SNAIL Forum Index SNAIL
☠ Vintage School 2CV
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Lowering... a few questions for the racers...
Goto page Previous  1, 2, 3, 4, 5, 6  Next
 
Post new topic   Reply to topic    SNAIL Forum Index -> Technic
View previous topic :: View next topic  
Author Message
2cvracer
Snailer


Joined: 05 Jul 2007
Posts: 12

PostPosted: Wed Aug 08, 2007 11:13 pm    Post subject: Reply with quote

Bart
this is typical of you to bring up 'technicalities'.
I don't have the details of the springs to hand but yes it will be weight verses movement (in CM or good old british inches) but right now i'm not sure of the calculation. I will try and post it.

As far as the shocks go you are correct, the ones i ran on my race car in the picture were not oil filled (although i have used them) and they were not Spax either, they were made by a company called Quantum, they are a low volume manufacturer making shocks for racing cars and bikes. Interestingly the ones for the 2cv were very difficult to do as they could not find a body big enough to give the volume they wanted and with enough suspension travel. Next they found out that 2cv shocks work backwards compared with 'normal' cars. eventually they found shock bodies from an American NASCAR, these had the big valves and bodies, they were then modified to get the travel required for the 2cv. They were very light, made of aluminium and titanium and worked perfectly. I found that other makes of uprated shock just didn't work or didn't last. I was worth the effort getting them made. They won 3 British championships and came second once in 4 years of trying - a worth while expense I think.

In answer to your other question, I used to put as much oil back in as I took out, once you have refilled it and 'worked' the shock to get the oil around and make it work correctly, you can then put the bolt and sealing washers into the top of the shock and it becomes air tight again. As I said, you just have to make sure that the shock works OK before fitting it and that regardless of what we have done to them, it gets fitted as the manufacturer intended, LIP shocks have the shock body towards the suspension arm with ball mark to the top and Boge have the body towards the suspension can/spring, there is not a ball mark as far as i can remember but please check - Boge are very rare here now.

All clear now?

Yes, my racing car was very shiney, almost too much, but it was an advert for my business and it is important for it to look good.
4x4 is in need of work, you might see it at the international.

see you soon
Pete
_________________
Now where did I put that supercharger.....
Back to top
View user's profile Send private message Visit poster's website
Bart
Lowered


Joined: 17 Jun 2007
Posts: 783
Location: Södertälje

PostPosted: Thu Aug 09, 2007 12:42 am    Post subject: Reply with quote

Top job, thanks Pete!
Back to top
View user's profile Send private message Send e-mail Visit poster's website
champy2k
Dropped


Joined: 02 Jul 2007
Posts: 116
Location: uk

PostPosted: Thu Aug 09, 2007 9:57 pm    Post subject: Reply with quote

due to leverage the lower the 2cv the softer the suspension, and as we know ami and acad have different knife edge pick up points, also the sping cans need the compliance of the rubber to work correctly and get good handling
_________________
the older i get the more projects i start!!!!!!

lower than a snake with tits

www.2cv-speed-shop.co.uk
Back to top
View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
dyanut
Dropped


Joined: 05 Aug 2007
Posts: 177
Location: North Yorkshire

PostPosted: Fri Aug 10, 2007 11:37 pm    Post subject: Reply with quote

Hi there Geoff,
are you quite sure about that, because the principal effect of lowering an A series car is to increase the offset of the pickup points for the rear tie rods, therefore increasing the effective spring rate...
This only applies at the rear axle btw, since the offset of the pickup points at the front remains relatively constant through an arc of movement extending either side of the 'standard' setting.
If I'm not mistaken, increasing the spring rate at the rear compared to the front could help reduce understeer, which is no bad thing for an A series.
Ken.

champy2k wrote:
due to leverage the lower the 2cv the softer the suspension, and as we know ami and acad have different knife edge pick up points, also the sping cans need the compliance of the rubber to work correctly and get good handling
Back to top
View user's profile Send private message
champy2k
Dropped


Joined: 02 Jul 2007
Posts: 116
Location: uk

PostPosted: Fri Aug 10, 2007 11:54 pm    Post subject: Reply with quote

dyanut wrote:
Hi there Geoff,
are you quite sure about that, because the principal effect of lowering an A series car is to increase the offset of the pickup points for the rear tie rods, therefore increasing the effective spring rate...
This only applies at the rear axle btw, since the offset of the pickup points at the front remains relatively constant through an arc of movement extending either side of the 'standard' setting.
If I'm not mistaken, increasing the spring rate at the rear compared to the front could help reduce understeer, which is no bad thing for an A series.
Ken.

champy2k wrote:
due to leverage the lower the 2cv the softer the suspension, and as we know ami and acad have different knife edge pick up points, also the sping cans need the compliance of the rubber to work correctly and get good handling

i was told this years ago when looking into spring rates and to be honest when i lowered on std springs the car bounces softer, so the driving seems to back it up but i willing to stand corrected
i have some were in my files (well some crisp boxes) the movement ratios of the suspension etc, i offered this info to avo once in 1999 but never did give it
_________________
the older i get the more projects i start!!!!!!

lower than a snake with tits

www.2cv-speed-shop.co.uk
Back to top
View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
JoZeF
Grave Digger


Joined: 25 May 2007
Posts: 1734

PostPosted: Sun Aug 26, 2007 10:31 pm    Post subject: Reply with quote

Oh, just a question :

What clearance is there between road and underside of chassis on a 2cv racer ?

cheers
_________________
"That bumper fits there like sunglasses on pig" Laughing O.E.


Back to top
View user's profile Send private message
dyanut
Dropped


Joined: 05 Aug 2007
Posts: 177
Location: North Yorkshire

PostPosted: Mon Aug 27, 2007 8:43 pm    Post subject: Reply with quote

Hi JoZef,
for the UK's 2CV racing club, it's 40mm to the lowest point of the chassis which is usually the damper brackets.
Ken.


