[6BATMAN6]

i have a 335i that ive been considering a serious build on but over the passed few months ive been running into enouph problems just keeping the car afloat as most people with an n54. rn the car is in getting new turbos and hoping this is the last straw. i bought this car over an m3 becuase ive always been a turbo guy and really love that power this thing can make. but can i make more power safely on an m3?

im considering a build around 8k $ . 335i would consist of FBO (im already half way there) RB turbos, i already have kw v1s, and an LSD, plus a few minor cosmetic things.and cobb

if i went m3 i would just do an ess sc kit (most likely used on the forum) full exhaust, and swap over my KW's

my question is what is going to be less problematic

boosted m3? or worked out n54 ? any thoughts or experience would be great

[Subaru335i]

The N54 was meant to be turboed from the factory and the S65 was not...there was a lot of engineering that went into making the N54 a turbo engine.
The S65 is strong and people make good power with superchargers but they also have their own slew of issues (rod bearings) and will be more expensive to fix if something breaks.
The M3 is a great car for many other reasons but you already put KW's and an LSD in the 335i, that will be a solid setup with RB's.

[Subaru335i]

what problems have you been having with your 335 lately? The usual injectors, fuel pump, plugs, coil packs?

[Zach1328]

Originally Posted by Subaru335i

what problems have you been having with your 335 lately? The usual injectors, fuel pump, plugs, coil packs?

Yeah what issues? Both of my n54's have been phenomenal engines apart from burning through spark plugs. I've had one HPFP issue on my 535i, and they both need intake valve cleanings soon which I will DIY. Also my water pump went out at 51k on the 535i.

Apart from that they've been bullet proof engines. I think the 335i will be easier to maintain than a supercharged m3. Before I got my 535i a few years back I was in the market for an e90 m3. I asked my mechanic about the 335i vs m3 reliability and he told me they'd both be expensive to maintain, but he see's more M's in his shop than n54s.

[Myrder]

Originally Posted by Subaru335i

The N54 was meant to be turboed from the factory and the S65 was not...there was a lot of engineering that went into making the N54 a turbo engine.
The S65 is strong and people make good power with superchargers but they also have their own slew of issues (rod bearings) and will be more expensive to fix if something breaks.
The M3 is a great car for many other reasons but you already put KW's and an LSD in the 335i, that will be a solid setup with RB's.

Don't get me wrong. I like my N54, but I have not seem a huge amount of issues with the S65 even when boosted. Sure the N54 is bulletproof...but it can have fuel issues, water pump, turbos, the auto can't hold that much power, be familiar with changing plugs and coils, injectors...hell basically anything that isn't internal engine can fail on these cars. Also there are quite a few blown motor threads for the N54, most were running too much timing so there's that.

Anyway, if I had the money to do whatever, I would consider a Supercharged M3. Though now I would just go new M4

[Subaru335i]

Welll if you can afford the new M4 do that. The S55 looks like an awesome engine to make power because it is factory turbo. We will see how reliable they are though.
There are A LOT less supercharged M3's than there are modified N54s so your impression that boosted S65's are more reliable than N54 is probably not accurate.
If you search around you will see quite a few people with S65 bearing failures even all stock and never tracked.

[ajsalida]

Originally Posted by Myrder

Anyway, if I had the money to do whatever, I would consider a Supercharged M3. Though now I would just go new M4

This is the point. M4 has all the best high-end suspension brakes handling etc that you'd want from an M3, but also add the twin turbo power of a tweaked, updated, and massaged N54. Absurd HP/TQ numbers out of just a mild tune os far over on N54 tech...IN that sense the M4 is closer to an updated and improved 1M than an e9x M3.

IMHO neither the e9x M3 or N54 is ideal, you drop another 10-15k on them and they still have issues, might as well go for the M4 which combines the best of both approaches, with updated tech and....weight reduction.

Sure I say that but I can't afford one now and will be lucky to see RB's or a big single on my e92XI any time soon.

