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Wingless Wonder
1988 Esprit Turbo
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My winter project is new shocks all round and I need some help on what is the best for my 1983 Turbo Esprit. I have Good Year front tires and rears are P600 Pirellis all brand new. So your thoughts???
Spax shocks are widely available, ask the usual Lotus Parts suspects what fits your year. But frankly, I'd get some miles on the car before determining that you need shocks on a 22K mile car.

If you go ahead with the shock or spring replacement, inspect the rubber suspension bushings. (Especially the sway bar to lower control arm on your '83) You MAY want to refresh those at the same time.

Its only money after all. :crazyeyes
 

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Integrator
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2,764 Posts
Like the title of this thread states "lower cost Bilstein option" - the same results can be accomplished buying components piece by piece on eBay (read previous posts), for a fraction of the cost of currently offered "kits".
When you changing shocks, the most important is to get adjustable dumping and adjustable perches to control car balance, corner preload and ride height.
Balancing corner weights on the scales would be the ultimate goal.

Remember, the static preload = spring rate x static compression in that corner. Preload can be changed only by moving the mass away or into the corner or adjusting the ride height. Spring rates never change.

Like Atwell said, drive your car for a while and determine any shortcomings. It is a highly subjective "seat of the pants dyno" experience.
LOL

Meanwhile read everything on the subject to get the feeling what can be or was done by others.
Start here: Turbo Esprit Wiki - Esprit.TechnicalData
 

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Let me throw this out there, please tell me if I'm in the ballpark.

I have Spax shocks and want to replace the stock springs.

I run the car normally with stock wheels, I have Proxes4s (245/50-16) on the rear and R1Rs (225/45-15) on the front. The fronts are stickier to mitigate understeer and I'm pretty happy with the balance.

There's way too much body roll with the current setup and I can't get the front down as low as I want. I do like the ride quality for normal street driving and want to avoid an overly harsh ride.

Next year I plan on tracking the car. I have a set of Ronal 17/18 wheels that I may put R-comps on for track days.

I'm thinking Eibach springs, 2.5" ID, 12"-275lb/in Front and 12"-300lb/in Rear. Does this sound about right?
 

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Wingless Wonder
1988 Esprit Turbo
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5,643 Posts
Pete, body roll does not necessarily cause a car to handle poorly.
Might cause the driver to toss his cookies, however...

Most Esprits roll more in the corners than is typical nowadays.


For a few track days a year, you are best off optimizing the 'nut behind the wheel'. (That is, spend your money on a driver training course, rather than your suspension.)
 

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You can't make this up
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1,167 Posts
Spax shocks are widely available, ask the usual Lotus Parts suspects what fits your year. But frankly, I'd get some miles on the car before determining that you need shocks on a 22K mile car.

If you go ahead with the shock or spring replacement, inspect the rubber suspension bushings. (Especially the sway bar to lower control arm on your '83) You MAY want to refresh those at the same time.

Its only money after all. :crazyeyes
What was your credit card number, I seemed to have misplaced it

lol
 

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183 Posts
Adapters for QA-1 bushings have to be made (chrome-molly steel).
Hi Mr. D.:

As I am ordering the QA1's this week, and am planning to have the adapters for the QA1 bushings made this spring, could you please post an image of the completed chrome-moly adapters?

I realize "Dimension B has to be calculated after you measure the distance between walls of the lower control arm opening,(A)" but it would be nice to see a completed representation of the finished product as used with your car.

Also, could you again post the part numbers for the front and rear thrust roller bearings (ebay or Amazon)? [I have the rears, but lost the numbers for the fronts (and posting the rear PN's should help those new to the thread)]...

Cheers,

Scott
 

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I am thinking we should put together a spreadsheet of this information so we can easily reference it moving forward regarding suspension parts. This way we could see what brands of suspension we've actually used and what associated parts were needed to make them work. Might be easier than having to search multiple threads and posts. Just an idea. I'd be happy to create a google spreadsheet to get the ball rolling...


Sent from AutoGuide.com Free App
 

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Integrator
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It is very simple, even without a spreadsheet.

In the nut shell, the lowest cost "Bilstein option" looks like this.
Shocks, MY to MY, are the same, just different springs were fitted.

1. Get 4 Gaz adjustable shocks w/adjustable perches from:
Gaz Shocks | Performance shock absorbers | Suspension Kits | Adjustable suspension kits | Camber adjusters | Top Mounts | Premium height adjustable suspension kits

(read previous postings for contacts). When you call or email, give them your car model and year and specify ID of the coil over springs you currently have on your car (or you intend to use). Specify diameter of the perches. They know what your car needs, they have all the specs.

