Rear Springs - Page 4

Chris Cussen · #61 14th June 2010, 07:22

I think that somewhere like Merlin Motorsport at Castle Combe can measure your spring's characterisitcs. (I can't get on thier website from work to confirm this though).

I would have thought that other motorsport suppliers can also do the same if you have one that is local.

morris · #62 8th November 2011, 17:54

Hi All,

Been back through all this and came to the conclusion that as I'm E36 based I'll follow mperman's suggestion and go for these as a first attempt

http://www.merlinmotorsport.co.uk/p5...duct_info.html

They are close to the
REAR
MR = 0.63
WR = 90lbs (220lb spring, freelength 8")
Freq = 1.24 cps (softer than front)

he quoted being 225lb, 2.25" ID 6" length

Only difference is that the free length is 6" not 8". Does this affect the calculation. I can't see the free length figuring in any of the equations directly but I may have missunderstood.

I've gone for 6" as that's the maximum travel my dampers allow so any extra length is just more hard work compressing them in the first place.

When the half shafts are almost horizontal (just sloping diff to hub slightly) the length with the top adjuster at a low point (40mm of lowering left on the thread) is 5".

I suppose another way of looking at it is if I go for the 8" at the lowest ride setting then there is no chance of them popping off where as with the 6", if I adjust to the lowest they could just about slip out of position, not that I plan spending much time shooting through the air dukes of hazzard style.

In this case the best option is
http://www.merlinmotorsport.co.uk/p5...duct_info.html

peterux · #63 9th November 2011, 21:18

My e30 based car has 291 lb/in springs at the back that were 185mm free length before fitting. The car is on the firm side but any softer and I think the car would ground when going over large humps or dips in some roads.

Now that Marlin have finished their latest Sportster, it might be worth checking with Mark what he now recommends?
(assuming the car at Exeter had some springs fitted?

)

morris · #64 10th November 2011, 17:55

Hadn't realised the factory car was actually done, have sent the question off to Marlin. Hoping they can give a definite answer on what spring rubbers to buy too. When I hear back I'll post the answer

peterux · #65 10th November 2011, 20:51

Chris Cussen posted some pictures under the 'New Hood' thread...

http://i913.photobucket.com/albums/a...1/IMG_8126.jpg

(...and I've just noticed it has Willwood rear brake callipers)

morris · #66 17th November 2011, 17:44

Terry has come back and said they still need to do road testing before confirming the springs so I still don't know which ones to get

Don't really want to waste £50 on a pair of incorrect ones but at this rate I may have to take the risk as otherwise my rolling chassis by christmas plan won't come off

morris · #67 22nd November 2011, 17:28

Terry has told me the testing is all done and they've placed an order with their supplier. they're going to be ~£20 each + VAT which is a fair price compared with what else is available off the shelf. There's going to be about a 4 week wait so I may get them in by christmas, just.

Still don't know what rate they will be but once they turn up I'll let you know the details

NigelB · #68 22nd November 2011, 17:55

Quote:

Originally Posted by morris

Still don't know what rate they will be but once they turn up I'll let you know the details

When I was talking to Mark at Exeter I asked him what springs he used on the back and he told me they were 300lbs/in and confirmed that was the same as the front.

But then I was also told that the car had failed IVA on emmissions because the engine was too clean..............??

peterux · #69 22nd November 2011, 20:18

Quote:

Originally Posted by NigelB

But then I was also told that the car had failed IVA on emmissions because the engine was too clean..............??

Patrick · #70 22nd November 2011, 21:25

I think my rear springs are 280/290 ish which is what GAZ recommended for my coil overs

NigelB · #71 6th January 2012, 23:37

Quote:

Originally Posted by morris

Still don't know what rate they will be but once they turn up I'll let you know the details

Any news on the new springs and what spring rates Mark has used on the latest sportster. I've still got solid springs at the moment (a couple of pieces of 2"x3" softwood from a stud partition wall!!) and I'd like to get some bounce at the back.

