i have a 98 bmw m3 and i want to put subs in the back and lets say it is 100lb heavier now. how much more horsepower do i need to make the car normal again. it has 240horsepower stock. how much more horsepower for 1lb. thank you
208535
What did your M3 weigh before? Maybe 3500lbs? Then it's easy enough:\n\n(3500 + 100) / 3500 x 240 = 246.9\n\nYou need another 7bhp. But pay attention to the other answer that mentioned the effect on handling.
671174
Are you fixing a 1987 Mazda RX-7?  Hehe...  I really am curious to know what this conversion is for...  Is your lawnmower on the fritz?  Hehe.  \n\nFirst off, let me ask you if the unit bearing measurements in KMPH or KPH has any sort of "tachometer" on it...  Some tachometers show both KMPH and RPMS, but others don't.  If you're in a situation where your tach doesn't have one, uh....  You're probably gonna need to check with the Autoguru.  \n\nAccording to him, to calculate your RPMs, you must do the following:  \n\n1) If your Road Wheel diameter is 'D' meters, then its circumference would be '^D' ( using ^ as a symbol for 'pi'=3.14). \n\n2) Assume you are cruising in IV gear @ 60 kph and the Car has a 'final drive'/FDR ratio of 4:1 and the IV gear ratio/TGR of 0.9:1. \n\n3) Then the # of revolutions 'per minute' the Road wheel would make would be = 60/60 x 1000/3.14 x D. \n\n(Assuming 'D' to be = 0.50 meters, it'd be = 636.94 rpm. The figure of '1000' comes in to convert 'kph' into 'mph' and '60' to convert hrs into minutes.  [*That's the Metric System at work, for ya, kids!]) \n\n4) To get the Engine rpm now, we multiply 636.94 x FDR x TGR or 636.94 x 4 x 0 .9 which = 2293 rpm. \n\n5) For E-Rpm in any other gear, '0.9' would have to be replaced by the drive ratio of that gear viz 1.33 for III and so on.\n\nThis is pretty close to the real life example of a Maruti 800, which when "tacho'd" does 80 kph/~3000 rpm!\n\nI hope this helps you!  Good luck!
39255
busch lighter car about 500 hp nextel weigh more and push ~800 hp
163020
Are you kidding me?  DO NOT get rid of that car!!  It's among the elite of import racing and will probably get some serious $$ because there are not that many off them out there.  Keep it, even if it's non-op registered, and just save up for the down on the new supra if you want it that bad.  The styling on that supra you have is still great and with all the custom options out there for a Supra, you'll have fun with it for years to come.
596420
engine power is given by,\n             Power = (2*П*N*T)/60  , W\nwhere, \n                N = speed of the engine,rpm\n                 T = torque = F * r, N-m\n                 F=Force,N\n                 r = radius of the brake drum,N\n                 \n If you want power in horse power,\n                   H.p = power( in W)/746
83407
I want a 1998 to 2000 BMW 3-series with low miles and in good condition. If you have a car like that, send me some information please.
465042
Alright Alright...I'll calculate this for you! Whatever! Ok...What 4x4 are we talking about here?\n\nAssumption:\n4x4 = JK Jeep Wrangler.  Here are the specs from Wikipedia:\nA 3.8 L OHV V6 producing 205 hp (153 kW) and 240 ft·lbf (325 N·m) will be the base engine, replacing the venerable AMC Straight-6 engine. \n\n205hp=153kW!!!!!  I can tell you straight up that to produce this amount of power from solar panels would be ridiculous!  If you go up to Home Depot and ask them for a 153kW System for your house, they will tell you to get lost! The average solar panel at PEAK Efficieny can produce roughly between 60 - 110 Watts! \n\nThus lets take the best case scenario.  At peak efficiency:\n153,000 Watts/110 = 1,390 Solar Panels!!\n\nSo...to power up your 4x4(Of course that 205hp to the crank and not to the wheels!) you would need around 1,390 solar panels.  Not that bad though!
70720
chip, GT40 air intake, cat-back exhaust, free-flow cats, h-pipe. The easiest thing to do is change the oil to synthetic. Less friction=more power
102464
14 bolt is PLENTY strong!\n\nBut why not sell it to a 4 X 4 enthusiast, use that money to go towards a narrowed 9" rear?\n\nI question the availability of gear ratios for that particular style of rear...That's one of the reasons why more people  aren't doing what you are considering right now!  Also think about housing ends, brakes, axles with the proper bolt patterns, etc...
