Are you madabout kit cars      
 "We've Got Kit Cars Covered" Information about Madabout-Kitcars.com Contact Madabout-Kitcars.com         Home of UK kit cars - madabout-kitcars.com Various kit car write ups All the latest kit car news Kit car related and general discussion

Search
Manufacturers
Kit Cars
Kit Car Data sheets
Picture Gallery
SVA Knowledgebase
Clubs & Communities
Build cost estimator
Kit cars for sale
Knowledge Base 
KitcarUSA.com
Classic-Kitcars.com
 

Go Back   Madabout Kitcars Forum > Mad Build Area > Marlin Sportster, Cabrio, Berlinetta and Roadster builds

Marlin Sportster, Cabrio, Berlinetta and Roadster builds Enthused or Confused about your vintage Marlin build? Ask away here or show off your build.

Reply
 
Thread Tools Display Modes
  #1  
Old 24th January 2011, 09:09
GlenSL GlenSL is offline
Member
 
Join Date: Aug 2010
Location: Oundle, Nothamptonshire
Posts: 31
GlenSL is on a distinguished road
Smile Rear Springs

Good morning all, Hope everyone is doing well. I know this topic has come up before but hope you dont mind answering it again, I am starting to put my rear suspension together and would like to know what rear springs people are have used. I am using the e36 suspension and I know I have seen people talk about cutting the original springs and then some saying they used lowered ones. I have original ones and the adjusting nut does not fit in the top. Any help here would be much appriciated with what to use and best place to get them.

Thanks

Glen
Reply With Quote
Available from eBay
  #2  
Old 24th January 2011, 09:19
GreatOldOne's Avatar
GreatOldOne GreatOldOne is offline
Senior Member
Enthusiast
 
Join Date: Sep 2005
Location: Northampton, UK
Posts: 1,891
GreatOldOne is on a distinguished road
Default

Glen,

I sent my original e30 rear springs to Marlin to be modified:

They chopped the top couple of turns off, and collapsed one to create a new seat.




At the time, I think the charged me about £15 to do it.
Reply With Quote
  #3  
Old 26th January 2011, 21:35
NigelB NigelB is offline
Senior Member
 
Join Date: Jun 2010
Location: Reading
Posts: 229
NigelB is on a distinguished road
Default

Quote:
Originally Posted by GlenSL View Post
I am starting to put my rear suspension together and would like to know what rear springs people are have used.
Hi Glen,

I spoke with Mark at Marlin about the rear springs for the E36. He tells me he doesn't know yet what springs to use.
He is currently building an E36 based sportster for a customer and told me that once he has sorted out the corner weights and ride height he will let me know what springs he is using. His plan is to have the car finished in the spring (didn't say what year) so we should know then.

But I've already got my 'fall back 'position with a local motorsports company.......!!

Nigel
Reply With Quote
  #4  
Old 27th January 2011, 22:08
GlenSL GlenSL is offline
Member
 
Join Date: Aug 2010
Location: Oundle, Nothamptonshire
Posts: 31
GlenSL is on a distinguished road
Default

Thanks chaps, that would be great to know what Marlin are planning, appriciate it if you could let me know when you hear anything. I too have a fall back plan with a friend of mine who has a rally prep and specialist car business (Qprep.co.uk Plug Plug) Difficult to work out ride heights etc until its on its wheels. Thanks again
Reply With Quote
  #5  
Old 23rd March 2011, 22:46
GlenSL GlenSL is offline
Member
 
Join Date: Aug 2010
Location: Oundle, Nothamptonshire
Posts: 31
GlenSL is on a distinguished road
Default Spring

Hi all, hope you are well, I have spoken to Marlin about sending them my rear springs to cut to length and they told me they are not doing that anymore. So I have to go to plan B, do it yourself!!! can anyone tell me what length they are cut down to.

Thanks G
Reply With Quote
  #6  
Old 25th March 2011, 22:12
NigelB NigelB is offline
Senior Member
 
Join Date: Jun 2010
Location: Reading
Posts: 229
NigelB is on a distinguished road
Default

Quote:
Originally Posted by GlenSL View Post
So I have to go to plan B, do it yourself!!! can anyone tell me what length they are cut down to.
Glen,

I spoke with Mark at Marlin earlier in the week about the rear springs. He hasn't progressed to the stage where the Sportster he is building is off the build stands so doesn't yet know the spring rate and length for the current model. Tim may be able to help though. I think he's the only forum regular that has got that far with an E36.

