More power- FI or 2.5?

[petone 0]

We all know tha the stock 318i is pretty dam slow, I've had mine for 2.5 years and really want more grunt. I've started researching a turbo setup and was all set to start aquiring all the bits I needed. (Turbo, injectors, sensors, blah blah) The only thing I hadn't decided on was ECU. Either Link, RRFPR with BTM, or one of the DIY options like MegaSquirt or VEMS. I'd also need to sort out the manifold.

Anyway, I've just picked up a M20B25 longblock with intake manifold, alternator, TB etc. Only missing loom, ECU, exhaust manifold. But there is currently a loom, ECU, AFM etc on Trade Me which would be perfect. I also have a Getrag 260 5spd gearbox. So the only things I'd need to track down would a radiator, oil cooler, and driveshaft. I'd keep my 3.91 Diff

Question is: Do I scrap turbo idea and go with 2.5 conversion? I reckon it would cost me another $500 buy the time I'd bought all the extra bits and pieces, but it would be a full factory conversion and more reliable not to mention heaps easier. But its heavy and only good for 170hp. I've also helped out with a 2.5 conversion so I know whats involved.

Or, sell all my current bits to help fund turbo parts and just go with that like I planned? The would require way more work and will cost lots more but it would be an awesome project. It would be lighter and I was hoping to make around 200hp at the crank without too much trouble. I could even go to a 2L M10 block as the crank is forged. Also this could be done in stages as funds allowed. Not too mention a Turbo 1.8 M10 would be badass.

Ideas welcomed

PS a Turbo 2.5 is not going to happen

PSS- Suspension will be all sorted by time this goes ahead. Brakes are all ready upgraded.

Edited November 9, 2005 by petone

[E30-323ti 66]

I'd go the M10 Turbo!!!

Boost your stocker gently while building up a 2.0l boost junkie

Go for a Link, cheap & lots of local tuning support.

[Carl 3]

You don't need the oil cooler Mike, most of the 325 guys i've seen have removed them for the weight gains.

[conrod 1]

2.5 is the conversion for not a lot of money, go the turbo if you want unlimited grunt-is gonna cost you though! A friend of mine has a 2.? M10 turbo in a 2002 racecar, putting out around 500hp and over 400lbs.ft of torque(no bull!)

[Guest Andrew]

2.5 is the conversion for not a lot of money, go the turbo if you want unlimited grunt-is gonna cost you though! A friend of mine has a 2.? M10 turbo in a 2002 racecar, putting out around 500hp and over 400lbs.ft of torque(no bull!)

delmont's car? damn - didn't realise it was that powerful!

[Gus 5]

turbo m10 would be awesome...but i dont really see how it would be any cheaper than 2.5???

do it...its totally badass....not many people have one yet!

[cainchapman 0]

You're being conservative Conrad.

Mike's M10 is legendary!

[conrod 1]

delmont's car? damn - didn't realise it was that powerful!

Bear in mind it has taken over 10 years of development and much money spent to get here, but yes, it really does make those sort of numbers.

[petone 0]

Gus- 2.5 conver will be way cheaper than Turbo M10, engine managment alone will cost more than 2.5L. (Unless I just use a RRFPR and lightly boost it)

If I was to go Turbo M10 then common sense says to go with Link as it is tried and true but it would sort of take the fun out of it, if you know what I mean. I need to have a chat with andrew about his Link.

I might just rock the 2.5 for a year while I get all the bits I need, as theres no way I'll get anything done on Turbo for the three months I'm home. At least I know I can get a 2.5 sorted in that time. I'd rather not wait another year for more grunt. That gives me plenty of time to work out exactly what I'll need and wait for bargains to come along.

Anyway what else have I forgoten that I'll need if I convert to 2.5? Engine is out of E34 BTW

I have (If I get that stuff on trademe): longblock engine, 6 cyl box, 2x (TB and intake mani), ECU, Loom, AFM, and a spare M20B20 long block engine with all the bits attached. (Good for oil pan, mounts etc)

The main thing I need is radiator as Driveshaft could be shortened. The 2.5 longblock is also missing the dizzy but I assume they wont be too difficult to come across. I also have to check whether I got a clutch or not.

Questions- Oil pans, are E30/E34 different? If they are will one from a 320i work ok?

Exhaust manifold- will 2.0L mani work ok on a 2.5L or are they too small?

I'd really like to Turbo but it wouldnt be possible for ages, also a 2.5 conversion is much more likely to actually happen.

Wow, turned out quite long post

ps That 2002 sounds awesome, is it a targa or track car?

[bmwsparkle 3]

i rkn a turbo M10 would be awesome, ive always wanted to do up an M10, just keep it stock till u can afford the turbo, thus, keep on saving money with ur tiny fuel bill

[petone 0]

Haha yeah changed my mind again. Turbo M10 is calling. I'll sell off my M20B25, and slowly start sorting out turbo bits. Its gonna be a waste of cash putting 2.5 in then going back to M10. Check TradeMe or For Sale section soon for longblock 2.5 In the mean time I just have a slow but cheap ride.

Besides M10 Turbo was a clear winner... Watch this space.

[Guest Andrew]

will be a cool proj