Mumford Suspension
#46
Posted 11 December 2006 - 08:47 PM
#47
Posted 11 December 2006 - 09:41 PM
A set of 31mm torsion bars might help that a bit...interested?
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.
#48
Posted 12 December 2006 - 06:09 AM
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive
#49
Posted 12 December 2006 - 09:04 AM
I am currently using 29mm torsion bars with the Integra front antiroll bar. I may be experimenting with an additional front bar at my next race in January. Not sure since it's at Sebring again and some sections of that place (the old WWII concrete) will shake your fillings loose...while other sections are incredibly smooth.
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.
#50
Posted 12 December 2006 - 10:15 AM
#51
Posted 12 December 2006 - 12:12 PM
#52
Posted 12 December 2006 - 02:23 PM
Randy
#53
Posted 12 December 2006 - 06:51 PM
There is a lot more involved in fixing that problem than changing the rear roll center. If your rear tire is getting that much air, then you need to increase the front roll stiffness by adding more spring rate, sway bars, and/or raising the front roll center. All of these changes will reduce the amount of weight transfered to the outside front tire, which is what is causing the rear to lift.
Changing the rear roll center is going to change the ratio of side force vs down force acting on the rear tires. A high RC has higher side force and lower down force than a low RC. This is exactly why these cars handle so well. They are naturally a little loose on turn-in, but once you lift the rear wheel, they get more stable. This is generally good, as long as it is controlable.
On my car, with the 30mm super short torsion bars, I have enough lateral grip to actually lift the front inside tire on a good surface (which can be a little scary). I would like to add some more rear roll stiffness to help keep the front more planted, but my car is already too loose on turn-in, so adding rear spring or sway-bar would not be good right now. By lowering the rear RC, I should be able to use a stiffer spring and get back to the same or better turn-in while reducing the total roll in steady state cornering.
I guess the short answer is that there is no one single magic part that's going to fix all handling problems. There are a lot of well proven CSP type setups that use stock Panhard bar mounting points. Adjusting the rear RC is probably one of the last things on the list of what to do to make one of these cars handle well, following springs, dampers, bushings, sway bars, ride height, corner weights, etc.
-Chris
#54
Posted 12 December 2006 - 07:51 PM
I am currently using 29mm torsion bars with the Integra front antiroll bar. I may be experimenting with an additional front bar at my next race in January. Not sure since it's at Sebring again and some sections of that place (the old WWII concrete) will shake your fillings loose...while other sections are incredibly smooth.
Jay
Thnx for your input ill be using 29mm torsions with a single Teg bar, please let us know about your experiment with the 2 bars ( what kind of 2nd bar are you planning on using ? ) And doesnt annyone use tracktion bars on the cars ? i made a set im shure they work greath.
Jay is planning on letting a factory make a custom batch of 31 mm bars if im correct
Changing the rear roll center is going to change the ratio of side force vs down force acting on the rear tires. A high RC has higher side force and lower down force than a low RC. This is exactly why these cars handle so well. They are naturally a little loose on turn-in, but once you lift the rear wheel, they get more stable. This is generally good, as long as it is controlable.
On my car, with the 30mm super short torsion bars, I have enough lateral grip to actually lift the front inside tire on a good surface (which can be a little scary). I would like to add some more rear roll stiffness to help keep the front more planted, but my car is already too loose on turn-in, so adding rear spring or sway-bar would not be good right now. By lowering the rear RC, I should be able to use a stiffer spring and get back to the same or better turn-in while reducing the total roll in steady state cornering.
I guess the short answer is that there is no one single magic part that's going to fix all handling problems. There are a lot of well proven CSP type setups that use stock Panhard bar mounting points. Adjusting the rear RC is probably one of the last things on the list of what to do to make one of these cars handle well, following springs, dampers, bushings, sway bars, ride height, corner weights, etc.
