[MRDANGERUS]

By changing the wheel/tire width or adding spacers the vehicle track width changes affect handling (push vs. loose).
Changing the spring rates, dampers and weight distribution affects handling as well.

If you have done any of the above, would you please share your original specs+changes (before and after) and your observations in regards to the ride quality/handling.


Do you agree with the following statement?
"A wider front track will make the springs feel weaker since you will be using a longer lever on them. So a wider front track will make the front suspension feel softer, promoting a reduction in understeer (adding oversteer)."

 

[sleekgt]

I went from 88 Esprit OEM specs:

15x7 front OZ Ruote wheel with BFG TA 195/60-15 ET23
15x8 rear OZ Ruote wheel with BFG TA 235/60-15 ET-20
Factory pressure of 21/25 lbs front/rear

Handled OK, but I don't push too hard (street-driven only). When tires got to around 25K miles, the left rear spins in rain at times.

Replaced with
17x7 front OZ Futura wheel with Dunlop Direzza DZ101 205/45-17 (about 5 lbs heavier than OEM) ET23
17x8.5 rear OZ Futura wheel with Dunlop Direzza DZ101 245/45-17 (about 10 lbs heavier than OEM) ET-20 (effective ET using a 50mm wheel adapter)

Modified pressure of 25/30 lbs front/rear.

The informal Dunlop handling observations:

1. The tires grip significantly better in clover leaf - it actually pushed driver door ever-so-slighty out during hard cornering to turn on interior light - the BFGs never did that.
2. The ride is slighty worse - given the higher pressure and lower sidewall, not a surprise.
3. On long highway trips to Los Angeles from San Jose, I increase to 32/32 front/rear - still a reasonable ride on HWY 101, but parts of HWY 280 can result in some kind of harmonic that causes the car to 'porpoise'. The Dunlops porpoise a little bit; the BFG TAs would loosen your fillers on select HWY 280 patches.

The Dunlops take more effort for the 4 wheel drift to occur, but definitely a gentle transition like with the BFG TAs.

 

[MeisterS4]

By changing the wheel/tire width or adding spacers the vehicle track width changes affecting handling (push vs. loose).
Changing the spring rates, dampers and weight distribution affects handling as well.

If you have done any of the above, would you please share your original specs+changes (before and after) and your observations in regards to the ride quality/handling.


Do you agree with the following statement?
"A wider front track will make the springs feel weaker since you will be using a longer lever on them. So a wider front track will make the front suspension feel softer, promoting a reduction in understeer."

I put 1" spacers on my 94 on all four corners and probably increased wheel width by an inch on all four as well. I have not seen or can tell any difference in handling. I only drive my car about 1K miles a summer and no tracking so my seat of the pants observation should be taken just as that...seat of the pants with no imperical data. I have yet to see any kind of unsual tire wear either FWIW

 

[MRDANGERUS]

Esprit OE wheel sizing and offsets

88 Esprit, Lotus Design OZ Ruote 7-spoke
Frt: 195/60, 7J x 15 +23.3mm track:1529 mm (60.0”)
RR: 235/60, 8J x 15 - 20.3* negative! track: 1553 mm (61.2”)
See: http://www.automobile-catalog.com/make/lotus/esprit/esprit_stevens/1988.html

89 –non SE, Lotus Design OZ Ruote 7-spoke
Frt: 195/60, 7J x 15, +23.3
RR: 235/60, 8J x 15, +30.0
See: http://www.automobile-catalog.com/make/lotus/esprit/esprit_stevens/1989.html

5/89 to 93’ SE, Lotus Design OZ Ruote 7-spoke
Frt: 215/50, 7J x 15 +23.3
RR: 245/50, 8.5J x 16 +30.0
See: http: http://www.automobile-catalog.com/make/lotus/esprit/esprit_stevens/1990.html

Chassis and start-point for the “Eagle” Esprit SE chassis
From 3/4/89 for SE, then a couple of month laterfor the different variants at the following chassis numbers:
SE (264 BHP) SCCFC20A 1KHF65000
GMP4 (225-228 BHP) SCC08291 0KHF62728
DOM (UK) Turbo (215 BHP) SCC08291 OKHD13587
DOM (UK) N/A (172 BHP) SCC08591 2KHD13582