[Myrder]

Originally Posted by Subaru335i

Welll if you can afford the new M4 do that. The S55 looks like an awesome engine to make power because it is factory turbo. We will see how reliable they are though.
There are A LOT less supercharged M3's than there are modified N54s so your impression that boosted S65's are more reliable than N54 is probably not accurate.
If you search around you will see quite a few people with S65 bearing failures even all stock and never tracked.

So...because the S65 has bearing issues, which I'm familiar with, means it's less reliable than an N54? I'm just saying, if you look at failure rates in all the different moving parts...pretty sure the S65 would come out on top. There is a reason BMW had to add extended warranties to our HPFP and wastegates... oh I remembered a few other things the N54 has going for it, valve cover gasket leaks, gummed valves(walnut blasting), and your serpentine set up can hit your sub-frame causing some fun.

I like the N54, nice engine. I have no disillusions it is a rock solid, low maintenance, or never going to act up.

[6BATMAN6]

lol all the arguments everyone is having are the same that are going on in my head..and the problems ive had are plugs injector and rn my cars in the shop getting new turbos under warranty. but its been there for 10 days and they tried to give me the car back twice saying nothing was wrong and i was crazy, i had to bring it back with engine malfunction light on within 10 minutes each time smh. then this last time they told me the car is throwing that reduced power cel but not throwing any codes and they were really confused, next call was saying they were going to strip the turbos and have them inspected..ill def tell ya one thing if it comes back with new turbos and problem is still there im going to lemon this thing

[135Pats]

The S65 is actually a pretty damn reliable motor considering it revs out so much and is so light. The issues it does have can be substantial, but you don't see the same degree of peripheral failures as you do on the N54. The 54 i'd put forth as one of the most maintenance hungry motors out there, it's ALWAYS breaking, leaking, fraying, etc some pump/hose/line/solenoid/injector/coil/canister.

Neither are cheap motors to keep on the road, bottom line. Hey you could own an S85- now that is an expensive motor to keep happy. It'll happily remove $3K chunks from your bank account with frequency.

[6BATMAN6]

and yes ive seen a few things on the s65 bearing issues especially when pushed to the limit but im not sure what i would rather..that or having to worry about hpfp, my valve cover going again (just replaced that to forgot to mention) that cam ledge breaking, boost leaks urgh (20 lbs of boost starts to find any imperfection) ..i mean i guess its all so minor in comparison to having to strip a block down lol which im sure bmw made it dam near impossible to take the engine out of that m3 lol but ya idk so ill just watch everyone argue about it for a while lol

[litxus]

I'm not sure about supercharged M3 reliability, but stock it even made it to consumer reports list of recommended used cars if I remember correctly (not that I follow that list too much).

The question you should ask is if you are going to track it at all. If you are going to the track then I think hands down M3, but if street only there are more parts for 335i and they are cheaper too, plus you have half of the mods for 335i already.

[6BATMAN6]

Originally Posted by 135Pats

The S65 is actually a pretty damn reliable motor considering it revs out so much and is so light. The issues it does have can be substantial, but you don't see the same degree of peripheral failures as you do on the N54. The 54 i'd put forth as one of the most maintenance hungry motors out there, it's ALWAYS breaking, leaking, fraying, etc some pump/hose/line/solenoid/injector/coil/canister.

Neither are cheap motors to keep on the road, bottom line. Hey you could own an S85- now that is an expensive motor to keep happy. It'll happily remove $3K chunks from your bank account with frequency.

lol i would love an s85 if the m5 wasnt so dam ugly. hands down worst looking car bmw ever produced was the e60 m5.

and yes exactly i feel like its just always something with the n54 and i guess it all comes to if you want to spend 500 to 1000 bucks in your engine bay every couple months ..or a 10k dollar engine rebuild every couple years lol

[Pr335bob]

This is a great question. But if your going to mod a car at all I'd go for the cheapest. Why? Cause usually parts and maintenance would be cheaper. A m3 I'd leave stock and track it every time I could. A n54 I'd mod the shit out of it and drag a lot and track a little. The n54 has a lot of little nagging issues but it is solid if you don't go super crazy and are on top of it. I'd take the n54 because it's a smaller investment not much risk. The m3 is pricier and if something goes haywire it's going to hurt you pockets! Worst case u can always find a 335 motor or trans easier than an m.

