Author Topic: Best improvements for emissions-sensitive DD (Read 3410 times)

JHZR2 · « **on:** December 18, 2007, 12:12:25 PM »

Hello,

Ive seen many folks with nice writeups on buildups that they have done to their M42 engines. Mine is similar to some European folks, in that I have to be very emissions critical. Additionally, I do not have a heated garage, and my garage is filled with my MB diesels (w123 chassis), to protect them from rust so that I can get 500k miles out of them.

Anyway, Ive seen the Metric mechanic engines, and my mind started to wander... sure would be nice to increase the pep of my M42 beyond the Dinan chip it has in it... while ensuring longevity and emissions.

Since I don't have a real workshop or devoted garage bay at my home to do anything major (nor do i have the know-how to do an engine pull, etc.), I am curious what the basic things are that I could potentially do as day-type jobs to improve overall power.

If you say there is nothing, that is OK. Ultimately, I might consider buying a MM engine, or having similar work done on mine. Preferably Id pay an expert for their time, and be able to take time off and watch and learn as it is all done, so I can learn. However, it would be nice to know my options. If Dinan claims 145hp (IIRC), so Ill assume that my 91 318i puts out maybe 140hp right now. If I could get to between 160-175, I think Id be happy...

If I went with an MM engine, I would likely have to choose the 210HP NA M42

Any comments or insight?

Many thanks!

JMH

DaveM-sport · « **Reply #1 on:** December 18, 2007, 12:36:25 PM »

180BHP will require a fair amount of work on the M42 to be honest, but it's achieveable
ITBs,
Lightened flywheel,
Head-work,
And management to run it.

160+bhp can be achieved with a good chip, head-skim, lightened flywheel and maybe remove the heater plate, custom airbox and electric fan.

Febi Guibo · « **Reply #2 on:** December 18, 2007, 01:06:24 PM »

emissions-wise, where are you located? california?

I agree with dave above... and would recommend trying the Mark D chip also... emissions wise, you can put the stock chip back in when you go for your inspection (or so I've read, haha)

JHZR2 · « **Reply #3 on:** December 18, 2007, 01:56:13 PM »

NJ, my car gets a dyno test since it doesnt have OBD-II. Failed last time until I replaced the cat with a new OE one... so this tells me that Ive not much wiggle room.

On OBDII cars, if theyre running without a CEL, youre done and out of the station, passed. With an OBDI car, you have to really prove youre clean...

JMH

Febi Guibo · « **Reply #4 on:** December 19, 2007, 08:05:22 AM »

Wow, I had no idea NJ was so strict about emissions...

I have a MM built M42... if you can get out to Long Island, yer welcome to take it for a spin.

The lightened flywheel and electric fan are nice upgrades.

How old is your O2 sensor, btw?

JHZR2 · « **Reply #5 on:** December 19, 2007, 03:38:24 PM »

I might take you up on that sometime, thanks!

O2 sensor was replaced in 03 or 04, have to look at my records... about 15-20k ago, and I used an OE bosch, no retrofits or soldering of harnesses, etc...

Thanks,

JMH