Turbo Technics E320 parts list, installation, reviews
 

I'm starting this thread to house all the information related to the Turbo Technics kit I have purchased for my 3.2L M104 engine. I will start by transcribing the parts list, installation instructions and magazine reviews that were faxed to me by Mercedes of Beaconsfield.

For those interested, this dealership in the UK is selling brand new conversion kits for 3.0L M103, 3.0L M104 and 3.2L M104 engines.
A total of 50 conversions were performed by the dealership using these kits and a further 25 kits were made to be sold for 3rd party conversion. Of the 75 total kits, approximately 25 were made for each engine. As of this posting date, kits are still available for all three engines. The price is £1000 per kit. You will either need to pick up the kit yourself or have a courier collect it as the dealership will not organize shipping for you.
If you are interested in purchasing a kit, speak to John Pearson j.pearson@hughes-group.net or phone +44 01494 672141 (he doesn't check his email that often).

Turbo Technics Mercedes Registry

50 Original Hughes conversions
25 3rd party conversions

Parts list. The kits include the shortened connecting rods.

Turbo Technics Limited
Fitting Instructions
Mercedes 24v 320E

1. Disconnect the battery, drain the engine oil and water coolant into clean containers.
2. Remove the air filter assembly.
3. Remove the complete exhaust system.
4. Mark the positions of camshafts to crankshaft and remove the cylinder head.
5. Remove the water radiator, support the transmission to remove the engine crankcase.
6. Remove the sump pan and carefully remove all pistons, marking their original positions.
7. Remove the pistons from the connecting rods, marking their positions.
8. On catalyst equipped cars, cut the catalyst from the exhaust downpipes.
9. Send the pistons, connecting rods, throttle body, clutch cover (manual transmission cars only), and catalyst to Turbo Technics, Northampton, for machining.
10. Position the intercooler under the offside chassis rail, parallel with the engine.
Slide the intercooler backward until the end tank (with two inlet pipes) touches the chassis cross member.
With the intercooler in this position, mark through the two mounting holes.
11. Remove the plastic plate behind the offside headlight (where two chassis rails converge).
12. Fit the intercooler with two self-tap screws.
Offer the GRP air duct up to the intercooler and locate onto the two studs used to secure the aforementioned plastic cover.
This operation is simplified if the front bumper assembly is removed.
13. Bolt through the air duct and intercooler lower bracket and through into the rear intercooler end tank.
(The tapped hole on the front intercooler end tank is used to replace the engine heat shield mounting).
14. Depending upon the type of front bumper spoiler, either:-
a. Remove the blanking plate behind the grille section to allow air to flow into the intercooler ducting.
OR
b. On plain spoilers with no grille, mark out and cut a number of neat slots to allow a maximum amount of air through.

