As the title says I was just curious as to which SL would be faster quarter mile, top end, etc. Pros and cons or whatever your thoughts are on this topic. Thankyou.

 

It's dead heat. Fastest SL55 on dragtimes runs 11.8 and fastest stock 65 is right about the same.

It would all come down to launch and traction. 65 would have an advantage as the turbs take a sec to kick as opposed to the Komp kicking in right off the line BUT 65 has so much torque that stock tires would really suffer.

I would say advantage to back to back runs goes to 65. 55 would suffer heat soak quickly with back to back runs.

Interesting topic. Be very close and a great race.

 

............65 for sure. As stated above the fastest SL55 is 11.8. I am not aware of any other sub 12sec SL55. 65's are mid 11sec cars all day long. Saw one totally stock on stock tires do 11.5 in Atlanta. So, will a heavvily modded SL55 you will be praying for sub 12sec and you may get lucky onece or twice. With a stock 65, you get in and drive your mid 11sec car all day.

Ted

 

Ted is dead on...... SL65

 

....upto the first corner. 350 lbs weight advantage on the SL55 will do wonders.

 

65 :d

 

Well, FWIW, the data I see is a bit more conflicted.

There are only three SL65s on Dragtimes marked as stock ('#"). The posted times are 11.91, 12.03, and 12.09. In terms of magazine tests, Car and Driver posted an 11.9 for an SL65 while Edmunds.com posted a 12.1. So while I completely trust that Ted saw what he reports, it's also the case that other stock SL65 drivers are seeing best case times of 11.9 to 12.1.

I'm real familiar with the 11.86 SL55. It's BMS' car. It has the equivalent of a Renntech Stage 5 (mix of Kleemann and VRP parts) plus VRP cams and a Kleemann LSD. It was on street tires when it ran 11.86 on a near-perfect fall day.

I'm also familiar with the 12.06 SL55. It's mine. It has a stock pulley but is otherwise fairly heavily modded. I was running street tires the day it hit 12.06. I'm planning to install a VRP pulley and am pretty confident I'll be in the high 11s after I do. That would make two SL55s in the high 11s but neither would be at "just" the RT-5 level.

My guess is that a heavily modded SL55 (RT-5 plus cams plus Quaiffe LSD) will launch slightly faster than an SL65 presuming similar tires, track conditions, and driver skill. The 55 is slightly lighter and the Quaiffe locks up better than the AMG diff--both of which favor the 55 on launch--and the 55 mods cut into the 65's huge torque advantage.

Afterwards the SL65 will reel in the SL55--look at the difference in trap speeds!--so that a 1/4 mile race is a toss-up but the 65 easily wins a longer race.

If its really just a straight RT-5 SL55 versus an SL65, I think the SL55 loses some of its advantage on launch and the SL65 wins the 1/4 mile

Just my two cents....

 

This was about drag racing....

 

I have never posted my times on drag times but I have run a best of 11.45 in my stock SL65 on drag radials and a best of 11.69 on stock RE050's.

At this same track, I have seen two other SL65's run in the 11.7's all day long.

Mine was the car that Ted was speaking of.

While I have not raced any modified SL55's I did own a SL55 that I ran on the same track a bunch of times. In stock form and on stock tires, I ran a best of 12.5 in my SL55 on this track.

As for 60' times, they have always been fairly similar in the 1.8x range for both cars on stock rubber.

Traction is certainly the limiting factor for any SL65. My guess is that it is just as big of a problem for a modified SL55.

The weight savings really doesn't help you and the AMG LSD works very well so I don't believe that you will gain any advantage from that.

In my personal experience in running modified E55's it was never a close race. The SL65 had them full track. The torque of the 65 was made for drag racing. These cars pull like freight trains and don't stop until you take your foot off the gas.

Schiz

 

350lb difference?

SL65: 4,555
SL55: 4,365

The difference is 190lbs

 

Nice times, Schiz!

