Cutting the rear springs on a GT

[Slopel]

did a few searches, but did not find any solid info.

Cutting coils off the bottom of the spring, should I just start with 1/2 coil , or would I be safe cutting an entire coil off.

the car is being lowered ~2" up front with shackels, and new shocks are coming. I do not want a 'raked' look. I like when the rear is sitting flat with the front. Any advice would be greatly appreciated.

[nobody]

Ok I know it will be ill recieved but for a 2 inch drop is about 1 1/2 coils removed. Rear will be a bit soft unless you add a real stiff antisway bar and stiffer shocks. Look at your panhard rod too, it will be too short. A 2 inch drop crosses the fulcrum point unless you raise the body mount side for the panhard. Do a search for adjustable panhard and you will see a few things. Mine is lowered so I've been down that road.

[simplemind7]

actually i was thinking of doing the same thing, but i've heard alot of bad things about it, poor ride and what not. but without the money for the proper way to lower it, and an extra set of springs kicking around, seems like a possibility. i don't know if the experts will be speaking too highly of the idea, but at least its cost effective

[CDN OpelNut]

When I Installed my front sport spring from OGTS, it came with a note that indicated that only up to one coil can be cut off or the springs may jump out of the hats under hard cornering.

[baz]

i dont like the idea of cutting of coils
i much prefer the proper way
have a spring company reset the hight and then retemper to a harder spring rate
thats what happens when you have a blacksmith on the site

[RallyBob]

Originally Posted by CDN OpelNut When I Installed my front sport spring from OGTS, it came with a note that indicated that only up to one coil can be cut off or the springs may jump out of the hats under hard cornering.

I don't see any real problem with cutting springs as long as all the side effects are taken care of.

1. One of them is the panhard bar length, as Nobody has stated.
2. Make sure the coils are cut from the bottom, not the top, so the spring sits correctly in the seats.
3. Check the bumpstop proximity to the axle. You may have to trim them to avoid early bottoming out.
4. Lastly, the spring rate will increase with the cutting of the coils, and the length of the coils will naturally be shorter, so they in fact may fall out of the seats if the car is jacked up or under hard cornering if you lift a tire. The rear shocks should be shorter than stock in order to prevent bottoming out the shock shaft, as well as limiting suspension droop and the potential for a spring falling out of it's place. It should also be stiffer to dampen the cut spring's higher spring rate (and therefore the spring frequency is higher).

Bob

[GTJIM]

Far better to have coil springs reset and retempered to a shorter length than to "hack" coils off! GT rear springs are old and tired by now and retaining all the coils and retempering done by a proper spring shop will usually give better results and maintain spring rate.

[simplemind7]

around how much would the retempering cost?

[GTJIM]

Originally Posted by simplemind7 around how much would the retempering cost?

Just look up "Springs" in the Yellow Pages of your local telephone directory and find a Spring Maker and ask - it is usually surprisingly inexpensive. They can even make whole new springs with diferent diameter wire and number of coils if you need a diferent spring rate for "off-roading"

As Bob says, it is OK to cut the spring if necessary.

[GT_Pheel]

I was told to use a set of wagon springs since they have a larger gauge wire coil. I have the set, but am on hold while moving everything to my new place with a two car garage....ie more project space. I have a large project ramping up over the next few months and will start posting more as things come together...2.4 L bottom end, 2.0 L head, dual side drafts, interior mods, and suspension mods will eat up a bit of my time. I would also like to see an educated comment as to where the spring should be cut and why... If the thin (flat/ground) part that locks into the rear end is cut, it seems that the spring would be able to move around too much if the suspension is unloaded. I am prepared to experiment a bit, but would rather make use of the knowledge base here. Thanks,

Philip

[GTJIM]

Originally Posted by baz thats what happens when you have a blacksmith on the site

So that is what "baz" is short for: Black (a) Zmith!

