Lets see your Numbers!

[CrJdMc]

I have a 1987 325is ( with a m20 2.5L) and i am wanting to do some stuff, I already have a cold air intake, and a ghetto exhaust, which will be changed to headers to a borla muffler soon, but i was wandering if you could tell me what you have done to your car, and what rear wheel power you are pushing, thanks alot guys,

[CrJdMc]

bump?

[jlevie]

If you want performance from the car, replace the the CAI with the stock airbox. It is almost impossible to do better than the stock air box. The only low cost performance upgrades that will actually increase power on this motor are exhaust and a chip. After that you are into money. If I were going to chip an engine it would be with a WAR chip.

A race built engine, using the stock engine management system and stock engine internals, can make 160-165rwhp on a DynoJet. My Spec E30 made 162rwhp the last time I had it on the dyno. My DD has a freshly built built engine, but I didn't put quite as much attention to it in the build and it made 156rwhp on a DynoJet. The Spec E30 rules require everything to be OE or equal and porting & polishing is not permitted. The only thing the race engine has, which my DD doesn't, is a very free flow exhaust.

[CrJdMc]

ohh ok,
i was thinking,
-polished and ported heads,
-chip,
-eventually cam.
-light flywheel,
and clutch
will these be noticable?

[NigelStu]

Whats the consensus on stock paper air filter vs. K&N / Afe Pro5 / AFe Pro Dry / etc. drop-in filter? What flows the most air? Is there a paper brand (STP, AC Delco, Mann, etc) that is better than the rest? on par or better for flow than a foam/gauze panel?

(note - I am NOT talking about replacing the airbox, only the filter element)

[jlevie]

ohh ok,
i was thinking,
-polished and ported heads,
-chip,
-eventually cam.
-light flywheel,
and clutch
will these be noticable?

That would be noticeable. You might want to look at what the folks at Metric Mechanic have to say about porting/polishing a head. Porting works if done exactly right, but correctly roughened passages flow better. If you are going to port the head, do the cam at at the same time.

[kid325e]

^ Listen to that guy. He's a guru of sorts.

[CrJdMc]

That would be noticeable. You might want to look at what the folks at Metric Mechanic have to say about porting/polishing a head. Porting works if done exactly right, but correctly roughened passages flow better. If you are going to port the head, do the cam at at the same time.

Yes, my plan was to do both at the same time, how much power could i get with the list i made? could i see the 200-ish range?

[TurboJake]

how much power could i get with the list i made? could i see the 200-ish range?

More than likely, No.

To reach 200, you pretty much need:
Custom 10:1 pistions
135mm S50 rods
B2.7 crank 284/272 cam
Head Porting.
really well done exhaust
Megasquirt...

Reaching 200hp on an m20b25 with stock internals? Not really gonna happen.


Read up.

http://www.metricmechanic.com/pdf/M20-Engine-Booklet.pdf

[CrJdMc]

So would a swap be in my best interest if i wanted to see anything about 200whp?

[jlevie]

Yes, my plan was to do both at the same time, how much power could i get with the list i made? could i see the 200-ish range?

Not even close to that. As a guess, 170-180. To get 200ish you need an overbore to about 2900cc, custom pistons, a stroker crank, cam, tuned head, and a MegaSquirt or similar.

[TurboJake]

So would a swap be in my best interest if i wanted to see anything about 200whp?

Boost.

[Kvasi]

Boost.

[TurboJake]

Nah.

[Kvasi]

Nah.

You Americans.. Bigger isnt always better :)