HP Tuners 515 (wheel) HP Merc A45 AMG - Too Fast For The Road?
Do you really need an uber hatch with somewhere in the region of 550hp at the crank? Er, probably not, but it ain't half good fun. This car is bonkers...
PICS - Chris Wallbank and Jimbo Wallace
There aren’t that many cars that take us by surprise these days, but the latest breed of uber hatches like the Golf R, Audi RS3 and the AMG A45 have totally transformed and redefined not only what’s possible in an all-wheel-drive hatchback, but also the tuning landscape that goes with them. With little more than fairly straightforward bolt-on modifications it’s now possible to keep pace with or put the frighteners up supercars. Yeah, yeah you're thinking, we've heard it all before and we always say stuff like that, but this time it’s for real.
Jumping into the HP Tuners A45 AMG for the first time is almost a little underwhelming – it’s pretty dark in here with a fairly conservative smattering of fake carbon and some red accents here and there, you could easily be in an entry level model apart from the swanky seats and 200MPH speedometer! How fast can a 2.0-litre turbocharged engine be after all? One word – VERY!
Jumping into anything with 500+ hp should be really intimidating, right? Having stepped out of a mildly breathed upon and very old (remap, exhaust, hybrid turbo) Passat Estate 130PD 1.9TDi and into this fearsome looking little A45, we were conscious that self-restraint was going to be very necessary on the greasy, winding A453 that led north towards Coventry on our way back to HQ. We needn't have worried though, as the new-age breed of uber hatches have upped the game considerably when it comes to deploying power levels akin to supercars of yesteryear with flippant, carefree ease. Simply drop it into third using the flappy paddles, mash the accelerator and hold on. Only once during our tenure of the vehicle did we actually see the traction control interfere, and was as a result of some very silly late braking.
Look at the size of those brake discs. They're standard issue but provide more than enough retardation to stop from keenthree figure speeds, not that you'll have to very often on UK roads. Cough, cough m'lud!
Pulling away from HP Tuners HQ near Letchworth we obviously engage Sport mode immediately. The viciousness of the acceleration as the 4WD system hooks all four Nankang tyres into the tarmac is astounding, as you back off, drop a gear or even shift at high revs there’s also some pops and bangs programmed into the fuel tables as the injectors overfuel the four cylinder turbocharged engine slightly – we feel like BTCC drivers at this point. Watch out Plato! Generally, with somewhere in the region of 515hp at your disposal in a car that belongs to someone else it’s safe to assume you take it easy, but not in this, it inspires confidence immediately. It's arguably not quite as involving as the most tactile front wheel drive hot hatches as a result (shout out to the Megane RS Trophy and Golf Clubsport) but by heck does it propel you at the horizon with a sense of security and a disregard for a clean driving license.
It’s a visceral car this. The ride is fairly nuggety and firm, particularly as low speeds around town, yet it remains composed even when crashing down potholes. Around town it might even be too firm for some, particularly with Sport mode engaged, but as soon as speed builds though the H&R -40mm springs on Mercedes shocks loosen up slightly and start to flow with any imperfections that the road might present. Given how accessible the performance is it’s difficult to imagine much that’s currently available off-the-shelf that could keep pace with this cross country or along a tight, winding B-road. Seriously, even hustling something Italian or a big AMG product along twisty roads probably wouldn’t be as much fun as piloting this absolute weapon.
The classy satin wrap sets this 2014 model apart. HP Tuners has also added some W176 aero canards up front and a rear spoiler to try and amplify the performance potential on offer.
So, how did this car go from already rather rampant 360hp to a frankly borderline unnecessary 515hp and 480ft/lbs of torque, can the 4matic gearbox withstand the punishment and what have HP Tuners done to extract the additional, very impressive urge? There’s no doubt that it’s effortlessly, epicly fast, but the really clever thing about the HP Tuner solution is its unlike most remap packages out there. For starters, it’s a system that you can, should you so desire and feel you have the knowledge and laptop hardware, tune and develop the fuelling, ignition and boost tables yourself. Unlike traditional ‘tunes’ where you pay for each map and update separately, this system allows you to plug the MVPI2 OBD port uploader in, fire up your laptop and upload your individual tune using what’s termed as a ‘credit’ by HP. Each credit costs just £50, the MPVI2 dongle and VCM software suite will set you back £299, so if you group together with some mates to buy the dongle, you could feasibly remap your car and as many others as are listed on the HPTuners application list for £50 each - how's that for value for money!
The software required to produce the map is free from the HP Tuners website (www.hptuners.com), so you can play, tweak and refine to your heart’s content. This revolutionary flexibility means you can upload and play with multiple different ‘files’ for a fraction of the cost of other traditional remapping methods. Of course, that could be a double edged sword for many of us, so HP will also offer pre-approved code from a variety of dealers.
In the case of this car the code was written by Peron Automotive, but HP Tuners will soon have a team of in-house code developers to craft the maps for a variety of Europe-centric brands and models. As HP Tuners are predominantly US based currently, this means much of the code developed in Europe will eventually find its way back across the pond and vice versa. So, if you don’t fancy the risk of blowing your engine up with the incorrect click of a mouse, you can always buy an off-the-shelf map from HP themselves. It’s not just a remapping one trick pony either, the MPVI2 will read, write and diagnostically scan a variety of OBD2 vehicles via the 15-pin port, so you’ll never have to pay a garage to scan your car for fault codes ever again!
