ACE CAFE RADIO

    dimanche 10 février 2013

    BIG HACKS !!! KRB’S ESPRIT GETS SOME SERIOUS FIREPOWER


    When is a Lotus Esprit not a Lotus Esprit? How about when it’s a Group C prototype underneath? It sounds like a match made in heaven, taking the aesthetics of the most recognisable two-seater sportscars of the ’80s and matching it to the underpinnings of a thoroughbred racing car.
    What’s not so surprising is that the car is in the possession of Kai Bakken – he of KRB Trading, turbo-wizard extraordinaire and the man behind the bewinged monster that is the Gatebil Audi S1. We briefly mentioned this car towards the end of last year here on Speedhunters, just after Kai had got hold of it, but I was able to spend an unhealthily long amount of quality time with the Esprit during my recent Gatebil On Ice trip, and can’t help but want to show off the updates to this build in more detail. It looks like I’m determined to keep last month’s ’80s theme running…
    Kai had been chasing this silhouette Esprit for years: it was well known in Scandinavia as the fastest racing car in Norway. It had been built in the late ’80s by a Swede who had been working for British C2 racecar constructor Tiga: he bought a wrecked car, took it back to Sweden and decided on this perfect combination of form and function. Bo Ridström raced it in the late ’90s Swedish GTR Championship, and most recently Dagfinn Larsen campaigned the Lotus in the Nordic Supercar Challenge, which is where it forged its reputation.
    Kai: “The Esprit was my childhood fantasy car – this and the Audi Ur Quattro. I like all these older cars. It’s like the old M3 as well – they’re more rectangular. Probably not very efficient but they look brutal. I bought the Esprit last October, after I sold the car I normally run on the ice. I had known about the car for a long time, and I’d even been driving against it many years ago. Larsen was the star in those days: it was the fastest car in Norway by a good margin, running in Special Saloons against old Porsche GTs and DTM cars. It was powered by a big NASCAR Chevy V8, which I didn’t like – I don’t like the sound or weight, and I really like boost on my engines. But it was really fast…”


