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These guides will consist of different setups ranging from a basic street configuraton to a motorsport oriented setup depending on how much you want to spend, and how much work you want to put into building your coilovers.
The beginning of this guide will go over the install I did on my 1991 Audi v8. This guide will apply to D11 V8's, T44/C3 200 20v's, and to C4 UrS4/Urs6 cars.
To do coilovers properly on 10v 5000 and 200 cars you will need to convert to 200/v8/c4 rear shocks and upper mounts and 20020v/v8 upper shock mounts on the front and rear of the car.
This first guide will not require any welding at all to help out those that don't have easy access to a welder.
Later more advanced guides will include the need to weld spring sleeve perches and steering arms.
Front
Part Numbers:
2x Koni 86-2149 Sport fronts
Multiple places to purchase from. here's an easy one. Be sure to check other places to get the best price.
https://www.amazon.com/dp/B003620QXK/?c ... _lig_dp_it
2x Coilover sleeve perch
https://www.amazon.com/gp/product/B002E ... UTF8&psc=1
2x Coilover sleeve
A1-12452-H from a1 racing
https://www.a1racing.com/A1_Racing_Prod ... leeve.aspx
2x Coilover spring perch
A1-12460
https://www.a1racing.com/A1_Racing_Prod ... g_Nut.aspx
2x Coil spring top mount
A1-12470
https://www.a1racing.com/A1_Racing_Prod ... r_Top.aspx
UPDATE: Myself and others have used these low profile spring perches from Kaplhenke racing with great success to drop the car a little bit without changing spring travel. I wouldn't use them on the rear as they have a bigger diameter shaft hole and so it will slide around on the rear shock rather than sit on the top.
https://www.bneshop.com/collections/ind ... ring-seats
2x coil spring floater for attaching spring and take-up spring together UPDATE
I prefer to buy things from smaller companies rather than amazon, but I've found that the Eibach spring floater/coupler has smaller edges than the A1 version which is required if you're using helper springs.
Part# Eibach Coupling Spacer SPACER250
https://www.amazon.com/Eibach-SPACER250 ... B000QJJ0AG
The A1 version is fine if you're using tender springs.
A1-12487
https://www.a1racing.com/Coil_Spring_Floater.aspx
2x Eibach XT Barrel 450lb 2.5" diameter 6" Length springs.
I like to use the Barrel springs as normal springs will rub on the shock nut on the inside of the spring and wear it out. You also can occasionally hear it rubbing against it on hard compression. Barrel springs are slightly softer than their straight up and down counterparts so keep that in mind when purchasing them.
Part number for 6" 450lb Eibach XT barrel spring
0600.2530.0450
https://performanceshock.com/index.php? ... fcc7540996
2x Tender Spring (200lb)
https://www.a1racing.com/eibach-0175-25 ... in-id.aspx
ATTENTION
Tender springs will add to the ride height of your vehicle. If you are trying to go as low as possible, you will still have a small fender gap if running tender springs when at the lowest height adjustment setting. Tender springs help with a smoother and softer ride in comparison to a helper spring.
Helper springs will provide a lower height and harsher ride, but you must use a shallower spring connector like one from Eibach instead of a1racing
2x Needle bearing for helping to prevent spring binding when turning.
806990017376
https://www.a1racing.com/qa1-7888-109-c ... aring.aspx
Or
https://www.summitracing.com/oh/parts/q ... /overview/
Or
https://www.speedwaymotors.com/QA1-Coil ... ,6001.html
2x Koni front bump stops
70.34.67.000.0
https://performanceshock.com/index.php? ... ts_id=5496
1x Coil over spring bag, for protecting springs and bearings from dirt, dust, and the elements (purchased as a pair)
https://www.a1racing.com/eibach-esb10-2 ... -10in.aspx
First thing's first. We will need to cut off the factory spring perch.
Get a grinder, a grinding wheel, and go to town on the weld. Be careful to not go deep and actually cut into the strut tube as that's not easily fixable.
Once the weld is mostly ground through, you may be able to smack the spring perch with a hammer and break it off the rest of the way. Once it's broken off you can get to the weld a little easier and get it completely gone.
You can cleanup the last of it with a sanding flapdisk to get it nice and smooth.
Once the spring perch is off you can then attach your coilover sleeve perch.
There are two different ways to do this.
The tried and true method is cutting out a ring and welding it onto the strut tube.
The method I've used for this first guide is using what I've seen called a clamping collar.
It's just a 2 piece ring that is clamped down to tubes.
They look like this.

Here is the one I used for the front struts. They are different sizes on the front and rear so pay attention to the sizes you are getting. They need to be as close to the size of the strut tube as possible for a snug fit.
https://www.amazon.com/gp/product/B002E ... UTF8&psc=1
When you have that clamp on there you can then work on sliding the coilover sleeve onto the housing.
The coil sleeve itself will be too long to fit in between the shock nut and the sleeve perch if you're running your steering arms at the stock length (we'll go into lowering the steering arms later on.)
I was actually able to just cut the sleeve in half and use one half on one strut housing and the other half on the other strut housing. This leaves a little gap in between the shock nut and the perch but I was okay with that for now. If you want to cut costs this will allow you to only purchase one sleeve for the front's if you'd like. If you want the sleeve to run all the way up to the shock nut, order two and cut them as close as possible to exact length from the perch to the shock nut.
