E30 Newbie, what car is right for you?

[TopOfTheLine89]

you could pick up an eta for cheap, throw on an I head which would lower your Compression ration to 8:1 or even lower which would be suitable for boost.

[yberther]

so the super eta would be a good proponent for boost...
but it still has less power than a normal i.

[vr2jetta]

Just the forum I was looking for! I myself will be looking for an e30 to start as a project soon too, but have a lot of the same questions. I have done a couple hours of research and I think I am ready to ask some questions myself. I dont mean to hijack this thread but I though this would be the best place to post. From what I have seen the best looking e30 (as far as the #'s go) would be a 90-91 325i. It baselines at 168 hp and 164 ft lbs of torque, with a curb weight of 2811, about 4-100 lbs lighter than the other 325's. That appears to be the best starting power to weight ratio. Throughout my searching, I noticed that the M3's were 4 cyl powered. Why is that? Is the M3 motor the same as the 318's, just higher performance parts, or is a completely different design? Why would someone search after a less powerful 4 cyl 318 vs. a 6 cyl 325? I would like to know the strengths and weaknesses of both motors in order to start with the right platform. I have been driving MK2 VW's (85-92 golfs and jettas) for years and I know what motor is best...... in my opinion. I have always loved the styling of the e30's for years but now I am just getting the nuts to buy one, but I don't want to waste my money and buy something I am going to be dissatisfied with. Any information and opinions will be greatly appreciated! Thanks in advance!

[Farbin Kaiber]

The 318i has an m10 engine, 1.8l displacement, the 318iS has an m42 1.8l engine, and the m3 has an s14 2.3l engine. there is more to it here...

http://r3vlimited.com/tech/models/models.htm

Third chart down.

[JasonC]

Sounds like you just need to look for a 325i or 325iS.

[Jordan325iC]

Just the forum I was looking for! I myself will be looking for an e30 to start as a project soon too, but have a lot of the same questions. I have done a couple hours of research and I think I am ready to ask some questions myself. I dont mean to hijack this thread but I though this would be the best place to post. From what I have seen the best looking e30 (as far as the #'s go) would be a 90-91 325i. It baselines at 168 hp and 164 ft lbs of torque, with a curb weight of 2811, about 4-100 lbs lighter than the other 325's. That appears to be the best starting power to weight ratio. Throughout my searching, I noticed that the M3's were 4 cyl powered. Why is that? Is the M3 motor the same as the 318's, just higher performance parts, or is a completely different design? Why would someone search after a less powerful 4 cyl 318 vs. a 6 cyl 325? I would like to know the strengths and weaknesses of both motors in order to start with the right platform. I have been driving MK2 VW's (85-92 golfs and jettas) for years and I know what motor is best...... in my opinion. I have always loved the styling of the e30's for years but now I am just getting the nuts to buy one, but I don't want to waste my money and buy something I am going to be dissatisfied with. Any information and opinions will be greatly appreciated! Thanks in advance!

90-91 325i/325is's are not 100lbs lighter than other 325s. All 6 cylinder e30s approximately the same weight (excluding convertibles, those are 200lbs heavier). The advantage of the 89-91 325i/s's is the smaller plastic bumpers, which most people believe are more aesthetically pleasing.

BMW had various reasons for going with a 4 cylinder as opposed to a 6 cylinder. Wikipedia would probably tell you more.

There were 3 different 4 cylinder engines put into the e30 chassis, so it's important you specify which one you're talking about. (US models).

1984-1985 318i : 1.8L 4 cylinder engine, M10 engine, 105hp/105tq
1990-1991 318i/318is : 1.8L 4 cylinder, M42 engine, 136hp/125tq
1988-1991 M3 : 2.3L 4 cylinder, S14 engine, 200hp/177tq

The early 318's are not well loved. The engine is the least powerful of any US e30 and not remarkable in any category.

The late 318's are well loved. They all have the small bumpers, they are fairly peppy and they are very rev-happy. Plus, great fuel economy. Also known as the poor man's M3.

The M3 S14 is loosely based on the M10, but it's a completely different beast. High revving, finicky, peaky, but amazing. You are probably not going to buy an e30 M3 as a your first e30, mostly because they are about 5x (no exaggeration) as expensive as a non-M e30 of similar condition. They are niche collector's cars, for those with an e30 fetish. The M3 itself is a significantly different car than the standard e30. Just look at pictures of the two and you will see obvious differences. The M3 has completely different bodywork all around (only shares hood), 5 lug suspension, bigger wheels, etc...


Somebody would choose a late model 318 over a 325i for several reasons:
Lighter
Better fuel economy
Newer engine requires less maintenance (no timing belt)
Only down ~30hp


The "s" at the end of an e30 model name indicates that the car (probably) has sport seats (awesome), LSD (awesome), slightly more aggressive bodywork (front and rear spoiler), and basketweave wheels, plus a few other little things. The LSD and sport seats are what really make it better than your standard non-s model (though those things were both factory options).

[rThor432]

Newer engine requires less maintenance (no timing belt)

Well I wouldnt go that far.. I'd rather change a timing belt than remove the head just to get at a failed profile gasket.

The '89 325is seems to be the most loved car, in general. No airbags and it has plastic bumpers.

In my opinion, the '87 325es is the best starting point. It will readily accept Euro bumpers, has the big sway bars, factory Bilsteins, great gas mileage, TORQUE, and they are hard to kill. You can also throw a 731 or 885 casting head at it to make a hot little street stroker for just a little money.

