W8N2SQZ

iTrader: (6)

Terry I would say that it is about 1/2 maybe a little more. I have done that same thing. I like the way the car looks with the Eibach pro front springs and the rear stock springs without the rubber spacer on top. Just my 2 cents.

Glenn

Pro Stock John

iTrader: (34)

It's more like a one inch drop Terry.

I have had my car like this for a year years since the 9" makes the back of the car sit up.

After a few years the radiator hose is not split and is doing fine.

OBSSSD@work

Don't take the rubber spacer out. Cut the spring 3/4 of a coil and you'll be almost an inch. What I did was get some LT1 springs and I cut them 3/4 of a coil. The car sits dead level and it squats hard on launches and that's with a wussy 3500 Yank in it on Nitto's.

The rate will be unsignificantly affected. My father designs coil springs for Rockwell and he cut his on his heads/cam Z28. What does that tell you?

Again, do not remove the rubber piece in the rear.

Next week the PT4000 is going in - I can't wait!

Pro Stock John

iTrader: (34)

I have read that cutting stock springs is a no/no but cannot back it up, but I can defend the !spring cushion mod by saying I have like 12,000 miles like this and there is not real downside.

Mike Hoffpauir

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by OBSSSD@work:
<strong>Don't take the rubber spacer out.

Again, do not remove the rubber piece in the rear.

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Why not? I've pulled mine out and had NO problems.

Could you substantiate this advise?

Colonel

Yeah, just pull the spacer (why not OBSSD?) and replace it with a some thin rubber. Many have done it (myself included) and it works like a charm for lowering the rear without any negatives.

Pro Stock John

iTrader: (34)

First time I started doing this was in fall of 2000 got this advice from Madman.

OBSSSD

Well the company I run manufactures and distributes leaf and coil springs to OEM customers. We sell 50 million dollars/year and I'm telling you cutting the springs with the stock doughnuts in place is the best option.

I wasn't planning on writing 2000 words on raw steel chemistry, heat treatment of alloy steels, and factors influencing spring rates but I guess I could consider it if it's that important.

I'm not saying you'll have problems either way, just offering an engineer's opinion to the forum. There are no detrimental effects to cutting the spring unless you lower the car 2-3" and the shocks are bottomed out before you even take off.

If you want to take the doughnut out by all means please do, but I'd rather leave that nice sound deadening device in place while I cut the coil. JMO for whatever it's worth...

Pro Stock John

iTrader: (34)

But I was told that cutting the stock springs changes the rate, what does that mean?

I drove around without the cushions OR sleeving for an afternoon. Sounded like stuff was breaking off the car. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

The radiator hose trick works fine, no noises at all.

Mike Hoffpauir

PSJ, if a spring is a progressive rate spring it means that as the spring compresses it takes more force to compress. So as the suspension travels up it gets more and more difficult to do this traveling.

If you were to cut a progressive spring you would affect how stiff the spring is in comparison with the amount of suspension travel, and probably end up with a rougher riding car. A little movement would effectively put the spring where alot of movement used too.

But if the spring is a linear spring there should be no adverse affects when cutting it other than losing that nice flat coil seat.

GeorgeC

I've done both before with no ill affects from either one. Stock rear springs are available cheap from SLP (AFAIK they still are, anyway), so you don't really have much to lose no matter which way you go.

FWIW, if you remove the rubber isolator, I'd use some nice thick heater hose on the spring vs. a thin flimsy piece of garden hose.

NastySSoo

Myself, and three of my racing buddies have cutoff one coil. We measured before and after, it dropped the rear one inch. You feel no difference at all driving it. I did it last week than went to the track that night and got my best shorts ever. I dont know if it was because of the springs as the track was hooking very well, but it definately didnt hurt!!! My 02

OBSSSD

Stock springs front and rear on V8 f-body's are linear springs so cutting them will affect the spring rate less than 5% which is not noticeable.

Spring rate on a coil spring is a factor of the wire diameter and the spacing between each coil. It is usually measured in pounds per inch (#/in). In other words how much force will it take to compress the spring an inch. For example the stock front springs are 290#/in. The 1LE springs are 360#/in - so they are stiffer for roadracing and high g-forces. A progressive front spring like the Bilstein may be something like 250#/in - 400#/in. So the spring rides well under a lighter load (normal driving) because of the lower (250) rate. But when pushed down and the lower part of the coil engages it will resist compression at a much greater rate because of the higher spring rate (400) at the bottom. This is how the Bilstein acheives a better ride under daily driving conditions than a 1LE.

The problem is that progressive front springs suck for roadracing because the front can deal with a linear load under racing conditions and maintain better control than a progressive setup.

In a nutshell the doughnuts are there for a reason. Why put radiator hose in your suspension when you're driving at very high speeds when you can cut the coils with equal to better results? I've done this on about 20 cars guys and this is my job every day. Just as a guideline cutting a full coil will lower the car more than an inch. I have found cutting about 7/8 of a coil will get you around what you need - dead level with the front at the stock height.

Whatever you do - good luck guys. Hope this helped...

Terry Burger

iTrader: (4)

I'm happy with my spring rate, but I'd like to lower the rear of my car 1" or so. Can I just cut 1/2 a coil off the stock rear springs? How will that effect the spring rate? (Will it go up or down).

Thanks!

Terry Burger

iTrader: (4)

I'll probably cut a full coil off. I'd like to get the back down more than removing the isolators will allow. Thanks for the tips. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

CHRISPY

I wouldnt do it, you will get lots of bounce. The stock springs are progressive rate AFAIK and you will not enjoy the ride too much. Might fu@k up your traction at the strip too.
Chris

Terry Burger

iTrader: (4)

So you think the spring rate will go up?

JAS

Terry - Just take out the rubber OEM spacer at the top of the spring and take a piece of garden hose or equivalent and pull it over the first spring coil to isolate the spring from the body. Free mod, effective drop, and it's worked for 3 years now. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Terry Burger

iTrader: (4)

JAS that's about a 1/2" drop right?

Colonel

"In a nutshell the doughnuts are there for a reason. Why put radiator hose in your suspension when you're driving at very high speeds when you can cut the coils with equal to better results?"

Ok, what reason? To prevent noise transfer to the body, right? Right. And you can do the same with a simple piece of inner tube. Many, many have done it and not one single person has ever reported ANY negative effect (nope, not even at those SCARY high speeds!) So why do it? It's a helluva lot easier than cutting the springs, it's easily reversible, and it won't effect the spring rate in the slightest. Not even the formerly mentioned %5.