Nigel

morris · #72 7th January 2012, 08:42

Afraid not. Originally I was told 4 weeks, after 5 I chased them and they said there was a supply issue so it would be after christmas. I did ask for the spring rate so I could just grab some off the shelf but they refused to tell me

I was going to chase today as it's starting to get a little bit silly as I need to roll the car out of the garage so I can get the engine in. I had thought of doing the same as you but using some thick walled plastic tube but I should be able to pull together some wood to do the same. I just had horrible visions of something slipping out

morris · #73 10th January 2012, 11:39

Nigel,

Terry got back to me had has said the springs will be with me by the end of this week

so I'd give them a call and get your name down too.

Still not sure what to do about spring rubbers though. I may make my own or just go without and see how noisy they are

GreatOldOne · #74 10th January 2012, 11:47

Can you not reuse the rubber spring seats from the donor? I managed to to modify mine to fit the marlin mounts.

NigelB · #75 10th January 2012, 13:22

Quote:

Originally Posted by morris

Nigel,

Terry got back to me had has said the springs will be with me by the end of this week

so I'd give them a call and get your name down too.

Still not sure what to do about spring rubbers though. I may make my own or just go without and see how noisy they are

Hi Ian,

I've taken the plunge and gone for a pair of Faulkner 300lbs spings with a 6 inch length. I measured between spring seats with the rear wheels at there lowest point (governed by the shocks) and at the shortest distance (the sping seats aren't parallel)I had 6 1/2". I figure I can then use the adjustable seats to get the right ride height and to ensure the springs are still slightly under compression at the lowest point of suspension travel so that they don't jump off. I think it will work or it could be a pricey 'suck it and see'.

Why are Marlin being so secretive. Its not as though they can make big margins on springs. Unless they use buy cheap springs to start with. (which was the opinion of the motorsports outfit I talked to when I changed my front springs a year or so ago)

oaktree11 · #76 10th January 2012, 14:19

I am seriously considering going down the rear coil over route. As far as I can see only Patrick has done this so far.

My bumpstops are way out of line so i have to address that and frankly, the coil over seems to me to be a much more elegant solution anyway.

I have looked at the Gaz ones. Can you buy the rears alone or only in sets? I have two front ones.

Are thgere any problems with them fitting in to the rear turrets?

Any advice is welcome! - John

morris · #77 10th January 2012, 19:45

The rubbers from my donor were pretty worn so I binned them. Also because the new kit comes with replacement seats that bolt or weld into the rear suspension top arms, the old rubbers are too narrow in the centre and you'd have to cut loads out anyway. I think what I'll do for now is take an old floor mat and cut it up while I decide what to do (it's not like I haven't got a few years before IVA to think about it).

Nigel, you've done what I didn't have the balls to though you may have got the better spring. we'll see what they're like when they turn up.

I don't know why they don't want to share the info. I did say that I couldn't see the problem as it's just a spring but they want to protect the investment they've put into the recent changes I guess.

I've noticed that the spring seats aren't parallel too (the bottom is about 30-40mm inboard from the top mount) but it was after I'd already bolted mine into the top arm. I need to take them out anyway to fit counter sunk screws so at the same time I intend cutting out the inner half of the original seat so the new one can move outboard a bit. Hopefully cutting this part won't compromise the strength of the arm too much

MartinClan · #78 11th January 2012, 07:44

Quote:

Originally Posted by oaktree11

I am seriously considering going down the rear coil over route. As far as I can see only Patrick has done this so far.

My bumpstops are way out of line so i have to address that and frankly, the coil over seems to me to be a much more elegant solution anyway.

I have looked at the Gaz ones. Can you buy the rears alone or only in sets? I have two front ones.

Are thgere any problems with them fitting in to the rear turrets?

Any advice is welcome! - John

My Bumpstops were also way out of line. Several people have had this problem. I fixed it by drilling out the spot welds that hold the spring plates on the suspension arms and removing them. I then made up some new ones and fitted them where they did line up! It was quite simple to do and I incorporated adjustable bump stops while I was at it...

oaktree11 · #79 11th January 2012, 10:51

I saw the way you did it and in fact have bought a spot weld cutter to emulate you but then I got to thinking about coil overs....

Bobnic · #80 11th January 2012, 18:16

My bumpstops seem to line up ok, but not sure how different the rear suspension is on an E36 M3 compared to others. Also, I heard from Terry today and a batch of springs are on their way to them, so hopefully will be the ones for the job! No mention of spec of them though, sorry.

Rob