Turbo S38-swapped 850bhp BMW E9


850hp turbo S38 E9

For some people, owning a fast car is all about making sure that everyone knows what your ride is capable of – we’re talking citrus-coloured Lambos, bright red Ferraris, loud exhausts, aggressive aero, the sort of car that people will look at and know not to mess with because they’re going to get blown into the weeds.

You’ve got a lot of power and you want the world to know about it, and the appeal of owning or building a fast, powerful car and then showing it off is completely understandable. But then you’ve got the people who want something fast, really fast, but don’t want to shout about it; they want to slip by, largely unnoticed, they don’t want any attention, they don’t want to give the game away. What they do want to do is confuse and embarrass owners of full-on extrovert performance machinery as they absolutely destroy them in a car that just shouldn’t be able to do that. That’s the undeniable appeal of the sleeper. Sleepers, or Q-cars, have been around for a long time and they follow the same basic principle – super subtle on the outside, super powerful on the inside. There are varying levels of sleeper, from a light sleepers like an F10 550i, to a serious sleeper like the completely stock-looking supercharged V8-powered E30 Touring we featured back in August 2018. But there’s still one more level of sleeper, the deep sleeper, and while there are very few cars that achieve this ultra sleeper state, this E9 is one of them.

“The turbocharger is a Garrett GTX3582R, which allows me to have approximately 850bhp and 1000Nm (738lb ft) of torque and the car still has a good range of usable power with that combination”

At first – and second, and third – glance you might well be wondering why we’re featuring a stock E9. It’s gorgeous, there’s no doubt about that, it’s an iconic machine, a part of BMW history and heritage, but a PBMW feature car? Besides, who in their right mind would modify something as rare and special as an E9? The answer to the second question is Finn Jari Kihlman, and the answer to the first question is that we are not featuring a stock E9, we’re featuring an E9 running a race gearbox and a turbocharged S38 making 850hp. Now it all makes sense.

Jari loves BMWs – he really loves BMWs. He might have the most incredible collection of BMWs we’ve ever seen, in fact, over 30 in total and they include rare treats like an E9 3.0 CSi, an E34 AC Schnitzer Silhouette S5, two different Alpina B7s, an E32 Alpina B12, five E36 M3s, two E36 325i rally cars, an E36 M3 rally car, and that’s just scratching the surface. Where did his incredible passion for all things BMW originate? “In 1988 BMW started their winter driving school/ winter testing on our ice tracks in a northern Finnish city called Kuusamo, which is my home town. Me and my brother were ‘official snow blowers’ there at that time (1988-1998). Our job was to clean ice tracks in the evening, and as a trade BMW’s test drivers, Jutta Kleindzmit and Rauno Aaltonen, gave us permission to drive different kinds of factory BMWs with a tank full of petrol every night on the ice tracks. I fell in love immediately,” he grins and that’s one hell of an introduction to the marque.

“The interior, meanwhile… was beautifully reupholstered while in the previous owner’s care, with black Nappa leather on the seats, door panels, and even the dashboard”

Jari kicked his personal BMW journey off with an E36 323ti Compact, before moving on to bigger and better things and growing his collection exponentially over the years, and he’s not shy when it comes to modding his BMs, either. “I’m building up two different cars at the moment,” he says, “an E23 735i with a 2JZ twin-turbo engine and a Mercedes Benz AMG seven-speed gearbox, and an E21 320i Group 5 race car with an M88 engine. The E23 will be my grocery getter for next summer – the basic car is a 1983 Opal green 735i with only 170,000km on the clock. From outside it will be as it was as new, but with 17” original Alpina Classic rims, while the engine is a 550hp 2JZ with Garrett GTX2560 turbochargers,” he grins and those two projects are already on another level to the sort of builds most of us ever do, so it’s clear that Jari is not your average BMW owner.