Nigel.
Reply With Quote
  #7  
Old 26th March 2011, 21:52
peterux's Avatar
peterux peterux is offline
Senior Member
Enthusiast
 
Join Date: Mar 2005
Posts: 3,075
peterux is on a distinguished road
Default

Quote:
Originally Posted by NigelB View Post
Glen,

I spoke with Mark at Marlin earlier in the week about the rear springs. He hasn't progressed to the stage where the Sportster he is building is off the build stands so doesn't yet know the spring rate and length for the current model. Tim may be able to help though. I think he's the only forum regular that has got that far with an E36.

Nigel.
I think Mark must be suffering amnesia or has maybe decided that shortening the original road springs is not such a good idea. The purple colour Marlin Sportster demonstrator (with no windscreen) that was around at Easter 2004 was an e36 based car.


Marlin Sportster by marlinpeter, on Flickr


I can’t really comment on an e36 build but on my e30 build, rather than asking Marlin to shorten the originals, I used some aftermarket springs sold for lowering. There are a few different makes around and quite a strong aftermarket for BMW fans that want to lower their cars.
Mine were made by Apex and turned out to be the right height and spring rate (according to Track developments). I picked up mine on eBay second hand and after a quick wash under the tap looked brand new so had not seen many road miles.

They are yellow and you can see one in this shot....

Bar fitted

There are a lot of new ones on eBay but second-hand ones do come up from time to time. (BTW eBay's daily automatic search feature is really handy for finding things like this)
Might be worth one of you trying this route as a quick and inexpensive step to get you on the road?

...peter
Reply With Quote
  #8  
Old 26th April 2011, 22:00
AndyDane AndyDane is offline
Senior Member
Enthusiast
 
Join Date: Jan 2005
Posts: 148
AndyDane is on a distinguished road
Default

Mines an E36 and I shortened my own springs using excessive heat. It passed the SVA at the time but then failed an MOT the following year. I got some standard lowering springs for mine off ebay at the time but the ride height has gone up quite a bit. My problem was that the shorter springs were in danger of "falling out" when the car was jacked up so the MOT man said they could come loose over bumps.
Sorry but I haven't got a picture to hand...
Reply With Quote
  #9  
Old 27th April 2011, 12:23
GlenSL GlenSL is offline
Member
 
Join Date: Aug 2010
Location: Oundle, Nothamptonshire
Posts: 31
GlenSL is on a distinguished road
Default

Thanks Andy, just one question if you used lowering springs how did you make them fit at the top as the ones I have will not accomodate the adjusting nut that marlin supply.

Thanks
Reply With Quote
  #10  
Old 27th April 2011, 13:39
AndyDane AndyDane is offline
Senior Member
Enthusiast
 
Join Date: Jan 2005
Posts: 148
AndyDane is on a distinguished road
Default

ummm.... I haven't got an adjusting nut... or if I have I've not put it together properly!

The top of my spring literally fits round the bottom of the roll bar tubing...

Andy
Reply With Quote
  #11  
Old 27th April 2011, 23:24
Patrick's Avatar
Patrick Patrick is offline
Senior Member
Enthusiast
 
Join Date: Feb 2005
Location: Hampshire
Posts: 2,495
Patrick is on a distinguished road
Default

I was somewhat horrified at the original suggestion of collapsing springs, I tried lowering springs but they were to high.

I ended up using some E30 coil overs, can't see why a similar solution wouldn't work for E36 based suspension as the damper connections points a pretty similar:





Reply With Quote
  #12  
Old 16th May 2011, 21:18
Will5's Avatar
Will5 Will5 is offline
Junior Member
Kit Car Dreamer
 
Join Date: May 2006
Posts: 22
Will5 is on a distinguished road
Default

I went a visit to get more parts from Marlin a few years ago and got round to talking about the rear springs. They had a set of cut down springs and suggest they should be match to cortina seat (see picture attached).
Attached Images
File Type: jpg Rear Spring Set Up 2.JPG (92.2 KB, 12 views)
Reply With Quote
  #13  
Old 4th August 2011, 19:50
morris's Avatar
morris morris is offline
Senior Member
 
Join Date: Jan 2011
Location: South Wales
Posts: 378
morris is on a distinguished road
Default

Has anybody an opinion on these springs for use on the rear

http://www.merlinmotorsport.co.uk/CO...ex.html?page=3

I was looking at them earlier and although they are designed for coil overs they not only will probably fit the current spring top/bottom mounts but also look very similar in size/style to the prototype ones Mark showed me on the as yet still on the ramp M3 sportster down at the factory.

I was wondering if anyone could give me a length and poundage rating to go on. I was assuming I could take my final estimate for the overall car weight (1200kg loaded) and divide by 4 (assuming 50/50 distribution). I may be missing the point somewhere.

