IMO I would stick within the Lotus spec for your model.
I would set the caster at the lower figure you've mentioned (ie +1.5deg)
This keeps the steering as light as possible while remaining within spec.
+3deg of caster adds a bit of weight to the steering feel.

Just my thoughts.

Andy.

 

What are you running for rear camber with the adjustable upper links?

Front?

When Lotus went to adjustable links they also added with Power Assisted Steering (PAS) so increasing the front caster might make the car difficult to maneuver in parking situations.

 

Any thoughts why the early cars are toe in and late cars toe out?

 

My guess: Because early cars don't have rear WINGS? 😁




More seriously,

Many factors at play. Sidewall height, tire width, bushing deflection?

 

I also wonder if the weight on the front axle went up a bit. I think toe in encourages turn in, maybe it was needed on the super light weight front end with early cars. The later cars had more stuff up there and were likely heavier. Combined with what Atwell said.

I wonder how manufacturers arrive at alignment settings? May be similar to how race teams do it.

Probably start with some baseline settings, do some laps and check tire temps. Start adjusting until the get the best compromise of feel, grip, balance, and long wear on the tires.

Thinking about that, how do you use your car, perhaps a slightly more "aggressive" alignment is in order. For instance I dont really care how long the tires last, they will age out before I run out of tread or I will burn them off on the track.

Also, as Atwell alluded to modern tires are completely different than the what was available when these cars were new. The alignment changes could all be down to that.

Have I seen recommended alignment settings that Lotus put out for track days? Seems like somebody has suggested alignment for DOT legal track tires on the web?

 

Is it worth and how hard is it to buy an alignment setup and do it yourself? After taking out the front radiator and taking off the plenum a few times in my own car, can it be harder?????? I have entertained the thought myself when I saw this thread. Just a thought, as I have seen what I would consider affordable laser type alignment devices that seemed affordable or am I having a senior moment????

 

There are several methods and tools you can use. You don't have to spend a lot of money unless you want to. It does take some understanding of the geometry, precision measurement, repeatability and patience. There are both books and videos on how it's done. I use a SmartCamber digital camber gauge to determine both camber and caster.

I use a set of mild steel "toe bars" that attach to the rack and gearbox of my Crossle for setting toe. I used them on my Elan by setting the toe bars on jack stands. Toe F/R is determined from the toe bars and a length of fishing line strung from front to rear and measured first with a scale, then with dial calipers for a little more precision. I use an old pair of kiddie fishing reels to store the line and set the drag when I extend the string from front to rear. It's important to center the steering wheel and the rack, determine the precise center of the front and rear of the car before you make any changes. The toe bars must be parallell to each other and the strings square to the bars at both ends.

Best regards,
Dan

 

Cheapo under-tire plates to allow scrub movement when fiddling with settings- Two 12" x12" linoleum flooring tiles with a thin film of grease sandwiched between.

 

An alignment can be done with some string, a bubble level, a pencil, a ruler and some tape. Or you can spend $30,000 on a alignment rack and there are a lot of things in between. IMHO it doesn't pay to get alignment equipment for the few times you need to have it done. Get the car to a good shop that really knows what they are doing and just pay for it. Once properly set it doesn't change unless you have an accident or things wear out. Stick with the specs for the model and year the manufacturer provides. A lot of R & D goes into them and it is doubtful you can do any better then they did.
David Teitelbaum

 

Thanks for all the input. I tried to find a local shop and no one is really interested. In addition, I get the feeling that many corners would be cut.

So, I started to order a few tools. The first being the camber and caster guage. I have a scissor lift so as long as I can get the car level, I should be able to start the learning process. I have Ramps that the car sits on (see the pic). If I get those level, then I would have a good starting point.

As stated, my car is a bit of a hybrid. All new bushings, S4s adjustable front suspension, Spax adjustable coil overs, and Toyo R888. (Tires provide more grip and less sidewalk, but they were the only tires that fit the rims)

Oh, and rear camber adjustments which the car did not have from the factory.

I honestly love the way the Esprit feels compared to other cars. I think learning to do the setup myself will allow me to tinker with a few things......like the Caster and Toe.

1) plan on setting the Ride Height first.

2) setting the rear camber at 1 degree

3) checking the current caster. Since it feels good now; I am curious what the setting is to start.

4) Next would be the Toe. I’m curious how slight toe in vs toe out will feel.

This will take a few weeks to get everything.

Please feel free to keep the comments and advice coming.

 

After you perfect it you can move over to the Testarossa!!!!

 

@Tremluf Earlier I mentioned utilizing geometry for alignment.

I'm fortunate my garage floor is fairly level from side to side and only 1" in 12 feet slope so it drains when the washing machine overflows... I use floor tiles as discussed above. I use one of my toe bars and the level from my camber gauge to determine level in the floor. I use vinyl floor tiles as discussed above and I taped stacks of tiles together and marked the floor with a felt pen to speed up the process. Grease between two tiles is an excellent poor man's turnplate as noted above. Later I made a pair of poor man's scale pads out of plywood for doing the cornerweights after alignment. Not really necessary for a road car unless you're really OCD.

May I suggest two books from the library of "**** to Win" by Carroll Smith. Since the Esprit lifts a basic Lotus race car suspension design to a road car these books can be helpful.

Prepare to Win was his first book and described basic race car preparation so you don't kill yourself or someone else your first or second time out. The section on chassis alignment are perfect for the beginner, as long as you don't mind a bit of Carroll's sarcasm. The section on determining the centerline of the car is crucial if you don't like the car going down the track as a crab.

The second book is "Tune to Win" which goes into significant detail of the basic physics of vehicle dynamics. Smith explains terms like tire slip angles, basic suspension theory and effects of bumpsteer, caster, camber and toe. The section on camber curves/camber gain are important for cars with wide tires. As an added bonus, there is more sarcasm.

The bonus is Carroll's "Engineer in Your Pocket" - a little flip book of wisdom when the car is misbehaving at the track and what to do about it.

Suggested tool to determine bumpsteer: Advanced Racing

I bought one of the above years ago and found it really useful for the setup of my Zink Formula Ford rack on the chassis after a complete rebuild. I didn't think I could obtain the claimed accuracy/repeatability but I did. The problem is, you use it once, maybe twice and then your buddy borrows it from you and you don't get it back for a year until you finally ask him about it......

Best regards,
Dan

 

Definitely agree about the Carroll Smith books, those were my bibles when setting up and racing the Europa. Another one very informative on suspension tuning is How to Make Your Car Handle by Fred Puhn.

For reference here are a couple shots of simplified method alignment checks being done at the track.

 

When my 87 Turbo Esprit was having suspension done ( new rubber bushings replacing bad unknown durometer poly bushings, Gazmatic shocks with reuse of OEM springs) the key item I asked was alignment with weights simulating my fat a$$ sitting in driver seat ( and 1/2 tank gas). For me that total combination resulted in much straighter tracking and better turn in. They didn’t recommend corner weighting as I’m just a street cruiser and not a track rat. All depends on how honest you think you’ll need such suspension precision.