Best bang for the buck, how do I get some good HP on my 318?

[alex318is]

I have many various questions on how I should upgrade my car. My main goal is to get 200-220 BHP from my 318is. I do not want to go forced induction and I will consider a bigger bore but it is not really in my price budget. I am looking to spend 1500-2500 US dollars. My ideas for upgrades are:
Obviously a chip
Exhaust (will I gain much benefit from a 4 cyl engine?)
Schrick racing cam (titanium parts and stiffer springs)
MAF conversion http://www.bmpdesign.com/product-exec/p ... h_model/31
Multi-throttle intake http://www.bmpdesign.com/product-exec/p ... h_model/31
Header
Higher Compression pistons

Not sure which is the best and cheaper way to go. I want to obtain 200-220 BHP and want to spend the minimal amount.

If I decide to go with cams will it be a direct replacement or will there have to be some machining. Will the cams just replace the stock ones? Also anyone have any experience with multi-throttle intakes with an MAF (this is my favorite idea but it is costly and doesn't seem very street friendly). I am not too sure about higher compression pistons, I wouldn't know where to start with those, maybe 10:1 compression or a little higher? The pistons with the cam shaft might get me some good numbers with a custom chip and intake. All idea greatly appreciated!

Cheers!

[Turbo-Brown]

Unfortunately, gaining a 50% power hike and not spending much are not really compatible goals!

I'd venture to say that you could gain that more cheaply with a turbo than other tuning methods.

[alex318is]

Yeah I was afraid some one would say this. Well in all reality I autocross this car and I could do very well with even 180hp.

If I go higher compression, let's say 10:1 or even 11.5:1 with same bore size with 274 maybe 288 cams, what else would I need to replace? Can I just switch out the pistons with JE pistons and I am good to go? When it comes to suspension I can do it but this whole engine modifying is new to me.

As for the turbo kit, the only 318is turbo kit I have seen was TDI's and I have heard bad things about them Have any suggestions for a turbo kit? Anyone able to put a kit together for me and I could have Turner Motorsport or Schenller in the US install it for me? Thanks.

[Demlotcrew]

I was told that the M50B25 pistons can go right in and will give the higher compression you are looking for. Might be a little less than buying JE

Andrew

[lukeb]

have you considered a engine conversion, putting in a 2.5 or 2.7 or even a 3.5 which is 220bhp standard. then some of the work you described you should be able to see the 200bhp mark.

[Motorhole]

Sod the chip! For that sort of power gain whilst remaining N/A you need programmable engine management. Cheapest is Megasquirt (About $400 US I think, but worth checking). It will need wiring up with all the necessary sensors.

Individual throttle bodies will give you better response and more power, and if using a megasquirt needing a throttle potentieometer anyway, might aswell have a go. Proper TB's are expensive, but superbike ones will do the job with a custome inlet manifold. Should get a set of GSXR Motorbike throttle bodies from a suitable breaker for less than $150. Make yourself a custom airbox. It will look and sound the dogs!

Then you sort yourself out with a de-cat exhaust. If your taking the block apart, you might aswell raise the CR with forged pistons if you want (Although i don't know if the 2.5i ones will fit as mentioned...HUGE saving if they do!), hot cams, vernier pulleys, touch of headwork (Again, I don't know if this is worth the effor on an M42, someone else here will know!) and uprated fuel pump, larger injectors. Get it mapped, you should see good gains, but still, 200bhp would be pushing it!! Don't see why 180bhp wouldn't be achievable though. If your willing to get your hands dirty and network properly, it should all come in for around $2-3K

[Jon_Bmw]

You need to speak to "tims" or search for some threads by him. He is in the process of building a 318is with throttle bodies and eventually making it a 2.1 litre or something like that. He seems very knowledgable on the m42 engine.

Failing all that I would turbo it, but i'm a little bias.

[alex318is]

"have you considered a engine conversion, putting in a 2.5 or 2.7 or even a 3.5 which is 220bhp standard. then some of the work you described you should be able to see the 200bhp mark."

i have been pondering this for far too long. the only problem with this is how much it costs. in the states for all the necessary parts and labor work done by my bmw e30 god mechanic would run me nearly $5000 in which just buying a 93 325i or is is cheaper.

I love turbo but the problem remains the cost, where a kit is available, and getting it installed. If I did such a thing I would run low boost, around 8-10 psi.

I have spent too much on suspension, redid everything brand new parts, aluminum m3 control arms, 5 lug conversion, billstein custom valved shocks, ground control coil over conversion, ground control custom coiled springs (800 lbs in the rear oh yes), suspension technique bar in the fron and H&R in the rear, urethane bushings to boot, aluminum everything, the list is long but you will have an idea of how much I spent on it. The car outhandles 2002tii's and I consider those to be the best handling BMW ever created. I just need a cheaper solution to getting some quick horsepower so I can compete with my brother m3's on the autocross course. I have a DAMN good mechanic who specializes on e30's but for quality comes a price in labor. keep the suggestions coming, helping me tons! (my mechanic loves a good challenge so any idea is appreciated).

[powerone]

Dont think so much about overall power, if your going to track the car keep it the way it is, bore the throttle body and match the inlet ports to the head.
use a decent chip and keep the torque nice and flat with a big midrange power band.
this will make the car very quick through a wide range of rpm.

this will be perfect for what your after,