Welcome to the Nitron Lotus Blog for Project N2

What is Project N2?  Well, back in 2004? We decided to build a Motorsport Elise with a 2.3 litre Duratec engine, and got a bit carried away with ourselves.  At that time, it turned out to be a bit of a monster, with over 400 hp per tonne with a normally aspirated engine.  We raced it, learned a lot, and then finally sold it when we became too busy at work to run it any more.

That was Project N1… we now have a new car ready for transformation, Project N2.  Over the next year we will transform our new car into a super-modified Elise, changing everything we can to make it go faster on the track, and the road, because it will always remain road-registered, necessary for the Nurburgring.  With Project N1, nearly all the parts were one-offs, some of them eventually becoming available through EliseParts in a production format.  The difference this time is that we are going to make all the parts available to anyone who wants them, as such they will all be fully productionised.

Our intention is to flex our engineering muscles (and brains!), and come up with the best solutions we can, within reason.  These will be serious ‘hard parts’, which will all be worthy of the Nitron name.

Project N2 will be extreme, there is no doubt about that, but how extreme only time will tell.  But it will certainly have to be a much bigger step than Project N1 was, as Lotus modifications have come on a bit since we build Project N1

Below is a list of the parts we will work on, and as they are finished they will be listed and available to buy from our online store.  We will of course start with the corners where the shocks bolt on, and work outwards into the rest of the car.

BRAKES

DISCS

We have designed a fully floating disc and bell combination based on current F1 and Sportscar designs.  Using a 12 bobbin drive system, based on a dia177.8mm PCD (Pitch Circle Diameter), there are a variety of discs that will fit.  We will use a 304mm x 25.4mm disc with a 14.5mm air-gap and weighing 4.1 kg (a 295mm diameter disc is also available to fit the same bell).  If we can use a 295mm disc at the rear we will do in an effort to reduce the rotating assemblies’ inertia.  This reflects the amount of work that each disc will need to do, so we will record the temperature the discs work at and decide what is the most efficient solution.  We don’t want to make the discs too light, or they will get too hot into the corners and then too cold down the straights, causing extreme thermal cycling leading to cracking.  This is a common misconception that the lighter the disc the better.  As energy is (mass) x (velocity)², the faster you go you build up a lot more energy that has to be transferred into heat energy in the disc.  Make the disc too light and it will overheat.  The discs will be fully floating on 12 titanium bobbins (F1 style), these will slide in slots on the outer edge of the aluminium bell as the bell expands at a faster rate than the iron disc.  The bell itself will be made from 7075-T6 aluminium, which will then be hard anodised, there is no higher specification aluminium available.

We are also offering a slightly smaller 290mm diameter disc for the rear where cars have to run a handbrake calliper, this will necessitate a different bell as the bobbin bolted diameter is smaller, but it will be to the same highest specification.

CALIPERS

At the front we will use APs great little 4 pot CP5040 caliper for now, used by all the serious Lotus racecars, however as there are no other calipers on the market with a 130mm radial bolt spacing designed for a 25.4mm disc thickness, there is little choice.  We have ideas to manufacture our own very high specification monobloc caliper to use the same pad shape soon, we have the machining capability… so watch this space!

At the rear there is a bigger issue – the heavy Brembo manufactured handbrake single piston ‘pin-slider’ caliper. The usual fix for track cars is to fit the front AP 2 pot caliper to the rear (however, as the rear upright is cast iron and has no radial mount facility, this is not easy and requires upright modification), which works well but then doesn’t offer any handbrake mechanism.  There are ‘pin-spot’ hand brake calipers available to add in addition, but having witnessed first hand a potentially huge accident at the ‘Ring avoided by some serious use of the handbrake on a production car, we don’t want to offer a pseudo handbrake, but one that can really do the business if required.  As such, we are working on a combined 4 pot caliper with a fully mechanical handbrake mechanism, again, we will keep you posted with the developments with this.

