[W126 Coupe] Turbo/supercharger

[Alexander Hochhausl]

Hi Alec,
 
Look at the archives for my post on 12/31/06. Yes New Years Eve. That is
when I first took my setup for a test run. I put a Vortech Supercharger
on the SEC. I had made promises (that I am very delinquent on) to
publish the plans. I will still do this. The problem is I was running
the unit off the AC pulley, and June came around I swapped the AC back
for the power - I do miss the power though. The second problem is when I
installed the Euro-headlights, their increased depth interfered with the
supercharger pulley. SO now I have to move the unit back about 1", and
in the process I am modifying the drive pulley on the motor. I am on
Vaca next week (work gets in the way of everything) so I think within a
week or two I should have this resolved.
 
But yes. With a little work and patience it is very possible and the
results are awesome. That 560 motor really likes to breathe, and given
the opportunity (through force-feeding) it puts out some nice power. I
did not, but do plan on putting it on a dyno. But I do warn people that
this is not a simple "bolt on". There is some drilling, plumbing for oil
supply (one hole into the oil pan for oil return) and wiring (to
override the EHA unit for air/fuel mixture enhancement. So if you are
squeamish about taking a drill to the oil-pan, or cutting into wires -
this may not be the project for you. However I put on a good 5000 miles
on with the unit, and the set-up performs flawlessly . and I smoked
quite a few cars along the way:-)
 
Responding to the comment below about nothing much happens until 3.5-4K.
The setup I have gives me boost starting at about 2K, and you know the
difference instantly. From a dead stop, it will absolutely smoke both
tires in first gear and leaves a good 10' dual patch when shifting into
second. I am only running about 7 PSI (I do not recommend more) and have
stock wheels/gears. I did not go the methanol/intercooler/headder route
cause this is my daily driver and I have limited time/money to throw
around. I think you can easily get 400Hp out of the motor reliably (I'm
guessing I'm in the 375 range)- more yes, but now you are playing with
fire and beating on the drive-train that (although over-designed for
reliability) it can withstand.
 
Finally - be careful when changing exhaust to headers - you loose a lot
more bottom end torque (where you do most of your driving) than you gain
in top end HP. The whole system has to be balanced and match. Exhaust
system design is actually a very complex and interesting. You can gain
or loose 10-20% based on the design and free-flow is not always a
positive. Even when it is, geometry (tube diameters/lengths, even firing
order greatly influences the output.
 
Typically you'd only go to headers if you upgraded to high flow cams and
heads and you are doing all your driving above 4K (like on a track).
Most people I know don't run their car on a track - otherwise it's a
waste. That may be why nothing much is happening below 4K. 
 
Stay tuned. 
 
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of John Poole
Sent: Monday, July 30, 2007 8:15 AM
To: Mercedes Coupes Mailing Lists
Subject: Re: [W126 Coupe] Turbo/supercharger
 
 

 



Has anyone had either success - or for that matter, failure with fitting
either turbo's or supercharger to an SEC motor.
 
The archives are full of posts dreaming about it but has it ever been
done?
 
Alec D.
  I had one of Jim Nowaks kits fitted to my car a couple of years ago
along with MSD spark, freeflow exhaust, aluminium intake bellows
(instead of rubber) and a methanol spray intake cooling system. I did`nt
duplicate his intercooler system, partly because the U.K is a lot cooler
than Florida but mainly because of all the sleeping policemen we have on
the roads near me. Jims system is basically an update of one that Steve
Lemberg designed then rejected because of the problems entailed in
getting enough cool air into the pump. Vis performance, nothing much
happens until 3.5/4 K revs, then the (197,000 miles) car flies ! The
obvious comparison is to my 500SL that I recently crashed, that car was
rated at 323HP compared to the SECs 300 ( now 298 at the wheels with an
inadequate feeder fan ) and it was a great deal less scary/fun. Having
said all that, I`ll repeat what has been said 27,000 times on this
forum, the best bang per buck (by a country mile IMHO) is a first gear
start switch. 
  
All the best, John Poole `91 560 SEC ( Quick, noisy & porsche 70`s sky
blue ).
  

  _____  

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