reliability/maintenance of FI 325 vs. NA M3

[imetis]

I'm curious what people have seen with regard to maintenance costs and reliability after supercharging, compared to normal maintenance costs on an M3. It seems that the price differential to add a supercharger or sell my car and buy an M3 are pretty similar (5-10k), and the resulting power would be similar, maybe a little better for the M3, but I like my 4 doors and bike rack.

My previous platform was the Dodge Stealth, and I started with a NA ATX, that ran great and was cheap to maintain. I sold that for a TT 6MT, and it was a money pit. I'm afraid of making a similar transition with the E46, and am thinking FI might be the better (most cost effective) way to get to the 300+ HP range.

Thoughts?

[BoostedBlack330]

First off you would have way more power with the N/a M3 than a supercharged 325i, plus you have to try and maintain a S/c alot more than a stock engine, if anything DEF get the M3!!! But my choice would be save for a 335i and chip it and put on a turbo back exhaust when they finally come out :4ngie: :thumbsup:

[imetis]

Yeah, that's what I'm thinking too. I really like FI, and the 335 is not tuned to the limit like the M3 is.

Interesting that you think a SC 325 would be higher maintenance than an M3. I suppose that could be right. I've never seen a modded car that didn't need constant work. It is a slippery slope...

[malina]

Difference in HP/TQ between SCed e46325 & e46M3 isn't that big

http://www.dragtimes.com/2004-BMW-M3-Dyno-Results-Graphs-10186.html

e46325 Dyno (http://stoph2o.us/video/DynoJets.jpg)

Maintenance costs are the same as for a stock one + SC belt every 5K miles, oil change no later that 5K miles. Driving hard will cost you extra $, of course.

[Nico3k]

A supercharged 325 will not have more maintenance issues than an M3. Besides doing a few more oil changes and swapping the belt (I doubt its every 5000 miles) there isn't anything that makes it less reliable. It's all about tuning/engineering; if the SC hardware and software is designed to keep the engine/drivetrain within stock healthy specs then no problem.
With that said I would probably feel more comfortable bouncing an M3 off the rev limiter for a minute than a 325 @10psi. Your driving style is a factor in reliability and if you are planning to mash your gas to the floor every second you are in your 325 then I would go with an M3. If you are just looking to get some extra (significant) power in the 4door then go with the supercharger.

My daily driver is a 325i track car and I have been keeping good tabs on everything that goes out. So far the engine is bulletproof, with minor failure of misc rubber parts of the suspension/drivetrain. I am just waiting on a good (better) deal on a supercharger and then it's back to the track to see what fails next.

[elite53]

M3's require valve adjustments every 60,000 miles and Mike Miller of Bimmer Magazine says it should be more like every 30,000 miles. While I don't have any idea how much the dealer charges for this service....I'm certain it ain't cheap. Meanwhile a 325i has hydrolic lifters that adjust themselves.

The insurance on an M3 would almost certainly be more than what you pay now.

[bigjae1976]

The insurance on an M3 would almost certainly be more than what you pay now.

I know its not a 325i...but that reason alone is why I got my 330Ci over an M3. Not to mention that it has been my family car so far.

Once you get the SC on and working right, I haven't seen any additional maintenance issues. If you have an auto, I would change out the tranny fluid more often.

[beanfree]

Spoke to Zolti at Technik E. and he said that the belts need to be replaced when they show signs of deterioration (cracks, frayed edges etc.). He doubted that it would be every 5000 miles. He seemed to believe that the supercharger could not possible reduce the life of the belt that much. Said there was no magic number. So I will check the belt every 5k miles till 15k and then every 2k miles till it needs to be changed. He said to make sure the oil was in good shape. So check that frequently, top off when needed and change when required. Other than that, he did not believe much maintenance needed to be done.

[Lemonsqr]

I agree with most everthing that has been said. I would like to add one thing though. The 325 will most definitely get better gas mileage than the M, and if you are 75% or so of the time driving mild and 25% of the time wild, a 325SCi would be my choice. On the other hand, if you are 75% wild and 25% mild, then the M would be your better bet. Maintanance-wise, if the 325SCi is tuned correctly, the M will definitely cost more both in parts and labor.

[Mike Benvo]

Hands down go with the M3. This isn't even a question.

[malina]

Hands down go with the M3. This isn't even a question.

Why is that?

[digitalinkartis]

My $02...
M3 is the wiser choice for the following reasons:
A) better performance (i.e. faster 0-60, faster 1/4 mile, Faster top end, LSD, 6 speed tranny, better performing OEM suspension, OEM front strut bar, Better OEM brake setup (etc)
B) High Revving NA motor with proven "track" record and less chance to overheat on a track or under hard driving conditions compared to fI e46.
C) Better Front Seats,
D) Motorsport pedigree which includes better resale(especially compared to a fi non m 325), recognized performance, status and better overall resale value retention.
E) Cast-iron engine block
F) Higher Top Speed potential
G) Higher redline

One other addition, It is my belief that the e46 m3 will actually be more reliable based on one fact... The addition of a supercharger to the non-m 325 is adding a considerable amount of components to the vehicle and therefore increasing the numerical odds of failure.