180 Naturally asperated horses???

[audirs7]

I just bought my first 318iS (95) and I was hoping to get it up to about 180 horses without forced induction...on a budget...
Is it possible??

[i8ur911]

Yes.

On a budget? Yes. What type of budget? $2k-$3k....maybe cheaper depending on parts used and connections.

[audirs7]

like 2k.  i'm cutting weight and trying to add some power...

[DesktopDave]

Cheap, fast, reliable.  Pick two.   

I don't want to sound like a know-it-all, but if you want more power on the cheap, buy a six-cyl.  The 328iS is a fine machine - trading your car + $2K would likely put you in the ballpark.  Or budget for an M52B30 swap.  $2K could get you really close to a complete swap if you cut a few corners.  The alu block M5x from the E39 drops right in with a few mods.  They aren't that much heavier than an M4x...and they make ~220HP right out of the box.

If an engine swap isn't your cup of tea, I'd consider cheap upgrades that add reliability first.  Getting the motor in top condition is a priority.  Make sure you have no stored codes.  Test all sensors.  Do a compression check to learn your motor's baseline.  Upgrade to top-quality fully synthetic lubes in the motor, tranny & diff.  Clean out the AFM/MAF and ICV.  Replace your fuel filter.  Make sure the PCV passage is clear, consider a catch can.  Be sure the DISA is in working condition, if installed.  Use only high-quality OEM air filters - the stock airbox is excellent as long as the filter is clean.  Eliminate all vac leaks, replace every rubber part under the hood.  Eliminate the engine-driven fan with an electrical radiator fan.  If possible (do you have a serpentine belt setup?), eliminate the A/C and P/S systems entirely.

I'd also install a cooler thermostat, lower-temp aux coolant switch, and thin out the coolant - up to 75% distilled water mix (with water wetter) will save you a bit of power and improve temperature transfer.  Keep the battery perfectly charged - maybe with a solar trickle charger, and test the system for shorts.  A dying battery or worn-out regulator makes the alternator work far harder - and that's all lost HP.

I'd also consider a WBO2 setup to see what the motor is really doing.  It gives a lot of insight, and they're only $200-ish.

Silicone hoses, upgraded injectors, a COP kit & good NGK plugs really help.  Give the car a MarkD or Midnight chip, a shorter diff and some carefully-considered wheel choices.  It sounds counter-intuitive but smaller circumference tires will bump up your final drive ratio & give you free acceleration, though they might look a bit odd and will raise high-speed RPM substantially.

Weight reduction is cheap - but murders your resale value.  BMW worked hard to keep weight down, but you might be able to eliminate 10% or so.  Exhaust systems can help with both power and weight loss, but they're pricey for their gains.

[audirs7]

I'm planning on a serious tune up; hoses, belts, injectors, plugs etc... and as far as weight goes i've taken out the back seats, door panels, stereo, speakers, everything from the trunk, and carpets with plans for lightweight race seats, wheels, and a CF hood/deck lid.  an engine swap is a bit more work than i wanna do at once... i was thinking, intake, exhaust, chip, pulleys, clutch/flywheel.  any idea how much BHP that might make?  and does anyone know if there's an EGR delete kit out there?

[audirs7]

oh, i've also removed all the internals from the windows and fabricated aluminum supports to hold the glass up.  and thanks for the suggestions. 

[DiRTY-D]

what injectors would best suit an almost stock m42

[e3091318is]

Slightly bigger bore, lightweight pistons, rods, cams, resurfaced head/block, ported head.  You are looking at $2000 just for that and might be able to squeeze 25hp out of it.

[i8ur911]

Slightly bigger bore, lightweight pistons, rods, cams, resurfaced head/block, ported head.  You are looking at $2000 just for that and might be able to squeeze 25hp out of it.

$2k for all that? Where are you getting your parts and machine work done because I want in? Take $2k x 2 and maybe that'll cover what you mentioned. I'm building a N/A M42 and my engine will be around $3,500 :fingers crossed: when done. The motor will produce what the OP wants too, 170-180hp.....and rev to 7500-8000rpm

[wazzu70]

I'm planning on a serious tune up; hoses, belts, injectors, plugs etc... and as far as weight goes i've taken out the back seats, door panels, stereo, speakers, everything from the trunk, and carpets with plans for lightweight race seats, wheels, and a CF hood/deck lid.  an engine swap is a bit more work than i wanna do at once... i was thinking, intake, exhaust, chip, pulleys, clutch/flywheel.  any idea how much BHP that might make?  and does anyone know if there's an EGR delete kit out there?

There is absolutely no way those modifications will get you to the hp you want.

Probably would net you around 150bhp. My car with similar mods and a rebuilt engine did 130rwhp for reference.

With big cams and a proper tune for them you will be much closer to your goal.

[bmwman91]

what injectors would best suit an almost stock m42

Stock injectors. Swapping injectors will lose you power and fuel economy unless you go and get a custom tune made around the different injectors. NO gains will come from just switching injectors, period.