93’ Sport-300, OZ Racing Futura Modular 5-spoke w/o cntr cap
215/50 7J x 16 +20.0
245/50 8.5J x 17 +6.0
see: http://www.automobile-catalog.com/make/lotus/esprit/esprit_stevens/1990.html

93-1/2 SE, OZ Revolution 5-spoke
245/45 8.5J x 16 +23.3
315/35 10.5J x 17 +30.0
http://www.automobile-catalog.com/a...om/make/lotus/esprit/esprit_stevens/1989.html

94 to 95-1/2 S4, and USA S4s, Lotus Design OZ Racing 5-spoke
235/40 8.5J X 17 +23.3
285/35 10J x 18 +30.0
http://www.automobile-catalog.com/make/lotus/esprit/esprit_stevens/1990.html

95 to 95-1/2 USA S4s (optional), OZ Racing Futura Modular 5-spoke
215/40, 7J X 17 +23.3
245/45 8.5J x 17 +30.0
http://www.automobile-catalog.com/a...om/make/lotus/esprit/esprit_stevens/1989.html

95’ to 96’nonUSA S4s, OZ Racing Futura Modular 5-spoke
215/40, 8.5J x 17 +19.0
245/45 10J x 18 +17.0

96’ to 98’ V8, Lotus Design AWI 6-spoke
235/40, 8.5J x 17 +19.0
285/35 10J x 18 +17.0

96 to 98 V8 (optional), OZ Racing Futura Modular 5-spoke
235/40, 8.5J x 17 +19.0
285/35 10J x 18 +17.0

99 to 01V8, OZ Racing Saturn Plus 6-spoke
235/40 8.5J x 17 +19.0
285/35 10J x 18 +17.0

99’ Sport 350, Lotus Design OZ Racing Crono Magnesio 5-spoke
235/40 8.5J x 17 N/A
285/35 10J x 18 N/A

02 to 04 V8, OZ Racing Nova 16-spoke
235/40 8.5J x 17 +19.0
295/35 10J x 18 +17.0

02 to 04 V8, OZ Racing Nova 16-spoke
235/40 8.5J x 17 +19.0
285/35 10J x 18 +17.0

Early Stevens Esprit's front wheel wells changed through the years. Early ones, including the '88, had smaller wheel wells.
Non-USA S4 and S4s got larger wheel wells, and 17x8.5 wheels with +19mm offset and 235/40 rubber.
The USA models got smaller 17x7 with +23.3mm offset and 215/40 rubber.
Then, in mid-1995 the molds were commonized and all markets got the larger wheel wells.

 

[Turbo R]

Great list you've compiled there, Mr. D!

If I could make one slight change...
The tire sizes you listed for the '89 1/2 to '93 SE are actually for the '89 non-SE and should all be 15" wheels front and rear

The '89 1/2 to '93 SE had
215/50R15 front
245/50R16 Rear

Roy

 

[Turbo R]

I was focusing on the sizes so did not put the speed rating, but those SE sizes were Z-rated tires

 

[sleekgt]

[snip]
Do you agree with the following statement?
"A wider front track will make the springs feel weaker since you will be using a longer lever on them. So a wider front track will make the front suspension feel softer, promoting a reduction in understeer (adding oversteer)."

In my front wheel case - I kept OEM offset of ET 23.3 but went from 195 to 205 mm width.

Laws of physics say it should have definite affect on spring action, but the harder ride due to the wider tire and heavier wheel/tire assembly may mask the additional leverage of 10mm wider tires.

Think of it this way - if I installed 3X wider tires that weighed 3X more, even though 3X wider tire would have HUGE leverage, the 3x WEIGHT would have to be over come too.

So not necessarily obvious that a wider tire would make for a noticeably softer front suspension feel.

I noticed no significant understeer (but since I increased both front/rear identically by 10mm width - that would be expected). The rear wheel assemblies each had a 2-3 lb wheel adapter (the front wheels did not) so my unsprung weight suffered a little in the rear, but not significantly noticeable at street driving.