[nobody]

Not that my feet are entirely made of lead or anything. Just past 110 is where the springs start to compress, around 130 it starts to get light again. Even at 150 the nose with the 2 inch spring doesn't budge. From 120 on the lowered rear end was a handfull. It has a tendency to change on you at speed and I could feel it. Roll rates with a lengthened panhard are all backwards too. It wants to go the wrong way on you and makes it a bitch to control. I have cut springs and the adjustable panhard is ready to install.

[jeff denton]

Or you can do it the way I did, which is essentially the same concept as adding a lowering block to a leaf spring car. You just lengthen the spring buckets! It was really simple, does not change any geometry except you still have to raise the panhard bar mount on the chassis. The only thing it does is raise the axle into the body. Like a lowering block. There are some pictures in a thread about this, look in Rally Bob's "adjustable panhard bar" I think you'll learn a bunch about it there.

[bosco]

I must have gotten lucky, maybe. I just installed a front sport spring and had planned to cut the rear springs to suit but as it turns out the rear springs are so sagged-out that the car looks nearly level. With a measure I was able to determine that the top of the fender opening in the rear is only 3/4" higher than that in the front so maybe the most I need to cut is half a coil and I'm assuming that wouldn't create a world of difference for me....?

Also...I had heard that the ride was alot rougher with the sport spring but I don't even notice that to be the case. It does corner much better tho.

[Derek Greenwood]

I have been cutting coil springs on Opel since 1977 when I did my 75 Manta. If you cut the coil and make sure what is left touching the seat is flat they work fine. I used to use a strap attached to the bottom and top of the shock mount to make sure the spring didn't become loose in its purch. Just like everyone said, fix the panhard rod length, make sure the shocks are good, the bushings are fine and it doesn't bottom out on the bump stops and it will work just fine. If you do the math on the spring you can figure out what the new spring rate will be when it is cut. It will of course become stiffer.

[svopel]

I used to use a strap attached to the bottom and top of the shock mount to make sure the spring didn't become loose in its purch.

Derek, how would a strap attached to bottom and top shock mounts keep the spring in place? I've heard of tethers being used to keep springs in their perchers, but never seen it done. The reason I ask is that I might need a "tether" to keep some springs in their perches that I had custom-made (made by "Coil Spring Specialties"). I haven't yet been on the road/track with these springs, but it would appear that with any lifting of a wheel the spring would fall out. Anyway, there are other specification issues with the springs they made for me that I am trying to get them to address.

Ken

[bosco]

Would the best method of cutting springs be to use a carbon blade in a hack saw???

[GTJIM]

Originally Posted by bosco Would the best method of cutting springs be to use a carbon blade in a hack saw???

An abrasive cut off disc in a disc grinder makes short work of it .......

[soybean]

Slopel, Here are two threads to read, however "Nobody and RallyBob" have the most experience in this area and I would defer to them. Jarrell
http://www.opelgt.com/forums/showthr...hlight=springs

http://www.opelgt.com/forums/showthr...hlight=springs

[Derek Greenwood]

The "tether" won't let the shock extend beyond a certain point. I have used them on Opels since 1977 and used them on my 1966 Abarth vintage race car.

[jeff denton]

A chop saw will eat right thru in five seconds, a cutting torch will get it in about three. If you don't have these, take the springs to a welding shop at coffee break time (ten am) and bring a dozen donuts. Done. Cheap.

[baz]

Originally Posted by jeff denton A chop saw will eat right thru in five seconds, a cutting torch will get it in about three. If you don't have these, take the springs to a welding shop at coffee break time (ten am) and bring a dozen donuts. Done. Cheap.

now jeff you know theres a bad case of fattyitis in the welding industry and bribing the poor folks will only make it worse
i can say this as when i am not on my diet i weigh in @ round 250 LB
give me 2 years @ the rate i keep going on it and i will be down to my birth weight

[nobody]

torch about 5 seconds. I know.....whip me, beat me call me bad names for using a a torch on spring steel. For you that don't know, heat can take the temper out of springs real quick. If you use this method be very quick about it.