Saijin_Naib

Coefficient of drag mostly explains our 140mph (CD 0.28). Keep in mind however that is with the car having the limiter removed, you're limited at I believe 135 or below otherwise. Mustang gets about 0.36 or more depending. Also, Mustang has shorter gears than the w124.
Civic SI 0-60 is mostly explained by its gross vehicle weight & the Weight/HP ratio.

zach1328

What price cap of $1300? All i said is i WANTED to get that much power for under $1300. I didn't know if it was possible, but most modern day cars can easily get an additional 40-50 hp for $1000. So i was just wondering if it was the same for an Old MB.

I have $6000-$8000 to spend if i wanted too, but turbo's arn't good for the car so i didnt really want them. So i was simply asking if there were any cheap upgrades that gave a lot of power.

zach1328

So if i get shorter gears on my 300E about how fast would it go 0-60? I don't necessarily need more power or top speed. I just want ways to accelerate faster.
And there must be other ways to make acceleration faster without spending loads?
I mean, why doesn't sending more gas to the engine work to increase hp and torque? How about sending more air into the engine?
There must be ways to increase power without spending thousands.

Saijin_Naib

Don't know, I've not run shorter gears yet. All I know is that the 300sl with the m104 and 3.69 rear diff does the 0-60 in about 8.4s, which is about spot on for the m104 300e/300ce.

However, the 300sl is about 500lbs or so heavier (4010lbs vs around 3505lbs). Therefore, with engine equal and time equal, the trans has to make up for the difference in acceleration.

A few members here have done the 3.69 rear swap, I think Wolf190e is one of them. Ask him for some hard numbers.

Sending more fuel and air should work. How do you plan to do so? Air is supposedly at the max right now. Keep in mind you want to keep the AFR at the perfect stoicheometrical balance to ensure full and optimal combustion.

RBYCC

More gas = Rich AFR
More air = Lean AFR
Optimum = stoichiometric = 14.7
Stock CIS-E or HFM settings = maximum power

We all know that you have mastered the rule of the "square engine" variants....
So surely you must be testing us on fuel burn ratio theory

zach1328

Well do you know if it the 3.2L or 2.8L edition of the 300sl that does 0-60 in about 8.4? B/c i thought the stock 300E 2.8L time was around 8.4 or 8.5. Which means if my car is 500 lbs lighter..then mine should do 0-60 in 7.8? Or would it not be quite that fast?
Oh and do you know how expensive it is to get the 3.69?? To be honest i would be very happy if i could just get my accel down to 7.8 maybe. Keep about the same top speed. And make my car respond faster.

Damn I don't understand how the earlier 300E with the 3.0L producing 177 hp is faster than the 300E 2.8L producing 194 hp.
Does the 200-300 lb weight difference really make a 0-60 time difference of 8.4 seconds (M104 DOHC model) and like 7.8 (M103 SOHC model). While the M104 2.8L is producing 17 hp more.

I was quite amazed though. I was driving around earlier today and put it in 2nd gear (I have auto transmission), and i was cruising at like 4500 revs, then i floored it.
When i floored it in 2nd gear it took off right away and the tires spun and screeched for a second. Why doesn't the car pull that hard when it is just in DRIVE?
If i could get my car to accelerate like that all the time, and have the same kind of responses in DRIVE i would be the HAPPIEST PERSON ALIVE!!


If you don't know what i'm talking about..try it out. Put it in 2nd gear. And then run it up to 4500-5000 revs, then floor it. It responds so quickly, pulled much harder than the usual, and screeched the tires.
Is that just because the transmission doesn't think about what gear it has to go into? Kind of like driving a manual?

Saijin_Naib

Dude, the power curve on our engines is LATE. Like, 3500rpm begins the real pull up to about 5800rpm or so. That is why you barely move when in D or from a stop.

Also, 1/2 are geared very much shorter than 3/4 (4 being a half-assed OverDrive gear).'

