Author Topic: as good as it gets...... (Read 27056 times)

rob walker · « **Reply #25 on:** December 24, 2008, 13:02:02 »

Well having drawn a blank in the UK trying to find a 3.69 axle through Roger Edwards and Mercman, I am back to square 1. I am a little worried about going down to the 3.46 route although Roger Edwards has one in stock.
Hmm! what to do $:-\$

JamesL · « **Reply #26 on:** December 24, 2008, 16:32:18 »

Get the 46

See above re discussion on "all that work for not a lot of gain"... same work for the 3.46, but more gain. My car is not appreciably more sluggish but is quieter on the motorway and feels more composed at 80 simply as the engine revs are lower

rob walker · « **Reply #27 on:** January 05, 2009, 09:23:36 »

Quote from: Tosh on December 24, 2008, 16:32:18

Get the 46

See above re discussion on "all that work for not a lot of gain"... same work for the 3.46, but more gain. My car is not appreciably more sluggish but is quieter on the motorway and feels more composed at 80 simply as the engine revs are lower

Thanks James for the comfort, when did you get your's installed?

JamesL · « **Reply #28 on:** January 05, 2009, 11:06:53 »

picked it up just before Christmas - Derrick Wells sold me the axle and installed it.

Very happy with it indeed

mdsalemi · « **Reply #29 on:** January 05, 2009, 21:59:08 »

Seems you are Americanizing these cars...

In the book I was urged to read by Brock Yates about the decline of the US auto industry, he makes some comments about RPM. In it, basically, American engines lumber along with their "low-revving" engines, while the (more desirable?) European cars have "high-revving" engines. He even goes on to say that "Mercedes engines are designed to cruise all day at 6,000 RPM!"

Just thought I'd share...

abe280SL · « **Reply #30 on:** January 05, 2009, 22:46:04 »

How about what happens 0-60? Thats where I have fun. Like mdsalami stated..,.you are americanizing the car. I kind of got used to that high rpm sound.
abe

rob walker · « **Reply #31 on:** January 06, 2009, 06:57:41 »

Quote from: Tosh on January 05, 2009, 11:06:53

picked it up just before Christmas - Derrick Wells sold me the axle and installed it.

Very happy with it indeed

Did he also recalibrate your speedo to match the axle ratio?

rob walker · « **Reply #32 on:** January 06, 2009, 07:04:03 »

Quote from: mdsalemi on January 05, 2009, 21:59:08

Seems you are Americanizing these cars...

In the book I was urged to read by Brock Yates about the decline of the US auto industry, he makes some comments about RPM. In it, basically, American engines lumber along with their "low-revving" engines, while the (more desirable?) European cars have "high-revving" engines. He even goes on to say that "Mercedes engines are designed to cruise all day at 6,000 RPM!"

Just thought I'd share...

Michael, good point, but as my ear drums are older than the car not sure they can cope with the noise

Actually from next year the car is going to be cruising up and down between Spain and the UK at least once per year and the road networks have changed in the UK since this car was designed and most of our driving seems to be motorways so to ease the stress on the car? this seems to be a good option.
However to challenge your point why then is the US car designed to rev higher than the UK/Europe car? :

rob walker · « **Reply #33 on:** January 06, 2009, 07:06:08 »

Quote from: abe280SL on January 05, 2009, 22:46:04

How about what happens 0-60? Thats where I have fun. Like mdsalami stated..,.you are americanizing the car. I kind of got used to that high rpm sound.
abe

My understadning is that yes it is slower off the line but once moving there is little difference although you may have to change down manually a little more, but with the auto box that is no hardship

JamesL · « **Reply #34 on:** January 06, 2009, 08:31:44 »

Quote from: rob walker on January 06, 2009, 06:57:41

Did he also recalibrate your speedo to match the axle ratio?

Not yet

Will get Speedy Cables in South Wales to do that - once I can get the sat nav on in the car to double check everything

Car is not noticeably slower off the line. It really isn't.

Peter van Es · « **Reply #35 on:** January 06, 2009, 11:28:50 »

Quote from: rob walker on January 06, 2009, 07:04:03

However to challenge your point why then is the US car designed to rev higher than the UK/Europe car? :

US: 55 mph speed limit and an obsession with times for a quarter mile with standing start!
Germany: no speed limit, and what's a quarter mile?