[Pr335bob]

And good luck I envy you both are great cars to chose from!

[Zach1328]

Originally Posted by Myrder

Don't get me wrong. I like my N54, but I have not seem a huge amount of issues with the S65 even when boosted. Sure the N54 is bulletproof...but it can have fuel issues, water pump, turbos, the auto can't hold that much power, be familiar with changing plugs and coils, injectors...hell basically anything that isn't internal engine can fail on these cars. Also there are quite a few blown motor threads for the N54, most were running too much timing so there's that.

Anyway, if I had the money to do whatever, I would consider a Supercharged M3. Though now I would just go new M4

These are all issues a boosted s65 would have!
The DCT is actually not much stronger than the auto tranny in the 335i. A boosted s65 could easily have fuel issues. Water pumps are problematic in ALL BMW's - not just the n54. Also any car running high boost is going to eat up plugs, coils, and potentially injectors.
HPFP isn't a big issue considering the 10 year, 120,000 mile extended warranty. Its all about having a service rep who is ok with your car having a few mods on it.

Sure the turbo's can be problematic, but an aftermarket supercharger can be problematic just as easily. It really comes down to the luck of the draw IMO.

Main things for the n54 are going to be plugs, coils, injectors, and intake valve cleaning. Also, they commonly struggle with rough idles when modded. For example, right after I installed my JB4 I was getting cylinder 1 misfire. An easy diagnosis told me it was the spark plugs so changed those on my own very quickly and easily (~30 minute job). However, immediately after changing the plugs I have a rough idle but it runs like a beast over 800rpms and at WOT - no misfires anymore.

After modding a 335i its tough to keep it running at its prime, but with a little bit of patience and work its usually nothing serious. As I said, main things are going to be plugs, injectors, coils, HPFP, and intake valve cleaning.
Keep those up to date and you'll have a very happy n54!

[Eat.Sleep.Race]

everyone always runs such slow times with supercharged m3's though, it seems as if they make 550-650whp and run high to mid 11's with that kind of power. seems stupid to spend that to get 1 second off 1/4 mile times..

335 spend 6k and go mid 11's

[Myrder]

Originally Posted by Zach1328

These are all issues a boosted s65 would have!
The DCT is actually not much stronger than the auto tranny in the 335i. A boosted s65 could easily have fuel issues. Water pumps are problematic in ALL BMW's - not just the n54. Also any car running high boost is going to eat up plugs, coils, and potentially injectors.
HPFP isn't a big issue considering the 10 year, 120,000 mile extended warranty. Its all about having a service rep who is ok with your car having a few mods on it.

Sure the turbo's can be problematic, but an aftermarket supercharger can be problematic just as easily. It really comes down to the luck of the draw IMO.

Main things for the n54 are going to be plugs, coils, injectors, and intake valve cleaning. Also, they commonly struggle with rough idles when modded. For example, right after I installed my JB4 I was getting cylinder 1 misfire. An easy diagnosis told me it was the spark plugs so changed those on my own very quickly and easily (~30 minute job). However, immediately after changing the plugs I have a rough idle but it runs like a beast over 800rpms and at WOT - no misfires anymore.

After modding a 335i its tough to keep it running at its prime, but with a little bit of patience and work its usually nothing serious. As I said, main things are going to be plugs, injectors, coils, HPFP, and intake valve cleaning.
Keep those up to date and you'll have a very happy n54!

I've never heard of water pumps or injectors being an issue in the S65. Also with supercharger kits you get new injectors. Do you have a link to a thread or some more info?

Rough idle can be multiple things, plugs, injectors, or coils.