Forgot to mention:
My Quaife should not have any impact on my front wheel understeer at street-level speeds.

 

[MRDANGERUS]

Thanks for your valuable input Eddie.
Anybody else?

Turbo R
I have revised the list to reflect your suggestions.
If you see any other mistakes, please let me know. I'll be glad to correct it.

 

[MRDANGERUS]

Anyone else wants to chime in?

 

[sleekgt]

Actually, I'm thinking about the Bilstein shock/spring package since I'm coming up on a major service interval (may as well get the other stuff done too).

While I realize the Bilstein kit was tested with specific newer rubber (and not necessarily the bigger 17" wheels I have now), it wouldn't hurt to get factory OEM tuned shocks to replace the 26 year old stockers.

And I'm secretly hoping it will minimize the porpoising/rough harmonic ride I get on some freeway sections. The current shocks *seem* OK but they are just too old.

Anyone out there with the Bilstein kit? I saw an S4s poster that had it done and they thought it was superior on track in terms of ride/handling than some Porsches. Surprisingly because he felt it was very soft on street.

 

[ragingfool35]

I have the Lotus Bilstien/Eibach setup, poly bushings, S4 wheels and 20 and 25mm spacers. Jarring when going over the slightest road imperfections but highway travel, esp ramps, is bliss. I have cheap General Y-rated summer tires fitted. IMO tires affect ride quality more than any other factor. the run-flats on the stock SE wheels, stock bushings and dampers were just as jarring. IMO tires affect handling more than any other factor. Pressure, compound, tread, etc. So credit what you will on my car, but it now understeers less than when it had all OEM parts. Other Esprit owners commented they like my suspension

 

[jtrealty]

I have the Lotus Bilstien/Eibach setup, poly bushings, S4 wheels and 20 and 25mm spacers. Jarring when going over the slightest road imperfections but highway travel, esp ramps, is bliss. I have cheap General Y-rated summer tires fitted. IMO tires affect ride quality more than any other factor. the run-flats on the stock SE wheels, stock bushings and dampers were just as jarring. IMO tires affect handling more than any other factor. Pressure, compound, tread, etc. So credit what you will on my car, but it now understeers less than when it had all OEM parts. Other Esprit owners commented they like my suspension

Yes, tires are the single biggest factor in handling and suspension. That's why tinkering with tire pressures makes such a difference. In many cases the limiting factor in any suspension upgrade IS the tires. For most drivers the stock suspension is more than adequate as long as it is in good shape.
David Teitelbaum

 

[MRDANGERUS]

It seems that certain Ford (Taurus SHO, Cougar, Focus), Volvo (S40, V40, C70), Jaguar, Lincoln and Mercury have 5x108 bolt pattern, exactly as Esprit.

 

[sleekgt]

It seems that certain Ford (Taurus sho, Cougar, Focus), Volvo (S40, V40, C70), Jaguar, Lincoln and Mercury have 5x108 bolt pattern.

Confirm, anyone?

Definitely some of the larger Fords (not the smaller Focus like my 2007 - it has 4x108). Select Volvos definitely were 5x108 - when I was looking at my failed attempt to upgrade to OZ Novas, I ran across custom wheels in 5x108 catering to Volvo (Centerlines).

The problem is most of those cars had huge offsets (38-45mm) so they were not usable on Esprit without spacers. The wheels also tended to be narrow (7" or smaller) - very few were in 8-10" range for rear wheel use.

eBay had a set of 4 OZ Nova 5x108 17x7" wheels (35mm offset?) for $399, but they are still too small for Esprit use for the rear.

 

[redfox]

On my 1990 SE I went from stock Wheel and tires except for a 255 rear tire, to AWI V8 6-spoke Wheels with v8 sized tires as per factory.
I feel a better faster steering, less understeering and a slightly more bumpy ride, though not the damping in itself.
When I've gathered all the needed parts, I'll go new arms, ajustable, Lotac poly's and then hopefully some adjustable dampers.
As I also changed my seats from standard SE to Sport300, there was a difference there as well. The car simply feels more direct. Like going from a slight delay between steering input till it could be felt in the seat, on to no delay.
I know, it does not have anything to do with Wheels, but it made the Esprit more direct.
I really dislike soft suspension and comfort.
I am currently looking into making the Futura's ½" wider at the rear to fit 315 rear tires.

