Hey tech-heads – hows it going!? We back for the final

Hey tech-heads – hows it going!? We back for the final article on the Purple People Eater project – BUT
first, here is a dyno graph of the TurboDirect Golf 2.0 16V Turbo, which we installed the NOS onto, which
had the busted gearbox. Right as promised here it is – the golf runs 0.7Bar boost, turbo alone and makes
nice power. We ran the car twice on the dyno without NOS and the best result we got was 217KW and
365NM, and then did the first NOS run. We used a 0.028” Fuel jet and a 0.040 NOS jet – the power
figure was an ok number but running rich, we then changed the Fuel jet to a smaller 0.024” unit and
maintained the 0.040” NOS jet, and we awoke the beast that Nitrous Oxide has a reputation of brining
to life!! – NO we never broke the engine --- !
Here is the graph – see for yourself. From 217KW and 365NM all the way up to 317KW and 509NM – I
loved it, but my tires hate me right now! Just a quick note, the engines bottom end is stock standard,
with 3.1mm machined off the pistons (as you will recall in a previous article) you will notice we tapped
off the throttle early on the first NOS run, due to the rich A/F’s -- On the R59 highway on the way home,
in 5th gear, around 4000RPM, as the NOS is activated, the tires let go, and you start changing lanes – the
beauty of front wheel drive cars, gotta love em! Lastly – the kit we used here for this install, is the same
unit we gave away in last months TurboDirect / MMR competition draw, and the very same WET kit
available from TurboDirect for R3500.00 it is the single fogger WET KIT - NOS 07006 product code, and
will produce UP TO 175HP – the kits sold by other companies are the NOS 07005 kit and are nowhere
near as complete as the 07006 kit, and makes only UP TO 75HP – don’t be fooled, consult the experts
before purchasing NOS products.
Right – lets get back to business with the Purple People Eater – there was more work done to the
turbine housings inlet, here are the difference between the two housings, you will see a substantial
amount of work done on the inside of the housing, including removing the protruding bolts that hold the
bearing housing onto the turbine housing. All turbos have these bolts protrude into the turbine housing
volute – we machined this away.
We also made some mods to the wastegate outlet for flow and heat reasons –
Here is a picture of the manifolds which required modification to flow match the turbine housing, and
next to it, the machined unit ready for installation.
OK lets compare the two turbochargers next to each other now –
Some information on the HKS 2540 and Garrett GT2860RS turbos – firstly the HKS unit runs a Garrett
CHRA – all the rotating assembly parts are GARRETT, HKS use their own housings, and actuators. Many
people argue over this fact, but its true -- here is a picture which will verify this for you.
Here is the name plate on the HKS CHRA – you will clearly see the GARRETT logo on the name plate.
OK -- the HKS turbine wheel and A/R of the turbine housing are IDENTICAL to the Garrett GT2860RS
turbo, the only difference is the mismatched compressor wheel – (mismatched for this application!)
HKS Compressor wheel Measurements:Inducer – 52.7mm
Exdcuer – 76mm
Garrett Compressor Wheel Measurements:Inducer -- 47.2mm
Exducer – 60.1mm
The HKS wheel has a 5.5mm larger Inducer and a 15.9mm larger Exducer than the Garrett compressor
wheel – we will see what happens when we run the comparison on the dyno later. First lets get the
turbos installed. At this point I would like to extend a huge thanks to Shane from No Sweat Racing –
Shane and I started this turbo swap at 10H30AM on Saturday Morning, and finished at a touch before
Midnight including the dyno tuning which Stevo did – shot gents, job well done – as usual!!
Some pics of the day – Shane with his mitts in the engine bay - and the flying Dutchman (Armani)
braai’ing for us okes – sweet boedie!
One Garrett turbo done – one to go –
Two down -- piping to go
What a job!!
JOB DONE!!
OK lets get the nitty gritty sorted and onto the dyno –
OK – this is the dyno result of three runs, the HKS2540’s versus the GT2860RS units – this KW outline
shows the HKS in RED, and then 2 consecutive runs with the GT2860RS units in blue and green. As you
can see the HKS units are very laggy – power starts really coming on strong around 5500RPM – upwards.
The blue and green lines are almost lying ontop of each other, these were two separate runs one after
the other with the GT2860RS turbos, you will see that there is almost 20% more power under the graph
in comparison to the HKS graph, the power increase starts showing its head from 2500RPM all the way
to red line. You will also notice that by the shape of the graph, the GT2860RS turbos due to their smaller
size, move the power delivery to the left of the graph by approximately 1000RPM.
Next lets look at the torque curve – is looks much the same as the power one, except that there is a
considerable increase in torque throughout the entire RPM range – from 4500RPM until 6500RPM there
is 100NM more torque and this tapers off to an increase of around 30NM more at 7500RPM –
NOTE:- the GT2860RS turbochargers are exceptionally smaller and were boosted 0.2bar less than the
HKS turbochargers and made such a massive improvement over the larger counterparts – this proves
once again that bigger is not always better – here is an example commonly associated with this –
numerous customers have come to me and asked me to spec and build a turbocharger for their 2.0 16V
engine, with a power delivery of around 600HP + These customers have all used the cheap Chinese T66,
and T72 copy ball bearing turbochargers which failed and let them down – naturally! When I pull out the
GT3582R and GTX3582R turbochargers to show these customers, they question the turbochargers
ability to make anywhere near the same power as the huge Chinese turbochargers purely due to the size
of the Garrett Turbo – one customer challenged me on this until I took him for a ride in the TurboDirect
Golf which we built for MMR a while back – which is not even using a Garrett Dual Ball Bearing
turbocharger – instead it’s a hybrid Journal bearing unit, I cranked up the boost, to 1.5bar and the
customer came back with his mind made up – once the GTX3582R was installed onto this customers
Mazda FE engine – he came in and thanked me! He made more than 120KW extra power and 170NM of
Torque at less boost than the Chinese T66 turbocharger which has a 4mm smaller inducer and 12mm
smaller exducer compressor wheel! The turbocharger chosen for a specific vehicle/engine MUST be
made correctly based on the type of driving and application the vehicle is going to be used for – it gets
in-depth, and there are plenty fallacies surrounding how to best MAP a compressor for a specific engine,
however I will go into this again in articles to come – to clarify and set the fact apart from the fallacies.
In closing—guys two things, firstly – make sure the company/tuner/sales person supplying you with your
turbocharger knows what he is talking about, has the technical training from the turbocharger supplier
(ask to see some certification) before you just buy the first cheap turbo you see advertised In the
magazines or on the internet – you can go horribly wrong with the incorrect purchase of the correct
turbocharger.
Secondly – the mods we did to the turbine housing, and manifold most certainly accounts for HP
improvements and boost response – from experience, if done correctly, you should see around 20KW
and possibly 35NM additional over the stock units ability. Well I hope that has shown you something
interesting, and look out for more in-depth technical insight coming soon – don’t worry I haven’t
forgotten the EVO dyno graph, it is coming – we have a busted gearbox thanks to some reckless driving,
but its all part of the fun I guess, take it easy and remember – you enjoy horsepower – WE OWN IT!!!