Author Topic: 6.9 on the dyno >>>>  (Read 5862 times)

Bandolero

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6.9 on the dyno >>>>
« on: 05 August 2006, 03:56 AM »
Well, got the 6.9 dynoed today.
Was put on the rollers and he revved it out to 5000 rpm in second gear...WOW!!! Sounded great!!!!
Checked the timing and the mixture.
Puts out 173 BHP at the rear wheels.
Does this sound about right??
He said the power seemed good, the only problem is the injectors do need replacing as they were a bit "daggy" at part throttle.

Still can't get over the great sound of the motor @ 5000RPM.
The exhaust note was fantastic!!
Russell Bond - (Adelaide, South Australia)
1978 450SEL 6.9 .... #5166 .... 12/78 (Sold.) www.ezycoat.com.au

oscar

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Re: 6.9 on the dyno >>>>
« Reply #1 on: 05 August 2006, 04:18 AM »
Bandolero, I'm having trouble downloading the sound file, I can't find the link.   :D 

The job of a V8 is to provide power foremost, then secondly, make the owner (and others) aware by feel and/or sound that a V8's packed under the bonnet. ;D.  I reckon my 350 has a nice tone and yes, at over 4000rpm it sounds great but I must stop doing that.
Never get's deafening like some older Holdens and Fords with homemade exhausts that "crack" like a Harley.  Converesly, a colleague with a genIII 5.8l Berlina (think that's right), with stock exhaust, you can hardly hear the motor let alone pick what's under the bonnet.

Does the Dyno do torque and power? ie newton metres and kilowatts.
1973 350SE, my first & fave

Bandolero

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Re: 6.9 on the dyno >>>>
« Reply #2 on: 05 August 2006, 04:43 AM »
"Does the Dyno do torque and power? ie newton metres and kilowatts."

I dunno... ???

The reason I had it dynoed was to get the timing and mixture right.
He asked me if I wanted Kilowatts or BHP and seeing I am over 50yo, I wanted BHP. Not interested in modern words like "Kilowatts."  :)

All he said was that it put out 173 BHP at the rear wheels at about 4400 rpm.
He gave me a printed graph as well.
Russell Bond - (Adelaide, South Australia)
1978 450SEL 6.9 .... #5166 .... 12/78 (Sold.) www.ezycoat.com.au

Denis

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Re: 6.9 on the dyno >>>>
« Reply #3 on: 05 August 2006, 08:34 AM »
Hi fellows

173 RW hp ? Sorry for being so candid but isn't that rather low ?

I understood that RWhp is usually 25% less than flywheel DIN horspower.

Please explain...

Denis

Paris, France


Des

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Re: 6.9 on the dyno >>>>
« Reply #4 on: 05 August 2006, 03:01 PM »
The factory australian 6.9 brochure tells me that the 6.9 motor puts out 198kilowatts at 4200 rpm
but thats the motor not at the rear wheels, you loose some power through the drive train.

198 kilowatts converted into horsepower is 269.20,
does seem like a fair bit of loss
but then again you are looking at a 30 year old car, there would be a lot of compoents that wear and reduce performace.


Here is a link to convert kilowatts to horsepower and vise versa:

http://www34.brinkster.com/fjcsuper/hpkwcalc.htm

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OzBenzHead

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Re: 6.9 on the dyno >>>>
« Reply #5 on: 05 August 2006, 03:55 PM »
Des:  I couldn't get that site to work in any of six browsers (IE not amongst them, as I refuse to have such a crock of Microslops fertiliser on my Mac); it comes up okay, but when I enter a number in either field and click on 'Convert' nothing happens except both fields go blank.  It's not a lack of Javascript or anything like that, so I threw away the site.

Here's a much broader conversion site that I frequently use for conversions:  http://www.onlineconversion.com/.

Bandolero

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Re: 6.9 on the dyno >>>>
« Reply #6 on: 05 August 2006, 05:21 PM »
The mechanic said to expect at least a 60 BHP loss through the drive train.

I am going to put new leads, plugs, injectors and clean the fuel system, including the fuel distributor, then try it again.....need money first.. :(

He also said that he would have liked it a bit richer at full throttle and to check the fuel flow specs with the correct equipment.
After all this is done I certainly hope to get even more performance.

Must admit though, the car sure "flys" now!!!

Russell Bond - (Adelaide, South Australia)
1978 450SEL 6.9 .... #5166 .... 12/78 (Sold.) www.ezycoat.com.au

Des

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Re: 6.9 on the dyno >>>>
« Reply #7 on: 05 August 2006, 05:28 PM »
Have you considered a performance warm up regulator at all?
see here:

http://www.m-100.cc/forum/topic.asp?TOPIC_ID=789&SearchTerms=UTCIS

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116.025

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Re: 6.9 on the dyno >>>>
« Reply #8 on: 05 August 2006, 07:05 PM »
The mechanic said to expect at least a 60 BHP loss through the drive train.