    The Esprit last raced in 2008, at which time the car was sold on – Kai wasn’t able to secure it that time, but the despite big plans the new owner didn’t seem to get anywhere with the project. After it had been sitting in pieces, gently mulching down after its last racing outing, the owner finally relented and agreed to sell.
    At first glance it looks a bit battered… No, let me rethink that. At first glance I think it looks amazing.
    Forget the chipped bodywork. The lines of the Esprit are the key. The wedge shape has been amped to obscene levels with the silhouette body, the shaping of the fibreglass panels making it far more extreme than the GT1s of the mid-90s, and it even leaves the Group 5 Esprit from the early ’80s looking simple and unassuming compared to this level of brutishness. It’s an object lesson in racing car aesthetic. If it looks fast, it probably is. And with this Esprit, which wasn’t slow before, now Kai has his plan in motion it’s just going to get faster.
    I’ve seen a number of Esprit-a-likes, but many look like like they’ve been made from cereal boxes and tape: all flapping bodywork and lack of finesse. But this one is different. Maybe Colin Chapman wouldn’t claim paternity, but it has more of a proper Lotus feel to it: the lines just seem right; the air looks like it will flow over it. It looks light and fast. It emphatically says Esprit.
    Maybe it’s that louvred rear deck?…
    Underneath the bodywork is the full tubeframe chassis from a 1984 Tiga C2 prototype: the chassis number is gone, so it’s difficult to tell what the specific race history is. The front and rear suspension are stock Tiga parts, but the frame was rebuilt using a Tiga design and a new rollcage fitted. Tiga Race Cars folded in the 1990s, but handily have recently reactivated and started up a spares business.
    Kai: ”The base car is built extremely heavy. When you look at the chassis there’s a lot of tubing, and you can see the big frame rails down the side. It’s very solid – too solid in a way! But there’s a positive. When you have a lot of power and torque it’s good to have a very stiff chassis.”
    On the rear wing you can still see a Spice Engineering sticker: another classic C2 team who campaigned Tigas and tuned V8s in the ’80s (later becoming a successful constructor themselves), and showing that the wing is another part of the car with direct links to the C2 original.
    Kai: ”I haven’t even driven the car yet! I got it in pieces. I have a big trailer – 3 x 2.2 x 5.5 metres – and it was filled to the roof with car in two halves, tyres, rims, spares…”
    The cockpit is functional and basic. There’s a custom-made fibreglass seat which has definitely seen better days, and the cramped cockpit and gear linkage make access a challenge.
    Kai: ”It’s a pain to get in and out. It’s actually easier to go in from the passenger side!”
    Amazingly, the Esprit does have space for a passenger seat. Well, not space – more a slot. You’d have to be size zero to fit in comfortably, though Kai isn’t aiming to take passengers… So, the seat sits propped up against the wall along with some other spares.
    Kai: ”Before there was an old dash with a lot of different gauges everywhere. I want everything in one place, and luckily it’s not expensive to do that any more, so we’ll be ripping out everything. I’ll have a Racepak data logger behind the steering wheel, which is the only thing thing I need like that. I’ll change the wheel, and integrate all the switches.”
    Another modification will be to make a new fuel cell and mount it in the dead space at the rear of the cockpit. It only has a 50-litre tank at the moment, but Kai plans to build in a new cell with a catch tank to drop straight into the fuel system, with a mechanical fuel pump.
    The doors need some serious work: currently you have to lift them up over the sill to open them, the result of a bit of a botch job on the hinges, and they feel like they’ll drop off if you don’t hold them up. Similarly, the mirrors look positively agricultural and in need of replacement, which is even more pressing given the rear view through the plexiglass screen…
    …of the louvred rear deck.
    There’s also some asymmetrical cooling intakes courtesy of the previous engine configuration, although they look pretty cool. Though it’s best not to talk about the damage done with what looks like a chisel to the roofline at some stage in the recent past…
    Kai: ”Ah yes, we’re going to fix all these things: Just look at those mirrors! There was a GPS logger on the roof as well, but I won’t mount mine up there: it reads through glass fine, so I can have it on the dash. The windscreen is a stock piece: I like to have real glass.”
    Although all the mechanicals were pretty sound, the electrics were a different matter after almost 30 years of ‘evolution’. The wiring threaded its way through the car with no shielding or seeming order: all of it has been ripped out, and a totally new wiring loom is just about to be fitted.
    Kai: ”I’ve bought in a ton of mil-spec motorsport wiring and Raychem heat-shrink. We’ll route everything properly, and mount all the units on the rear bulkhead, like a proper racing car would have.”
    The front lights are hilarious: the series regulations dictated low-voltage running lights, so these puny little things were hanging off the front…
    The rear is worse…
    Kai: ”They look like they’ve been robbed off an old Brian James trailer from ’73! I’m thinking of making three separate rectangular pieces out of LEDs, using the full width space of the original lights. It looks too narrow at the moment. The guy running the car before just put these in as the regs said he needed something. The originals were from some old Rover I think.”
    “Lotus just grabbed parts from everywhere. The door openers are from something else. A Morris Marina or something? Which would be terrible! But it’s like the RS200 with all its Sierra parts. It was the way to get the price down with the non-essential parts.”
    As befits a racer based on a C2 sportscar, there’s a lot of serious kit in each corner.
    Ohlins coil-overs provide the damping…
    …and enormous 380mm Brembo disks (as per the original C2) the stopping power.
    The wheels and tyres are similar oversize: 18″ centre-lock BBS rims, 11″ width on the front and 13″ at the back.
    The rubber on the rear is 31x71cm – on a car which is just 102cm high!
    The sale came with a big stack of rims and rubber; not all the rims are entirely round, having seen plenty of battle damage over the years.
    Kai: ”Yes, but with a car like this, where the wheels are so wide, you don’t seem to feel much shivering. I’ve been running with non-balanced front wheels, with rims that you can see aren’t that good, and it’s fine. On a street car it would be all over the place, but the width of the tyres evens things out I think.”
    The original fronts match the mesh BBS rears…
    …but Kai’s also tracked down some newer style Y-spoke BBS rims for the fronts, which make it look more modern. Those are likely to make an appearance on the final result.
    The big shock for a Gatebil car will be the front-mounted radiator. Size? Big. Air flow will not be a problem, and it’s just a cleaning and renovation job, with the piping needing some upkeep and potentially changing the old-fashioned hoses.
    The car came without an engine, so a new Audi engine (of course) has been inserted.
    Kai: ”The original C2s usually ran with big-block V8s, but I think this had a more modern unit, with eight trumpets and 800hp – maybe 750-800nm of torque. But it was always smashing up the gearbox: it would run six or seven races and the crown and pinion would go. It was an old Hewland – they make Formula parts, and when when you look at the crown and pinion they’re huge, but as all good English racing companies do, they lighten stuff. They drilled out the centre of the pinion, leaving only a small amount of metal! And the V8 is no soft engine: the power is just on or off. With progressive power it might have been okay, but with the on/off hit of the V8 I think that’s why it kept breaking.”
    In its place is a 4.2-litre Audi V8, mid-mounted low down in the chassis so you can barely see it. Kai and his team are already well progressed with the engine work: the new manifolds and intake are made, with just a bit of welding left on the wastegate and new cylinder heads and lifters to fit.
    Kai: ”I hope the turbo Audi engine will be a lot smoother. It will make more power, but not instant power: it should be more controllable and easier to drive. We’re rebuilding the engine now, with steel liners and everything, rebuilding the heads, taking out the bigger lifters and mechanical camshafts. Hopefully we’ll have 400hp even without the turbos.”
    Ah yes. The turbos. This is a KRB car after all. Two Comp turbos have been mounted, connected via some very tidy piping to the intercooler and ancillaries, with one turbo either side by the rear body intakes.
    Kai: ”There are those two babies to make a small breeze! Not much: one bar or something, just sitting there controlling extra horsepower.”
    “I know that this gearbox can handle 800nm, and when Hewland say that you know it can take that for 24 hours – and we’re only running 50 minutes or so! So I’m sure it can handle more. But if you think that the car only weighs 1,050kg, how much more than 800nm do you need? To go fast you don’t really need anything bigger.”
     