2. Get misc components, like seats and thrust bearings, per posting #128
3" ID rubber seats for rear springs can be bought from JAE, just call Jay.
Front seats are abundant and cheap on Amazon

3. Purchase Eibach springs from eBay/Amazon according to your ID diameter and a chart below.
You want 2.5" ID, 10" long +1" Coleman spacer at the front.
Rear:
Pre-89 cars had 3" ID springs, 14" long. 89 and forward- had 2.5"ID springs all around.
Note: if you intend to use any other shock type/brand, buy shocks first Using shock geometry measure/calculate spring adjustment range and preload.
QA-1 has excellent double adjustable shocks, Proma Star (2.5" perches only), but they are more expensive ( QA1 Shocks, Suspension, Driveshafts & Rod Ends | Street Performance, Hot Rods, Drag Racing, Circle Track Racing, Industrial).

OEM Spring Rates
88 Federal & non-SE 89: (17% anti-dive geometry),
Front: Rate– 22.8 N/mm / 130 Lb/in, Free Length–369mm (14.5”), Static Length– 203mm (10”), 585-610# preload, ride hgt 170mm
Total with ARB in the corner = 270 lbs/in; ARB rate=0 in the straight line motion
Rear: Rate– 27.5 N/mm / 157 Lb/in, Free Length–334mm (13.15”), Static Length– 205.7mm (8”), 800-850# preload, ride hgt 170mm
ARB: 17.5 mm dia. front anti-sway bar, confirmed! Rate: 140 lbs/in

89+ SE (22% pro-dive geometry)
Front: Rate– 29.1 N/mm /166 Lb/in, Free Length–372mm (14.6”), Static Length– 219mm (8.62”), 692-720# preload, ride hgt 190mm
Total with ARB in the corner = 306lbs/in, ARB rate=0 in the straight line motion
Rear: Rate– 27.5 N/mm / 157 Lb/in, Free Length–347mm (13.7”), Static Length– 218mm (8.6”), 800# preload, ride hgt 170mm
ARB: 17.5 mm dia. front anti-sway bar Rate: 140 lbs/in

1990 X180R
Front: Rate- 40.3 N/mm /230 lb/in
Total with ARB in the corner = 370* lb/in; ARB rate=0 in the straight line motion
Rear: Rate- 31.0 N/mm 177 lb/in
ARB: 17.5* mm dia. front anti-sway bar Rate: 140 lbs/in OR * ? To be verified

S4
Front: Rate – 36 N/mm / 205 Lb/in
Total with ARB in the corner = 290 lbs/in; ARB rate=0 in the straight line motion
Rear: Rate – 39 N/mm / 225 Lb/in
ARB: 15 mm dia, Rate: 85 lbs/in

S4s
Front: Rate – 41 N/mm / 234 Lb/in, Free Length - N/A, Static Length– 214mm (8.43”) (From Jeremy Walton’s book “The official story”)
Total with ARB in the corner = 319 lbs/in; ARB rate=0 in the straight line motion
Rear: Rate – 45 N/mm / 257 Lb/in, Free Length - N/A, Static Length– 227mm (8.93”)
15 mm dia. front anti-sway bar, Rate: 85 lbs/in

The front damper platform height for each of these measurements is 59mm. The rear platform height is 115mm. The extended/compressed length for the front is 12in./10in., and the rear is 16in./12in.

Sport 300
Front: Rate – 43.2 N/mm / 280 Lb/mm
Total with ARB in the corner = 365 lb/in; ARB rate=0 in the straight line motion
Rear: Rate – 48.8 N/mm / 320 Lb/in
ARB: 15 mm dia, Rate: 85 lbs/in

> For OEM spring color coding, see this thread:

http://www.lotustalk.com/forums/f164/info-request-spring-rate-color-codes-113033/

4. Dependent on the car intended use and MY decide if you prefer to upgrade the anti roll bar to the next size available, I.E. 15mm->17mm
or 17mm->19mm (!) (recently on US eBay)

Always measure everything 3 times and make notes.
If you value your your fingers, always use a robust spring compressor when playing suspension games, LOL.

Here is what I use with great results
Goplus® MacPherson Interchangable Fork Strut Coil Spring Compressor Extractor Tool Set
by Goplus


.
 