Fit the plastic dividing plate to direct air flow into the ducting rather than through the water radiator.
15. i)Slacken and remove the engine drive belt.
ii) Remove the air pump, alternator and mounting bracket.
iii) Remove the idler mounting bracket.
iv) Re-fit the idler pulley onto the new mounting bracket and re-fit.
v) Re-fit the alternator onto the new lowered bracket.
vi) Fir the new drive belt and tension.
16. Remove the water drain plug from the engine block - this will supply the water coolant to the turbocharger.
17. Drill and tap both oil drain positions into sump (drawing number 3177). Carefully screw in the 45° oil drain fitting using thread sealer.
Fit the soft washers into the inside of the sump and screw onto the nuts. DO NOT OVER-TIGHTEN.
18. Remove the oil pressure switch above the flywheel and replace the fittings used for the turbocharger oil feed pipe.
19. Re-fit the pistons to the shortened connecting rods carefully, and re-assemble the engine.
20. Re-fit the modified clutch cover to the flywheel (manual transmission only).
21. Replace the crankcase back into the vehicle.
22. Remove the exhaust manifolds from the cylinder head,
i) Remove the air pipe above the exhaust manifolds.
ii) Fit core plug into the hole to seal.
23. Fit the new exhaust manifolds to the cylinder head. Bolt the exhaust elbows into the turbochargers, (the elbow with the heat shield must be used on the front turbo).
24. Fit both oil drain pipes into approximate positions, they can be tightened after aligning, once the cylinder head is fitted.
25. Replace the cylinder head. Re-fit the cam chain.
26. Replace the sparking plugs.
27. Fit the water pipes from the engine block to the turbochargers.
Fit the 'P' clip onto the front turbo water pipe, securing with a bolt into threaded boss in the side of cylinder block.
28. Connect the oil drain pipes.
29. Fit the rear compressor outlet silicon hose, slide the short length of silver convoluted hose into position to protect the horizontal length of silicon hose from the exhaust manifold heat.
30. Connect the front compressor outlet to intercooler silicon hose.
31. Fit the air filter inlet duct at the top of the gap between the headlight and the radiator. Fit the convoluted hose to the duct.
32. Replace the radiator and mount the air pipe vertically next to the radiator. Remove the nearside headlight to drill through.
Gauge the position by ensuring that the link pipe from the intercooler is horizontal.
33. Cut the nearside plastic under shield to allow flexible ducting to pass through to the air filter.
34. Position the air filter under the nearside inner wing. Mark around the outlet and cut a hole in the inner wing.
Drill through the mounting lugs on filter body. Fit the air filter element and mount the air filter assembly.
35. Fit the 110.0mm long silicon hose to the outlet. Fit the metering unit, metering unit outlet hose and air pipe casting, using the bracket supplied.
36. Cut the original air pipe over the engine, as close to the end of the oval section on the nearside as possible. Fit to the casting using the silicon hose supplied.
37. Fit the compressor inlet silicon hoses.
38. Remove the front bumper. Cut away the plastic fan shroud below the cross member to allow more cooling for the radiator.
39. Screw the breather stub 90° into the air cross pipe casting.
40. Cut the water hose from the electric water pump to the engine just after the 90° turn at the pump end.
Turn around the longer remaining hose onto the engine. Fit the steel extension pipe to re-connect the hose to gain clearance from the air filter lid.
41. Fit the oil feed hose to the turbochargers. Use three double-ended studs to mount 'P' clips on.
NOTE: Ensure that the oil feed hose maintains clearance from the brake pipes across the bulkhead.
42. Fit the short fluorocarbon hose to the throttle body inlet.
43. Assemble injector to throttle body casting using the 'O' rings supplied. Fit the assembly to the hose.
44. Disconnect the fuel inlet hose at the fuel rail. Fit the 'T'-piece and short 50mm long hose to connect up to the manifold. Use the other hose to connect to the injector.
45. Fit the wiring loom for the additional injector. Carefully wrap to the contact pins with insulation tape before pushing through the grommet on the bulkhead.
Locate the DCU under the passenger side floor panel using the bracket supplied.
46. Connect the over boost protection relay next to the Mercedes ECU behind the battery. Remove the MAS unit adjacent to the ECU by turning the top knob.
Locate the fuel pump feed wire (black/red with white stripe) at the front of the multi-plug to the over boost relay red/black wire.
Connect the remaining black/white wire to the longer cut wire. Solder all connections and insulate using shrink wrap.
47. Connect the silicon hose from the intercooler outlet pipe to the injector mounting.
48. Fit the two turbo water outlet 90° pipes. Connect the molded silicon hose from the rear turbo to 'tee' into the water coolant hose adjacent to the expansion bottle.
Connect the straight silicon water hose from the front turbo water outlet to 'tee' into the same hose between the radiator and the air filter box.
49. Fit the engine breather systems incorporating the mio-filter and one-way valve.
50. Fir the complete exhaust system. The catalytic converter is not retained in the system, but the Lambda sensor must be fitted into the boss.
On Coupes, the outlet pipes from the center silencer need reducing in length. The original exhaust mounting bracket from the gearbox is retained.
51. Fit the two turbine chrome heat shields.
52. Run the engine, checking for leaks, until normal water temperature is achieved.
53. Re-torque the cylinder head bolts.
54. Road test the vehicle, checking boost pressure - see service instructions.

TURBO TECHNICS E-CLASS
PERFORMANCE & STYLE INTERNATIONAL JANUARY 1995

Jump straight from an ordinary car, as I did, into the Turbo Technics E-Class Mercedes conversion and your first impression is of the effort required to operate this German coupe.
Mercedes-Benz never made a floppy switch or a feeble control in their life. They certainly haven't fitted any to the E-Class cars.
Apply positive pressure to the door-mounted controls and almost silent electric motors place you exactly where you want to be in relation to the pedals.
Click another switch and you get the steering wheel in your chest or at arm's length. Click it again and you get it just right.

Now turn the ignition key - positively. After a brief display of warning lights the 24-valve engine awakens and instantly adopts a 600rpm idle.
Plant you left foot (or right, if you prefer driving autos conventionally) firmly on the brake pedal and select D via the robust looking gear lever.
Release the handbrake and move off. Hang on - release the handbrake. But where is it? Not beside the seat, for sure. Of course, this is a Merc.
The handbrake is actually an extra pedal snuggling against the transmission tunnel and you need to pull a handle on the dashboard to release it.