I've heard this figure before, but that seems a little ludacris...If that figure were true, my '71 220D would have 0 HP at the wheel...
Chad Johnson

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oscar

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Re: 6.9 on the dyno >>>>
« Reply #9 on: 05 August 2006, 07:20 PM »
The mechanic said to expect at least a 60 BHP loss through the drive train.
I've heard this figure before, but that seems a little ludacris...If that figure were true, my '71 220D would have 0 HP at the wheel...

"At least 60bhp", maybe rounded up by one.  ie 59bhp drop and 1 horse to keep the 220 rolling.  :D Good point though.

I wasn't so sure about the dyno figures only because my 350 is supposed to be 205hp.  Assuming that's not at the wheels, but if you take mine down to 150bhp and 173 for yours bandolero, there doesn't seem to be too much difference for a motor that's twice the size.  It will be interesting to see what improvement is made with new parts.
1973 350SE, my first & fave

Des

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Re: 6.9 on the dyno >>>>
« Reply #10 on: 05 August 2006, 07:23 PM »
60HP seems a rather blanket statement to make for all cars.

every car would be different, different transmissions, diffs, all transfer the power differently to the road and have different affects of the final power output from the wheels.

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oscar

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Re: 6.9 on the dyno >>>>
« Reply #11 on: 05 August 2006, 09:42 PM »
Interesting link Des from your last post.

A summary on the HP: for a "fresh" 6.9 is for a US spec car; 250hp motor with approx 200hp on the dyno and for a Euro; 286hp dropping to 228hp on the dyno. Working on a 20% difference for rated hp of motor and on the dyno.
1973 350SE, my first & fave

Des

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Re: 6.9 on the dyno >>>>
« Reply #12 on: 06 August 2006, 02:01 AM »
Interesting link Des from your last post.

A summary on the HP: for a "fresh" 6.9 is for a US spec car; 250hp motor with approx 200hp on the dyno and for a Euro; 286hp dropping to 228hp on the dyno. Working on a 20% difference for rated hp of motor and on the dyno.

Yes it seems Australian and US spec motors were choaked down with polution gear, maybe even the compression ratio in the motor isn't as high as compared to the Euros?

One of the first things on any 6.9 owners mind who is looking for extra power would be to unchoak the motor, remove/disconnect pollution (power sapping) equipment and fit a air cleaner and exaust that allows the motor to breathe better.

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AMG69

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Re: 6.9 on the dyno >>>>
« Reply #13 on: 08 August 2006, 12:50 AM »
Nathan, we should get together the 6.9 guys here and visit a DYNO in Perth; we could get all the cars done on a Saturday morning...what do you think?
sigh....sitting back contemplating the next purchase..!

michaeld

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Re: 6.9 on the dyno >>>>
« Reply #14 on: 10 August 2006, 06:26 AM »
H have followed this topic with a great deal of interest and found the dyno results of Bandolero's 6.9 somewhat disappointing, but I guess the dyno test doesn't lie.

Not having a 6.9, I could (and probably should) keep my big mouth shut.  But...

First of all, I think the more exciting (albeit subjective) means of evaluating your car's power is relative to other cars.  Now, I have your standard, boring (to you 6.9rs, anyway) 450SEL.  But this car really seems to motor relative to a lot of traffic - and that without my having to stomp on the accelerator.  And when I really do need to get into that other lane and DO a little stomping, I rarely don't get into that lane.  And I can only imagine what that extra 2-plus liters gives you guys.

I wrote a post once that included horsepower figures from bygone musclecars to show that the 6.9 - even the Euro - wasn't lord and master in the power department.  But let me say this: there is also gearing and rear ends to consider, and MBz seemed to have built these cars with the right balance of zoom-attributes to "get there."  I've got some friends w/ new V-6 and 8 engines that supposedly WAY overpower my 4.5L in horses; but somehow they don't really seem to do it on the road.  And if I'm doing 60 and decide to go 80 - uphill, no less - I feel like I've got some major "oompha" relative to most of the other cars on the road around me.  And again, your 6.9s have all the more "oompha."

I think Bandolero's got it right; he's using the dyno to improve the individual performace of HIS car.  Yeah, cars lose power as they age - and our cars are old - but that doesn't mean that he can't make his the best it can be.

If you have a 6.9 - particularly a Euro - you've got a great automobile that continues to have legendary status.  I don't think there's anything to be disappointed about.

But what do I know?  I just have a 4.5.
Mike