e500slr

Heavy engine though, it's cast iron not aluminum but yes it makes it stronger, sort of why the 2JZ is a beast, iron block is indestructible. By the way I'm referring to Cobra engine not the 55k.

e500slr

By the way I'm thinking what if the drivetrain loss was less? A friend of mine has a race car STi he built for track days and he got a carbon fiber driveshaft from ACPT, now he says the car revved more freely and the dyno number without further modifications increased. I'll try to get the sheet for before/after but it definitely helped alot, plus it's much safer. Now that's rotating weight, so are wheels and brake rotors. With carbon driveshaft, lighter rotors and wheels, should the whp number be closer to the crank HP therefore increasing the power but reducing drivetrain loss.

GT-ER

Blocks, regardless what they are made of, are rarely the issue when it comes to an engine blowing up. The single largest reason for catastrophic engine failures are connecting rods. fix that, then you have pistons. But very rarely do blocks go first.

e500slr

Of course not, blocks aren't even moving parts, the rods are vulnerable because a huge amount of pressure is put on them when they being slammed. So why did they use the iron block then, iron blocks are rarely used now, they weigh too much and they're not exactly necessary. I heard BMW made a magnesium block. Thought Magnesium was unsuitable for internals.

BenzoDoc

Must not have made much power, or it cost him a pretty penny. I'm well aware that they are custom made for drag and monster truck applications, so I'm sure they can be made, but at a price.

I shattered an OEM CF driveshaft on my last race car because it couldn't take 400 crank hp and like 200lb-ft of torque [rotary]. Anecdotal evidence, but it sure wasn't fun. Granted, it's not exactly as messy as if someone snapped an aluminum or steel driveshaft.

You seem to not like the answers you're getting because you keep asking "what if" as if we haven't factored these things in already. If you search the forum for CF driveshaft there's a long discussion in the C32/C55 forum, along with one in this forum:
https://mbworld.org/forums/c32-amg-c...riveshaft.html
https://mbworld.org/forums/w211-amg/...iveshafts.html

FWIW, your understanding of drivetrain loss needs a bit more research. A driveshaft loses 0 HP, so changing it will not change the HP read on a dyno. You will achieve peak horsepower faster, yes, but your peak horsepower will not change appreciably.

It will have the same effect as a lightened flywheel, except not as great in magnitude. The flywheel > driveshaft because radius is squared in that equation, and the flywheel has a huge radius compared to the driveshaft. Less rotational inertia etc.

Moral of the story - would be effective to drop your ET's, but if your goal is 600 wheel, that's not going to ultimately help you in your goal. Case and point - the heavy *** GTR dynoing low and running wicked times - the usually parasitic AWD system isn't as evil as usual thanks to the CF driveshaft.

One last .02: the number quoted all over this forum since the beginning of time is that 700bhp equates to 130 trap. I don't know many people trapping over 130, so the likelihood that anyone is putting down 600 to the wheels is even less likely.

e500slr

Actually it cost him $1200 and has never failed on him, his car is a rally spec 600bhp race gas and anti-lag, I have no idea what carbon driveshaft you ran that broke on you at 400 crank HP but that must have been a very badly made one or not even carbon. A proper carbon driveshaft can handle insane amounts of torque and power, it also runs with less vibration and definitely "adds" HP and torque, not just altering the curve.

I'm not repeating "what if", this thread is about combining information everyone has to answer questions, have you seen how in threads users ask a newbie to use the "search", well this thread might just come up in a search and help said newbie. We are also figuring out the drivetrain losses and the power upgrades, there is no "what if". Should I just not even research and maybe run the car on vegetable oil? If you dislike power and weight discussions then that's fine, to each his own.

Getting back to my point, rotating weight anywhere along the driveline contributes to loss. Diff, driveshaft, brakes, wheels, gearbox and down to the crankshaft, the pistons etc. Anything that moves contributes. Now reducing rotating weigh definitely does, the question was how much.

e500slr

I just has a read of that thread with the guy who was BS'ing about NASCAR not using it and how it's bad. I don't think AMG, the maker of our car, would put a CF shaft in the SLS if it was unreliable. See this is what I get annoyed of, people who don't know ANYTHING about mechanic giving their "0.02 cents" and making other uninformed individual believe them. Kind of reminds me of this guy who explained how a turbocharger "takes the exhaust gases and pumps them back into the cylinder" , dear God... Carbon driveshaft is one of the best modifications for a high performance car, it provides better fuel economy, more power and torque, smoother acceleration, less risk, more reliability and less vibration.