-Chris
allready try'd all of the above and i was always experimenting with the setup of my car's suspension. Current setup is/will be : Tein SS Adjustable Coilover shocks, 29mm torsions, RPR adjustable panhard , Welded rear internal swaybar, 350lbs rear springs, External rear Swaybar, energy suspension full bushing kit, Front Tracktion bars, and a stitch welded cassis to remove body roll / twist, Adjustable front suspension arms (prototype im currently building for adjustable camber/caster), lots of braces & 6 point cage.
Thats what will be on my car, but hey i allways need something to test and build so trying a mumford rear link setup for maximum adjustability will be the next thing on my list.
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
#55
Posted 13 December 2006 - 08:32 AM
Just curious, what tracks do you run at? I guessing Zandvoort based on your location, but are there other 'club' racing tracks near you?
#56
Posted 13 December 2006 - 08:49 AM
Just curious, what tracks do you run at? I guessing Zandvoort based on your location, but are there other 'club' racing tracks near you?
I have run at diffrent tracks ,
Zolder ( Belgium ), small but verry technical circuit, my favorite.
Posterhold ( Netherlands ), Small Oval.
Drachten ( Netherlands ), airstrip , dragracing.
Assen ( Netherlands ), verry big TT circuit.
Zandvoort ( Netherlands ), large circuit.
Nurenberg Ring ( Germany ), Verry big dangerous track but always open for all kinds of cars.
Most of them have open track days , the drag racing airstrip needs you to be in a class ( OSL/DHRA , under devision of the NHRA ). and at nurenberg you pay a little amount of money to take a piece of the nordsleife. and there are rally events on normal industrial zones etc and races on parts of not ready highways organized by the governament but that kind of thing is only once a year.
But im rebuilding my car as we speak so i have not raced those tracks for some time in my own car ( i can borrow some race cars from sponsors etc if i want ) . but im building the car for those tracks and all kinds of racing. so there are places enough for racing over here.
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
#57
Posted 13 December 2006 - 05:59 PM
Jay is planning on letting a factory make a custom batch of 31 mm bars if im correct
Erwin, the additional front bar will be a custom one that I made, or am making as the case may be. I made one several years ago that bolted to the bottom of the front subframe and worked pretty well it just kept hitting the ground and I thought I was going to tear it off eventually. It was mounted in pillow blocks and they were getting pretty worn down.
When I figure out just how I'm going to mount the new one I'll let you know.
As for the 31mm torsion bars, yes I am going to have some made. It's just a little behind schedule right now.
This time of year is probably pretty busy for most of us and I'm trying to get race car parts made on top of all the other stuff I need to be doing!
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.
#58
Posted 14 December 2006 - 02:42 AM
As for the 31mm torsion bars, yes I am going to have some made. It's just a little behind schedule right now.
This time of year is probably pretty busy for most of us and I'm trying to get race car parts made on top of all the other stuff I need to be doing!
Jay
Thanks ill be waiting for the news . And yes im trying to build some prototype front suspension arms and its christmas etc so yes a busy month.
1. EDM 1986 Honda CRX AS - B16A1 engine - OBD1 - Turbo - Stitch welded chassis.
2. EDM 2001 Lexus IS300 3.0 RWD - Daily Drive
#59
Posted 20 June 2007 - 05:42 PM
I once spoke to EPCRX and asked for the plans. He said he would send them and never did. I also have found some information on a Nissan setup that is similar to the Mumford link.
http://www.not2fast....sis/mumford.gif
http://www.bevenyoun....au/config.html
I'll try and find the info and post it. JS
If you want one of these Logos send me a PM
Austin Mini Van with DOHC Honda HP
http://www.angelfire.com/droid/strudel
Honda reliability and power combined with Mini cachet and style.
#60
Posted 21 June 2007 - 12:20 AM
http://www.se-r.net/...c/oct98/tb.html
Here is another discussin on linkages for a Mini.
http://www.16vminicl...opic.php?t=5242
From the Nissan manual for a 87-91 Stanza I believe or similar to 87 Maxima.
EPCRX's Mumford System
If you want one of these Logos send me a PM
Austin Mini Van with DOHC Honda HP
http://www.angelfire.com/droid/strudel
Honda reliability and power combined with Mini cachet and style.