At last we're moving now - ever so slowly. Around 3.2 litres of straight-six engine is good for about 3mph at idle revolutions.
The large floor-mounted throttle pedal is the key to extra speed but the unaccustomed effort needed to alter its position results in jerky acceleration.
Until you get used to it of course.

After but a few miles you do. And after a few more this dimensionally unchallenged car begins to feel like those old shoes you are reluctant to throw away.
The comfortable leather seats help, of course, as does the efficient air conditioning.
With a total absence of distracting squeaks and groans from the interior trim you brave the myriad tiny controls on the Sony entertainment system.
What a pity that Mercedes dealers, Hughes of Beaconsfield, who lent us their converted demonstrator, don't apply their good taste in cars when it comes to the choice of CDs.
But who cares about listening to music (Muzak, actually) when you can tune in to over 300bhp accompanied by the low-pitched moaning of two Garrett turbochargers?

If only... Bumper to bumper rep-mobiles heading north on the A1 on a wet Friday night restricted speed to between zero and 40mph.
An occasional gap in the traffic allowed a brief burst of acceleration that must have left a few Mondeo drivers scratching their heads.
Presumably they had come across E-Class coupes before and learned to differentiate between easily overhauled 2.2-litre versions and the somewhat less vulnerable six-cylinder cars.

Nevertheless the rapidity with which the visually stock Hughes E320 consumed the horizon will have come as a surprise. I hope so, because it served to dissipate some of my frustration.
Even so this was probably the most boring eighty miles I've ever driven.

At last Scotch Corner loomed out of the darkness and with it the relief of turning onto the A66.
The arrival deadline was fast approaching but as Roman Way red mullet and a bottle of chilled Beaujolais are preferable to cold sandwiches,
all considerations of saving the planet were swept to one side.
Selecting Sport mode on the automatic transmission, I pressed even harder on the throttle pedal.
Lorries and their attendant slow-moving followers were dispatched rapidly and safely with fierce bursts of acceleration.

Sheer size and the cocooned feeling that you get within the virtually silent cabin prevents the E-Class coupe from producing an intimate driving experience in the manner of say a Mazda MX-5 or a Caterham Seven.
In fact, enthusiastic cross country motoring takes some getting used to.
The power steering feels over-light either side of the straight ahead position, and when combined with the car's long bonnet this makes following the white line somewhat of an imprecise affair.
Relocating the ever-recognisable trademark, the three-pointed star to the right-hand corner of the car would help matters but would probably not find favour in Stuttgart!

Because of my unfamiliarity with both the E320 and the A66 I approached each corner with caution while attacking the straight sections with gusto.
There is no doubt that the Sportline suspension of this Mercedes complements the standard 15in wheels and 205/60 Michelin tyres extremely well.
It drops the car 9-10mm - similar to the E500 version, yet even with the uprated suspension the ride loses none of the standard and renowned Mercedes comfort.
However, the excellent damping characteristics ensure that the coupe will rapidly return to a level attitude even after enthusiastic cornering.

Unevenness in the road surface is absorbed without the harshness that might be associated with lower profile tyres.
No doubt a better driver could have made full use of the available power and tested the car's cornering ability to the limits.
Nevertheless, my point and squirt approach achieved the desired objective.
Just as the clock struck nine we took a last sip of our aperitifs and moved into the the restaurant. No need for sandwiches thanks to 350bhp.

Cambrian weather was certainly not conducive to photography that weekend and Appleby Manor's Return to Eden break seemed misnamed -
until we learned that the hotel is actually located in Eden. The roads around that area are, however, exciting whatever the weather.
Damp tarmac did little to unsettle the Merc's road manners although a sudden application of the throttle on a leaf covered corner had the automatic skid control light blinking at us from the dashboard.

The brakes are standard discs all round with ABS, a feature which I never had call to bring into play on this particular occasion.
But considering the top speed capability of this 1500kg car the anchors are best described as adequate.
I would expect press-on drivers to regularly find replacement brake pads popping up on their servicing bill.
Talking of which, Mercedes-Benz dealers will have no trouble applying the normal service routing to this particular car -
on this engine only the spark plugs and oil are of a different specification to the standard model.

With the four-speed automatic transmission in Economy mode the Turbo Technics Mercedes will cruise around all day at low revs and minimal boost pressure.
The Mercedes 24-valve boats a dual inlet system, which below 4000rpm behaves like two three-cylinder units, and at higher revolutions reverts to the normal six cylinder operation.