I think somebody did post your 11.69 on Dragtimes: http://www.dragtimes.com/Mercedes-Be...slip-4298.html. It'd be too much of a coincidence for two different Schiznick's to have run identical 11.69s in an SL65! It wasn't marked as a stock vehicle, though, so I didn't use it when I pulled SL65 times from Dragtimes.

You may be right about 60' times. By the Dragtimes numbers, though, the two SL55s with LSD have 60' times that are 1/10 to 2/10s faster than the SL55 without LSD and are also 1/10 to 3/10s faster than all the SL65s with stock tires, other than yours. Your car's 60' time is a bit of an anomaly: 1/10 to 3/10s faster than the other reported SL65s running on street tires. Differences in track prep, maybe. Or maybe you just have the "touch."

But back to the original poster's question, it looks like the fastest known stock Sl65 ran 11.69 on street tires while the fastest known modded SL55 ran 11.86 on street tires. That's a .17 second difference or around 2 car lengths if I'm calculating distances correctly.

Interestingly in this comparison the SL55 has the higher trap speed: 119 MPH versus 117 MPH for the SL65. Don't see that too often!

Let's see...to get my 12.06 down to 11.68, I'd need another 50 HP. Probably too much to expect from just the VRP crank pulley but maybe with the pulley and VRP heads like the ones Jakpro just installed....

 

Not too mention that the 55 Kompressor will most likely suffer heat stroke on the last 1/8. (without proper cooling mods)

 

My information (official Mercedes brochure) lists the difference as 160Kg which is 350lbs:



Anyway, 190lbs would still make a difference in the corners

 

...........I think you are making my point. The fastest car in each chasis is not a good basis for comparison, especially if you are a potential buyer. Yours may not be the fastest of the chasis. For example there are stock E55's running 11.7 secs. An E55 buyer is not going to expect their car to do 11.7secs.

....... Essentially an SL65 is a mid 11sec car all day while a modded SL55 is a low 12sec car all day. This what a potential buyer should expect. To get the the 11's the SL55 owner will have to struggle, while the SL65 owner just gets in and drives........no hassle, no fuss.

Ted

 

Ted, you may be right but the available data says a stock Sl65 on street tires is an 11.9 second car, +/- 0.2 seconds while the highly modded Sl55 is a 12.0 second car, +/- 0.1 seconds.

Even counting Schiz' 11.69 time and the two other 11.7x SL65s he's seen run at the same track, the data set of known SL65 times, stock on street tires, is: 11.69, 11.7, 11.7, 11.9, 11.91, 12.0, 12.09, and 12.1. (I've rounded 11.7x down to 11.70.) The average time for that data set is an 11.91 second median and an 11.89 second mean with a standard deviation of 0.17 seconds.

The data set of modified SL55s that I was describing is: 11.862, 12.026, 12.067, and 12.127. The average time for that data set is a 12.067 second median and 12.02 second mean with a standard deviation of 0.11 seconds.

In terms of comparing times, regardless of whether you compare fastest time to fastest time, median time to median time, mean time to mean time, or slowest time to slowest time the differences between the stock SL65 and the modded SL55 are less than 0.2 seconds. Chart attached.

YMMV, as the saying goes.

 

In the future, please remove the AMG badge from the vehicle and replace it with an M badge prior to making that argument.

 

This is great!

 

trying to compare the data of the cars is ridiculous....different tracks and weather conditions, we all know the answer as to which car is faster and quicker, the 65 hands down.....

 

.............you have just shown that the average 65 is an 11sec car and the average modified SL55 is a 12sec car. I don't thing there is much of an debate as to which is faster.

............The debate really will come in when comparing a fully modified E55 and a stock SL65. Now, that will be close. The nod may go to the modded E55. Yet, you can expect the SL65 to be consistently running in the mid 11's while the modded E55 will hit or miss the mark depending on the conditions.

Ted

 

I got my numbers from MBUSA.com

Thats a huge difference, someone at MB ****ed up

 

I suspect the US numbers are accurate for US cars, which are equipped differently than Euro models. Note that your table shows the SL55 having 18-inch wheels, while US SL55s have the same (heavier) 19-inch wheel and tire size as the SL65.

