Hey guys,

I just did a little searching on the net, and though a little hard to find, some specs. were available, and I thought just for a point of comparison with regards from 1/4 mile "only" perspective, the result I've calculated you may find interesting....Remember this is from a 1/4 mile perspective only....

The weight of the car is actually quite high ( I thought ) at 1,888 Kg's. Must be for high speed stability at 400+ km/ph.

The displacement of the W16 engine is 7,993cc's or if you rather, say about 488 Cubic inches, ( Yes, this over double the '"old rule of thumb" figure generalized earlier, but remember it's been designed from scratch to do this, so realistically the rule doesn't apply as we've already exceeded it's perspective yes ?).

However, the given 1/4 mile time for this Bugatti is surprisingly in at 10.2 seconds...

So using the formula as posted earlier, the amount of Hp delivered from the car over the 1/4 mile is not as large as you may think....

We have 1888kg x 9.81N x 0.4ff x 0.4Km / 10.2sec's = 290.53 Kw. This multiplied by 1.34 is equal to 389.31 Hp..

So it looks like the designers have limited engine out-put in the interests of safety and traction, to provide the Max output at the high speeds the cars capable of.

I hope I'm not wasting your time or anything, ( or making out to be a smart ass or anything like that ), I just wanted to put things into a "clearer" perspective from the 1/4 mile point of view. Have fun !

Cheers,

Rastus

gerryvz wrote:

---

Yes, I find around 10 1/4-mile runs with my 10-pound bottle is about all I get. I remember how everyone under the sun was insisting I was going to blow up my motor, die in a ball of flame, rot in hell, etc. if I installed the nitrous kit (which is a modified 5-liter NOS brand Mustang box kit), 100-shot. Well, 9 years later my engine is still kicking.... and I'm still around to give RSJ, PowerStroker and ManBoobs McClare plenty of shit.

Well Gerry, the 5.0 Mustang Dry kit is a very good kit and it fits way more cars than just the Mustang, Mercedes and Camaros. It just got a great reputation with the 1988-1992 Mustangs because them models come from the factory with forged pistons and people REALLY abused them without any damage.

Truth be told I usually had my bottles overfilled by 1-2 lbs and used a mini-propane torch to heat them up till they just started to reach the pressure where the blowoff valve would start purging the nitrous. People thought I was crazy, but there really is no feeling like that first race with a hot overfilled bottle. I would literally spin a set of 10.5 inch wrinkle wall slicks @10.5 psi pressure properly heated (burn-out) with VHT compound. Thats no small feat, in fact I have torn out numerous torque boxes, literally ripped them from the frame. Torque boxes are the steel cages that hold the lower control arms that hold the rear axle (on a Mustang). I have not been brave enough to try this on a Mercedes yet, but I imagine the flex discs only survive on many of these V12 modified SEC coupes *cough* Satish *cough* because the tires break loose.

I should add the guys filling my bottles always looked at me funny when I would bring in soot covered bottles with the blue paint burnt off. LOL Sometimes I would really have to lean on them to overfill them, but back then Hamilton would always sway them to my way of thinking.

You are right that I have a conservative install. I could jet it upward (I tested the fuel system...remember my nitrous kit is a dry, not wet kit) to 125 HP, but I'd feel uncomfortable going beyond that. M119s are considerably more expensive used than M117s too. I'd love to install a NOS system on my SEC, that would be a nice complement to the 3.07 rear end that I installed about 8 years ago....

I use to think 125HP was a lot of Nitrous! LOL, and I use to think the small 5/16 supply line was big too! LOL That was until I started messing with Big Shot kits in the 300-400 HP range that came with garden hose sized supply lines. LOL.

M117's are pretty expensive too and in my opinion they are more of a pain in the ass to work on than the later M119's because a lot of things changed with regards to the way the camshafts were mounted to the heads. But I do agree the M119 has more valves, springs, keepers and such so naturally there is more money there should it blow up. Not to mention M119 parts are generally a bit more expensive too.

I can see why you worry, and I tip my hat to you for having the balls to use even a dry kit. Most are just too much of a pussy.

Now, I've got to head out to the garage to "de-ASR" my car.... ;)

LOL! What an accomplishment that would be! LOL!

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-- Edited by SELLC on Friday 1st of June 2012 12:16:51 AM

Hello Guys,

It looks like whatever you've done or said to RJS has worked !- ( For the short-term anyway !).

I was thinking that perhaps as a rough guide, that if you weren't too sure about what Horse-power numbers are considered "safe" for your engines, that won't affect long term durability, there's an old "rule of thumb " that still holds up well today, as it did yesterday....