Peter

mdsalemi · « **Reply #36 on:** January 06, 2009, 13:27:02 »

My comment from Brock Yates (he also went on to say in the book about how Mercedes cars are basically devoid of chrome and that's one reason why they are better than American cars) was true from his point of view, but a joke from me. And regarding that parenthetical comment here, you 230SL owners who love the chrome would laugh if you saw just how many times he blames chrome for being an American car problem.

I mentioned a long time ago, but it bears repeating. I have as stock a 280SL as you can get; about 2 years ago I had the pleasure of driving Tom Sargeant's 280SL modified with rear axle and a Gernold-installed kickdown switch. With the factory windscreen up, and the lower RPM, you could (and we did) hold a quiet conversation at ~~60 MPH~~ 100 KPH while on a highway; had a long-haired beauty been my passenger as opposed to Tom, her hair wouldn't even have been mussed. Modern improvement on an older gal to suit our current driving needs.

Whatever performance "off the line" suffering their was because of the axle change was not relevant. The car was wonderful.

As for German speed limits, or lack thereof, it's been at least 10 years since I've driven there...but my last recollections on the E35 around Darmstadt/Heidelberg/Mannheim is that between perpetual construction and congestion, there was a practical if not posted speed limit. Perhaps late at night one could cruise at 140-200KPH but other times were difficult if not impossible. I can only imagine how it is today. Then there is the E5...often on this road (call it bad luck) I've encountered a "stau" which quickly backs up traffic for many, many KM's rendering traffic movement impossible; once in the middle of the night, throwing me off in Bavaria w/o any direction home...

Give me I-90 in Montana anyday!

thelews · « **Reply #37 on:** January 06, 2009, 13:52:20 »

Quote from: mdsalemi on January 05, 2009, 21:59:08

Seems you are Americanizing these cars...

In the book I was urged to read by Brock Yates about the decline of the US auto industry, he makes some comments about RPM. In it, basically, American engines lumber along with their "low-revving" engines, while the (more desirable?) European cars have "high-revving" engines. He even goes on to say that "Mercedes engines are designed to cruise all day at 6,000 RPM!"

Just thought I'd share...

I agree with this. The assumption would have to be that the Germans did not drive their cars fast for long periods of time in the 50's and 60's. Obviously they did, and with style and confidence in Mercedes. Low revs, less pollution, more gas economy, more insulation from the driving experience are more recent phenomena.

Case in point, the previous owner of my car drove it flat out floored for long periods several times. (Begin at reply #22 http://www.sl113.org/forums/index.php?topic=5816.15 )

Better ones time and dollars should be spent keeping these cars in top running condition, as they were engineered, and enjoy the vintage experience. If you want the contemporary experience with the reliability, smoothness, quiet, low revs, torque, perfect climate control, precise steering, warm seats, concert stereo, why not just buy a new BMW or MB? It's not what our cars are or were. For me, the fun is in how it was.

That said, everyone and anyone should do whatever they want to get the most enjoyment they personally can out of these cars.

glenn · « **Reply #38 on:** January 06, 2009, 17:18:41 »

What is the relationship between RPM and expected engine life? Engine life is approximately equal to the inverse of RPM or RPM squared or RPM cubed....

.... Inquiring minds want to know... What is life expectance at 9000 RPM?

mdsalemi · « **Reply #39 on:** January 06, 2009, 17:43:23 »

Quote from: glenn on January 06, 2009, 17:18:41

What is the relationship between RPM and expected engine life? Engine life is approximately equal to the inverse of RPM or RPM squared or RPM cubed........ Inquiring minds want to know... What is life expectance at 9000 RPM?

Just a guess Glenn, but since the 9000 RPM is past the redline on all the W113 engines, I would suspect that the engine life at that RPM is "not very long".

More to the point however, I think it is common knowledge that your engine--any engine--will generally last longer at lower RPM's, on average. They'll last longer in light duty; and highway duty, too, as opposed to all ths short stop and go, running around town duty. Europeans typically designed and built engines with higher redlines; my guess is that compared to the generally higher HP American car engines of the era, you needed the higher RPM's to get more torque. Higher revving engines require lighter valvetrains and usually OHC which the American engines were late to bring to the table. There's all kinds of data and articles written about this, just shovel the BS aside and you can get to some common sense facts about valve train weight, RPM vs. HP vs. torque, etc. A Google search will keep you busy for a long time.

