The Lotus Grand Tourers

Does anyone use 16" rims? I'm looking to use 16" rims with 225/45 16 Toyo R888 tyres and have three options:

1) Buy compomotive 8x16 MO rims ET15 with PCD114.
2) Modify the hubs to change the PCD to 108 and use Ford rims which are easily available.
3) Use 7x16 BBS rims from the Volvo S40 T4 with spacers.

Any thoughts? Which should to go for??

Graham.

If you change rims you might upset the steering geometry with the wrong offset.

Lotus will have selected the offset for the rim width (7J) so that an imaginary line through castor angles etc intersect the tread at the right point on the road to give optimum turn-in and high speed stability.

Someone (?Angus) on this forum has contact details for technical folk at Lotus, so hopefully he can provide an email address for you to seek proper advice on offsets for a given change in wheel width.

The standard offset on the OZ's is ET8, I believe the speedlines were slightly different ...

My car has Compomotive MO's in 7x17 with 215/40 17 .. they are stamped as ET15 on the front of the spokes but I believe they were a special factory order so may not be ET15 at all, just from the ET15 mould! Looking at the mounting face, it's not quite how I'd expect an "off the shelf" wheel to be with respect to a taper near the mounting face.

Someday I'll remember to measure one when the wheel is off!

By my calaculations ET15 with a 8inch rim should leave the geometry as close to standard while still fitting the arches. I'll have a check with the chap at lotus but I think it's the only way to get an 8 inch rim, which will work far better with the tyres.

The ET mark on any compomotive rims should be accurate unless they have been machined after leaving the factory. They always mould the rim size and then stamp the offset once the rims have been machined.

Hi GMxl

I bought four wheels from Rimstock to my own specs (including heat-treatment) for £520: Thought that was good value. The service was excellent.

Pete

Hi Pete

Just spotted this Doh

Do yo u have any pics and specs of the wheels?

Martin

Hi Martin

I'm fairly sure you'll recognise the wheels - I think you have the same type on your M3. I can't take any pics at the moment - probs with the camera. I'll post some when I get it sorted. The front wheels are 8x17, e20; rear wheels are 9x17, e35. These are my "starting-point" wheels; things may change when I eventually get the car on the road!!

Pete

Do you have a date for that Peter - I have rather a lot of wheels for my M3 are you referring to the black Team dynamic Pro Tech 1.2's?

Martin

You mean like these?

http://www.apcs77.dsl.pipex.com/GrifNewWheels2.jpg

(7x17, 215/40 17 and 8.5x18 245/35/18)

ps .. they're light too .. despite going up from 15/16 to 17/18 wheels, they were at least a couple of kg lighter per wheel / tyre combo compared to the original Grif 500 Estorils (Oz?).

pps. yeh, they make the brakes look crap, but focus RS 324x28mm discs match the hub centre bore and stud pattern

Steve C wrote:You mean like these?

http://www.apcs77.dsl.pipex.com/GrifNewWheels2.jpg

(7x17, 215/40 17 and 8.5x18 245/35/18)

ps .. they're light too .. despite going up from 15/16 to 17/18 wheels, they were at least a couple of kg lighter per wheel / tyre combo compared to the original Grif 500 Estorils (Oz?).

pps. yeh, they make the brakes look crap, but focus RS 324x28mm discs match the hub centre bore and stud pattern

Steve, are you upgrading to Focus RS discs and calipers for the Excel? Are you making any brackets yourself?

Nope, the offset on the focus disc puts the disc too far inboard.

For the Excel I'm using 325mm x 26mm MG ZT 190 discs .. I picked up two sets of EBC standard discs for about £70 a pair on ebay, huge discs for the money. I've had them machined for larger centre bore and mounting holes re-drilled. The discs are HUGE and should dissipate heat pretty well so I'm going to use bog standard road pads with them and see how it goes.

I've currently got the PNM 285mm kit with hi-spec calipers and I'm rebuilding the calipers (with hi-spec kit) to allow them to be used with the thicker discs and I've had adapters made up to space the caliper out radially by 20mm and inboard by 5mm.

Apart from the stub axle to PNM bracket mounting bolts (I now need 5mm longer bolts), I've pretty much got everything I need. I think the brake pipes with the PNM kit will be ok because they seemed a bit long but I'll make sure I check them on full lock / bump / rebound to make sure!

Rears will be modified 350z (Brembo) rear discs, these are 322x22 (from memory), which will work nicely with the Esprit V8 rear brembo calipers with handbrake mech....

I'm hoping for stonking performance on a relatively low budget ...

I'll write this up and take some pictures when I finally get around to fitting it!

Yep. They're the ones! Front discs are 335x32 with 6-pot calipers from HiSpec. Rears are 330x20 with HiSpec ultralight handbrake calipers. On their recommendation I've bought Ferodo DS 2500 pads.

Steve - are the Esprit rear calipers 2 or 4-pots?

This time last year I said to myself I would have the car on the road next summer. Saying the same thing 12 months later!! Slowly getting there.

Pete

For the Excel I'm using 325mm x 26mm MG ZT 190 discs .. I picked up two sets of EBC standard discs for about £70 a pair on ebay, huge discs for the money. I've had them machined for larger centre bore and mounting holes re-drilled. The discs are HUGE and should dissipate heat pretty well so I'm going to use bog standard road pads with them and see how it goes.

========

This looks like an interesting conversion as the original Lotus discs mount behind the hub whereas modern cars mount the disc over the hub. Be very interested in pics when you have this done, thanks.

John

Dear God, is there no end to Steve's talents ....

I ran my old bus out the other day prior to the dreaded MOT, had been driving a modern Golf for a couple of days ....

Excel went nicely and brightly, and then ...

Erm, brakes ...

Not exactly the best braking experience I've ever had, and the calipers are free and pads/disks good ....

Sign of the times I guess, keep us informed Steve et al

I feel a brake upgrade is needed before tinkering with anything else.