Too tired to research the rest of your post sorry. Had a miserable day.

ps2cho

Lock it down into 1st gear, feather the throttle until about 2500-2800rpm then floor it and as long as you are in 1st gear, it should move you in your seat. I've found that is about my peak in torque right there. On the stock 15" wheels that I used to run, it would chirp them shifting from 2-3 sometimes on a dry road! Can't do it anymore with 16" wheels, but nonetheless.

zach1328

Just wondering..
Why is the stock 0-60 time so slow?? I mean there are so many cars with much less torque, much less hp and much smaller engines. And they seem to be abut .5-.8 seconds faster 0-60.

The reason i want faster acceleration is because:
The W124 is really a great car. The only problem is.....NO_ONE ELSE THINKS SO! No one truly admires the car, unless they own it.
All of my friends are like, Well its 93', its slow 0-60, therefore its a piece of ****.

I still like it though..It just PISSES me off that some people are so close-minded. They hear 1993, and automatically assume it is a piece of ****. What they don't understand is..a W124 was manufactured just as well as most cars built today, if not much better. In my opinion ateast. For what its worth.

But if anyone knows why it isnt too fast 0-60, please let me know. I just assume there is a way to make it much better, knowing that many cars with 200 torque can do 0-60 in about 7.5 seconds if not better.

And saijin:
Your comment about the civic just being so fast 0-60 because of its HP/WEIGHT ratio. I thought HP has nothing to do with acceleration?
Because a civic Si has 1 torque per 20.5 lbs.
And a 300E has 1 torque per 17.6 lbs.

Which means a 300E should technically accelerate much faster.
But once again the Mercedes 300E seems to fight back in top speed.
Although

300E HP/WEIGHT RATIO : 1 hp per 18 lbs
CIVIC SI HP/WEIGHT RATIO: 1 hp per 14.3 lbs
And a Civic Si only goes about 4-6 mph faster.

But im not too sure about a 300E 2.8L weighing 3505 lbs. I thought that was the 3.2L edition. And the 300E 2.8 weighed more like 3420. There later edition atleast.
I dont know though, i did the calculations using 3505 lbs for a 300E and 2850 for a Civic Si.

Ps2cho:
Thanks for the info. And i dont know what you mean lock it down in first gear? I've been told that the later models, which mine is, always started in first gear.
It seems to like to get out of first gear veryquickly though. If i just give it like half gas, then it runs up to like 2200 revs, and shifts really fast.
Where as my 2nd and 3rd gears like to run a bit higher on the revs. On a normal accel it seems to shift about 2k in 1st..2600 in 2nd..and like 2900-3100 in 3rd. Thats just what ive noticed a few times.

zach1328

Oh..Almost forgot.
Ive got an important question.

Where do you guys find all the info and do all of this research on the W124's? Or is it jut stuff collected from different people on this forums?

Saijin_Naib

Read:
http://en.wikipedia.org/wiki/Power-to-weight_ratio
http://auto.howstuffworks.com/horsepower2.htm

Our gearing is rather conservative. Not only the final drive ratio but also the individual gears themselves. These are luxury cars, not sports cars. As such, they are geared a bit differently and behave a bit differently.

If you truly want the most acceleration out of your car without touching a thing, start it cold and put it into 2nd and then let it drop info 1st.
Do this with the engine temp below 60C. If you do so, the car will likely still be on its warm-up mix which is a much richer AFR and you will feel some serious power.

Once the engine warms to about 80C or so it leans the fuel back to improve emissions, smell, and fuel economy. This also is better for longevity of the engine and exhaust components, most especially the catalysts.

A quick study in descriptive statistics. Basically, there is a strong correlation within the data points for both Power:Weight and 0-60 times. Moreover, there is a strong correlation between Power:Weight Ratio and 0-60 times, though it is a negative correlation. The negative simply means that as Power:Weight ratio goes up, 0-60 times go down. Simply, as Power:Weight approaches 1, 0-60 times approach 0.

ps2cho

I have found both my car's are significantly slower until they reach operating temperature and hit closed-loop. I'm not sure that what you said is correct...
I wouldn't recommend doing it either as you should never run a car hard without it the oil at operating temperature. Engine temp on the cluster =/= oil temperature. Oil takes longer to get up to operating temperatures.

