JACK FLASH Posted June 27, 2011 Share Posted June 27, 2011 The first 6 years of Twin Cam ownership I spent most of the time working on the car, doing test runs and getting it 100 % reliable. Finally I am starting to "use it" and I have come up with following questions. 1. The settings at the front have always been "straight ahead". What is the experience with toe in or toe out for road use. Values for settings? 2. The rear axle has the annoying habit of surprising me with serious bump steer at unwanted moments. Ideas for improvement? This is an absolutely standard Super Seven Twin Cam with the absolute standard LA suspension. A set of new Spax shocks and new springs were mounted a couple of years ago. No intend for trackdays or racing, this is a strictly road use classic Seven! Jack Flash j.jackflash@hotmail.com Link to comment Share on other sites More sharing options...
Pezky Posted June 27, 2011 Share Posted June 27, 2011 Not sure about toe in / out values. But the rear has significant unsprung weight so can have a habit of throwing you sideways mid corner. Link to comment Share on other sites More sharing options...
Jason Plato Posted June 27, 2011 Share Posted June 27, 2011 I would be looking at spring rates front and rear and more suited dampers than the Spax ones ?. Then ally diff carrier, lighweigh 3 piece wheels, gun drilled half shafts and forward arms extended to your thighs to control articulation. The live axle is a bit of a buggar to control mechanically. Link to comment Share on other sites More sharing options...
elie boone Posted June 27, 2011 Share Posted June 27, 2011 A live axle has to have Toe in = 0°20" +/- 0°10" If the rear axle surprises you ? you need to be awake when you drive 😬 start with the softest damper setting and only later with softer springs. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted June 27, 2011 Share Posted June 27, 2011 Assuming spring rates are in the right ball park and nothing is hanging off, I'd look to rose joint the lower coil over mounts on the LA as the mounting bolts go the wrong way and the limits of the axle travel are more than the standard bushes can handle resulting in a sideways loading on the damper shaft - effectively trying to bend it which adds significant stiction mid travel in a very unpredictable manner! Rose joints on the front dampers too make for much more reliable and consistant damping charateristics. I understand that Protech do some suitably valved dampers for LA's too. Link to comment Share on other sites More sharing options...
Blue-Lines Posted June 27, 2011 Share Posted June 27, 2011 I second fitting rose joints to the rear shocks if not already done so. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted June 27, 2011 Share Posted June 27, 2011 Conventional wisdom has it that toe-in on a 7 gives stable steering in the straight ahead position but at the expense of a snappy turn-in. Toe-out gives you a very rapid turn-in at the expense of a car that doesn't feel very stable in a straight line and tends to wander at speed. Racers favour toe out, they want the thing to pitch into corners very quickly and don't care about how it feels in a straight line as they don't aim to spend much time doing that. Road users have different priorities. My DD K series was set up parallel, it felt nice. With a 22% rack it will always change direcion. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted June 28, 2011 Share Posted June 28, 2011 DeDion will have differing charcteristics to a LA though as the Dedion has a slight positive rear toe where as the LA by design can only be parallel. Link to comment Share on other sites More sharing options...
JACK FLASH Posted June 28, 2011 Author Share Posted June 28, 2011 Great ideas and valuable information. Everybody can imagine my difficulties. So I' ll start with the easy things: 1. Set the toe in at 0°20" +/- 0°10", thanks Elie (walking encyclopedia) 2. Soften rear dampers, I stiffened them last year and they stand about halfway 3. Consider rose joints at the back, I heard about it but is there advice on suppliers. I have no problems with the front, it is neutral and has a sharp response. I know that there are ways of improving the front but to my opinion that is not really the priority. The only thing is perhaps changing dampers and springs. Is there some-one with practical experience of other makes of dampers and spring rates for a LA. Another variable is wheel / tyre combination and tyre pressure. I use the standard 185/70 with pressure between 1.6 bar and 1.8 bar. I believe that is about 22 psi and 26 psi. Is there any benefit in going to lower tyre pressures for road use? Jack Flash j.jackflash@hotmail.com Link to comment Share on other sites More sharing options...
elie boone Posted June 29, 2011 Share Posted June 29, 2011 Not much use to you but i run Nitrons with 140lbs springs, the nitrons are from the first batch so the damping is not really adapted to a seven. Tyres pressures i have 19psi all round ( 26psi is way to high ) Link to comment Share on other sites More sharing options...