[techwhiz]

Originally Posted by Myrder

I've never heard of water pumps or injectors being an issue in the S65. Also with supercharger kits you get new injectors. Do you have a link to a thread or some more info?

Rough idle can be multiple things, plugs, injectors, or coils.

All current BMW engines use electric water pumps.
It's not a matter of "if", it's "when" will they crap out?

[Zach1328]

Originally Posted by Myrder

I've never heard of water pumps or injectors being an issue in the S65. Also with supercharger kits you get new injectors. Do you have a link to a thread or some more info?

Rough idle can be multiple things, plugs, injectors, or coils.

It shouldn't be plugs unless they're miss-gapped which I didn't check. The n54 ecu is pretty good at adapting to plug gaps over time and I've noticed its getting slightly better each time I drive so that may be the issue.
Possibly coils or injectors but its tough to diagnose without a misfire or any codes being thrown. I'll be cleaning the intake valves in the next few weeks which I assume will solve the issue, but back to square 1 if that doesn't work.

My 335i has 78k miles on it and I just bought it 2 months ago so I have no idea if the intake valves have ever been cleaned.

+1 to the e9x m3 1/4 mile and 60-130 times though. The best supercharged e9x m3 60-130 time is 6.16. The best e9x m3 bolt on 60-130 is 9.7.
The SC m3 barely beats shiv@vishnu with his 6.46 and there are tons of FBO 335i's running quicker than 9.7 60-130.
I believe a SC m3 ran a 10.7 @ ~130 mph in the 1/4 mile, which is pretty good considering no n54's are in the 10's yet. However, we're also seeing ~130mph trap speeds. The quicker times are likely due to the heavier weight and LSD the m3 comes with, but it also indicates the n54 has more high end potential since we're trapping similar speeds just slower off the line.

[Myrder]

Originally Posted by Zach1328

It shouldn't be plugs unless they're miss-gapped which I didn't check. The n54 ecu is pretty good at adapting to plug gaps over time and I've noticed its getting slightly better each time I drive so that may be the issue.
Possibly coils or injectors but its tough to diagnose without a misfire or any codes being thrown. I'll be cleaning the intake valves in the next few weeks which I assume will solve the issue, but back to square 1 if that doesn't work.

My 335i has 78k miles on it and I just bought it 2 months ago so I have no idea if the intake valves have ever been cleaned.

+1 to the e9x m3 1/4 mile and 60-130 times though. The best supercharged e9x m3 60-130 time is 6.16. The best e9x m3 bolt on 60-130 is 9.7.
The SC m3 barely beats shiv@vishnu with his 6.46 and there are tons of FBO 335i's running quicker than 9.7 60-130.
I believe a SC m3 ran a 10.7 @ ~130 mph in the 1/4 mile, which is pretty good considering no n54's are in the 10's yet. However, we're also seeing ~130mph trap speeds. The quicker times are likely due to the heavier weight and LSD the m3 comes with, but it also indicates the n54 has more high end potential since we're trapping similar speeds just slower off the line.

Offtopic: If you have a rough idle on a cold start up it could be a leaky injector. You can check your plugs after the car has been off for an hr and if any are wet with fuel that means an injector is leaky.

No desire to compare performance of the two. Each has its own merit.

OP, in order to be running mid 11's on RBs you have to run them hard and we all know our turbos regardless of hybrids don't last forever running them hard (over 20psi).

I think if you would be happy at mid 11's then a supercharged M3 would be a mild kit and would therefore be less problematic.

[6BATMAN6]

yaa id be more then happy with mid 11's. im going to do some test drives next week when i get my car back so i have a direct comparison. at the end of the day its not all about horsepower, theres a big difference between a super car and a fast car. the m3 just has so much more attention to the small details that count. and yes the n54 is impressive i would never in a million years call it bullet proof lol. but idc who you know or what u have from j2z to rb when you get in the 20 psi range things can get crazy. and if i supercharged an m3 ide start off running 6.5 maybe and never break 8lbs.

does anyone have any specific horror stories on s65 sc's ?