Generally speaking......The best figure to aim for is 0.8 - 1.0 Horsepower, for every Cubic Inch of engine displacement......So how do you get this figure when your engine capacity is in Litres ? All you have to do, is multiply your known capacity ( in litres ) by 61. Approximately 61 cubic inches is equal to 1 litre.. This means that your 5.6 litre Merc engine displaces about 342 Cubic inches...Should we then multiply this by a conservative 0.9, we arrive at the figure of about 308 Horse power...You can of course go straight to the 342 figure, (when multiplied by 1.0 ), but this would possibly be the upper limit of maintaining your reliability. - (this may seem like a small figure, but it is 100hp over a standard engine, and look how well it goes...). You may also find that the fuel injection system could be reaching it's Maximum delivery capacity beyond this thresh-hold...This is when things will start getting expensive, as you now have to buy aftermarket products, that will throw an in-balance into the overall design and operational characteristics of your motor, not to mention a depleteing bank balance.

Should you decide to want to go further, (with regards to a carburetion aspect), the " general" rule of thumb has always been to aim for a carburetor (cfm) of about 2.0 - 2.3 times the size of the engines cubic capacity...eg, 342 x 2.3 = 780, this would mean that a single 780 cfm ( Cubic Feet per- Minute ) Carburetor could be used...(You should be asking yourself now what's the diameter of my Bosch CISE throttle valve, and how does it compare to the added total of the 780 cfm carbs 4-throttle vaves in size ? If it's large enough or larger, how do I get more fuel delivery through the injectors ? What is my current fuel pressure at the distributor, and how much can I increase this pressure ? Do I need a higher pressure fuel pump / Can I get one ?)...Am I getting full throttle ?

Possibly the best Carburetor to consider for your type of application, would be to source one called a "Predator."...This is basically a self calibrating fuel metering device that's been shoeboxed into the Carburetor catagory....By all means they work very well, but you'll drink more fuel... Always remember that if you want more horses, you've got to feed them...

The possibility of a tunnel-ram and multiple carbs exists, however drivability will suffer dramatically, you'll be forever tuning the bastards, as they always go out of synchronization ( you'll have two carbs working at once remember, so this means two throttle vaves (at least) that have to open and operate at exactly the same time and range..) and you'll consume fuel like you wouldn't believe...Not to mention a very large hole in the bonnet to fit it all...

Tunnel ram set ups are hard core, and specifically tuned for an operating RPM range that's usually quite narrow, maybe a peak power range spanning all of 1,000 rpm that you then have to determine with camshaft selection, diff ratio, and a finely tuned twin-system exhaust...All working together harmoniousely...Very expensive stufff, but it can be done...

All of this is playing around really, and probably doesn't belong in the realm of a Mercedes Benz motor vehicle, however, at a certain predetermined point inherant within an engines design, if you want more power, and can't increase the engines displacement (capacity), you have no choice but to find more RPM. This means camshafts, induction system mods, and exhaust-system improvements, you cannot avoid this...

Wow, where did all of this come from ? I hope I didn't put you to sleep, or wander too far left of centre...Just trying to give you guys more food for thought and things to think about, as sometimes seeing things from say a carburetors point of view can help you understand what you aready have under you bonnet...or what you might need to do to get things going along a little better. I do hope to hear or see something written soon, even a question or two to get me thinking proper again. Have fun !

Cheers,

Rastus

Dude,

I appreciate your posts. They are thought provoking and informative, and that's what counts.

You are right on with your assessment of RSJ. He is best worth ignoring and only referencing indirectly, not in a direct way. RSJ is not worthy of direct conversation from anyone on this board, with the possible exception of his pal PowerStroker.

Cheers man !

YOU CAME TO DA WRONG FORUM MY FRIEND.................... YOU ARE IN A WORLD OF SHIT NOW!!!!!!!!!!!!!!