Baz Hemsley Posted June 29, 2011 Share Posted June 29, 2011 I suggest you drop the tyre pressure. My 185 60 13s I run at 17lbs. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted June 29, 2011 Share Posted June 29, 2011 Most people settle on between 16 and 20 psi for tyres. You can play tunes on this and establish which you prefer. Best of all, it's free, and if you like the way the car handles then you can sit back and enjoy it. Link to comment Share on other sites More sharing options...
bstark Posted June 29, 2011 Share Posted June 29, 2011 I'd talk to Redline about the spring rates and shocks. My LA Xflow is set parallel toe-in and is spot on for the road and pretty good on track. No bump steer issues, and it takes a pretty poor road surface to upset it at all. Link to comment Share on other sites More sharing options...
jonboylaw Posted June 29, 2011 Share Posted June 29, 2011 I have a rose jointed A-Frame that bolts to the bottom of the axle to limit sideways movement caused by the usual bush, also have rose jointed bushes on the dampers that work well. Rear springs are 125lb on the softest damper setting, fronts are 300lb (x-flow), 2 clicks up and running a smidge of toe-in and the orange ARB, athough I have converted to a full DD front set-up which helps a lot. Edit, Tyre pressures are 18 front and 16 rear on 021Rs Edited by - jonboylaw on 29 Jun 2011 14:49:44 Link to comment Share on other sites More sharing options...
LesG Posted June 29, 2011 Share Posted June 29, 2011 A little tip about tyre pressures; not all tyre pressure gauges are accurate! Buy yourself a decent gauge, and then only ever use the same one to read your tyre pressures with. Take advice from others as to what pressures work for them, try playing around accordingly, but when you find what works for you, stick with it and don't get too hung up about what others say they run, as their pressure gauges may be out! Link to comment Share on other sites More sharing options...
JACK FLASH Posted June 30, 2011 Author Share Posted June 30, 2011 Guys, A lot of usefull and wise advice. in the mean time, I had the toe in adjusted and I must say that the values Elie stated are much better. As for the bump steer, this weekend I'll start playing with the tyre pressure and soften the dampers. Technical upgrades are for the next stage. Today I have passed the Belgian MOT and apart from some fidddling at the carbs to get below 4.5 % CO, everything worked out. At the first test I had 5.0 % and afterwards I managed 1.6 % with idle at 750 rpm and a lot of backfire. An interesting remark was that there was a significant difference in the left and right dampers at the front. I know the front is always critical, I never have problems at the rear. To be continued after the tests in the weekend ... Jack Flash Link to comment Share on other sites More sharing options...
Brian Soper Posted July 1, 2011 Share Posted July 1, 2011 Get rid of the Spax , I had them for 25 + years on my S2 (3 sets actually) I replaced them with AVOs and the transformation was brilliant, keep the springs soft ie standard for road use < I have 175 front ( BMC A series engine) and 125 rear ( needed for fully loaded touring) tyre pressures 20 rear 18 front for normal driving increase by 2 psi if fully loaded or circuit laps on parade!!! I have fitted AVOs on our S4 as well great drive again just uprated the rear spring to 125 and 20/18 tyre pressures Brian Link to comment Share on other sites More sharing options...
Sam Monoogian Posted February 14, 2012 Share Posted February 14, 2012 Bit of a deviation from the original thread title, but I'm looking to upgrade the springs/dampers on my Ital LA Classic, and am a bit out of touch about what's in vogue at the moment. I'm looking to add adjustability, improve road comfort and reduce the mass from the current (what I presume to be ) Spax. Any recommendations? Link to comment Share on other sites More sharing options...
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