Saijin_Naib

I never said it was a good idea. I just said that the warm-up mix is much richer and can perform better. It does here. I find that once I'm at 85C or so my acceleration decreases on the lower end but fuel economy (as measured on my cluster) also decreases and high-speed highway cruising is facilitated.
The fastest my car has ever felt was when the thermostat was stuck open and it was running perpetually on the warm-up mix. The car had some serious ***** my friend.

zach1328

Yeahh...Uh that graph makes no sense to me whatsoever.
And how do i lock the car in 1st gear at 2500-2800 revs?

So assuming that the 2.8L edition with the M104 DOHC engine does weigh 3505 lbs, then the car has 1 HP per 18.06 lbs.
And then lets say i shed 200 lbs off the car, then it weighs 3305 lbs.
The new ratio would be 1 HP per 17.03 lbs.

How much faster would my car go 0-60?

Saijin_Naib

Why doesn't it make sense? Look at the graph and read it. It will show you the trend of Power:Weight and 0-60 times for a selection of cars (mine included) and also the correlation between Power:weight and 0-60 times. Basically, as power:weight ratio increases 0-60 times decrease at almost 1 (a perfect correlation, which means it is a universal truth in this situation).
If you look at each of the two lines, you will see a black trend-line through it. This line represents the best fit curve and shows what the "ideal" Power:weight or 0-60 time relationship is.
If you look at the m104 300ce, you see that it fits the graph and the curves fairly well and falls between the 3000gt TT the Focus.
You put the shifter into 2nd and then wait or let it roll forward slowly. You should feel the car kick down into 1st after a few seconds. It will not go back into second until you redline it under full acceleration.
Don't know, look for a car with similar Power:Weight ratio and similar gearing and you should have a good idea. Or, simply extrapolate the data and figure it out for yourself.

zach1328

But then if i leave it in 2nd gear i can only go so fast. I thought he meant lock it in 1st at 2500-2800 revs while you are in drive.

zach1328

bump..

Saijin_Naib

1st is good for around 40mph
2nd is good for around 75mph
3rd is good for around 110mph
4th is good for ??? (I've only ever been 125)

ps2cho

Come to a stop. Lock it down in 1st for 1-2 seconds. Accelerate to redline, it will shift automatically into second. At redline in 2nd shift up to 3rd via shifter. You can toy with the throttle to find the best place to give it your foot....play with it and figure out the place that gives the quickest acceleration. It's not just foot to the floor = fastest.

Chappy

Put your car on a diet. Less weight means better performance!

Remove the entire interior (seats/carpet/door panels) tools and spare tire. Cost = $0

Fab up a nitrous kit. Cost = less than $1K

Done.

RBYCC

Sunroof panel has some weight to it...just replace it with lexan...same for the side windows.
Take the AC compressor out along with all the components.
You don't need most of the exhaust system...
Don't ever have more then 5 gallons in the gas tank...

I think you got it Chappy...
Still not light enough for a low 7 second to sixty with a 2.8...
But a bit better !!

pifcat2

Replace steering wheel and air bag with an aftermarket, there's about 20 lbs. Replace Seats with shell type, save ~ 50lbs ea. Wasn't there a thread about this before? lol

Saijin_Naib

Might have been my thread back from when I first joined :P

I've heard that if you were to gut all the wiring that you don't use (after you gut the power seats/etc) that you can save about 50lbs or so. If you wanted to go crazy-go-nuts, you could try and completely strip the interior as well as any sound deadening materials or adhesives on the body.

Also, I would not doubt that the polymer undercoating weighs a fair amount. Do not recommend removing that unless your car will never see a salted winter road.

pifcat2

50 lbs is about right, I had all the harnesses in a box and it was not easy to lift. All this is common race prep, the question is why not start with a W201 instead? It's a lighter car and you can find it with a 5 speed or replace the 2.6 with a 3.0 or 3.2 to increase PTW ratio. In the end, you'll have a stripped Benz that will still be beat...

Saijin_Naib

I don't know. I'm only interested in making my car faster because its the only car I have :P

I do agree though, if you had the ability to choose your project car a 190e would certainly be a nice place to start.