 

I also just noticed your table is for Dutch, not German, cars. They may be equipped differently as well.

 

Love reading this stuff. Just for arguments sake I want to add that the 11.86 SL55 is mine and it has 41000 miles and it is a real ball to drive daily. I had a SL600 prior to The SL55 and I didn't like it so I let it go to a friend and got the 55. I didn't like the turbo lag accelerating or decelerating on the 600. Also the brakes and sound were much superior on the 55. The AMG 55 seemed sportier to me. I had heard the 600 was much harder and more expensive to work on. Resale was better on the 55. All that said I must admit the 600 ran like hell and still does. My friend had it modded at Motorwerks with Rentech equipment and it is faster than ever. Without tires I doubt he can hook it up. The SL65 is a much better car than the 600 as it is an AMG car. Keep in mind engine replacement for a non warranteed 65 is over $100,000. The 55 is over $50,000. Hope you all enjoy your Mercedes' no matter what style. I also had a BMW Z-8. No comparison to the SL! Nor were the 6 Corvettes I owned. Have had 3 SLs'. I think the best buys on the market today are used SL65's. Horrible depreciation, but great for the buyer in the market for a used rocket with a great ride. Make sure you have a warranty or real deep pockets. Jm003-- you are the man

 

Well, a stock SL65 is easily faster than stock SL55. And a modded SL65 is easily faster than a similarly modded SL55.

Whether a stock SL65 is faster than a heavily modded SL55 will depend on the mods. Surely no one believes it's impossible to mod an SL55 to the point where it could run with an SL65 in a 1/4 mile.

The original question was whether a Renntech Stage 5 SL55 could run with an SL65 in the 1/4 mile. My guess was no, but if you add cams and LSD, it gets close. Other people have different opinions and that's fine.

I absolutely agree that the same car can run different times on different tracks, the same track on different days, or even the same track on the same day but at a different time. Track prep differs and air density differs. The resulting time difference can easily be as much as 0.3 to 0.4 seconds on good track and much more comparing a good track to a bad track.

If you'd rather use specific comparisons instead of averages, there's an NHRA correction factor to adjust for differences in air density. It's documented in various places and embedded in an online calculator here: http://www.modulardepot.com/density.php

The density altitude for the 11.86 and 12.06 SL55 runs was -46 feet, or near sea level. Correcting to sea level, those times stay at 11.86 and 12.06.

Of all the SL65 times, the only one that I'm sure has been corrected to sea level is the Car and Driver time, and they're calling 11.9 for the SL65.

You'll notice--and I'll suggest it's not coincidence--that the Car and Driver time is right on top of the median and mean times for all SL65s. Averages have a tendency to average things out.

Ted, the question isn't whether a modded SL55 can beat a stock SL65 in a 1/4 mile. It can. The question, what level of modding does it take.

Let's assume Schiz can run 11.69s "all day long" even though he's done it only once. Let's further assume that time happened at an air density of 0 which makes it an "honest" 11.69 instead of an air density inflated 11.69.

My car ran 12.06 at an air density corrected to 0. By the numbers, I'd need about 50 additional HP to match Schiz. More HP would put me ahead of him; a lot more HP would put me significantly ahead.

I'm running a stock pulley, so there's some HP on the table there. Similarly, I'm running stock rather than ported heads, the weaker SLR cam instead of the hotter VRP cam, and shorties instead of long tube headers. Then there's NOS. I'm not running any but could.

My guess is that a pulley and heads would bring me even to Schiz in the 1/4 mile, but I could be wrong. It might take more than that.

 

Here is the German Brochure:



Weight difference: 160Kg

The weights are different, but that's because the German regulation states half a tank of gas and a driver should be taken into account, and Dutch regulations state empty weight.

But the difference is the same: 350 lbs

I cannot imagine US spec and EU spec SLs would differ that much...