What did you all base your AFR tables on? My engine runs okay but I'd like to tune it nicely. I have a general understanding of the AFR tables but what did you all base your selections on? (I am running an LC-1)
most of the driving i wanted to do was economy so all the high values are the highest AFR i could run my engine without it missing/surging. Most of the values are just plucked form my head and the seat of the pants feeling and a small amount of knowlage that the higher the value the less fuel i am using, the lower the value the more fuel but more power made. My engine runs well between 12.5 and about 16, any higher or lower and it gets too rich or too lean for it to run well.
I should get it dyno tuned at some stage but.....well eventually lol
I have been following this thread (lurking in the background) for couple of month with great deal of interest. My family used to own 1975 SE which passed into another life when my mother overheated motor on I-80 between Sacramento and SF in a middle of summer. But, I have always been fond of these older MBZ because of their build quality and classic lines.
Enough said - I am looking into couple of possibilities of acquiring a '75 SL. Both candidates are fixer-uppers (what ever that means, pending closer inspection). One has dead 'computer' the other is unknown. In interim I've been looking over old Chiltons and Haynes manuals and I hate to say that original injection system is a nightmare to service and maintain. I had my share of curses with our original SE when it failed smog back in the early '90s.
I am not new to DIY EFI - my other ride ('75 C20) sports TBI system which made hell of difference over carburetor! Building Megasquirt is not an issue - I am EE.
My reason for '75 (or earlier) is to avoid dealing with eco-nazi rules here in Kalifornia, while bringing reliability and style of an older SL back on the road.
Question to all - would you do it again?? Any thought what I should look for while looking at a 'fixer-upper'?
It was much (much much) more work than I expected. I am quite happy with the outcome although I really should take my time to tune it (for me it was much more interesting to do the conversion than to tune it). I believe all of us are either EEs or CEs
I am afraid though I am not sure what my answer is for the "would I do it again"? I probably spent more time on the EFI conversion than what I planned originally (putting a 300D engine in it ). If you get a D-jetronic you will be much better off. Make sure you budget for a wide-band O2 controller (make tuning much easier). Make sure there is no rust on the car (probably not an issue in California), everything else is relatively easy to fix (while I lived in a four season climate I had to do too much rust related bodywork and you can never really get rid of it - North Texas is great from this perspective).
Took me about 1 weekend to get my 1974 450SLC running on fuel only with MS II, if you follow oughtsixs webpage its very easy to do, i have had the car running for about a year on the same fuel maps and its economy and power is much improved over stock.
Recently i decided to do the Wasted spark MSII extra install as well hopefully to get rid of my problems with Cylinder 8 not firing properly. The installation of all the parts for spark was actually easier, less parts to modify. The hardest part was getting a good signal from the VR sensor, had to change a diode and 2 capacitors to get it working, but it is now .
I cant say how much difference having ECU controlled Wasted spark is as i dont have a timing light to set my base advance properly, nor do i have a handy dyno meter to tune for power lol and i only completed it yesterday so i have not had time to tune it properly. But i can say my sparks are now very strong, will jump 20mm and easily see able in daylight compared to the stock sparks that barely jump 5mm and are fairly hard to see in daylight.
If u have any idea about electronics, even just high school soldering MS is a every easy ECU to install. All the tuning information is on the Website, and if you do get stuck they have a forum as friendly as this one with many many experienced and knowledgeable people to help you out.
If u have any idea about electronics, even just high school soldering MS is a every easy ECU to install. All the tuning information is on the Website, and if you do get stuck they have a forum as friendly as this one with many many experienced and knowledgeable people to help you out.
Thanks for kind words. I have 20+ years in EE field ( I put my first wireless set when I was 13 with the help of my uncle). I have access to a fully equipped lab which I can use should a problem arise with MS2.
If I am going to tackle this job this will not be my first EFI conversion, although all my previous conversions were based on GM C3 ECM and components. Assembling MS2 unit together would be a welcomed joy from paper drudgery. My problem right now is finding a suitable platform (aka host 450SL ) that needs MS2 conversion to stay alive.
Today (Dec30) I took a drive into a back country and found a first possible candidate (C1). Its 1974 450SL. The car is in a sad shape - its been sitting outside for while. At one time in its past it was repainted (rather poorly) into a deep (non stock) blue color. There is some rust due to old body work that was done incorrectly. According to the owner - an old gentleman that have shuttered his long running automotive business - the engine will fire-up if gas is poured into throttle body. Fuel pump will not turn on. His nephew monkeyed around with analog computer and harness (butchered by poking through harness wires) making any stock resurrection impossible. But the price is dirt cheap (less than you think).
bluefang - I like the idea of wasted spark approach using Ford EDIS modules. Last time when I was at my local JY I picked up a complete set - EDIS-8 control module, 2x coils packs and pick-up in addition to 8x ford 19lb injectors of 5.0L town car. How did you mount 36-1 wheel (other what Russians tried to do)?!
Back to 450SL, I would rather have a running car to begin with (if it runs poorly - that's OK)
Links to photos (BTW I do not want to clog this thread)
Honestly, DONT EVEN GO NEAR THAT RUST BUCKET, unless you want specific parts that have not rusted away lol. You will spend way more on getting the interior up to scratch along with rust removal and respray then you would on a nice 450SL, and if your planing on having it drive well you will need to replace all the rubber mounts, guides etc, steering couplings etc etc etc you will be able to get a nice 560SL. These cars are very hard to do up from a bad state, much cheaper easier and quicker to spend some extra dough and get one that is drivable and in reasonable condition.
Dont think of the MSII mod as just away to save a dead motor, think of it as a way to show the true power of these german V8s so get something nice to start with.
The EDIS 8 was the way i was going to do my car, but in Australia there are almost no cars that run EDIS-8 so i went for the direct control approach, its better this way just a little harder to do.
Yes, I agree - rust is almost always a show stopper. And, it never sleeps - it just keeps on eating... I'll pass on C1 - I do have couple of '75 (in much better shape) to look at in next couple of days.
Since I live in Southern 'Kalifornia' any car 1976 and newer is subject to bi-annual smog inspection. Installation of MS2 would automatically result in failure - since it is not certifiable replacement of OEM analog computer. Hence, I am sticking to 75 and older model years as these vehicles are exempt from bi-annual sniffers.
BTW, all of my carb to EFI conversion resulted in much cleaner cars when we transferred '90 fuel delivery and control onto late sixties - mid seventies bodies-drivelines.
IMHO I like cast iron 450 vs later alloy 560 motors.
I have seen better cars in the pick and pull. Even if you got it for free you would have half the price of a nice 560SL into it. There are a lot of nice SL's in these parts to select from.
Tony
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Tony
111 3.5 Coupe
Manual trans S/R P/W A/C
3.27 Axle
yeah, you guys are lucky with the old SLs and SLCs been pretty much half price to what they are in Australia.
Why do u like the iron motors better then the Alloys, to me the alloy are alot better in terms of weight/power and ability to dissipate heat. The most you would need to do is grab a old 73-75 intake so that you have the appropriate injector holes etc. Other then that the alloys are a lot better in my mind and been made in a time when Mercedes were more concerned about quality they are just as good in their build as the iron blocks.
Like a nice MSIIed 380SL will probably put out more power then a 450 anyway mainly due to compression and other little things. So really you should be looking for the latest year, best condition car you can find. I would have loved a alloy engine, but there is only like 2 380SLCs in australia at the time for sale each costing over $20k, and a 560SL here is in general $30k lol i can get a 1990 500SL for that money tho......but its way out of my budget atm and i like the SLCs more
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