Matt's 1989 Turbo 328iS



I was first introduced to BMW’s by a few friends, who both had e30s. I was hooked after my first ride, and still remember exactly how I felt back then. 2 months later, after checking autotrader, ebay, and the forums everyday, I finally found my car. It was an 89 BMW 325i, 2 door, lachssilber metallic with 171,xxx miles. I would be the 3rd owner, the previous only had it for a year, and the original owner had it maintained at the dealership, and kept all records. Almost everything on it was stock, I eventually found out it had upgraded sway bars, Bilstein HD shocks and Yokohama AVS-I tires. I was pumped, I had finally found a car that was in excellent condition, had very few modifications, and still had a reasonably strong engine. I test drove it, and bought the car on July 6 th for $4500.

My Progess:

This started the beginning of something that I got hooked on, like many e30 owners, these cars consume our lives. I found myself draining paycheck after paycheck on my car, upgrading bits at a time, as I could afford. Suspension came first, and then wheels; these contributed most to the looks of the car, and made it stand out in the crowd. After entering a car show, and talking to a local e30 M3 owner, I decided I needed more power. August of 2002, I started looking at engine modifications that would give me some decent power. I looked at boring and stroking to 2.9 or 3.0 liters or the more drastic m50 conversion, but decided to do something a little "different." I finally decided to make a stroker 2.8l turbo out of the m20b25 engine. I bought all of the parts, and started tearing down the engine. This was my first experience with engine rebuilding, and taught me as I went. When finished, I broke the engine in for about 5 months, and researched exactly what I needed to do to turbocharge it.

Turbocharging turned out to be tougher that I expected. I first used the stock engine management coupled with 19lb/hr injectors see what I got myself into. After a couple months driving like that, I finished building and assembling my Megasquirt engine management system, and immediately installed it. It took about a week for me to get it running well enough to take it to a shop with a dynamometer, so I could finally tune it. The first time on the dyno, I had issues with my stock clutch. It did not like the 272 ft-lbs of torque it was receiving, and slipped badly. I went home and ordered a Centerforce dual friction clutch, and installed it. The next time on the dyno, I had issues with a crankcase vent I had fabbed up the night before, and was smoking oil badly, and had to cancel the session. Lucky number 3 had finally given me some positive numbers for my labor. It put out 267hp, and 271 ft-lbs of torque at the wheels. I could not run higher than 12psi due to exhaust backpressure; the 2.5” exhaust was too small. I was ecstatic, I finally had a tuned car that was still reliable at the same time. But not for long.

After being turbocharged for almost a year, my catalytic converter finally bit the dust. It was causing a lot of back pressure in my exhaust system, so I decided to upgrade the exhaust to a 3” setup. I bought a few mandrel bends, and about 8 feet of straight pipe, and started welding away. I had a great time doing it, and took about a day. Once done, I took it for a drive, and instantly ran into a problem. My turbo was putting out 21psi, and the power my engine put out, was unbelievable. However, this wasn’t as great as I thought it would be. I blew my head gasket after a few runs, it was a straight blow out the front of the head, no coolant involved fortunately. So, I ordered a new head gasket, and bolts, and took her a part. The “overboost” situation was caused by the lack of exhaust flow around the turbo, which was due to the wastegate attachment being too small. When the head was off, I custom fabricated 2 tubes that drew from both of the collectors on the exhaust manifold adapter. This way, it would flow a lot more exhaust around the turbo, and keep the boost under control.

After that was out of the way, the next week I was driving, and started to overheat. I found out my front crank pulley for the water pump had cracked, and the belt had fallen off. I waited for it to cool down, and had a friend get a new belt. About 5 minutes later, I was at 12psi, and all I could see behind me was white smoke, my engine was engulfed with coolant smoke. I blew the head gasket again. This time I was frustrated, having blown it not a week before. This time it was due to a few factors. One being that I had too much cylinder pressure for the gasket to hold, so it “pushed” out. The second being the head bolts may have stretched due to the overheating, or the cylinder pressure, it’s hard to know which. I rebuilt again, and didn’t drive it for about 3 months, because I chose not to bring it to college with me. When I had a chance, I upgraded the head bolts with Metric Blue grade 12.9 bolts. I feel this will cure a few problems with blowing my engine.

In the future, I plan on modifying my car even more. With this new power, I have found I need more traction, so beefy tires are a must. I’m still unsure what wheels/tire combo I will go with, but it will be over 8” wide for sure. I am also planning on upgrading my suspension again, with coil-overs, and urethane bushings all around. I will also upgrade my Megasquirt so it will control a 3 coil EDIS based ignition system. Currently the car is putting out more than 300whp, and will get it on the dyno as soon as I have time. As time and money allow, it will be even faster, and better than it is now. I am proud of my car, and I hope it has influenced people to take pride in their work, and modify their cars as they please.


Known Performance: (as of 02/16/05 )

Power: 267 whp, 271 wtq at 12psi

1/4 mile: n/a

0-60mph: ~4.5 seconds

Top speed: Unknown.

Engine: 2.8l 2754cc turbocharged and intercooler inline 6 cylinder, Single overhead cam, 12 valve, Megasquirt engine management.

First Dyno (clutch failure) Graph vs. Stock





Engine Modifications:

2.8l Turbo Engine:

524TD crankshaft

Bored to 85mm

2.05mm head gasket

Ross Racing 85mm low compression pistons

Crome-moly wrist pins

All new bearings/bushings/gaskets

Garrett T04E turbo (.50a/r compressor, .68 a/r turbine)

Turbonetics 35mm deltagate wastegate

Blitz dual drive blow-off valve

32lb/hr Accel injectors

IE adjustable fuel pressure regulator

Modified Starion intercooler with 2.5" pipes

Custom 2.5" intercooler tubing

Proturbo exhaust manifold adapter with custom wastegate adapter

3" mandrel bent exhaust with Magnaflow muffler

Custom manual boost controller

Bosch W5DC spark plugs

Cone air filter

Walbro 255l/hr fuel pump


Drivetrain Modifications:

z4 short shift kit

Clutch stop

13lb flywheel

Centerforce Dual Friction Clutch

Electronics/Engine Management:

Megasquirt standalone fuel computer

Autometer A/F ratio gauge

Autometer oil pressure gauge

Autometer fuel pressure gauge

Autometer boost gauge

MSD 6-BTM ignition control

MSD Blaster2 coil


Kopi Alpina wheels (17x7.5)

Kumho 215/40-17 tires

Stock bottlecap wheels painted gunmetal

205/60-14” Yokohama AVS-I tires

“is” front lip-spoiler

Painted valences/rocker panels

Painted mirrors

Cut front valence for intercooler flow

Rolled fenders

ACS style racing seats

Euro rear license plate filler

Euro rear fog lights

Smoked turn signals and sidemarkers

Smoked tail lights

Blaupunkt Hamburg head unit

Phoenix gold QX300.4 amplifier

Infinity reference front component speakers

Infinity Reference rear 5.25"


H&R Cup Kit suspension (with thicker rear spring pads)

21/16mm swaybars

Ireland engineering strut tower bar



Stock replacement rotors

Stock replacement pads












Other modifications:

Removed P/S

Removed A/C

Removed undercoating on rocker panels and rear valence



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