I was thinking 2.25 ID 6" long 600lb at £22 each

They are pretty cheap so if they only do till IVA time they'll probably be worth a shot and if I can get the right ones they could have a life post IVA too.
Reply With Quote
  #14  
Old 4th August 2011, 21:29
peterux's Avatar
peterux peterux is offline
Senior Member
Enthusiast
 
Join Date: Mar 2005
Posts: 3,075
peterux is on a distinguished road
Default

No experience, but it looks like worth a try. It's probably what Mark is doing anyway. I think my car weighs about 750kg unloaded. Somewhere there is a thread on rear springs?

I think Robin (Martinclan) is our spring calculation expert.....
Reply With Quote
  #15  
Old 4th August 2011, 21:31
NigelB NigelB is offline
Senior Member
 
Join Date: Jun 2010
Location: Reading
Posts: 229
NigelB is on a distinguished road
Default

Quote:
Originally Posted by morris View Post
I was wondering if anyone could give me a length and poundage rating to go on. I was assuming I could take my final estimate for the overall car weight (1200kg loaded) and divide by 4 (assuming 50/50 distribution). I may be missing the point somewhere.

I was thinking 2.25 ID 6" long 600lb at £22 each

.
Your loaded weight estimates feel about right which makes me think a bit about the front springs that marlin supplied me with 300lbs stamped on them.

But then I've have absolutely no idea how to work out spring rates....................
Reply With Quote
  #16  
Old 4th August 2011, 21:43
Patrick's Avatar
Patrick Patrick is offline
Senior Member
Enthusiast
 
Join Date: Feb 2005
Location: Hampshire
Posts: 2,495
Patrick is on a distinguished road
Default

Weight bias on mine is towards the rear but only by a few %
Reply With Quote
  #17  
Old 4th August 2011, 21:47
morris's Avatar
morris morris is offline
Senior Member
 
Join Date: Jan 2011
Location: South Wales
Posts: 378
morris is on a distinguished road
Default

750Kg!! I'd assumed the 800Kg quoted by Marlin was a optimistic target. So if we assume 750 + two people at 100Kg and a full tank of fuel we're closer to 1000Kg meaning 250Kg(500lb) per corner.

I'm not convinced that the force quoted on these springs is the weight they will support but either the force they'll exert at full compression or the force per unit length of compression (ie. the rate).

If that's so then after one inch the 500lb spring will give 5" and push up at 500lb and after 2" be pushing up at 1000lb.

Nigel, if I'm right about this then your 300lb springs compressed by 2" in the coilover would be giving 600lb at rest which should be pretty firm.
Reply With Quote
  #18  
Old 4th August 2011, 21:50
peterux's Avatar
peterux peterux is offline
Senior Member
Enthusiast
 
Join Date: Mar 2005
Posts: 3,075
peterux is on a distinguished road
Default

Quote:
Originally Posted by peterux View Post
No experience, but it looks like worth a try. It's probably what Mark is doing anyway. I think my car weighs about 750kg unloaded. Somewhere there is a thread on rear springs?

I think Robin (Martinclan) is our spring calculation expert.....
Search for another thread called 'Rear Springs' started in March 2006.
Lots of food for thought.....
Reply With Quote
  #19  
Old 4th August 2011, 22:14
morris's Avatar
morris morris is offline
Senior Member
 
Join Date: Jan 2011
Location: South Wales
Posts: 378
morris is on a distinguished road
Default

here we go

http://www.madabout-kitcars.com/foru...read.php?t=551

I'd forgotten to take into account the lever effect of the spring being inboard from the wheel too.

on the initial height side I guess there is also a little over an inch of adjustment in the top plates of the E36 car so we only have to get to within an inch of the right length
Reply With Quote
  #20  
Old 5th August 2011, 23:19
peterux's Avatar
peterux peterux is offline
Senior Member
Enthusiast
 
Join Date: Mar 2005
Posts: 3,075
peterux is on a distinguished road
Default

Yes that's the one!

The key quote is from Stuart who had his car set up at Track Developments.....(his car is an e30 based Sportster)

"I took the Sportster to Track developments near Castle Combe. I still have standard springs in the back and Marlin supplied on front coilovers. He recommended the following after doing corner weights and a lot of measurements of the vehicle.

quote:Hi Again Stuart

I have managed to get some more info. At last I have found the formula I needed. Before I was transposing from Metric units and getting conflicting results.

Your choice is :- for comfort go with 250 Front and 260 rear. This would still be stiffer than a family saloon.
For a more sporting set up try 280 Front and 300 rear.
end:"

So I think your suggestion of 600lbs would be too hard. My Apex springs are 291lbs.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +0. The time now is 01:55.

copyright © madabout-kitcars.com 2000-2024
terms and conditions | privacy policy