Hey man,

In case you're wondering what these emmission constraints were all about, they were essentially a government dictatum requiring all manufacturers to lower the exhaust emmissions from their new vehicles by a certain percentage, and to follow more revisions year after year....Starting more or less from the late 1960's, and still on-going to this day. Most manufacturers will spend years (up to 5+ years for Benzes ) in the design, R&D, prototype testing and developement of their products / engines, with the intention of 5+ years of production relatively unchanged, or with minor enhancements. This caught a lot of makers by surprise,as they all want a slice of the"American Pie"market place, as your the largest consumers of this market type world-wide. So these manufacturers, world-wide, had already spent millions of dollars in developement of their products, and were now forced to add "bolt-on" emmission reducing items such as air-pumps (these blow fresh air directly into the exhaust manifolds to burn away unburned fuel), EGR Vaves ( these recirculate exhaust waste gasses back into your intake tract to be re-burned, and lower peak combustion temperatures), Electrically Controlled Vacuum Advance to your Distributor in top-gear only (via a switch located on your transmission) etc. etc. All these things added up to Much Higher fuel consumtion, loss of power, but apparently lower emmisions.
One of the main tests for emmission out-puts, was to determine exhaust emmisions at speed, during highway use, over a certain distance...( I think it was a mile in length, at 50 mph, and measuerd in parts-per- million, then calculated as a percentage). The quickest and easiest way for manufacturers to overcome this particular hurdle (and a lot did so ), was to fit a numerically lower diff-ratio, thus lowering emmission output due to much-lower engine rpm, over the required distance...This cost the consumer in performance output..So what you were left with was cars that drank more fuel, performed terrible when compared to the same spec. vehicle made a few years earlier, but met the required emmision out-puts. So the next trend for manufacturers in restoring performance to their vehicles, was to increase engine capacity, and of course this leads once again to higher fuel consumption and cost to the consumer, but provides the legal requirements of the governing bodies.. Then of course Un-leaded Fuel and Catalitic convertors become legal requirements in 1976(?), and the same cycle happens again, - eg. engines grow larger to try and maintain performance, whilst emission levels are "apparently" reducing, whilst our fuel bill is growing quite considerably for the same(?) performance.. Kind of sounds like a scam doesn't it ?
Your going to have to work out some numbers for your drag racing quest man. Ask youself these things...
1 What is my terminal speed over the finish line ?
2 What gear am I in ?
3 What RPM am I doing over the line ?
4 Can I take off in 2nd, to reduce the number of gearshifts through the race ( each gearshift possibly costs you 0.2 sec.s) ?
5 What diff ratio will give me Max. rpm over the line, at best speed, within the little window of Max. Torque & Power out-put ?
6 Can this be done or am I better of racing over the line in 2nd or 3rd gear ? (a standard 560 will change from 2nd to 3rd @ around 160 km/ph, and 3rd to top @ around 220 k's, so I figure your probably in 3rd gear for memory)
7 Do I need to extend my gearshift points with a lower diff ratio to minimise gearshift changes, or to I need to go the other way ?

Have fun man,and I hope your times get better !!!

Cheers,

Rastus

BUUUUUUUUUUUAHAAHHAHAHAHAHAHAHAHHAHAHAHAHAHA!!!!!!!!!!!!!!!!!!!!!!!! HEY GAYRRY........ HE'S TALKIN ABOUT A 560 AND NOT A 500E!!!!!!!!!!!!! LOOK AT YOU WITH YOUR CASCADE MOMENT..................... WAITING FOR THE OPPORTUNITY TO POST A VID OR PIC OF THE 500E WHEN NO ONE HERE ASKED FOR!!!!!!!!!!!!!!!!!!!! AHAHHAHAHAHAHAHAHAHAHHAHAHA!!!!!!!!!!!!!!!!!!

THOSE VIDEOS SHOW JACK SHIT.................... CAN'T SEE TIMES AND EVEN BETTER................ CAN'T TELL WHO WON!!!!!!!!!!!!!!!! WHAT A FUCKIN LOSER!!!!!!!!!!!!!! AHHAHAHAHAHHHAHAHAHAHA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! NICE TRY FAGGOT!!!!!!!!!!!!!!!!!!

Hello Sir,

It's me again, Rastus, and I don't particularly like being told to F### Off! But I thought it best to elaborate further the considerations you may need to enhance the possibility of better results regarding your Drag Racing Quest...Talking from a "standard vehicle's" point of view, please consider these suggestions, as they're based on FACTS, and ALL ENGINEERING of any form is based primarily on KNOWN MATHEMATICAL CALCULATIONS..Engineering is all about Mathematics, like it or not.... Please take the time to think about these suggestions, as they're hard-earned and proven FACTS...

1 The Benz factory quotes 230bhp @ 4750 rpm, and 279ft/lb of torque @ 3250rpm for the 560 engine. Keep your gearshift points below say 5000rpm max (even less) as the "little window" of Max. Eng. Output is about 1500 rpm, in-between 3250rpm and 4750 rpm. Go over this upper rpm threshold, and your moving forward more slowly than you would be by selecting the next gear and revisiting this window of Max Torque and BHP.