PADS

We are going to try the new generation of Performance Friction 06 compound, this is meant to be kinder to discs than the previously notorious PF products.  It has been developed as an endurance pad, so it has slower wear properties, and as a result is easier to use for us non-pro drivers!

PEDAL BOX

We converted Project N1 to a balance bar set-up and it worked very well.  We will do the same to this car which has the alloy pedals and cable throttle, and then also fit the later ‘fly by wire’ throttle so we have a solution for both types cars.  The conversion involves removing the standard single master cylinder, attaching a plate to the box that then allows two master cylinders of different bores to be mounted, one for the front brakes and one for the rears.  The balance bar is then attached to the pedal, which will allow the pressure to be biased from one cylinder to another by turning a dial.  This way you can adjust your front to rear balance.

SUSPENSION

OK, this really is our area of expertise, and although we are known for our shocks, we actually have a heritage of serious suspension design, having designed and made rockers and wishbones for all kinds of single seaters and GT cars in the past and early days of Nitron.  We are going to start off with full blown GT style suspension for the serious racer, and Project N2!  We will then offer other versions of these parts.

BUSHES

It is well accepted that the standard bushes allow too much compliance for track use with grippy tyres, so stiffer bushes are the first level of fix.  We will initially manufacture a full wishbone bush kit using a material called ‘Ertalon’ which is a more specific material suited to slower rotating high load applications, with less water absorption characteristics than nylatron (they are all made by the same company).  Our bushes will be in one piece rather than in two halves so there will be no alignment issues, reducing friction.

The next level up with be a full spherical bearing kit.  Using the PTFE lined bearings fitted in our shock ends (already well proven to take the loads with good durability), these will be located in a hard anodised aluminium drums to keep them in the correct place in the wishbone tube end, then two stainless spacers with seals will be fitted to the bearing centre to provide the correct width and bore.  The assembly will be corrosion proof and sealed from dirt.  The ultimate bearing kit without the need for going to full blown GT wishbones.

REAR TOE-LINK KIT

All Lotus variants can suffer from toe-link failure when subjected to hard track use, the small track rod ends fitted to the standard link are not designed for this kind of use.  There are a number of kits on the market but none of them have been designed for really fine tune adjustment which is necessary to get accurate rear toe settings, and they are all awkward to get to when the car is in one piece (i.e. undertray in place) as they follow the design of the original link but replace the track rod ends with spherical rod ends.  The Toyota based cars particularly do not have a good option for the inboard joint, which is based on a 10mm shaft as it is common with the inner wishbone joint.

Our kit design has been approached from a strength, adjustment access and durability point of view.  First of all, the kit has been made from the best materials available, providing a very high strength solution and using the highest quality German motorsport joints.  Starting at the outer end, a tapered Titanium pin (as used in F1) is inserted into the bottom of the Lotus upright, with special stainless spacers allowing bump-steer adjustment to the outboard joint.  Although single shear, this pin is incredibly stiff and is almost identical to the Porsche Cup car design which is subjected to much higher loads than our Lotus item. At the other end, the inner joint is then bolted in place with a high tensile bolt that is common with the inner wishbone joint, but being only 10mm diameter it is supported in double shear on it’s outer end with a special stainless bracket that is bolted to the rear subframe and requires two additional bolts adding to fasten it rigidly enough to remove all flex.  The connecting link between the two joints is machined in two parts, the long inner part is a large bore 7075-T6 hard anodised aluminium shaft machined from a billet, and on the outer end a stainless adjuster barrel is screwed into it and then the outer joint is screwed into the adjuster.  The shaft is connected to the adjuster with a different thread pitch than the rod end is to the adjuster, so turning the adjuster barrel lengthens the total link assembly by very small amounts, allowing really fine tune adjustments.  This type of link design is used on serious race-car push rods.  But the real advantage is that the adjustments are all accessible on the outer end allowing easy adjustment with the undertray in place.  In addition, the inner bracing bracket can be attached leaving the standard exhaust heat shield in place, and no need for a bracing tube across the entire rear subframe between the two inner joints.  The ultimate high strength high specification motorsport part!