[vr2jetta]

This is exactly why I wanted to post my questions here. You guys have been there, and I just want a few opinions to make a more educated decision. I got some specs of the e30's from http://e30world.com/specifications/BMW-E30-specs-table.
I am not sure how accurate the tables are but that is what came up on Google search. So I am guessing the M3 motor is a completely different animal than the sohc and dohc M10 and M42. I am well aware of the price difference between a M3 and standard e30, and some of the visual differences (flared fenders are sick!!) It just seemed funny that the "badass" came with a 4 cyl when the standard came with a 6. I am starting to understand better now. So what is the advantage of owning a m20 b27 with less hp over the m20 b25 with almost 40 more hp and only 3-4 less ft lbs of torque? Is it just what I want to do with the car? (ie, turbo-super-N/A)? I really appreciate all the input I am getting from you guys! This is helping a lot!

[EN318isPDX]

M42 318is and 318i are IMO the best overall E30 design. Its called the poor mans M3. Its lightweight and peppy compared to the nose heavy 325s. It has self adjusting valves, no moving parts in the ignition. The timing chain last 200k+ instead of 30k or w/e the timing belt lasts in the M20.

All E30's have the same basic issues, driveshaft's guibo needs to be inspected, clutch and sensors should normally be replaced depending on miles.

If your interested in the M42 you should check out http://www.m42club.com/

Oh ya i forgot to mention you can get 30+ mpg in an M42 E30

[vr2jetta]

What about performance parts for either motor? Are parts cheaper/more readily available for either motor? My motto is start with the most powerful motor available and go up from there. I like where you are going with that though! Lighter, nimbler vs. front heavy sled. I guess it all depends on the application. I greatly appreciate all the helpful information you guys have given me and feel free to add another opinion why you think something else is better. I will be on doing more research and I am sure this thread will help me and the other guy who actually posted this thread!

[rThor432]

only 3-4 less ft lbs of torque?

Guess again. There is a big difference in torque. Eta's are super efficient and that's what is good about them.

You can supercharge the M42. It will be as fast as an E36 M3.

[vr2jetta]

Well, about 6 ft. lbs of torque difference between the b27 and b25. Keep in mind I am going off of the specs I found at

http://e30world.com/specifications/BMW-E30-specs-table

This is what I am basing my numbers on. If these specs are incorrect please let me know and lead me to a more reputable and accurate source. I think this forum (and everybodys input) has all ready been a ton of help in choosing what platform for me to start with. I have also noticed alot of you guys own VW's too, is there going to be a significant price increase on parts when I make the step up from vw to bmw? I do ALL my own work (with exception to machine work and alignments) on my cars and was wondering if general upkeep and repairs are going to kill me? I am used to VR6's when it comes to VW's.....hence the name VR2jetta. I almost always go to the local foreign auto parts store to get replacement parts, because they tend to be of more quality than what you would get from advance or auto zone.

[rThor432]

If these specs are incorrect please let me know and lead me to a more reputable and accurate source.

I used to know all of the X lb/ft @ X rpm specs, but I stopped caring about baseline numbers. My right foot tells me that the b27e has about 30 lb/ft over the b25i. You can general search around the forum to find the numbers. Once you start modifying the car those stock numbers go in the garbage.

Oh, and if since are coming from VW's, you are in for a treat (if you do your own services). BMW's are so much more serviceable than VW's. Most VW's from the 80's and earlier are good, but anything really early-mid 90's and later sucks ass to work on. Parts are cheap if you use the right sources.

[Igor325]

That appears to be the best starting power to weight ratio. Throughout my searching, I noticed that the M3's were 4 cyl powered. Why is that? Is the M3 motor the same as the 318's, just higher performance parts, or is a completely different design?

It's a different motor. e30 m3 has a four cylinder S14 motor which is 'detuned street version' of race motor. It's a fun motor but it needs frequent tuning/adjustment to run right

Why would someone search after a less powerful 4 cyl 318 vs. a 6 cyl 325? I would like to know the strengths and weaknesses of both motors in order to start with the right platform.

people like for cylinder versions for different reasons - fuel economy, some swear that 4 banger is more balanced car, etc.

This is exactly why I wanted to post my questions here. You guys have been there, and I just want a few opinions to make a more educated decision. I got some specs of the e30's from http://e30world.com/specifications/BMW-E30-specs-table.
I am not sure how accurate the tables are...

Those performance numbers are accurate. You mentioned torque numbers +/- 6 lbs.-ft , but note that they are in different power band (look at the RPMs)

So what is the advantage of owning a m20 b27 with less hp over the m20 b25 with almost 40 more hp and only 3-4 less ft lbs of torque? Is it just what I want to do with the car? (ie, turbo-super-N/A)?

m20b27 or "eta" engine cars get decent gas millage. Both eta and m20B25 are interference motors and have to have timing belt replaced regularly - see m20 timing belt replacement procedure for DIY steps.

I am not sure what do you want to do with your e30 - turbo, supercharger, or some 'smaller' mods... I'll take unpopular approach and tell you that it's probably not worthed ($ / power gain), although it can be a fun project. Best buck per power is to get a chip (JC, D sylva), and perhaps diff for eta (3.64). Suspension upgrades are different and worthed if done right.

If you really want e30 with some 'umphhh' you would be better of (IMO) swapping M5x / S5x engine in it. It's a lot of work, but a lot of people have done it and it is well documented. That will give you more bang for your buck.

If you are bent on modding M20 and want fun project, say turbo a M20, I would start with eta engine and go from there...

[vr2jetta]

If you really want e30 with some 'umphhh' you would be better of (IMO) swapping M5x / S5x engine in it. It's a lot of work, but a lot of people have done it and it is well documented. That will give you more bang for your buck.

I am not new to motor swapping, I have done a few vr swaps into vw's so that is not an issue for me, but what scares me is the price of the parts to do the swap. I guess spending a lot up front instead of dumping numerous small amounts into the car would be better if the end result is the same or better (not to mention cooler!). I did see an old 2002 with an inline 6 m3 motor in it and it was sick!