Date: Wed, 24 Oct 2001 11:06:57 EDT

Subject: Re: Pushing the N/A engine

>What can I do to the NF engine in my '89 90q. I know, I know, swap for a turbo. Well...assume for now that it's not an option (I have).

WHY?? Ohh, more on this later ;)

>What are my options here?

On the street? Not much, you only have a few options if you are ruling out a turbo swap or going to the 20v head.

-Flow- A cam will help, as will port matching the manifolds and polishing the ports in the head on in the intake manifold, but you already have the big valve head. A good exhaust is a must, the stock manifold is pretty good, a small improvment can be had with the triple outlet manifold from the 4kq. Not much you can do on the intake side, you could bore the throttle body for some high end increase, but not much. As long as you are sucking throught that CIS metering head you are limited. I would estimate a really hot motor with a well executed porting job, cam, throttle body, free flowing exh manifold/system would loose some bottom end power, but could probably make 150hp at 6k RPM, a 20hp increase over the stock 2.3 NG/NF output. Still not a fast car, but might pick of a second or so in 0-60. Cost to do all this, probably $1k to1.5K after the head rebuild, etc, pretty expensive for 20hp IMO.

-Displacement- Using the Eurovan 95.5mm stroker crank, you could create some additional displacement, about 2.5l or so. Add this to the upgrades above, and IME you could have about 170hp, with much more torque to boot. This would be a real stump puller, super long stroke, you would loose some high RPM performance and smoothness, but have a great bottom end. This one starts getting expensive, after machining, custom rods, stroker crank etc, you could easily have another $2000 into it. Of course, this stuff always starts adding up, well, now that you're in there, the clutch, etc, etc. So, after these two areas of modification, you could have a quick, peppy car, very tourqey, with good all around power, for about $3.5k-$4k (probably a lot more), a 50 hp increase.

Remember, the 1994 BMW 325i came with 190hp and variable valve timing. Those are not considered "FAST" cars, and you would be lucky to keep up with one of those, and you can pick one up in great condition in the low teens these days.

My recommendation is to do a turbo conversion, simply by swapping in an MC motor into your car, but keeping your stock fuel and ignition system, you can safely run 8psi boost which equates to about 180hp too, with a lot of torque, especially if you used a K24, turbo lag would be non-existent. This swap could easily be done for under $1k, get a junk yard motor and replace the seals and headgasket. Very hard to beat, without all the wiring and fuel system swap you have to worry about with a full MC conversion. I ran my 80q like this with a similar conversion for over 30k miles, performed very well and reliably, and I have assisted others in doing similar conversions with similarily great results.

Javad Shadzi

80tq.com