STEERING ARMS

The standard Lotus steering arms are heavy and do not allow enough camber to be added to the front wheel for optimal track use.  We knew this when we built Project N1 and resolved it with a mix of S1 and S2 parts, but the best solution lies with different steering arms.

We have two different steering arms available.  The first is a high strength lightweight aluminium version of the standard arm with the ability to add more camber than the original arm but retains the ability to use the standard steering track rod ends with their tapered pins.  The second is a race car part that allows even more camber, but also allows for bump steer adjustment by using a spherical rod end on the steering track rod and a spacer kit.  The arm is machined in 7075-T6 alloy and hard anodised.  Both arms are available with our own camber adjustment shims, we also have shims for the rear camber too.

UPRIGHTS

The upright is the large steel casting that connects the upper and lower outboard suspension joints together, and holds the bearing assembly and hub unit.  The upright is sometimes incorrectly called a ‘hub’, the hub is the central part that spins inside the wheel bearing and has the wheel bolted to it.  We designed the original machined uprights on Project N1, but we now have the chance to take them to the next level utilising our 5-axis machining capability and latest CAD techniques.  We have 2 designs available, one with a standard hub height (for those restricted by regulations), and one with a 20mm raised hub height, more suited for lowered cars.

Lotus suspension geometry was designed to run at a higher ride height than we all want to run at the track, the more you lower the car the further away from the original design you get.  It actually works better to start with, but as you continue to lower it does go quite badly wrong, with increased bump steer, increased camber gains on bump and lowered roll centres (these are not optimal).  By raising the hub centre height in the upright, you immediately lower the car by 20mm without altering the suspension geometry at all.  You can then lower it a little further as normal, and the result is an optimised ride height and geometry condition.

Our uprights take the standard hub/bearing pack, which in reality was designed for much heavier cars than Lotuses so does not give any trouble in use (and you will already have a set!).  At the front, the original heavy steel upright is replaced with a single piece billet machining that is both stiffer and lighter than the original, but has the benefit of internal cooling slots with the option to add a cooling duct pipe to the inside face of the upright forcing cold air into the eye of the disc and around the hub bearings.  The outer face of the upright can be ‘sealed’ to the eye of the disc ensuring the cooling air is forced through the disc vanes, as in all serious race cars.  The lower fitting on the upright can be changed to either a tapered hole for standard ball joints or a straight hole for the use of a racing joint pin (see Nitron racing wishbones).  The entire upright is hard anodised to finish.  At the rear, the same applies, with the exception of the driveshaft joint being in the centre.  The upright is designed to take the 4 pot AP caliper.

RACING WISHBONES

The standard wishbones fitted by Lotus are not made from very stiff material, so they need to be quite heavy as a result.  Our wishbones are lighter and stiffer, but will collapse in an accident to avoid damaging the chassis, where possible.  Manufactured from T45 tube and TIG welded together, they represent the best solution for the serious track car.  They come complete with all bearings on the inner and outer ends, with a full spacer kit to fit the chassis, the outboard end is converted to a motorsport spherical bearing with Titanium mounting pins to the uprights.  In addition, we have designed the front upper wishbones to provide more castor, this allows the camber to build faster when the wheels are steered, avoiding the need for huge static camber settings which will affect the braking performance.  These wishbones represent the ultimate wishbones available for the Toyota engined car.

ENGINE AND DRIVETRAIN

Although not our area of expertise, we will work the top professionals in various disciplines to make sure we fit our car with a strong and reliable engine, gearbox and drivetrain assembly.  In principle we plan to turbocharge our car, as we prefer the characteristics of a turbo car over the supercharger system.  The following are notes and initial ideas more than fixed plans, so we will remain quite flexible in our approach as we work on the car.

