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Login to post Forums » Grassroots Motorsports » Cutting springs - (cut twice and still too low)

May 19, 2008 11:27 p.m. Nomad New Reader

OK, I'm embarking on a little project here.

Useless backstory: I've got a 2002 Protege5 for fun daily driver status with eibach prokit springs and the struts have finally given out up front. I stumbled on to a set of Mazdaspeed Protege racing beat springs. I've got newer struts to go in and am going to swap out the Eibachs for the MSP springs since it's just a daily and I can sell the Eibachs to help get springs for my E30.

Problem: Others have tried installing MSP springs and nobody tries anymore because the rear ends up 1/2" lower than the front and it looks "odd".

My Goal: Make the front match the rear by lowering it 1/2" to get a nice even stance. The springs are linear and stiffer than OEM, and would end up being a tad higher than the Eibachs which is not a bad thing for daily driving and keeping the struts alive.

The solution: Cut the front springs. How would I determine how much to cut off? I figure a 1/2 coil should do it but don't want a situation where that ends up being way too low and I can't go back. Should I just do 1/4 coil at a time? do lots of deinstalling and reinstalling. Any way to tell the compressed height of the spring after removing 1/2 coil? Only looking for 1/2" max decrease installed height.

I've got my sawzall and wd-40 ready
May 20, 2008 12:14 a.m. RealMiniDriver New Reader

Lift it, pull a wheel off, then lift with a jack on the suspension so the hub is at wheel center height, compressing the spring to what it would be like if the wheel was on, on the ground. Measure from one coil to the next. Whatever that height is, is how much removing one full coil will lower the car. If you want half that height, cut half a coil. You get the idea.

I just cut the springs on my Sonoma and the coil to coil distance was 2". I cut one coil and got 2" lower, even though the coil flattened out at the top.

Cut slowly. You don't want to add alot of heat, springs don't like that. I did mine with a cut-off wheel, a little bit at a time, dunking it in water to keep it cool.
May 20, 2008 12:14 a.m. SkinnyG New Reader

Struts, isn't it? Cutting off one "dead" coil would lower it approximately the thickness of the dead coil. Possibly a touch more. Struts are somewhat predictable that way.

The double-wishbone of the Sonoma will drop much more per coil than the strut front end would.
May 20, 2008 6:01 a.m. 914Driver None

Drive it for a while before whacking, it may settle in and level out.

Dan
May 20, 2008 6:55 a.m. moxnix None

914Driver wrote: Drive it for a while before whacking, it may settle in and level out.

Dan

Not going to happen.

The MSP has a different (higher) rear perch height than any of the other proteges or aftermarket shocks. If you had MSP shocks it would ride at the correct height. You could also try shimming the perch in the rear to get the correct height.
May 20, 2008 10:11 a.m. ditchdigger None

if you have room between the upper spring perch/hat and the strut bearing you could modify the mounting point of the spring hat to lower the front of the car without cutting springs.

I did this to the upper perches on my E30 and brought the front end down just over 1/2".
May 20, 2008 2:11 p.m. Nomad New Reader

I like the position the rear sits from other people's pics, it's almost the same as the Eibachs. I plan on using a sawzall with a good metal cutting blade and WD-40. I don't want too much heat in them as you said.

I like what you did with the E30 hats. I need to look into that. I have no welder but that looks like a great option. I'll look at shimming the rear but I'm not sure I can do that. I have a set of struts already so I'm trying to avoid spending real money for MSP struts.
May 20, 2008 5:17 p.m. RealMiniDriver New Reader

moxnix wrote: If you had MSP shocks it would ride at the correct height

Shocks have nothing to do with establishing ride height. Ride height establishes what length shock is required, however.
May 20, 2008 5:53 p.m. moxnix New Reader

RealMiniDriver wrote:
moxnix wrote: If you had MSP shocks it would ride at the correct height

Shocks have nothing to do with establishing ride height. Ride height establishes what length shock is required, however.

That actually depends on the shock/spring design. On cars with separate springs and shocks that might be true(I don't know anything about those type) but on car like the miata (GRM demands that a miata be used as an example) it uses a coilover shock and the perch height on that along with the spring determines the final height of the car (Koni's for the NA come with 3 different perch heights available)

On the protege they are actually MacPherson struts not shocks like I said but the perch height on the strut and spring length/rate still determine the final ride height.
May 20, 2008 5:53 p.m. Nomad New Reader

The MSP spring perch is mounted a bit higher up on the strut than the OEM Protege5 spring perch. That's why the comment about the MSP struts being needed.

The difference in ride height from stock to this new height will not require shorter struts. The OEM struts will still be in their effective range.

But yes, your comment makes sense if I were starting from scratch.
May 20, 2008 11:19 p.m. RealMiniDriver New Reader

True, struts and coilovers are different than seperate spring/shock. I've only messed with coils and leafs on my truck and rubber cones on my mini, both vehicles with seperate shocks. :grin:
May 21, 2008 12:24 a.m. Nomad New Reader

don't get me started on rubber mini cones! :evil:

Those things were a paint to get off, but the sawzall did the job eventually. Put coils on a friends mini, he didn;t buy the adjustable rear trumpets so it was a real treat to get those together and was not a fun ride home for him.
May 21, 2008 4:48 a.m. foxtrapper New Reader

http://www.auskellian.com/paul/links_files/spring%20free%20length%20calculator_v7.xls
May 21, 2008 12:43 p.m. skruffy Dork

Nomad wrote: Others have tried installing MSP springs and nobody tries anymore because they aren't significantly stiffer than what came on the car stock.
Fixed

I don't think you'll be happy going back to a stock spring. You've already got a set of springs that do what you want, why are you trying to make springs for a different car/shock combo work?

PS: I've got s-techs on my p5 with stock shocks. Pretty low and still a tolerable ride.
May 21, 2008 2:33 p.m. Nomad New Reader

Referring back to my useless backstory section. I can sell the Eibachs and buy springs for my E30.

The P5 is a commuter that is fun to drive, but it's short on potential.
May 21, 2008 6:46 p.m. RealMiniDriver New Reader

Nomad wrote: don't get me started on rubber mini cones! :evil:

Those things were a paint to get off, but the sawzall did the job eventually. Put coils on a friends mini, he didn;t buy the adjustable rear trumpets so it was a real treat to get those together and was not a fun ride home for him.
I ditched the rubber cones for coils, too.
May 5, 2011 8:31 p.m. aussiesmg SuperDork

canoe struck
May 7, 2011 8:43 a.m. Javelin SuperDork

canoe strike round 2
May 9, 2011 6:41 p.m. OldGray320i New Reader

ditchdigger wrote:

if you have room between the upper spring perch/hat and the strut bearing you could modify the mounting point of the spring hat to lower the front of the car without cutting springs.

I did this to the upper perches on my E30 and brought the front end down just over 1/2".

I've done this to my old 280Z and my 320i. A 1/2" is about all you'll get though. You can usually find a machine shop to do it, I think it was somewhere between $80 and $100 on the 320i (for the Z, I knew somebody who had a metal manufacturing facility - free!).

You could also do some bone yard shopping, see if you can find something with a lower height to fit. I want to say I saw somewhere that E46 strut hats fit E30s, and drop the front 1/2" or so, so the idea is not unprecedented....

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