[W126 Coupe] 560 SEC Supercharger Upgrade Anyone?

[Alexander Hochhausl]

You know, I was think thing that, but then again, Germans do cars and
beer, not humor:-)
 
Right now I am using the AC pulley to prove out the system works. Once
this is reliable, I’ll add a dedicated pulley – just a matter of time.
 
People have to decide whether they want an extra 100 or 200 Hp. 100 is
relatively easy to get and will keep you car in one piece with sensible
driving habits. That is really all I wanted to get, just a little more
juice, and help the 560 exercise it’s lungs at the higher RPMs where the
stock design chokes. I got more than I bargained for, yet the motor
really seems to be capable of a lot more. But this is my daily driver,
so I really don’t want to blow it up. From my experience, with this
set-up and other Turbo systems I’ve built, keep the boost under 7 PSI on
a 8.5:1 +/- motor and just some slight ignition retard and fuel
renrichment will be adequate. Power gains in the 30-40% are easy to get.
If you are looking to get 50-75%, then you have to work the system, and
you are really going to compromise engine and drive-train life. 450 Hp
may sound like fun, but the whole car has to be matched to it.
 
As far as enrichment. The EHA on the fuel distributor is controlled by a
milli-amp signal from the ECU. Can’t remember the range right now.
“Probst” published a great book on the Bosch Fuel Injection System (It’s
a blue soft-cover with a picture of a twin hot-wire air-flow sensor on
the cover). Will tell you all you’d ever want to know about it. This is
very basic and crude, but it was a start: All I did was at install a
switch that at ½ throttle, energized a relay that disconnected the ECU
from the EHA, and instead connected the EHA to a potentiometer I
installed by the shifter. I created a voltage divider with some
resistors – with that and the potentiometer I can control the current to
the EHA during this “override” operation. (You have to be real careful
to test this to make sure you don’t send too much current to the EHA and
burn it up – that would be a $250 mistake). Once gas pedal is back under
50%, the switch is released and the relay returns control to the EHA.
This gives me an enrichment % over the normal 14:1 ratio. How much? I
don’t know right now. I’d have to hook up a CO2 sensor. Right now I am
going by feel (when it was too lean I got a lot of pinging-detonation.
Simply turned up the setting until it went away). Actually I stumbled on
this when my ECU bit the dust, and this allowed my car to run well in
cold and acceleration. 
 
The right way to do this would be to have a variable enrichment based on
the amount of boost. That can all be done, but gets much more complex.
In the end you have to decide – do you want an extra 100 Hp and spend
100 hours achieving it, or do you want to spend 200 hours to get 120 Hp.
Depends how much time you have available I guess. The 100 hours is just
a number I made up by the way. 
 
Look on E-bay for the book I mentioned – it gives you a whole tutorial,
theory of operation, etc. well worth the $50 or so. Another option is to
have the ECU reprogrammed which costs somewhere around $600 I’ve heard.
But I have a wife and kids, and this would be tough to pass off:-) A $50
switch is much more palatable. 
 
Anyway, if you are interested in more info I can get back to you on the
week-end. I work 1.5 jobs, and should be working right now, just taking
a break. I hope this helped. I plan on getting all my paperwork together
over the next few weeks. At that point, I’ll send you a sketch of the
electrical solution if you are still interested.
 
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Eddie
Sent: Thursday, January 04, 2007 8:49 PM
To: 'Mercedes Coupes Mailing Lists'
Subject: Re: [W126 Coupe] 560 SEC Supercharger Upgrade Anyone?
 
I think what bellamy means is that he’s got a 560 that’s blown a
cylinder

 
In all seriousness, can you outline how you enriched the fuel some more?
Any plans to upgrade the fuel system or ignition system?
 
There have been several supercharged 560s, (search for jim nowak’s car)
but the problem was the stock fuel system couldn’t keep fuel ratio
balanced once the compression was turned up.  Also, jim had an
intercooler as well as methanol injection, how do you keep your car from
detonating?
 
Any plans to go to the dyno soon?  Can you take a picture of how the
belts are setup?
 
Thanks,
 
Edward
 
  _____  

From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Alexander Hochhausl
Sent: Thursday, January 04, 2007 5:26 PM
To: 'Mercedes Coupes Mailing Lists'
Subject: Re: [W126 Coupe] 560 SEC Supercharger Upgrade Anyone?
 
Well, I am no expert. Attached is a pic of what I did. I guess as long
as you are 9:0 compression or less, can fit this in, tap into your oil
pressure line (by the oil pressure sending unit is a good place), add an
oil return line to oil pan, enrich the fuel distributor output, and find
a pulley with which to drive the unit, you are home free! Sorry, did not
mean to be funny, but those are pretty much the steps. No magic, just a
few tricks. 
 
That is one heck of a motor though. I’ve never heard of it. So you have
3 cyls on one side and 4 on the other? Got a picture of the motor – I’d
love to see it.
 
I hope that helps. All the best!
 
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Mister McGoo
Sent: Wednesday, January 03, 2007 12:05 PM
To: Mercedes Coupes Mailing Lists
Subject: Re: [W126 Coupe] 560 SEC Supercharger Upgrade Anyone?
 
Would it be feasible to supercharge a 490SEL with a 4.9 litre V7?
 