ENGINE

The Toyota 2ZZ engine is a high compression variable valve engine that works very well at high rpm but seems to lack some mid-range torque.  Supercharging is the Lotus solution to this, but there are some serious shortcomings with this solution that revolve around heat and efficiency.  This is the main reason for our move to turbocharge the engine, as well as the ability to make more power ultimately.  Initially we will leave the engine fairly stock and add a low pressure turbo system, which can work with high compression engines.  The next step would then be a high pressure turbo with a lowered compression engine.  We plan on using a garret roller bearing turbo and fabricated 4 into 1 exhaust manifold.  As this will increase the intake temperature, it will of course need an intercooler, and it seems accepted that in Lotuses this is immediately a problem.  Both our technical partners Simply Sportscars in Australia and Sector 111 in California have been working with supercharged and turbocharged Lotuses over the past few years in very hot environments, and the solution would appear to be a chargecooler system.  We will use one of these systems to cool the intake charge, and run a hybrid radiator in the front of the car.  The exact layout and design isn’t known at this stage, but by using an electric main engine water pump we will increase the efficiency of the front radiator so we might be able to have a single high performance radiator with 2 sections to it, one for engine and one for intake charge cooling.

We also plan to design and offer a dry sump system, the sump and pump we have already looked at but the issue is where to cite the oil tank.  We designed our own system for Project N1 which worked very well, but there was a lot more space in the rear of that car.

We have not looked at the gearbox or drivetrain yet, but we do know that cars running on slicks have repeated driveshaft failures, especially as the outboard shafts are short and don’t like it when the cars are lowered.  We plan to make a completely new assembly with the joint system changed to a Tripode style joint which will be F1 and GT car size, but lighter.  Gearbox internals may have to be changed, but eventually we will run a full sequential race ‘box so we can use full throttle shifting, paddle gearchange and assisted downshifts.

To control the engine we will make an early move to a full Motec engine management system and Motec dash, we will be working with Owen Developments on this as they have a lot of experience with Turbo GT cars, and are the UKs Garret Motorsport agents, as well as being one of the leading Motec specialists in the UK with a 4x4 rolling road.  And it is also very convenient that they are 15 minutes away.

OTHER ITEMS

As we mentioned earlier, anything we make for ourselves will be available to others, and we will do a number of other modifications to the car as we work our way through it.  We will make body modifications to suit a more track focussed car, and we will equip the cabin as a GT car like we did with Project N1.  Technology has improved since then, so there are a number of exciting items available to use on the new car, we will provide full details on all these parts as well as a fully detailed car specifications as things progress.  The one thing we will always lack is sufficient driving skill to get the best from Project N2!

ENVISAGED SPECIFICATION

Lotus Elise 111R base car
Toyota 2ZZ-GE engine

Garrett roller bearing motorsport turbo
Tial boost controller
Tial external wastegate
Simply Sportscars custom chargecooler
Nitron custom front dual radiator
Davies Craig electric engine waterpump
Nitron custom exhaust system by Primary Designs
Motec M400 engine management system
Nitron custom dry sump system
Nitron custom Tripode driveshaft assembly
Simply Sportscars uprated gearshift cable

AP CP5040 4 pot front calipers
Nitron rear handbrake calipers
Performance Friction 06 pads
Nitron front and rear disc kit
Goodridge braided brake line kit
Nitron modified pedal box
Nitron balance bar assembly
AP twin master cylinders
Bosch motorsport ABS system
AP in-line rear brake pressure adjustment valve

Nitron -20mm front and rear alloy uprights
Nitron GT steering arm kit
Nitron GT toe link kit
Nitron GT wishbone kit

Motec M*** dash display
AIM EVO 3 full 12 channel high speed data logger
Raised gearshift changer with custom quick change shaft
Sparco steering wheel with quick release
Sabelt HANS 6 point professional harness
MOG Racing carbon seat
Custom cages full bolt-in 6 point cage
Motec electronic wiring control system
Lifeline full electric extinguisher system
Front mounted battery conversion
Electrically heated front screen
Lightweight Nitron wiper motor conversion

Nitron lightweight full carbon doors with window frames
Nitron lightweight door hinges (available on exchange)
Nitron GT full carbon rear wing assembly
Rays forged Motorsport wheels
Nitron front and rear towing eye kit