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Hi guys... As you already know I had originally planned to use Konis in my car, but as I've been busy than ever, so to keep my project going I decided to go ahead and order a set of these.

So about a month or so I placed my order and my Shocks came in. They are a really good looking product and I'm very happy so far. However I made a mistake and I assumed this would come with 2.5" plates for the Springs and so never bother to ask Mark (Gaz salesman), for them. But the reality is that they came with "standard" 3" spring plates...

My only option is to have them machine down to 2.5" or to send these back. I will prob send these back since I don't want to get this machine and Mark has offer a free exchange.

I was just wondering if anyone in here will be ordering a set of this Shocks from Gaz anytime in the soon future?
I will like to know if it is ok with that person to have my set of 2.5" plates added to their box and when they get here I can pay you for the shipping to Florida?

They shouldn't add much weight to the normal set of shocks box, so shipping fees should be the same. But it will be help for me to avoid paying shipping from the UK in these...
 

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Integrator
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This may seem like a silly question, but do the G body cars (I have an 87) have the same suspension as the S body cars?

I want to update my suspension and lower the really high (USA ) front ride height.
 

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Wingless Wonder
1988 Esprit Turbo
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5,643 Posts
Your '87 should be the same as an early Stevens car. Earlier Esprits (pre- '86?) had different lower control arms where the sway bar located the components.

Later Stevens cars had a means of adjusting camber on the upper control arms that your car doesn't have.

More info here:

Esprit Chassis Modifications
 

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Integrator
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This may seem like a silly question, but do the G body cars (I have an 87) have the same suspension as the S body cars?

I want to update my suspension and lower the really high (USA ) front ride height.
Compare the pictures. Stevens suspension is shown.
 

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Integrator
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Would be nice to fit FSD technology shocks to our cars, but Koni does not make them in universal+adjustable height.
I've heard many good comments about quality of the ride.

KONI NA | FSD Technology

The traditional method of achieving good body control but allowing the wheels to follow the road is to make the damping rise steeply with vertical wheel velocity up to about 0.15 m/s and then flatten off to rise at a much lower rate - so called digressive valving is achieved with a relief valve that "blows off" to flow oil more freely from a preset pressure.

This is a compromise, because the shock does not know if the wheel is moving at a given velocity because of undulations in the road or because the vehicle body is resonating up and down, pitching or rolling - it applies the same damping at that velocity, and whatever force is applied to the wheel is applied to the body (by definition).

A key fact in the Koni FSD concept is that wheels tend to move at higher frequencies than the body because of the ratio of masses attached to the same spring. As such, FSD sounds like it has the potential to offer an even better ride than stock with good body control:

The ideal system would apply very little damping to the wheels so they can follow the road without applying disturbing forces to the body. It would also apply significant damping to the body to control its motion due to weight transfer during acceleration, cornering and braking, and especially should the body resonate at its natural frequency.

My only experience with Konis was to have them build me custom rear shocks for my 96 GTi VR6 to my damping specs. Konis tends to build shocks that are a little shy in low speed compression damping - high speed compression damping should always be limited on a street car or you can shock your fillings loose.

A rule of thumb for compression damping would be a max of 0.5 G X the car’s mass at that wheel at 1 m/s, or about 400 lb of damping at 3.3 feet per second for the E46 - most OEMs would use less aggressive compression damping.

To prevent pitching over long bumps on the highway the suspension needs to be phased so that the front and rear move up and down more or less together. This requires lower rate front springs compared to the rear (even with 50/50 weight distribution), and damping that rises more steeply at low speed at the rear, but that is more digressive than at the front.

Such a combination of springs and shocks just happens to also induce more weight transfer at the rear during turn-in – this helps the front tires bite and makes the car’s handling more responsive. Weight transfer is further fine tuned with anti–roll bars, with the rear typically being stiffer than the front to further help reduce understeer.

There are no force values given with the attached Koni FSD graph, but a 2:1 ratio of rebound to compression is typical for street cars on stock springs, and this appears to be the case up to about 0.2 m/s.
 

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Integrator
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When changing shocks/springs you may need to fit new spring isolators.

Energy Suspension has a variety of styles and diameters. I used 9.6103 Coil Spring Isolators - Style A - 96103


Energy Suspension Coil Spring Isolators

However,
Gaz-Matic shocks come with upper spring support "hats", which rest on the bottom face of the shaft rubber mount. If you replace OE springs w/2.5"ID coil-overs, if used with "hats", you don't need any isolators.
But (!) you're losing 1.5" of the spring length.
 

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