Kind regards,
Redfox.

 

[maxvelocity]

I have new 225/50ZR/15 and 255/50ZR/16 on stock SE wheels. I am waiting for the next driving season to mount and adjust suspension settings as they are stored in climate controlled storage.

I went of the recommendation of a club member with access to a track who tried a dozen or 2 tires for Esprit's. I believe the words he used for his recommended set up was "the road feel and handling was almost intoxicating".

 

[MRDANGERUS]

What brand/type of tires?

I have new 225/50ZR/15 and 255/50ZR/16 on stock SE wheels. I am waiting for the next driving season to mount and adjust suspension settings as they are stored in climate controlled storage.

I went of the recommendation of a club member with access to a track who tried a dozen or 2 tires for Esprit's. I believe the words he used for his recommended set up was "the road feel and handling was almost intoxicating".

 

[maxvelocity]

What brand/type of tires?

The tires are Toyo RA-1 really soft compared to a street tire. Before anyone chimes in about DOT comp tires. We really thought things through about tires and these are the correct choices for us but might not be for others. Club discussions can get intense because the high number of LOON's that come from an engineering background. The banter is always factual except for opinion but always friendly.

To start off we have the means and international sources to get street tires in the correct Lotus sizes but chose DOT Comp tires. The way we drive our cars in Minnesota (1/2 year in winter storage and non daily driver weekend use). Our street tires tend to time out rather than wear out. So in our situation the maybe 7K + miles or so on some really soft sticky tires every 2-3 driving seasons do not sound out of line. But to those that live in warmer climates, drive all year round or daily drive with higher miles to burn a set of $800-$1000 tires per year could be hard on the budget.

Tires like the R888 or Yoko Advan are superior dry tires but lack performance in the wet, some might say dangerous. So I and a few others went for the RA-1. We gained superior wet grip, gave up a little on dry grip (dry grip still way better than a street tire). but there is a standing water warning. But since we refrain from driving in downpour it's ok for us. Only time that will happen is if we get caught in bad rain on an outing. I talked to people and they all said the same thing. Tires may hydroplane while racing during standing water conditions, but wet surface is just fine. So don't race when standing water is present and just slow down to the speed limit or slower.

At 1/2 tread depth the dry grip increases but at the expense of wet handling.

A big downside is the tires will pick up and fling rocks and debris. Chip guards may have to be installed near hit zones areas rear of the tires. Also the person following the car must allow greater distance as rocks will be flung rearwards of the car.

 

[MRDANGERUS]

FRONT SUSPENSION SETUP:

SOFTER -> roll stiffness: DOWN
Roll angle: larger = LOOSE*
Traction : higher = Oversteer

STIFFER -> roll stiffness: UP
Roll angle: smaller = TIGHT
Traction: less = Push/understeer



REAR SUSPENSION SETUP:

SOFTER -> roll stiffness: DOWN
Roll angle: larger = TIGHT
Traction: UP = Push/understeer
Wider rear rims = front push

STIFFER -> roll stiffness: UP
Roll angle: smaller = LOOSE*
Traction: less = Oversteer

Stiffer rear = reduce understeer and squat

* UP the cross weight percentage to prevent LOOSE condition

 

[Turbo R]

Always love all your posts, MRDANGERUS...some other '88 Esprit owners and I were recently talking about how great it is that you are always pioneering and looking at ways to improve the Esprit. A lot of your posts are even more meaningful since you also happen to have an '88.

That said and done, I can't help, but poke a little fun at your last post.
Punctuation counts!!!

You wrote:
STIFFER -> roll stiffness UP
Roll angle smaller = LOOSE*
Traction less Oversteer

Okay...is that to mean:

Traction, less Oversteer

or

Traction less, Oversteer

Which one is it? LOL!!!

Keep up the good work!