, then i could also convert to a mumford suspension link setup.
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive
#39
Posted 11 December 2006 - 08:48 AM
I guess the question that most people are looking for is. Will the mumford allow you to keep the car from three wheeling?
#40
Posted 11 December 2006 - 12:15 PM
I guess the question that most people are looking for is. Will the mumford allow you to keep the car from three wheeling?
There are a lot more things than just the rear roll center that control how much or if your inside rear tire lifts. Actually, I believe it’s the front R/C that will affect the rear lifting more than the rear R/C will. That and the complete car set-up that you have.
FWIW, I have always strived to keep all four of my wheels on the pavement as much as possible when setting up my car. I always ask people when I’m at the track if they see any rear wheel lift or not. So far everybody tells me that all four wheels stay down, which is good.
This:
is the only evidence I’ve EVER seen of any wheel lift from my car on the track. And that was on the initial turn in. In other pictures I’ve seen from that turn that same wheel is down or at least touching the pavement.
I have seen many 1G/3G solo cars with the rear tires waaay higher than that in addition to some track cars. I probably did it too back when I had my car lowered a bunch in ITA years ago. But I also hated the way the car handled when I did that and after I raised it back up, which also raised the front roll center, it handled much better. Not to mention extended the tire life over the race distance.
Solo set-ups and race track set-ups, while striving to achieve the same goal, high tire grip, are generally different from what I’ve seen and heard over the years. There is no definitive, absolute right and wrong in car set-up. What’s right for you may feel terrible to someone else and they still may be able to beat your time with your set-up. all the while hating your set-up…it’s happened to me .
Jay
If you love the Elise, drive a Se7en - Caterham or whatever...
It has even less content than the Elise, is less graceful looking
...and changes direction like a ping pong ball whacked by Thor.
#41
Posted 11 December 2006 - 12:21 PM
#42
Posted 11 December 2006 - 01:13 PM
So would I! Except for the fact that it’s against the rules in the class I race in.
Not only that but some 4 links still require some sort of lateral axle control. Take a close look at the trailing links in this picture, it’s a four link if I’m not mistaken. Kind of hard to tell but I seem to remember that it was. Kirk? TJ?
If you love the Elise, drive a Se7en - Caterham or whatever...
It has even less content than the Elise, is less graceful looking
...and changes direction like a ping pong ball whacked by Thor.
#43
Posted 11 December 2006 - 01:40 PM
Not only that but some 4 links still require some sort of lateral axle control. Take a close look at the trailing links in this picture, it’s a four link if I’m not mistaken. Kind of hard to tell but I seem to remember that it was. Kirk? TJ?
yes it was here are some more pics of the same car and suspension linkage.
http://www.shamrockm...om/mumford1.bmp
http://www.shamrockm...om/mumford2.bmp
http://www.shamrockm...om/mumford3.bmp
Greetings Erwin.
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive
#44
Posted 11 December 2006 - 06:00 PM
#45
Posted 11 December 2006 - 07:51 PM
is the only evidence I’ve EVER seen of any wheel lift from my car on the track. And that was on the initial turn in. In other pictures I’ve seen from that turn that same wheel is down or at least touching the pavement.
Jay
Jay, does this mean the photographer managed to get that picture on the only time you were pushing hard enough to lift that rear? Maybe you need to push harder and get that sucker off every lap? LOL