-Bellamy




  _____  

From: jonnery at bigpond.com
To: mbcoupes at mbcoupes.com
Date: Wed, 3 Jan 2007 16:33:05 +0800
Subject: Re: [W126 Coupe] 560 SEC Supercharger Upgrade Anyone?
Would it be feasible to supercharge a 420 SEC 1986 model       Jack OZ
----- Original Message ----- 
From: Alexander Hochhausl <mailto:plustech at optonline.net>  
To: 'Alexander <mailto:plustech at optonline.net>  Hochhausl' ;
mbcoupes at mbcoupes.com 
Sent: Tuesday, January 02, 2007 10:00 AM
Subject: Re: [W126 Coupe] 560 SEC Supercharger Upgrade Anyone?
 

Sorry, can you change that to Dec 31st? Oops

 
-----Original Message-----
From: Alexander Hochhausl [mailto:plustech at optonline.net] 
Sent: Monday, January 01, 2007 8:24 PM
To: 'mbcoupes at mbcoupes.com'
Subject: 560 SEC Supercharger Upgrade Anyone?
 
Hi All,
 
This is my first time posting a message. I am an “Old School” Motor-Head
who appreciates the “Finer Cars in Life”, maybe older cars, but it’s
tough to be the original.
 
Hence I own an 89’ 560 SEC for 3 years. Barely still can any of the
modern new cars touch the luxury, performance and reliability of this
Model (all things you all know anyway), but I always wondered: “What
if!” & Why is the upper left side of the engine compartment so empty –
looks like a perfect place for a Super-Charger.
 
So in my Motor-Head way I added a Vortex S-1 Supercharger to my SEC
during the course of this year. Keeping my promiss to my wife to finish
this project this year, I finally took my first test run last night (Dec
31st), following which I called all my friends, not to wish them Happy
New Year, but to brag about my experience! My wife could tell the result
by the look on my face when I returned.
 
In my best (conservative) estimate I thought the performance gains would
be moderate. I’ve always thought the 560 has good performance with much
potential, but now I have exploited the potential and it is an absolute
Animal! I have not have not had it Dyno’ed but from my experience and
calculations I think it is pushing around 350-375Hp on the first run.
With some tuning (and a more free flowing exhaust) I think I can push
the 400 Hp mark. The torque gains from 1000-4500 RPM are astonishing –
there is no Turbo-type lag – just hit the gas and the car responds
instantly – and smooth – it is really amazing! I had the biggest __it
eating grin when I came back from my test ride. To be honest, above 4500
the stock ignition does not compensate enough to avoid detonation (at 8
PSI boost) so I still have to figure out how to adjust that. I added a
switch (blue item in the engine pic) to automatically override the
emission controls and provide an (inside cabine) user-adjustable fuel
enrichment during boost operation to help keep detonation down and
provide maximum power – so simple and works fabulously. 
 
So the question now is who else is seriously interested in this type up
“real” performance upgrade. I’ve seen all the garbage products out there
adding 5 hp here, 10 hp there. I spent 12 months (on and off when life,
work and family would let me) making and remaking parts until I got
Form, Fit and Function just right. Being an engineer by profession I
documented everything I did and parts I made. 
 
I don’t want to break any fan-club rules, but I am only trying to see if
there is any favorable quantity of people who are seriously interested
in this project. I would be willing to either A) Sell just the paper
plans of what to build, how to install it, where to get the parts, or B)
sell the parts and plans (minus the supercharger – you can get this
yourself without me bothering with it). I am not planning on making a
ton of money on this – maybe break even with my time and $ investment
(and take my very understanding wife out to dinner). Honestly this is
fairly simple “do-it-yourself project” for anyone with a decent set of
tools (drill press, chop saw and files) and mechanical aptitude (one
picture of the hardest fab-part is attached – but I made it myself with
a drill press and a-lot of patience). Once the remaining brackets are
made it is a simple bolt-in installation along with some plumbing and
wiring. I am not going to make any guarantees about the longevity of
your cars’ drive-train because I know this is a lot of strain on the
stock drive-train – but only when exercised – and will depend on your
driving habits. 
 
Some pics are attached for your reference (sorry, they are
Work-In-Progress and still need to be cleaned up & the engine pic has
raindrops on it). I know I do not have the nicest SEC, but except for
the 600 conversion I saw on the Web-Site, I bet it is one of the
fastest! 
 
Next I am eying my wife’s 380 SLC – will she notice the difference?
Hmm
.
 
Thanks for your time and let me know. Send emails to
plustech at optonline.net. Please put “SEC Supercharger” in the subject
line – it will go to a special mailbox so it is not deleted as spam.
Feel free to e-mail me with questions. I have a very busy schedule, but
will try to reply ASAP, may take a few days though.
 
Hasta-La-Vista, Baby!
 
Alexander Hochhausl, PE
 
89-560 SEC
81-380 SLC

  _____  


The MB Coupes Website!
W126 SEC Mailing List
Postings remain property of MB Coupes, L.L.C.
 
  _____  

Be one of the first to try Windows Live Mail.
<http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0
e-4911fb2b2e6d> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.pairlist.net/pipermail/mbcoupes/attachments/20070108/18f07ae1/attachment.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.gif
Type: image/gif
Size: 862 bytes
Desc: not available
Url : http://www.pairlist.net/pipermail/mbcoupes/attachments/20070108/18f07ae1/attachment-0001.gif