So he’s got an insane collection of amazing BMs, he’s building a couple of incredible projects, but what made him decide to create this insane E9? “I just love the look of 1970-1980s BMWs, especially the look of the E9. I think the E9 has one of the most beautiful designs BMW has ever made,” he says. “I love the hardtop roof and C-pillar lines as well as the real sharknose look of it; it has something similar that you can see in Aston Martins from the same period, for example. The other and more important reason was the condition of the car. I know the former owner very closely and I knew that chassis of this particular car is better than any other E9 in the whole of Europe. The former owner won, for example, a concours d’elegance with the car in 2006 and it was not driven more than maybe 500km after that. So in 2015 I called him and after eight months of ‘wrestling’ I was the new happy owner of that car,” he smiles. “I always have a plan for each of my cars. My buying guide has always been that first I buy rims, then some special/rare tuning parts from famous part manufacturers like Alpina, BBS, AC Schnitzer, Hartge etc. and after that I buy a car for them. I don’t know why but it has always gone like that. For this car my main plan was to do something that nobody else would be bold enough to do: to make it an ultimate sleeper that even I’m afraid of,” he laughs and we reckon he’s achieved his goal…

Having a plan is one thing, but executing it is something entirely different altogether, and when your plan involves swapping an S38 into an E9 and then turbocharging it, it is not a simple matter and requires some serious work. Step one was ensuring that the classic chassis would be up to the task of dealing with all the power that Jari was planning to put through it. “First I opened both frames under the car and added chromoly bars inside the frames, welded them very carefully, and closed the frames so that car can stand the increased power better,” he explains. Next came the suspension and for this Jari ordered a custom Bilstein setup from Rallysystems Kittela, which uses a combo of Bilstein shocks and H&R springs chosen to Jari’s specifications, and in addition to this all the steering and suspension components were replaced with new items.

With that sorted, Jari turned his attention to the engine and it’s a beast; “The engine is very modified S38B36,” he says, “it includes Accralite pistons, Wossner connecting rods and camshafts, the cylinder head is modified by V.S Motor in Norway as well as the whole engine block. The turbocharger is a Garrett GTX3582R, which allows me to have approximately 850hp and 1000Nm (738lb ft) of torque and the car still has a good range of usable power with that combination. Engine management is Maxxtuning’s MaxxECU RACE H2O setup with custom wiring made by TT-Speed’s (ttspeed.fi) Tero Talvensaari,” says Jari and that’s a serious lineup. That Garrett alone is impressive but it’s the additional engine work that Jari has carried out that really sets this build apart, and it’s the sign of someone who knows what is required to safely extract this level of power from an engine.

Impressive as that swap and the sight of that massive turbo under the bonnet are, if anything it’s the gearbox that really steals the show here. “The gearbox is a unique GD Transmission five-speed billet transmission that can handle up to 1200hp/1200Nm (885lb ft) of torque,” explains Jari. “GD Transmission developed this gearbox for my needs and I couldn’t be more satisfied with it. I used earlier Getrag Type 280 gearboxes but the E9 was eating them like a child eats candy,” he laughs. “Now I can accelerate full throttle and I don’t have to be afraid that the gearbox will blow up after every full boost moment. It takes only 40milliseconds to change gear at full throttle, and also Tero programmed an ignition pause for my car to protect the gearbox,” he say. The gearbox is an H-pattern manual, but once you’re under way you don’t need to use the clutch to shift, meaning Jari can just bang through the gears with his foot flat to the floor, which is awesome. The clutch is an Alcon twin-plate racing item with a custom flywheel made for Jari by Sarlin Race Team, the propshaft is a custom chromoly item, the driveshafts are made from special steel, and the diff is a BMW Type 210 with a 3.91 final drive.

While at this point we’d normally move on to discuss the other mods around the car, the beauty of an ultra sleeper like this is that the drivetrain insanity is really the bulk of the entire build and everything else has, for the most part, been left well alone, though a man like Jari is not capable of leaving anything on a car of his completely stock… “From the very beginning it was clear to me that the car had to look like an original, mint condition E9. In the beginning of the 1970s Alpina was mainly a racing part/tuning part manufacturer for BMW, so it is period correct that I have an Alpina steering wheel, Alpina’s ATE brake calipers, Alpina gear knob and staggered Alpina rims. Otherwise the car looks like an original,” says Jari, and we love how completely standard this car looks, right down to that classic Fjord blue paintwork.