BenzoDoc

Like I said, OEM, rotary. I'm not the only one to have shattered it either. Stock cars have. Perhaps you should search and educate yourself on that as well. You are benchracing way beyond your knowledge base here

You are rehashing things that have already been discussed, and I have shown you that is the case. Perhaps you would be more effective in "combining information" if you just simply STFF, made a thread with links, and then it might even get stickied

The name of your thread is "Top HP Numbers," so your last statement isn't topical. Take lighter wheels for example. You're making it easier for the available horsepower to pull your car around. Changes to dyno #'s will have more to do with tire size/wheel size. But your ET's will improve. Lastly, the more outboard weight on the wheel/tire, the worse, based on how moment works.

Your question was answered by the first person that replied.

BenzoDoc

On the contrary - I said that it was better to have shattered a CF driveshaft than a steel or aluminum one, and that they were used in drag cars and monster trucks because they are reliable.

I don't have to bear the brunt of someone invoking NASCAR as part of a discussion where it doesn't apply. I didn't make nor imply those comments were true.

What you're trying to do here is called a straw-man argument. You are failing.

BenzoDoc

What I hate is when I take the time to educate someone and they get offended because they don't like to be taught.

I wasn't aggressive in my original post. I didn't make fun of you. I searched when you were too lazy to do it yourself.

Grow up.

And like I said, if you don't believe what everyone is already telling you, do it yourself and report back.

And before anyone else...

e500slr

Believe me it's nothing but experience that makes me condone the use of carbon fiber driveshafts. You can believe what you want and to be honest I don't really care if you are bored and decide to hijack a thread just to troll. Like I said to each his own. The point is I'm making my arguments based on experience and physics. You on the other hand are just speculating which is hardly factual. Now I said that lighter rotating parts reduce drivetrain loss, the question was how much. It depends on car to car, driveshaft to driveshaft but I said it because if by any chance a member has done it they can share that information with us. It is irrelevant if you think it's worth it or not, or maybe you're going to throw that whole "E55 isn't a sportscar" and you shouldn't "waste" your money on thing that won't have sale value. That's not the point. I've said this before, most of us here are enthusiasts and if we were to judge builds based on return or efficiency we wouldn't be enthusiasts. I've seen custom jobs that are unbelievable done to cars which TECHNICALLY aren't worthy of them. Personally I can't say I haven't spent paychecks after paychecks on cars over the years, hell by the time I sold my E46 M3 I had spent 2.5x the amount I purchased it for. Do I regret it, no.

BenzoDoc

Sigh.

Like I have said twice already, nowhere do I state that it wouldn't improve efficiency. I simply noted that it was costly, and you reiterated that with your example of $1200, thus confirming my statement. There are better ways to spend your money in the pursuit of 600whp, and they have been listed in this thread.

Once again, you are trying to straw man me into defending things I never stated. But I'm going to let it go because anyone reading this thread can see what I've actually written.

An E55 is a sports car. I do not troll. I didn't hijack your thread, I replied to a question you had with two points of reference elsewhere on the forum.

e500slr

I'm not trying to make you angry or be your enemy or insult you, I was just discussing the cf driveshaft, not the price. Yes the price is important however that wasn't even the discussion and for $1200 for the benefits you get it is well worth it. Trust me the car feels better to drive. Not sure on the 55 how it would be but I have felt it on a few other cars and it's a great mod which doesn't have maintenance costs unless of course there is a defect in the shaft itself or something like a rock hits it at high speed. The point is most power mods will increase wear and problems pop up, with this there are no issues. It should last MORE than your stock counterpart.

BenzoDoc

Agree 100%, having experienced it.

My question would be how much of an improvement it would be over stock, as I've never held a stock driveshaft in my hands. I doubt that AMG would put one as heavy as, say, the old 5.0's, but that's not to say you couldn't make improvements.

Personally, I'd target the rest of the drivetrain first because it's more bang for the buck.