Many enjoy a quieter ride, but we all live in fear of thowing a rod--but let me tell you this: it does not make much difference if you throw a rod at 4500 RPM or 5500 RPM. It's kind of a disheartening experience. Having lived through one in an old Opel (thankfully not mine!!!) I can tell you it isn't pretty.

pauldridge · « **Reply #40 on:** January 07, 2009, 10:37:10 »

Brings back good memories... spent a month in Provence a few years ago.. can't wait to go back!

What is involved (work and cost-wise) in changing the rear-end ratio?

DavidBrough · « **Reply #41 on:** January 07, 2009, 12:48:05 »

Hi Phil,

I changed my rear axle last year and it isn't too difficult to do once you have mastered the removal of the compensating spring. I purchased the axle for about £350 and spent about the same again in new parts for the rebuild. The actual axle swap was completed in a weekend and its well worth the effort. When I was researching the swap I had a quote of £1k for the work and £1k for the new axle and I have also heard of people buying axles for £200 or so and fitting them straight in as is.

rob walker · « **Reply #42 on:** January 09, 2009, 07:42:18 »

James, are you gojng to post some photos of your car with its new wheels (and axle)?

hill · « **Reply #43 on:** January 10, 2009, 01:27:01 »

Quote from: abe280SL on January 05, 2009, 22:46:04

How about what happens 0-60? Thats where I have fun. Like mdsalami stated..,.you are americanizing the car. I kind of got used to that high rpm sound.
abe

I don't know on the manual trannies but the swap with an auto is a kick. First gear is now usable and will pull you up to 30mph preety quick.

dhunter · « **Reply #44 on:** January 11, 2009, 22:10:08 »

I've been following this thread with interest as I've recently inherted my father's 280SL and find it very busy, even on two lane highway. When I first drove it I remember thinking it might not have been in top gear, as it seemed at least 500 rpm high! On the freeway it is noisy and a bit bothersome. I was surprised with this as it has always been my experience that Europeans love tall gearing...as do I.

Of course an axle swap is an expensive and extreme move for a car that is an occasional driver... however the benefits in comfort, fuel econonmy and reduced engine stress are enticing! As some have pointed out I don't expect the difference in acceleration would be a big deal, particularly compared to the benefits...and I'm not going drag racing!

In my case I expect a little hard to justify all the work under present circumstances.

rob walker · « **Reply #45 on:** January 12, 2009, 13:50:51 »

Finally made the commitment and reserved a 3.46 axle from the guys that will do the work for me. They cannot do the reconditioning and swop until end March and given the weather that is not a problem. So will book a trip back to the UK early April have the work done and report back.

JamesL · « **Reply #46 on:** January 12, 2009, 15:53:39 »

rob

I'll happily post pictures of the car but you can't see any difference. The wheels have the old wheel covers on. Ride height is the same and the diff is a slightly cleaner, newer looking version of the old one

besides, the car is a bit dirty at the moment, having been used quite a bit over Christmas. Now the roads are all salted....

If you're over before April, gimme a shout and I'll see if I can get an exeat to come take you for a spin. I assume Gavin Edwards will be doing the swap?

Garry · « **Reply #47 on:** January 12, 2009, 21:21:24 »

Rob,

You will not regret the change over. The improvement on drivability is outstanding. In the manual, the first gear becomes really usable and cruising is an absolute pleasure. The loss of 0.5 second over a 1/4 mile acceleration, gee who cares when you are enjoying the drive. If it was that important I would have bought a McLaren SL The change over was relatively simple but I installed new brake cables and replaces all the seals. The axle cost me $AU600 and change over $AU1100. A lot cheaper (and reliable) than a 5 speed gear box.

jameshoward · « **Reply #48 on:** January 13, 2009, 19:07:52 »

I'm looking to follow Tosh's example and make the change over. I have - I think - found an axle but wondered if anyone has made the switch from a rear with drum brakes to a rear with discs? I wondered how much additional work that might be, especially in terms of costs if the conversion is too complex to do myself.

Any ideas/opinions?

James

rob walker · « **Reply #49 on:** January 14, 2009, 14:52:31 »

James, I will be there in April to get the car out of store up to Suffolk and then will take it to RE who will be doing the swop. Will let you know dates.
James (Howard) MercMan has an axle he wants GBP 300 for it! I can forward you his emails ref this if you want.

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Author Topic: as good as it gets...... (Read 27056 times)

rob walker

rob walker

abe280SL

rob walker

rob walker

rob walker

glenn

pauldridge

DavidBrough

rob walker

hill

dhunter

rob walker

rob walker