Yet just occasionally the engine appears to be confused by this dual inlet system working in collaboration with the additional engine management unit.
The result is a slight oscillation in the power delivery but, thanks to the smoothing effect of the transmission, it is something which you will hear rather than feel.

What about turbo lag? If a delay of about three nanoseconds counts as turbo lag then this car has it.
In truth, the excellent output of the standard engine means that the turbos steepen the torque curve rather than adding a step to it.

On the road this translates into impressively rapid levels of acceleration in all gears from any speed.
Hughes of Beaconsfield adjust the transmission pressures with the result that upchanges are taken at slightly higher speeds than the 35/60/90mph of the standard car.
At a constant 3000rpm the E320 is rolling along at around 75mpg in fourth gear.

Such impressive performance doesn't appear to come at the expense of economy.
Over 1000 miles of often enthusiastic motoring I recorded about 25mpg, which is par for a standard 3.2-litre coupe.

Having decided, like me, that 350bhp is exactly what the standard E320 needs you'll no doubt be expecting to be put off by the cost of having such an uprate applied to your machine.
Surprise, surprise, the conversion brings the price of a new car in at under £50,000, depending on the extras that you specify.
Compare that with the £75,000 needed for a 300bhp 500 coupe or the £52,000 for a BMW M5.
If you already own a six-cylinder E-series or 300-series then the twin turbos kit will cost you from £5870 to fit.

What will this mean to your car?
Well peak power will range from a little over 300bhp on a 12-valve, 3-litre engine to 350bhp on the latest E320 models.
Hughes of Beaconsfield offer an unlimited mileage, 12-month guarantee on the engine and turbo system, so there's no worries there.
Too much power? Not at all...

Performance Figures
Acceleration from rest
mph secs
30 2.2
40 3.2
50 4.4
60 5.7
70 7.4
80 9.3
90 11.6
100 14.4
110 17.8
120 21.9

Turbo Technics Conversion Brochure
Now you've chosen to drive a Mercedes-Benz...
...why compromise your driving experience?
Supercar performance with all the benefits of a luxury limousine.

Outline technical specification

3 litre, 6 cylinder, 12 valve engine
Reduced compression ration, modified throttle body and plenum chamber;
additional engine management unit, working in conjunction with the standard electro-mechanical fuel injection system, to optimise fuel flow and ignition advance curve;
two additional fuel injectors;
twin Garrett T2 water cooled, pressure lubricated turbochargers;
Intercooler;
cast nickel iron exhaust manifolds linked to large diameter stainless steel exhaust system incorporating the standard catalytic converter.

3 litre, 6 cylinder, 24 valve engine
Modifications essentially as per 3 litre/12 valve unit with appropriate detail adjustments.
The catalytic converter cannot be incorporated within the exhaust system on models using this engine.
The 155mph speed restrictor is retained.

3.2 litre, 6 cylinder, 24 valve engine
As per 3-litre/24 valve unit except that a single large additional fuel injector is used and the additional engine management unit works in conjunction with the standard, all-electronic fuel injection system.
The catalytic converter is incorporated within the exhaust system on models using this engine.

Note: 98 octane Super Unleaded petrol is required with all the Turbo Technics turbo conversions.

Owning and driving a Mercedes-Benz is a special experience, born out of its renowned engineering and legendary build quality.
The marque, in all its guises, undeniably provides levels of refinement that are widely regarded as the benchmark for the industry.

Recognising the product's huge reserves of durability, the UK's leading turbocharger specialists, Turbo Technics,
has seized the opportunity to produce a unique high performance engine conversion applicable to both the 300 series and 3.2 litre E series models.

Whilst the primary objective was to offer supercar performance with all the benefits of a luxury limousine, retaining the inherent levels of refinement was considered a prerequisite.

The result is quite simply breathtaking. By concentrating on enhancing the standard engine's torque delivery, as opposed to its outright power,
the conversions offer sensational low and mid range punch which permits effortless overtaking manoeuvres.
Throttle response is crisp and instantaneous, and drivability is in no way compromised.

The conversions call for no alteration in driving style or special procedures and, apart from the dramatically increased performance,
most drivers would be unaware that any form of modification had been carried out, unless they happen to notice the very discreetly placed components in the engine bay.

Even fuel consumption is unlikely to be adversely affected, although this naturally depends upon the driver's ability to resist the temptation to use the electrifying performance at every opportunity
and in most cases catalytic converters can be retained where fitted.

All too often a well-engineered conversion is spoilt by the quality of the installation.
With their fine reputation at stake, Turbo Technics had no hesitation in appointing the long-established Mercedes-Benz dealer, Hughes of Beaconsfield, as its exclusive fitting agent.