Around town it’s remarkably civil, keep things below 4000rpm in comfort mode and you could feasibly be driving a factory car – along with late 30 MPG if you realty tickle it along, but let the boost build beyond 4k and the AET Turbos fettled stage 4 hybrid turbo very quickly makes the world go backwards. It’s rather deceptive though and license losing pace is so easy to gather, the in-gear time for 50 -70 and TED when overtaking must be very impressive indeed. It’s a car that most definitely requires bags of self-restraint. The 7speed 4-matic gearbox can sometimes seem quite tardy to respond in comfort mode, but HP has also remapped the ‘box mechatronics to increase shift speed when the throttle is pinned in Sport mode. Forget about having stop / start mode enabled around town as the speed with which it responds away from lights might frustrate some motorists. We honestly wouldn't be surprised if the 0-62mph time is somewhere in the low 3 second / high 2 second bracket - it has that much grip and effortless traction off the line. Top speed - well, it's anyone guess, but we can't imagine it running out of grunt until 170 is visible. Not bad for a grocery getter, hey?
This car received so much attention from other road users during out test. Engaging sport mode also alters the engine mapping so that the Nortech 3.5-inch downpipe spits, farts, pops and bangs excess fuel out of the factory tailpipe.
With a set of OZ Superleggera wheels (8.5 x 19) the unsprung weight is reduced while the factory AMG brakes provide more than ample stopping power and are wonderfully progressive as well, unlike many of the over servo’d modern middle pedals out there.
At the helm it feels very responsive indeed, no doubt the Nankang AS-2+ 235/35 x 19 rubber and the revised suspension geometry help with initial bite and turn in. Granted, the traction of the AWD system makes it a point and squirt kind of machine as you build speed so quickly that you’re often back on the brake pedal to navigate the next bend and maintain sensible momentum, but with greasy, rain-soaked roads during the mainstay of our test, the chassis was always confidence inspiring and felt an awful lot more reactive to turn in than the factory setup. By dialling in a degree of negative camber up front initial bite and precision is increased, but to really provoke it you’d have to be travelling at warp factor 10 before things start getting out of shape, at which you probably shouldn’t be on the UK road network anyway. Traction, traction, traction is the order of the day and even full-bore starts don’t seem to upset the ESP system in the soaking wet.
Llightweight OZ wheels not only look very BTCC, but also the reduction in unsprung weight also aids handling and reduces the work the dampers have to do to stay in touch with the tarmac. Look killer with a -40mm drop on some H&R springs as well
Once you’ve recalibrated your brain to accept that the full force of the turbo won’t really kick in until 4k and above, we suspect this might be a traction gaining tactic from the HP Tuners programmer, this little car is unnervingly swift. A restrained 'dad-in-the-passenger-seat-drive' really upset him, and we weren't even going full bore. Seriously, it’s difficult to gauge the speed that you’re carrying in a straight line, and much restraint will be necessary to keep your license clean with so much grunt at your disposal given the 1555kg kerb weight (331bhp per tonne).
All that performance with hardly any compromises. The future of fast cars will definitely be dictated by tuners such as HP. HP reckon the gearbox and clutch could well be the weakest link if you choose go beyond the 600hp mark.
Injectors and the fuel pump remain factory spec – the Merc system able to deliver plenty of pressure and flow over and above factory expectations, the only other concession to outright performance is a Nortech 3.5-inch turbo downpipe to really free up the flow of the gases escaping to atmosphere. It sounds maybe a little uneventful at low speeds with low throttle inputs, but the best thing about that is that there’s no drone at all at motorway speeds – yet there are some subtle yet pleasant whoosh tisssch sound effects at maximum attack and plenty of pops and bangs once you've engaged Sport mode. This duality of personality makes it a really nice car to spend time with when you're not in maximum attack mode, and without the wrap it would be a true wolf in sheeps clothing.
An ITG ProFilter exists within the factory air box, but under the heat shield is the only two visible hardware upgrades required to take this uber hatch from fast to oh-my-good-god quick..
All-in-all the Peron derived tune maximises the flow potential and power of the hybrid turbo while keeping the car perfectly street-able and drivable day-to-day. For a package similar to this one you’re looking at around £5000 all in, but half of that is accounted for by the turbo upgrade itself which remains in the factory location using the standard manifold.
It's both planted and extremely capable, the ECU tuning in particular blessing this Merc with a duality of purpose that few other uber hatches can hope to match. Just be careful of that license as the way it builds speed is frankly crazy
So, if you need to unleash your A45 and really fancy having a go at the binary within the ECU yourself, HP Tuners could well hold the answer. For an even more ferociously fast version that’s a little bit more engaging than Mercedes intended - the modifications have definitely paid dividends.
If you'd like to catch up with HP Tuners UK to discuss anything, or see the car in the metal, head along to the Autosport Show at the NEC, Birmingham in January 2020.
Just imagine if this was all black and only sporting those tasty OZ 8.5 x 19-inch rims? Only the eagle-eyed would be aware that such devastating performance potential existed within this subtle sleeper
Engine 2.0-litre (M133) turbocharged four-cylinder; Factory front mount intercooler; Peron Automotive ECU code; HP Tuners MVPI2 OBD uploader; stage 4 AET Turbos Hybrid Turbocharger; ITG intake filter; Nortech 3.5” race de-cat downpipe; AMG injectors; HP remapped gearbox mechatronics
H&R -40mm springs; 8.5 x 19-inch OZ Superleggera wheels; 235/35 x 19 Nankang AS-2+ tyres; EBC Greenstuff brake pads; factory AMG calipers
W176 Aero Cannards; AMG A45 rear wing; custom HP Tuners wrap by Lussivo Automotive