JoZeF wrote:
Oh, just a question :

What clearance is there between road and underside of chassis on a 2cv racer ?

cheers
Back to top
View user's profile Send private message
JoZeF
Grave Digger


Joined: 25 May 2007
Posts: 1734

PostPosted: Tue Aug 28, 2007 10:23 am    Post subject: Reply with quote

Thanks

Quote:
40mm


Well isn't that just way cool...

Shocked
_________________
"That bumper fits there like sunglasses on pig" Laughing O.E.


Back to top
View user's profile Send private message
dyanut
Dropped


Joined: 05 Aug 2007
Posts: 177
Location: North Yorkshire

PostPosted: Tue Aug 28, 2007 10:58 am    Post subject: Reply with quote

Certainly is, but it's always advisable to keep a check on how much of the axle bolt heads may have been ground away from contact with the rumble strips.
One racer I worked on had barely 3mm left. You can guess how surprised the driver would have been if those weakened bolt heads suddenly let go, dropping the chassis on the deck... Sad

Ken.


JoZeF wrote:
Thanks

Quote:
40mm


Well isn't that just way cool...

Shocked
Back to top
View user's profile Send private message
JoZeF
Grave Digger


Joined: 25 May 2007
Posts: 1734

PostPosted: Tue Aug 28, 2007 11:11 am    Post subject: Reply with quote

Wouldn't it be a good idea to countersink the bolt heads so they fit in the chassis ???

that way they wouldn't get shaved ?
_________________
"That bumper fits there like sunglasses on pig" Laughing O.E.


Back to top
View user's profile Send private message
Lionel
Dropped


Joined: 11 Jul 2007
Posts: 258
Location: NANTERRE-PARIS suburb-FRANCE

PostPosted: Tue Aug 28, 2007 11:16 am    Post subject: Reply with quote

or build a protection from U chanel turn downward that you pass your bolts through as I saw on some off-road 2CV?
_________________
0 to 70 in the same day!
Back to top
View user's profile Send private message Send e-mail Visit poster's website
dyanut
Dropped


Joined: 05 Aug 2007
Posts: 177
Location: North Yorkshire

PostPosted: Tue Aug 28, 2007 1:11 pm    Post subject: Reply with quote

No worries folks, since I prefer to use a 'sacrificial' length of 10mm round bar welded to the underside of the chassis, chamfered at its leading edge and with a slight bend to shield the front bolt.
Titanium could be nice of course, but it's not something you find just lying around in scrap dealers' yards... Laughing
Ken.


Lionel wrote:
or build a protection from U chanel turn downward that you pass your bolts through as I saw on some off-road 2CV?
Back to top
View user's profile Send private message
JoZeF
Grave Digger


Joined: 25 May 2007
Posts: 1734

PostPosted: Tue Aug 28, 2007 7:15 pm    Post subject: Reply with quote

Well, protection, OK

the Alfa AMI had them...

but that just adds an extra "layer"... thus making the chassis needing to be higher...

Nobody countersinks the screw heads ?

Question
_________________
"That bumper fits there like sunglasses on pig" Laughing O.E.


Back to top
View user's profile Send private message
dieselflosse
Snailer


Joined: 20 Nov 2007
Posts: 72
Location: Finland

PostPosted: Mon Nov 26, 2007 1:19 pm    Post subject: Re: Lowering... a few questions for the racers... Reply with quote

JoZeF wrote:
So, we all know the cheap 'n easy way to lower a 2cv...


I don't Crying or Very sad

I am newest newbie on this 2cv area. I just handshaked a deal to exchange my Moto Guzzi to one guy's 2cv4 (equipped with 6 tech).

When I have looked these pages I have gotten many many ideas what I would like to use on my new friend. One is lower suspension...

What I should do if I want to lower my 2cv to level like picture bellow? I know that springs are inside the tubes and there is some kind of shank from the spring to suspension arm. And that shank is tunable. How much it is possible to lower only by tuning that shank? Is there any problems with the flexibility or it's shortage (I don't know exact English phrase for that)?

With my Mercedes I changed springs and shock absorbers. It was clear procedure. How about 2cv?

Edit: NO images or links, becauce I am too new member of this site... But I mean Etienne's "hoodride" 2cv.
_________________
Regards
Tero
Back to top
View user's profile Send private message
JoZeF
Grave Digger


Joined: 25 May 2007
Posts: 1734

PostPosted: Mon Nov 26, 2007 1:42 pm    Post subject: Reply with quote

Hi

No problem ! A forum is a place to learn stuff.

The cheap and easy way (but far from best, technically/drivability speaking) is to unscrew this part :



Beware, it's most likely going to be seized cause it does, over years...

You need to tap them with a small hammer, and another hammer behind to support... that should free the threads... use WD 40 or some other similar oil to help

Jack your car on one side, so that both wheels on same side are off the ground. Make sure it's properly secured, cause to get the wheels off the ground you need to go quite high ! and you don't want a Car falling on you this close to christmas Laughing

The idea is to get the tension off the suspension system.

You can then go about unscrewing, if you get them free to move (be patient, you don't want to snap a tie rod here...)

If you leave 1,5-2 cm screwed in it should be enough to lower your car quite a bit. you can also lengthen these parts by cutting and welding an extra piece in (that allows you to have more of it screwed in)



Bye
_________________
"That bumper fits there like sunglasses on pig" Laughing O.E.


Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SNAIL Forum Index -> Technic All times are GMT + 2 Hours
Goto page Previous  1, 2, 3, 4, 5, 6  Next
Page 2 of 6

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © phpBB Group. Hosted by phpBB.BizHat.com