Carobu Engineering - 560 Dyno Testing

[c107]

There is a company in the USA who is doing interesting Dyno testing on a M117 560.

https://www.facebook.com/Carobuengineering/

This is an average mileage USA spec engine (same as AU).

The first thing they noticed was that they needed to recondition the heads as the valve guides were worn and problematic for good power.

Next they compared the USA/AUS spec exhaust system. They found the Tri-Y system to be 11% more power than the USA/AUS spec.

They also looked at the intake and found that it is highly restrictive, although NOT the air filter which was actually better than the so called performance options such as K&N.

 

[motec 6.9]

Yep 65mm on a 6.9 72mm on a M117 5.6 . Why I have had a car scanned billet 85mm throttle body made for my 6.9

 

[SEL_69L]

Is the compression ratio in your 560 different to the US/AU spec. engine?

The test picture reminded me that AMG produced about a dozen quad cam M117 modified engines, and they were all installed in SEC 560's.
A Google Images search should be able to find you an example. Also seen a V12 installed in a SEC 560.
AMG also did dress up kits and wheel flare guards for the SEC 560. Many more than a dozen of those kits were produced.

 

[c107]

Is the compression ratio in your 560 different to the US/AU spec. engine?

The test picture reminded me that AMG produced about a dozen quad cam M117 modified engines, and they were all installed in SEC 560's.
A Google Images search should be able to find you an example. Also seen a V12 installed in a SEC 560.
AMG also did dress up kits and wheel flare guards for the SEC 560. Many more than a dozen of those kits were produced.

Yes, AUS/US is 9:1 and ECE is 10:1. KAT or RUF was 9 or 10 depending on year. Mine is ECE, as is the car oversize owns.

In their most recent update they swapped the European two piece exhaust headers for a tubular setup and only got very small gains.

 

[c107]

Next update was to advance the USA camshafts by 4deg. I don’t have the spec in front of me so not sure if it makes them more like ECE spec. In any case, only a minor gain in low end torque. no real impact on power.

So far the best upgrade has been the tri-y exhaust manifold and exhaust system by a long way.

 

[c107]

Most recent update they swapped the USA/AUS cams with the 300hp cams. These cams have a longer duration than the regular ones.

The engine they are using is a 9:1 engine, but when the swapped the cams they found the engine had gained top end power, but at the expense of low end power. It was a fairly big difference in both cases.

Its not clear if this would be different on the 10:1 compression engine.

 

[c107]

Today's update was advancing the '300hp' cams by 4 degrees using an offset key.
overall they found a decent increase in power and torque through most of the rev range, except for the very top where it was a bit lower.

 

[Oversize]

Aussie versions slotted between the USA cars with Cats & very stringent emission regs & the Euro ECE & RUF versions (220kw). I have recently discovered how to unleash lots more power, but it has to be fully tested before I can explain in more detail.

 

[Oversize]

I’m still at mock-up stage, pre fabrication.

 

[Oversize]

The air filter design loss is as much as 10hp!!

 

[c107]

The latest update is intake related, but they didnt reveal much yet about the changes they have made. We will see soon I hope!

 

[c107]

Interestingly the dual snorkel intake is apparently worth 25hp over the single one (after their other mods like cam timing etc).

Seems like a pretty no brainer improvement to a car with a single snorkel like the 560SL, 420SE/L etc. Also potentially the 6.9.

 

[motec 6.9]

Yes Bryce that is why i have a 560 air cleaner for my 6.9

 

[Oversize]

Yep there’s no way they can breathe through this!

 

[motec 6.9]

I believe it and the exhaust headers were a crude style of power management. To protect transmission much like S65 was torque limited to 1000nm

 

[Oversize]

Agreed the trans was probably the strongest passenger vehicle auto available at the time and still the weakest link. Along with the lack of traction control, it might explain some of the strange engine limitations we’re finding now...

 

[motec 6.9]

215 tyres were a speed and traction limiter unto themselves.

 

[Oversize]

According to another site and with a different M117 560 engine (this one was a modified high compression unit) they managed 382hp & 423lbfts on the engine dyno! If true, they’re huge numbers and suggests the 6.9 could demolish all competition if given the same treatment!!

 

[Oversize]

Oh and that update was early March 2017!! No huge progress since then...

 

[motec 6.9]

At least I know what figure to smash past.