2 Use the best (highest octane number) fuel you can find and also the freshest.(Aviation fuel for Light aircraft is the best, but highly illegal to use and probably hard to get, and also quite expensive...). Each drop of fuel (or gram rather) has the potential to release approx. 142,000 + kj of energy...This equates to about "140Bar +" peak pressure inside each of your 8-cylinders. The efficiency in which your engine converts this potential energy is what you need to harness...The CISE fuel distributor on your 560 engine is tuned to meet strict Californian emission levels, not the optimum "Stoichiometric"air / fuel ratio of 14.75 : 1. You can adjust this by removing the little yellow plastic cap on your fuel distributor, and by then using a 3mm allen key to richen the fuel mxture. Turn clock-wise, very slowly and in very small increments until the engine begins to "run rough", then back it off, and do it again until you find that nice sweet spot..."If you want more horses, you've got to feed them..."Very important to re-fit a new yellow plug as this maintains a steady fuel mixture, eg, no air-leaks.

3 Use say Shell full synthetic Engine oil, as its lighter weight/viscosity reduces puming losses at your oil pump ( more power as there's less oil drag every-where and better protection ).

4 Consider the same Synthetic Oil option for your Transmission and Diff for the same reasons. (Slick-50 is also a proven trade secret that really works).

5 A wheel alignment is crucial, as if the wheels aren't pointing where they should, they're scrubbing out costing you Horse-power to keep the car in a straight line. Don't underestimate this, as the scrubbing gets worse as you go faster, costing you more power. Try picturing 2 wheels, one pointing straight ahead, the other pointing say 2 degrees to the left. After say 1km, how far has the offset wheel moved away from the other going straight ahead ? This distance is what your engine has to make up in terms of power from scrubbing, to keep your car going straight ahead. Use correct tyre pressures also...

6 Remove your accessory drive belts before you drag, that drive your A/C & Power Steering. Both these items might give you an extra 5-10 bhp to drive your car further forward faster once removed...

7 If your doing burn-outs off the line, your'e not moving forward as fast as you can to the finish-line, so regulate your throttle movement off-the-line to avoid a burn-out.

8 Possibly the best(?) alternative that's not a stock item to your car, would be to fit a " Hi-Stall Torque Convertor " to your Transmission with it's requisit Oil Cooler. If you can find or have one of these babies made to suit your needs ((3,250 rpm is where peak torque occurs so aim for this figure(stall speed)) You will be able to access this "sweet spot" of your engines Toque at any time, any gear, any where....You need pure Torque in ubundance to "pull you off the line" with a car that possibly weighs in at close to 2000kg.

I do hope you consider these suggestions, as they WILL HELP, and I'm NOT a smart-ass, as I like a good performing vehicle as much as anyone. I've maybe delved a little deeper as to what needs to be done to achieve these things. I would advise you to not use the internet as your only source of information, but to buy and read a number of different performace type books, and then cross-reference all the common revelations, as these are the general facts that each different author (and now yourself) would have determined individually, as to what really makes things go faster. Every car/ engine and combination(s) is different to the next, and what works for one won't necessarily work for the other. Just look for the simple things first, and remember that your Engine can be thought of very loosely as an air-pump, so the bigger the pump(motor) to start with, and the more air that you can let into it, and escape from it, the more potential for power output can be harnessed...Enough said. I hope I've explained things in a more digestable manner (as suggested by another sight user) and hope you have fun working thing out...

Happy motoring,

Rastus

P.S. What car do I drve you may ask ? I'll keep it my secret, but I do now finally own a Benz, and it happens to have a nice 8-cylinder orchestra that performs beautiful music !

Hello Sir,

It's me again, Rastus...And I also thought that you might consider this for your Drag Racing efforts....After 360 degrees of crankshaft rotation on any V-8 engine, only 4 of the 8 cylinders have provided a firing stroke... Why people who Drag Race use gear sets of say 4.11 - 1, is so that each cylinder of your V-8, has placed over 2-power-pulses to your diffs pinion gear for 1-turn of your rear wheel...This maximises the available torque output of your engine per 1- revolution of your wheel. Or rather, let me say that all 8-cylinders have fired a little more than twice per each turn of the rear wheel in top-gear, (1 :1 ratio). Calculate it out yourself.....

Cheers,

Rastus

I was getting about 15.1 seconds in the quarter-mile with my stock 1989 560SEC with the standard 2.47 rear end. With the 3.06 I have in there now, I don't know (yet) but I'd expect it to be in the low to mid 14-second range.