Drag racing a 6.9

[Bandolero]

Has anyone taken a 6.9 to the drags to see what times they can get over the 1/4 mile?
I would like to dyno my 6.9 and then take it to the AIR street drags here in Adelaide to try it out.
It would be good to get a contingent of W116 owners to go for both support and compete.
Any takers?

[AMG69]

Russell, would LOVE to - but I'm over here (way out West!); I noted on the M100 site that if they go ahead with that M100 Rally in 2008 we'll all need to book out the Eastern Creek Drags!! As for the dyno - I'm going to run mine over a dyno as soon as I get it back from the trimmers - will be very interesting to compare notes as it were! Keep us informed - would love to hear vwhat a 6.9 does down the 1/4; I know a guy in the USA (M100 site again) did 14.07 with a short diff (3.27) and sports exhaust I think....I'd be aiming for say 16sec for a 25yr old 6.9!

[Des]

16 secs sounds pretty conserative, v8 holdens will do mid to high 16's in stock form.

GTHO Phase III's are only 1 second faster to 100 than a 6.9 so would be expecting mid to high 14's in stock from from a 6.9.

From what I have read on the net there are some pretty easy mods to get the 6.9 up and going a bit faster.

560SEL twin air intake,
custom exaust,
300SDL alloy bonnet, heck you could get someone to fabricate fibreglass front end panels and boot.
Unwired WUR,
shorter diff
new timing chain, spark plugs, injectors etc, bring the motor as close to as new.

[Bandolero]

I am hoping to get about 15 secs (or Less) down the 1/4 in standard form.
I might try to get that aircleaner first.
I would love to put a lower ratio diff into it but what do I use?
I think a ratio of 3:1 down to 3.2:1 would certainly work well.
A holden HZ (1978) V8 uses 3.08:1 ratio in standard form which seems to work well.
Too lower ratio and you loose out in cruising speed. (revs too high)
We don't need high autobahn speeds in Australia, just speed off the line.  and reasonably low revs at 110 KPH.

[jjccp]

I have a bunch of videos saved on my hard drive of 6.9's, 6.3's and other MBZ's at the drag strip. They are fun to watch.

If someone can tell me where to up load them, I'm glad to share. Can we upload video files to the gallery here?

If I recall the 6.9 did around 16 seconds in the quarter mile.

Jim

[oscar]

Hi jjccp,

I'd love to see em.  Try uploading to the gallery like you did those trailer hitch files.  I don't know what the mb limit for uploads are but give it a try.  My email's in the members section if your interested in emailing me the vids.

[Bandolero]

Hi JJCCP,
I would love to see them as well, please.
If I give you my email address, would you be able to send them to me please.
Regards, Russell.
PS: The email is ezycoat@ezycoat.com.au

[AMG69]

I seem to recall 6.9's were tested at 15.7sec for the 1/4 mile in 1978; I'd be very suprised if anyone managed to get their 25 year old version under 15sec unless they put in a 3.27 diff.  Dont forget you cant compare these cars to a v8 Holden over a 1/4 mile - for a start the Benz weighs in at a porky 4400pounds; add a three speed auto and 2.65 diff and even 7litres of V8 isnt going to get you anywhere near (say) a manual 5litre V8 VH Brock let alone a genuine tyre shredding Falcon Phase 3  (and I've driven all three) However, and this is the big BUT, should you find yourself on a freeway at 100kmhr next to any of these cars and you both flatten it in top gear you can probably say bye bye at any speed past about 160, all the way to 230kmhr 550NM of Torque Talks. (!)

[jjccp]

Oscar & Bandelero,

I'm away from my home computer for a couple of days on a sailboat trip. I'll probably be able to get the videos uploaded here on Sunday. I'll also send them to you guys directly also.

Chris M,

I think I recall a Euro 6.9 doing like 15.85 secs in the quarter mile. So your numbers are right on.

Jim

[Des]

I seem to recall 6.9's were tested at 15.7sec for the 1/4 mile in 1978; I'd be very suprised if anyone managed to get their 25 year old version under 15sec unless they put in a 3.27 diff.  Dont forget you cant compare these cars to a v8 Holden over a 1/4 mile - for a start the Benz weighs in at a porky 4400pounds; add a three speed auto and 2.65 diff and even 7litres of V8 isnt going to get you anywhere near (say) a manual 5litre V8 VH Brock let alone a genuine tyre shredding Falcon Phase 3  (and I've driven all three) However, and this is the big BUT, should you find yourself on a freeway at 100kmhr next to any of these cars and you both flatten it in top gear you can probably say bye bye at any speed past about 160, all the way to 230kmhr 550NM of Torque Talks. (!)

GTHO Phase III specs:

http://members.iinet.net.au/~zippy@iinet.net.au/assignment/xygt.html

0 - 100 6.5 seconds

1/4 Mile 14.4 seconds


If you say 15.7 for a 6.9 that is a pretty good score for in affect a stock car, some easy mods and it would go head to head against the aussie icon.

[AMG69]

Dont forget the 14.4 qtr in the Ford Falocn Phase 111 was achieved with a very short 3.9 diff (Phase 111 owners could choose between between 3.25 a 3.5 and 3.90 diffs depending on where they were racing eg Bathurst versus the sprint rounds of the ATCC);

I bet if you managed to build a 3.9 diff for a 6.9 Mercedes you'd do a low 1/4 qtr without even trying!!!! 

[Des]

I've heard on the rumour mill that AMG offered a 3.46 diff in their modified 6.9's,
anyone able to confirm this?

[Bandolero]

Yes, please. I'll take one.
That would be great. Blow off those rice burners!!!!

[Bandolero]

Thanks jjccp, I look forward to checking it out.

I rang a speed shop here in Adelaide and he told me that AIR is not hosting any drags till the lights are working again. Also, AIR is for sale, there is a buyer I believe but there are a few hassles at the moment.
However, there is a new drag strip being built at Barmera (in the Riverland) that should be ready about July.
That would make a great club run for an overnight stay. Take in the drags and do some sightseeing.
I am going to ask the Merc club here in Adelaide to see if anyone is interested.
If they are not, I will organise the run with interested parties.
It doesn't have to be just 116's, any Mercs are welcome, even their owners
Will keep people informed, I first of all have to change my car's engine mounts, change the vac advance module, change plugs and leads, then get a dyno done. Then it will be ready.
I have just changed the thermostat and found out why it ran too cool, had a 71c thermostat fitted. Now the coolant sits on about 87c where it belongs.
Also, the idle is better, because before I changed the thermostat, the WUR was not cutting out fully as it thought the motor was still warming up. Consequently the idle was fast one minute then if the motor got hotter, (ie; city driving,) the idle would go lower. Great now.

[jjccp]

I uploaded the biggest video file to the gallery, but I don't see it. It's over 8 megs, so I don't know if it's over the limit. I have others if someone can tell me if that worked or what plan B might be.

I also emailed it and a few others to Oscar and Bandolero directly.

Jim