    There’s a big change in maintenance philosophy with a car like this: everything rear of the cockpit bulkhead hangs off the engine and the whole car can be literally separated into two, which makes a huge difference when working on it.
    Kai: ”If you take out all the tubes and loosen the engine you can just take off the whole of the rear. It’s very easy to work on: you can split the car in two in 15 minutes. Then you have the two halves and you can stand in front of the engine to work on it. You can also take two bolts off and the rear bodywork pivots up like an old hatchback.”
    “The Audi V8 has got a really nice power band. This 4.2-litre has 400nm at 4,000rpm even with no turbo – in the S1 until the turbo kicks in there’s not so much torque. We’re using the Lotus as a bit of a test: if the V8 does what I hope it will do, I’ll put the same size engine in the Audi. The Hewland transaxle is rated to 800nm, but the Audi ‘box can take 1000nm easy. To have that kind of torque from the bottom end will be amazing in a 4WD car.”
    Out back, the single-pipe exhaust routing is being finalised – it will exit out of the left rear of the car.
    Driving wise it’s going to be a step-change for Kai – even from the Audi.
    Kai: ”The Esprit is definitely a grip car. To go sideways with this one? There’s just too much downforce, so it’s not going to be good for drifting. The steering lock is virtually nothing – it’s built to go forward! It’s like in the Audi, which has such tremendous grip in the rear that it’s difficult to go sideways, unlike our other more stock Audis where we’re sideways all the time. But you can see if a car is fast by the way it makes a turn. In a normal car, you see the transition, but with the Audi – and this – it will just turn, bang.”
    “I was talking to the guy who ran the Esprit before with the Chevy engine and it could be rough when you hit the throttle. This one had eight barrels so it was probably very rough, and he told me that even so he really had to provoke it to get the rear out. You almost need to use the clutch to slam it out. I was afraid it might be a bit nervous but he told me that it had so much grip: it’s never sideways out of corners, it just goes.
    “I’m a little bit spoiled from the Audi with its four-wheel-drive, as you can just hit the throttle mid-corner and it will pull you through. I think I might miss that a little bit: 800hp and 900nm of torque… But the corner speeds in the Esprit should be a lot higher, as should the top speeds on the straight – especially when you look at the front of this compared to the S1, which is almost like a truck!”
    “I really noticed that when I was doing 260-270kph on the straights, the last 10-15kph wouldn’t come easy with the Audi. You can really feel that the 4WD system is taking away a lot of power, with the differential and propshafts and driveshafts. The Audi is all about low-end grip and power rather than high-end speed. But with the Lotus, the slippery shape and new engine should make it better.”
    As Kai points out, the car is in need of a lot of TLC to bring it back into racing condition, but this is a long-term project with the short-term goal of just getting the car back on track.
    Kai: ”If you look at the front we have 10 different yellows showing through… But I have bad fantasies so I’ll make it white! Bright white with black detailing, plus the sponsors like the white. For this first season I’ll be short of time, so we’ll see.”
    “I have the moulds to make everything, except the front. Well, I have the front too, but it was remade from the old style Lotus that won’t have space for the big front wheels. They redesigned it, so I might have to make a new mould for it. But for now I’m just going to clean it up… and change the old Volvo indicator lights!”
    Kai is aiming to have the Lotus on track for the May Gatebil event at Våler, and if possible for the first round of the Norwegian GT series which is even sooner.
    Kai: ”I’m aiming for the Porsche 993s in the Gatebil Extreme series! It’s been difficult to keep the reliability against those factory built cars, but I think the Lotus should be up there. Våler is the target for sure.”
    In that case, Våler – and those Porsches – had better watch out. I can’t wait to see this mechanically complete and out on track, and even better when the body is revitalised. It’s going to be quite a sight.

    Jonathan Moore from SPEEDHUNTERS

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