OP, 180bhp NA from an M42 will require a minimum of increased displacement, higher compression and head work (slightly larger valves, hotter cams). There is also the shape of the power band to consider. It isn't super hard to hit 180bhp with an engine that you need to keep over 5000RPM all the time just to drive anywhere, but it is a lot of work to make a balanced engine that doesn't suck on the road. Simple bolt-ons like a chip and lighter flywheel will make the car feel a lot more alive, but as wazzu mentioned, it'll get you around 150bhp. Intakes do NOTHING as the stock one is fine. Exhaust will do nothing and putting bigger pipes on will kill your mid-range torque. Pulleys...honestly, don't even consider underdriving the water pump or alternator and you might as well cut off the PS hose rather than waste money on a pulley for that. The M42 does not have an EGR system either.

Any head work, exhaust work, hot cams or increased displacement will also require dyno time to actually take proper advantage, and that'll run you around $1000 for a proper tune.

The M42 is fairly strung-out from the factory. There are literally no cheap easy mods to do except a performance chip (the stock tune was VERY conservative). Believe me, there is no low hanging fruit with this engine. Lighter flywheels do help, but they are not exactly simple bolt-ons. I run a ~205bhp 2.1L M42 that was built by Metric Mechanic, and there is literally not a single stock moving part to be found inside of it. For the money it required, I could have done a supercharged aluminum block M52 with an OBD-I conversion, or just bought a faster car. So if you want cheap and easy power, you are looking in the wrong place. The M42 is a fun little engine that is a great balance of performance and fuel economy, but it doesn't deliver the instant gratification that some people want.

[Slowered318]

I just bought my first 318iS (95) and I was hoping to get it up to about 180 horses without forced induction...on a budget...
Is it possible??

For $2,000 you should be able to make it sound like 180 hp. lol

Unless this is your first car, I'm assuming your coming from a 6 or even 8 cylinder car and expect a 318 to perform because it's "BMW".

These cars held their own back in the 90's and still get respectable fuel economy and performance, especially for a 20 year old 4 cylinder. The problem you will face is that the engine is not designed for high RPM horsepower like a Honda F20C (for example). It just doesn't get enough air at 5000+ rpm and no CAI, chip or exhaust is going to significantly change that.

To get the most out of a the M42 without forced induction or redesigning the entire engine is to aim for mid band torque. With the compression and AFR up to spec, clean/tight pistons and valves, a good ECU and maybe a little tweaking of the cams. You should have yourself a peppy little 318 and just enjoy it, down the road if you really love the car and you are ready to invest 5-10 thousand but 2 thousand is not enough and can easily be soaked up by maintenance items alone.

I pulled my motor 8 years ago - gave it a good cleaning and replaced the pistons, bearings and timing chain. The car ran great and kept me happy for 6 or 7 summers, I enjoyed the reliability of the stock engine but i'm finally at the point where I want to make it into a toy by adding a turbocharger. My point is that you can enjoy driving these cars without ALL the typical "performance" modifications, just don't expect the high RPM power that you will not achieve without doubling your investment in the car.

[audirs7]

well... CRAP!  I love the car, the engine runs beautifully and it handles well enough on factory suspension.  I just want a little more kick. I was hoping a very modest 180hp might be on the table for a reasonable sum.  but it seems the germans already engineered it to it's limits.   

So, I think the new plan will be to just swap wheels, rotors, clutch/flywheel, hood, deck lid, seats, LSD, and put a stainless exhaust on. whatever that gets me will have to be enough.  I had considered a supercharger (despise turbos) but i cant seem to find anyone that still produces a complete kit. 

and no, my other car is a subaru legacy... naturally aspirated 2.5L flat 4... largest engine i've ever owned was a 3.0L 6.   I bought the 318 for the fuel economy and the fun small underpowered coupes sometimes bring... all fine for the first few months but now i'm desperate to get a few more horses. lol.

[e3091318is]

Slightly bigger bore, lightweight pistons, rods, cams, resurfaced head/block, ported head.  You are looking at $2000 just for that and might be able to squeeze 25hp out of it.

$2k for all that? Where are you getting your parts and machine work done because I want in? Take $2k x 2 and maybe that'll cover what you mentioned. I'm building a N/A M42 and my engine will be around $3,500 :fingers crossed: when done. The motor will produce what the OP wants too, 170-180hp.....and rev to 7500-8000rpm

$300 for boring, $450 in pistons, $400 in rods, $600 in cams, $300 for porting.  You need to find better machine shops around they don't see a young guy who just whips out money saying he wants to do all kinds of crazy stuff to his car.  $3500 for a M42 rebuild?  You are getting taken to the woodshed on that one.  HARD. 

[i8ur911]

Right now it's... $700 cams, $200 valve springs, $800 machine work (valve job, PNP, clean and assembly), $2k Dbilas ITB's and Alpha N controller, $200 eBay header, $150 M44 crank, $30 19lb injectors (which will be tossed for 24lb'ers), $300 for machine work to lighten and balance M20 single mass flywheel, $100 for VW 35mm lifters....this doesn't include gaskets, timing components and other little pieces that will be replaced along the way.....including powder coating multiple engine pieces.

Sounds crazy and I could've built something else that would've made more power, BUT I wanted to build a M42 because of the weight balance AND because no one really does.