But ultimately, to hit 600whp you're going to have to drastically change the output of the motor, as that would increase whp more linearly than the approach of decreasing rotational mass.

GT-ER

I guess we aren't talking about the supercharger anymore? LOL.

e500slr

There's nothing to talk about when it comes to upgrading the supercharger though, it's not like Ford or Corvette where there's market filled with aftermarket blowers. The AMG unit is actually very good, I think better cooling would help out alot, that's were the SLR exceeds over other 55ks. Built internals are more of a response to high HP than actual upgrades. Cast pistons are actually lighter, the point being that the forged internals are needed so things don't break. I think a little more dedicated tuning would go a long way, Evosport pay attention to the 63 engines and have come up with alot of modifications for them, I know Kleeman and others have done tuning for the 55k but I'm talking about dedicated tuning that goes further than bolt ons.

BenzoDoc I agree with you, it's better to seek engine mods than rotating weight reduction however like the second poster said, 580-600whp seems to be the limit for engine mods without the use of nitrous oxide. I still can't believe that's the limit for this car with such a big engine but I guess experienced people are saying this from their EXPERIENCE and I respect that. Although rotating weight is still a great option for getting more out of your car because you are in essence wasting less power which is I think the goal for anyone. That's why I asked about the HRE carbon wheels project in the other thread, a 14-15 lb wheel would shed major weight in terms of rotating, couple that with driveshaft and brake rotors and you have a good combo with decent savings. A Quaife weighs more than the stock diff however I think that's the case not the actual rotating parts so no weight gain there. By the way regarding the driveshaft Mercedes uses, I'm pretty sure it's steel not aluminum therefore even a high quality product is always going to be heavier than a carbon fiber counterpart, you just can't make steel that light and if you did it would be weak and break easily.

AMG_RL

where did it all go wrong BTW, the STi CF driveshafts are a mass produced item which reflects the cost. I would put my car on it that one built specifically for our E55's would be much more costly.

GT-ER

Well, to be honest I think I'd just remove the SC all together and get turbo my car. It'll be faster regardless.

Too bad there aren't many E55's compared to Vette's and similar cars, our aftermarket could be huge if there were simply enough interest.

AMG_RL

+1000000000 single greatest factor holding the platform back is the lack of support. simply not enough money to be made for most companies to justify the R&D to produce products for our cars like the domestics and imports do. I think Ill be happy with 530-550whp until you get cracking on the turbo kit and then can sell it to me bro!

GT-ER

Hehehee...we'll see I guess...lol.

e500slr

Although a turbo kit will allow more power and boost, it will lose the sound of the 55k which I think is a really good thing in the car. It will also lose sale value, I know I said earlier in this discussion sale value is irrelevant but a massive change like that will cripple the value. You will either get a person who will really like your custom job and buy it for more than the value or someone who will look at it intelligently, I don't think you can get warranty if you do that, I don't think with such a custom job people will be interested as they can't consult a dealer with problems etc etc. If only a company dedicated it's tuning to this engine it would really be awesome. I remember when I had my E46 M3, everyone in 2005 on the forums said that a turbo or sc kit was crazy and that the internals had to be built and everything would start to break now HPF is making really good packages that are built and have achieved over 1000hp. The point is nothing is really impossible with enough time and money. I think the cooling issue is really important, I've seen retrofitted customs jobs but would love to see a mass produced unit that solves the issue.

Regrading the driveshaft, it is mass produced now but when he got it ACPT was taking group orders, he didn't place the order one of the members of the Subaru forums sent the stock one in and had them make a CF version, I think they had like 40-50 orders so yes it ended up being cheaper than if one did it. However I have asked ACPT and they don't mind making a one off, it's just that it would be twice the price. Also it doesn't matter what car it's from, all they need is the original one and specs of car which they already have. They put their finished products through ALOT of testing for defects and torque and RPM thresholds so it's a quality product. It's not RPMs that destroy driveshafts (extremely high RPMs do) it's the torque.

skratch77

Kleemann has an upgraded sc and top mounts for our cars!

skratch77

Roverron

@skratch
whats the price? What do you get for performance what kinda numbers are we talking?

skratch77

I think only 1 person has it and it was never really marketed.Price is about the same as a used 2004 e55 lol

I think they were rated 650hp for the k6 kit