9065
You should size the turbos based on your horsepower goal:\n\nA turbo helps support about 1 horsepower per 1.345 cfm airflow (that the turbo is rated at). Take the cfm rating of the turbo you are considering and multiply by two (to get the total cfm provided by the two turbos).\n\n\n----\n\nWhat I referred to was the cfm ratings of the turbos themselves. Those are usually specified by the turbo manufacturer in the form of a compressor map. The 1.345 figure I gave is the most commonly quoted estimated. For example, if you wanted a 250hp car, you would need one or more turbos rated a combined 336 cfm.\n\nAnother factor is making sure you have enough exhaust flow to spool the turbos quickly. In other words, don't oversize the turbos or the turbo response will not happen until a high rpm, thus reducing drivability somewhat.
121232
To start, I'm not a "tuner guy". It seem one would want to istall a performance exhaust to allow more air flow and a computer reprogrammer to override the fuel efficient factory settings. These things alone will gain you maybe 40% more horsepower. Tuning the suspension is a big next step to get the most from your newfound power. \nThere are tuner shops who could give you lots of tips on performance or try this site. http://importtuner.com\n\nGood Luck !
421829
Short answer: Install a large turbo.\n\nIt depends on what type of engine you have.  If you're running a KA18DE, good luck.  You'll have to tune that engine about as heavily as possible to take it up to that much power.  However, if you have an SR20 engine, you're in a much better situation, as those can withstand much more power.  \n\nIf you have a KA18DE engine, I would suggest saving your money for a SR20DET engine, and having the SR20DET rebuilt.   That will cost more than your current budget, but will be worth it. Then, install a large turbo on the SR20DET.  I would guess that all that work may cost as much as $8k-10k, depending on how the SR20 market is right now.  \nYour other option with the KA is to install a turbo, and hope for the best. I don't know if you'll be able to pull 300HP though, especially with a tired old engine.\n\nNOTE: If your engine is naturally aspirated and hasn't been recently rebuilt, I wouldn't reccomend installing a turbo, as you're likely to blow it.\n\n**for reference** "S13" refers to an older model  (86-92?) Nissan 240SX\n\nDisclaimer: I drive a Mazda RX7 (FC3s), and have not personally  done any work of this nature on an S13.\n\nFeel free to send me a private message (I think you can on these boards) and update me/ask for more info  on the situation.
7114
Well, if you could just remove the small ring the gear ratios wouldn't be the same.  The "normal" gearing for a double is 53 / 39 and on a triple is something like 52/42/30.  If it were me, I'd definately upgrade to Ultegra.  But that's assuming money isn't an object.
39292
the 3 cylinder will have more horspower..just cuz for the simple fact it is DOHC...but where it gains in horse power it gonna lack in torque...the SOHC will produce more torque at low RPM to get the vehicle moving..the DOHC will gernerate more HP at high RPM....example i used to have a 98 neon DOHC..my friend had a 95 cavelier SOHC..both 4 bangers...when we race he can take me off the line due to the torque but once the DOHC reaches bout 3500RPM it pulls hard and can cathc up and pass...\ni knowall that is kinda unessesary info but....i would go with the 4 banger for the simple fact of the extra piston and the better torque curve
208728
I have a 72 monte (currently in restoration) and the new ones are CRAP compared to the old ones.  I have a friend who just traded in a 02 ? Monte because the trans was starting to slip.  I love chevys dont get me wrong, but if the stang is a V8 it is better as far as construction and life after miles is concerned.  As for the women thing, I see a lot of chicks driving mustangs, so if you get the stang you better trick it out if you want to stand apart from the ladies.  The monte has sexy lines, but the mechanical soundness is a turnoff.  (Dont pull up on a girl and try to talk to her if she cant hear you over the rattle under the hood) Go old school, chicks really dig that.
64889
Go with the heads definately. While widening the ports and displacement would give you some gains the heads go alot farther. While you're doing the heads throw in a solid custom cam with hydrolic lifters and forged rods. Not only will you get bigger bang for the buck but it'll give you better runs at the track or on the street.
10725
You'll get a better answer on a Subaru forum than here, but at least keep in mind that heavier wheels degrade both performance and ride.