Standard service intervals and routines remain unchanged, and the reliability of the installation is such that Hughes offer a 12 month, unlimited mileage guarantee with complete confidence.
The conversion applies equally to saloon, coupe and estate variants and, subject to engine condition, can even be carried out on vehicles having completed as many as 60,000 miles.

Hughes of Beaconsfield can also provide a wide range of ancillary equipment to complement the turbo conversion and thus create what is arguably the ultimate executive express.

The UK's foremost motoring magazine, Autocar and Motor, probably summed it up best in their road test of the 3 litre 12 valve model:
"The Turbo Technics conversion works like a dream".

There's two more reviews still to post but I need a break from squinting at grainy text for a while. :dizzy2:

98 octane required........hmmmmm.
Can you get 98 octane from an available additive?

Do you have any pics of the units installed?
I've been looking for something like this for a while. Please post or PM me.
Thanks,
Joe

I second the above request for pictures. I am in the process of swaping a m104 motor into my w201, and I have been planning on turbocharging as well. I would like to see the dimensions of the kit to see how much extra fabricating would be required to fit it into the small w201 engine bay.

The kit hasn't arrived at my mechanic yet (should get here late this week or early next week). When it does, I'll be sure to take photos before, during and after installation.

Ortolan:
If you don't mind me asking, where are you located?
Thanks. Brian

Maybe I missed it someplace, what specific turbo unit(s) are they using? Is there a way to get separate parts or is the whole deal?

I'm in Melbourne Australia.

The turbos are Garrett T2 units.

Hughes might sell parts separately, you'd need to ask them.

Alrighty, thanks. Will do.

First Drives - Twin-turbo Mercedes E320 Coupe
Iron fist swells in velvet glove
Twin-turbo engine conversion takes 3.0 six to a potent 325bhp - but you wouldn't guess from looking at the car

As someone who has enjoyed a Mercedes E-class coupe for the past five years, I can attest to the appeal and satisfying practicality of this elegant two-door four-seater.
Just last week, whipping through the West Country, it reaffirmed its fine blend of refinement and spirit.
Comfort and aplomb when you're wafting; great top-end performance and sharp handling when you open up the 24-valve six.
Coupes don't come much better rounded than this.

But what if you'd like more iron fist in this silken glove?
What if not even the gutsiness of the new E320 (which has the same 220bhp as my older generation 3.0-24 but at lower revs and with a lot more torque) is enough?
Talk to Merc dealer Hughes of Beaconsfield (0494 672141) about their conversions by proven firebreathers Turbo Technics of Northampton.

Nothing externally suggests that their latest handiwork is any different from a standard E320 coupe with Sportline suspension (firmer and 2in lower).
But under the bonnet it's a different tale.
Twin small Garrett T2 turbos balanced to 100,000rpm are the main additions, with back-up from new exhaust manifolds, stainless steel exhaust,
new air supply feeding through a split-path intercooler and remachined conrods and pistons to drop the compression from 10:1 to 9:1.
There's also an extra fuel injector that fires on boost in a fuel system managed by a Turbo Technics-mapped digital control unit.
A knock sensor nudges the ignition back on boost and the turbos are kept sweet by a pressurised oil supply taken off the engine's main feed.

All this costs an extra £7285 on top of your E-class coupe (or saloon, cabrio or estate).
What it buys is a massive power hike from the standard 220bhp at 5500rpm to 345bhp at 6400rpm and a hefty torque increase from 229lb ft at 3750rpm to 332lb ft at 4500.

The in-line six's smoothness stays but now there's a huge surge of torque from standstill and anywhere else in the rev band,
making the coupe feel as potent as a Porsche 928 or Mercedes' own £59,950 E500.
Where the power in the standard 320 is almost always usable without further thought, in this one you must floor the throttle with real care:
it gobbles distances like a ravenous tiger shark.
In the bends, you need to prepare for power-induced oversteer that you'll rarely encounter with the unblown engine.
It's not unmanageable, but it does need a high level of attention.

What the power does do is change the nature of the E320 coupe.
The feeling of factory-set balance is distorted by this massive injection of muscle in a way that the E500, whose chassis is re-engineered to match its power, is not.

Not that there's anything hard to live with in Turbo Technics' tweakery.
The in-line six starts as instantly, idles as evenly and revs as smoothly as ever and there is no detectable turbo lag.
As a conversion that delivers extra power with no apparent downside, it's a masterful job.
The question is whether you simply want that much power.
So far, 25 Hughes customers have said yes please.