The Alpina Classic wheels are tiny by modern and modified standards, measuring just 16” across and 7”-wide up front and 8”-wide at the rear, and they’re fitted with very narrow 205/50 and 225/45 Michelin Pilot Sport 4 tyres, which sounds crazy when you’re trying to put 850hp down, but there’s method to Jari’s apparent madness. “The reason I’m using such small tyres is that I want to keep the car looking like an original E9 3.0CS and there needs to be a fuse somewhere in the drivetrain. Mine are the wheels. Even though the grip is actually very good, I can spin the wheels whenever I want to and the car is still very drivable,” and this logic makes sense. Jari’s tyres are excellent and provide a lot of grip but there’s not so much that the rest of the drivetrain is in jeopardy of breaking, hence his comment about having a fuse in the system, something that will let go before anything gets damaged.

The interior, meanwhile, Jari has already touched on and it was beautifully reupholstered while in the previous owner’s care, with black Nappa leather on the seats, door panels, and even the dashboard, and it all looks seriously lush. “The only problem I had was getting the gear knob to fit onto the GD Transmission shifter. I had to modify different kinds of threads on the shifter,” explains Jari, and the final addition you’ll find in the cabin is a Peltor noise-cancelling radio headset as there’s no in-car radio and the gearbox is quite noisy, as you might expect.

This E9 really is something else – the engine and gearbox combo is incredible and combined with the totally stock exterior – and interior – Jari has truly built the ultimate sleeper and it’s an achievement worthy of extreme praise.

Perhaps most impressive of all is the fact that, while the build itself was spread across a number of years, the amount of time that the major modifications took was really very short. “I did the first engine version in April 2017 and the final version was ready three months later. The gearbox/ECU modification took place this spring and it took about three months to get the car fully working,” says Jari.

“My favourite modification has to be the gearbox. It really is a game changer,” he continues. “The engine is also awesome but after adding this gearbox the car was born again. Now while changing gears the turbo boost doesn’t drop down and I think the car is twice as fast as it was before that modification,” he grins.

“I like the car as it is now. I could have built three race cars with the same amount of money this car has eaten but it is worth of every cent,” he laughs and we’re not surprised to hear that. What we are surprised to hear is that while Jari does have some more mods planned, they’re not what you’d expect. “I will try to drop the horsepower a little and try to get an even wider power band for the engine. I think it will be even faster and more reliable with smaller turbo,” he says and it’s rare to find someone looking to lower their power level, but seeing as it’s to make the car even faster, it can only be a good thing.

Pillarless coupé design is beautiful. Alpina Sport steering wheel. Interior has been fully retrimmed.

Classic Fjord blue metallic suits the E9 so well. This E9 is immaculate and completely stock on the outside

DATA FILE Turbo S38 E9

ENGINE AND TRANSMISSION 3.6-litre straight-six S38B36, V.S Motor custom cylinder head and engine block, Accralite pistons, Wossner connecting rods and 286° camshafts, Garrett GTX3582R turbo, custom stainless steel exhaust manifold and exhaust system, MaxxECU RACE H2O ECU. GD Transmission billet five-speed race gearbox

MAX POWER Approx. 850bhp @ 6590rpm

MAX TORQUE Approx. 738lb ft @ 4400rpm

CHASSIS 7×16” (front) and 8×16” (rear) Alpina Classic wheels with 205/50 (front) and 225/45 (rear) Michelin Pilot Sport 4 tyres, custom suspension by Rallysystems Kittela with Bilstein dampers and H&R springs, Alpina ATE calipers

EXTERIOR Fjord blue metallic

INTERIOR Alpina Sport steering wheel and gear knob, black Nappa leather seats, door panels, and dashboard, electric front and rear windows, electric sunroof, Peltor noise-cancelling radio headset

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Jean-Claude Landry
Jean-Claude is the Senior Editor at eManualOnline.com, Drive-My.com and Garagespot.com, and webmaster of TheMechanicDoctor.com. He has been a certified auto mechanic for the last 15 years, working for various car dealers and specialized repair shops. He turned towards blogging about cars and EVs in the hope of helping and inspiring the next generation of automotive technicians. He also loves cats, Johnny Cash and Subarus.