The next step is to assemble it all together. Put the gold spring perch onto the sleeve, slide the sleeve onto the strut tube, put the needle bearing onto the spring perch, slide on your bump-stop if you have leftover OEM ones or if you purchased new ones, slide the spring on, put the spring coupler onto the spring, slide the take-up spring onto that, put the top gold spring perch onto the take-up spring, put the factory mount onto that perch, and then bolt it together. it will look like this once you have it all complete. I will add pictures of each step in the future.
ATTENTION
I put a heaping amount of Antiseize all over the strut shaft before attaching the 2 piece perch and then slid the coil sleeve down onto the strut tube as the tolerances are so tight that any paint may get scratched right off of the tube when sliding the sleeve over it. Be sure to do this especially if you live in a climate with salty winters or humidity.
Rear
Part numbers:
2x Koni 80-2630 Sport
https://www.amazon.com/dp/B000RU3VMM/?c ... _lig_dp_it
2x Rear sleeve perches
https://www.amazon.com/gp/product/B002E ... UTF8&psc=1
2x Rear sleeves
A1-12450
https://www.a1racing.com/A1_Racing_Prod ... leeve.aspx
And then the same parts for the spring perch, and top mount.
2x Coilover spring perch
A1-12460
https://www.a1racing.com/A1_Racing_Prod ... g_Nut.aspx
2x Coil spring top mount
A1-12470
https://www.a1racing.com/A1_Racing_Prod ... r_Top.aspx
2x coil spring floater for attaching spring and take-up spring together UPDATE
I prefer to buy things from smaller companies rather than amazon, but I've found that the Eibach spring floater/coupler has smaller edges than the A1 version which is required if you're using helper springs.
Part# Eibach Coupling Spacer SPACER250
https://www.amazon.com/Eibach-SPACER250 ... B000QJJ0AG
The A1 version is fine if you're using tender springs.
A1-12487
https://www.a1racing.com/Coil_Spring_Floater.aspx
2x Tender Spring (150lb)
https://www.a1racing.com/eibach-0175-25 ... in-id.aspx
ATTENTION
Tender springs will add to the ride height of your vehicle. If you are trying to go as low as possible, you will still have a small fender gap if running tender springs when at the lowest height adjustment setting.
(This guide was originally done with helper springs which I no longer recommend due to driveability and spring and spring perch collisions)
2x Eibach XT barrel 400LB spring
0600.2530.0400
https://performanceshock.com/index.php? ... ff0b3fdffc
2x Koni rear bump stops
70.34.53.000.0
https://performanceshock.com/index.php? ... cts_id=756
1x Coil over spring bag, for protecting springs and bearings from dirt, dust, and the elements (purchased as a pair
https://www.a1racing.com/eibach-esb10-2 ... -10in.aspx
I'd still recommend using Barrel springs even on the rear of the car as they will help clear the coil over sleeve. Normal springs can rub the sleeve under normal use and can rub off the threads of the sleeve. I will upload a picture of what I'm describing.
Most will say to run stiffer in the rear of the car to help with rotating the car. I'd definitely fully agree with this unless you're looking for comfort as having a stiffer spring in the rear can kind of upset the normal frequency of the car and gets weird over bumps.
I've listed a 400LB spring part number here but you can easily just replace that with a 450 or 500 spring depending on your needs or wants.
ATTENTION: Because of the welded on factory spring perch design of the Koni's and the thickness of the clamp for the sleeve, anything taller than a 6" spring will not allow you to go as low as you may want. I would recommend against anything longer than 6" springs on the rear.
To start, We'll take the rear shock and attach the collar to it.
Don't forget to slide your bumpstop on. Be sure to use one that looks better than mine as I'm sure mine has crumbled to dust after just a trip down the street.
Next you can slide your sleeve on.
The sleeve itself is a bit long for the way we're doing this. If you can find the same diameter sleeve, but just shorter, that would help a lot here.
Slide the springs on
Before you finish assembling it, you'll want to take your factory rear top mount, and cut it in half essentially so the coilover gold top mount sits closer allowing more thread engagement on the top nut.
Some of my photos went missing that I took during this process. I will update later with a proper photo but will try to get the point across with the photos that I do have.
Here's a photo of the rear suspension without cutting the top mount. Photo provided by Chris(loxxrider) in his original T44 coilover thread where it all began.
Here's one after cutting it.
It is HIGHLY recommended to cut this, otherwise there may not be enough threads to safely tighten the nut
Once that is cut you can assemble and install
Links
To find part numbers for potential springs you can use the tool on Eibach's website here:
https://eibach.com/us/c-109-products-mo ... rings.html
Ground control also has a selection of barrel springs for sale. Not many of them are actually stiff enough but there are a few in the 6"-7" range that are stiff enough.
https://groundcontrolstore.com/collecti ... e8n4P11Udg
Other locations to find Barrel springs
https://www.resuspension.com/index.php/ ... x-2-5.html
Reseller I prefer to purchase from
https://performanceshock.com/index.php? ... ff0b3fdffc
Spare Coilover perch set screws
https://www.a1racing.com/A1_Racing_Prod ... Screw.aspx
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