6.9 racing

[gf]

Does anyone know if mercedes actually entered the 6.9 cars in competition racing?

[wbrian63]

I've never heard of such an event. Other than the famous Bob Bondurant (if I've got the name right) press event when the 6.9 first appeared on US shores, and that wasn't a race.

The 6.9 isn't really suited for "racing", unless the challenge is Point-A to Point-B.

The most famous Q-ship that MB raced (and I'm not certain it was "MB" per-se) is the highly modified Red Pig that had it's start in life as a 300SEL 6.3. What raced on the track bore little resemblance, both visually and mechanically to the run-of-the-mill (as if any 6.3 is run-of-the-mill) "bankers hot-rod."

There are several members of this esteemed forum that race W116's in Australia, and I continue to be impressed at how "floggable" these cars are. However, unless I'm forgetting something, the cars are either the 3.5l V8 or 4.5l V8 models.

Others will know better than I.

[s class]

Selfor50 (Cameron) races a 450SE equipped with a NOS 6.9 engine. 

[oscar]

True, a 6.9L in an SE, 13B in a 4.5L d-jet 450SE and me putting round in a 280S carby.  All without MB financial backing of course.  Though we should ask, can't hurt

When I started I scoured the net for info trying to find an example.  If not a 6.9, at least any racing w116 that I could perhaps copy their racing livery but there weren't any.  Any involvement in racing was usually rally events and private affairs though some might have had contacts within MB or AMG.  I'm not up with the Red Pig's history but I thought there was some kind of rule change that made it not worth MB's or AMG I should say, compete again.  I don't think there was any serious involvement again until the 107 rally cars and then the 190's during the 80s in the DTM.  Such a shame.  Would've loved to have seen what the could've achieved with a 6.9 W116 platform.

Two of the more interesting cars I've come across are these:
There was this 350SE http://www.oocities.org/motorcity/downs/9323/w116r.htm
This interesting 450SE http://forum.w116.org/test-drive/305hp-450se-0-100kmhr-in-5-4s/

And most recently I stumbled across this one in Aus - sorry about the text quality, but 50% more power with "motec engine mangement, special pistons and valves and is blueprinted"  Oh and it's a manual.

[TJ 450]

Wow, I thought the car in the article may have been my 6.9 for a moment.

But it's a 450, so the history of my 6.9 remains a mystery.

Tim

[thysonsacclaim]

I'd have thought the SE chassis would be slightly more favored due to its shorter length, but I suppose there really probably isn't much of a difference in weight between the SE & SEL.

Selfor50 (Cameron) races a 450SE equipped with a NOS 6.9 engine. 

Sounds like it would be quite peppy!

Can the 6.9 still be bought as a crate engine? I know the 4.5 can...

[bb]

Wow - that 450SEL racer is a beast!

Regarding 6.9 racing: I nearly cooked my 6.9 on a track day. Does that count ? 

[TJ 450]

You nearly overheated it bb? I would imagine that to be easy to do after a bit of track action, particularly if your radiator is showing its age, and maybe even if it isn't.

Tim

[bb]

I overheated it good and proper - the temp was off the dial - but I was having too much fun to notice. I still don't dare try and guess how many laps I did with it like that. 

It just goes to show how harsh driving conditions can show up issues. The cooling system was always quite ok in normal driving, even with the A/C running on hot days, but the track day made light work of it.

[gf]

So by the sounds of it people prefer to race 450s! Im guessing this would be an avaliability thing with so many around. would the 450 handle much better? thanks for the articles oscar was real interesting! ill have to have another look at your racing articles. So you ever considered sticking the radiator in the boot like that other car?

[oscar]

450 versus others.  I would've preferred one and selfor50 started in a k-jet one.  IMO they're great bang for buck, value and power wise and are plentiful.  A decent sizeable V8 and well, that's all you need.  The 280S kind of fell into my lap via selfor50 and had a manual trans so that's why I went the way I did.  All of us paid 3 figure sums for our start up track cars but obiously the final figure to convert is much more with all of us approaching or surpassing 5 figures.

I'd consider any number of upgrades or changes as the imagination can run wild but as usual the cost factor comes into play.  Not sure I'd bother move the radiator but 13B has moved the battery into the back and put a fuel cell in to replace the 20kg 96L stock fuel tank.  We've all done a number of mods but nothing meaty yet when it comes to engine performance.  Though Selfor50 is going to come back with some major mods to the 6.9 but it'll take some time.  I'm basically waiting for a rebuild and going to start from scratch again, so haven't raced in just over a year.  13B's the only one flying the flag at them moment.

Since getting the 280 and becoming hooked on the M110 I'm convinced it has plenty to offer.  You'll see in the 350SE rally article it mentions the weight loss gives it a power to weight ratio similar to a regular 6.9.  Furthermore, from our own experiments and from youtube the m110 2.8L v m116 3.5L in regular cars show very little if any difference in performance, both doing 0-100km/h just on 10sec.  So although a 4.5L is preferred, any of the engines can be adapted to be fast enough for the type of sprints we do.  

Handling round bends really comes down to tyres, brakes and suspension more so than the engine size as I've managed to tail more powerful cars around bends.  However, exiting on to straights or transitioning in between bends is where size does matter and more importantly throttle control.  Everyone usually glides away from me on a straight of course but around bends I'm not as suscepetible to overpowering the rear wheels.  I can go WOT and control speed with left foot braking but the V8s and others have to be more careful when selecting throttle position.

One more link if you're interested.  The Carlsson tuned M110 W123 coupe.  I nearly went down this path, a CE but by it was hard to find a cheap body.  Too many good examples around and I wouldn't have the heart to mess with a "good" example.  Great sound from the M110 I reckon.
http://www.youtube.com/watch?v=RMA5cQwn3nI

[TJ 450]

I concur with that oscar; the M110 has a great sound. I'd say it was hard to beat really. Even the M103 doesn't sound as good.

V8s can be a bit raucous sounding in comparison, as you would expect IMO.

Tim

[13B]

I did a lot of research before buying and decided that the best bang for buck was going to be the 450SE short wheelbase with D-Jet M117 engine, because its supposedly a higher compression ratio than the later K-jet engines.  I also liked that the cars came with an oil cooler.  Setting out looking for one and I found a white 1975 model which had no sunroof (a big plus, it just takes weight and always leaks), it also had new brake discs fitted, a new sports exhaust (ask Oscar how it sounds), and there were no oil leaks.  It also had a new water pump installed fairly recently and came with a set of 15" rial alloy wheels. On the downside it had SLS (removed it), air con (removed it), electric windows (removed them), and while i was at it removed most of the interior and stuff in the boot.

Performance wise I changed the diff to one from a 350SE which had the effect of giving the car 50HP more.  Most people are surprised to see the car smoke the tyres off the line.  There is a reduction in top attainable speed but that not important on the straights of the tracks I've raced at.

The car is very reliable, having never overheated or DNF'd any events, and has competed at over 30 track days in and around Melbourne since 2007.

Cam's 690SE is faster but has been burdened by reliablity issues of late.  The 450 V8 is tough to beat for a car which can be reliably driven to and from events, and go around race tracks all day.

I.

[oscar]

a new sports exhaust (ask Oscar how it sounds),

Hehe, true, I love it and I say so everytime I hear it.  Gives no illusion as to what's under the bonnet and does so without bursting eardrums.  The bassiest 450 I've heard.  Everytime 13B blips the throttle in the pits you're inclined to say "do it again, do it again."

[calvin streeting]

ohhhh tell me you have a recording of that, then we all can here..