[Joe_E]

Hey guys, looking for some advice and opinions from you guys! I'm currently driving a 14 328i. It used to be Full Bolt Ons, now it's stock with wheels and kw v2 coils on it. Im considering switching over to a 2 series. However I need some help. I'm between getting a m235i or m240i. Biggest deal is whether I should pull the trigger right now on a m235i low miles MT, or wait another year for the m240 to drop and get one?
My starting goals for the car are to go FBO with a nice set of coils so I can track the car every now and then and also have a beast in the canyons. Plan would be FBO + some e85. After this is my final goal of upgrading the turbo and going 500-600 whp
I know the m235i has the n55 and fbo is around 350ish while the b58 is around 400. In the long run do you guys think it would make a difference? Should I wait the extra year for the m240i or just get the m235i?

[p912guy]

Excuse my ignorance but FBO?

[emtrey]

likely means Full Bolt Ons as stated in first sentence.

Next question-what is his definition of Full Bolt Ons ?

500-600 hp ?

I drove a Dinan M235 with 486 hp. Very, very strong. Can't imagine needing more power than that.

[USA-RET]

Agreed. Limitations by other components would more than likely prohibit any full realization of exceptionally high HP/Torque numbers.

[aaaaah]

The biggest advantage you would see from the 240 is that the B58 is a closed deck block.

[XutvJet]

A FBO 328 is a bit slower than a stock M235, especially above ~70mph. The FBO N-series hits hard in the lower rpms, but doesn't have the lungs of the N55 or B58 above 5500rpms. That's why the N55 or B58 will walk away from higher speeds. I think you'll be surprised by the stock power, especially the B58.

The B58 does have a closed deck block, but the open deck N55 and N54 blocks have never shown much problem in terms of handling a lot more power thus I think the deck design isn't much of a factor here.

A FBO M235 6MT will make around 370-380whp and 390-400wtq. A B58 will see about 15-20whp/wtq more on average. With meth and/or ethanol, there's really no power advantage between the two motors. They'll both make essentially the same power and are both limited on the fueling side of things.

The N55 is tried and true and pretty dang reliable, the issues with the motor well known, and things are generally easy and cheap to fix (for a BMW). The N55 is pretty simple. It's got the VANOs and timing chain in the front, it's got an accessible single turbo, the oil filter system is on the upper front side of the motor, it has a very standard air to air intercooler, easy to access injectors and coil packs, the coolant pump is fairly accessible and generally cheap to replace, and the DME can be flash tuned now. The MPPK equipped N55 in the M235 has stronger crank bearings and forged crank compared to the standard issue N55 in other BMW makes. It also has additional cooling capacity.

The B58 appears to be reliable as well but long term reliability is not known at this time. The B58 has a slightly larger turbo, is much better at managing air intake temp, and makes around ~15-30whp/wtq over the N55. It also does a better job holding power from 6500-7000rpms. The B58 has a liquid to liquid intercooler which is built into the intake manifold, it has two cooling pumps (one electric and one mechanical), it has two coolant expansion tanks, it has the timing chain and VANOs on the back side of the motor, and the oil filter system is under the intake manifold. All these things could be rather expensive to fix especially if there's a VANOS issue or coolant issue.

There have been numerous reports of B58s consuming/loosing coolant. It's not readily known the exact cause. We do know a handful of turbos have been replaced as BMW believed there was a leak in the turbo where coolant was being consumed in the exhaust turbine area.

As for making 500-600whp in a M235/M240. I'd seriously reconsider going down this path. It's certainly possible with either motor, but it takes a lot of mods, a lot of trouble shooting, plan on a lot of down time, and a lot broken or worn out parts. IMO, go FBO mods and leave it at that. If you want more power, buy a faster car.

[3rdcoast228i]

If you are going to mod it, then m235i is going to have more parts and tunes available.

[sev1]

Originally Posted by XutvJet

The MPPK equipped N55 in the M235 has stronger crank bearings and forged crank compared to the standard issue N55 in other BMW makes.

Just wanted clarification. Did you mean that the M235 w MPPK has the forged crank or that all M235's have the MPPK and thus the forged crank.

Thank you!

[B58togo]

FBO for the B58 is currently either Dinan or JB4, intake, and exhaust. There is no aftermarket intercooler and unfortunately, a catless DP just causes throttle closures and does little for power. And the B58 is not at all e85 friendly. Sucks no one has cracked the DME yet. Since the intake and catback do little for power, the only two real power adders are the tune and meth.

I have just the JB4/intake and have run as quick as 12.3, so the car does move, but top end seems just a bit weak to me. I will be adding meth soon. Guessing I’m around 370 SAE at the wheel now and hoping for maybe 410 with WMI and an extra ~4 lbs boost. Pure does have a Stage 1 upgraded turbo for the B58, but it’s only good for ~30 whp. I’m wondering if a catless DP would respond better on the Pure turbo. Could be good for 450-460 at the wheel, all in. There are some guys with mid 11 second 340i’s, running Pure Turbos over at n54tech.

[Transfer]

Dude needs an M4 or a ZL1 not a 2 series. This is just silly.

[Joe_E]

Originally Posted by Transfer

Dude needs an M4 or a ZL1 not a 2 series. This is just silly.

I really want a 17 zl1 too much tho or a 14

[Jerich0]

Originally Posted by B58togo

FBO for the B58 is currently either Dinan or JB4, intake, and exhaust. There is no aftermarket intercooler and unfortunately, a catless DP just causes throttle closures and does little for power. And the B58 is not at all e85 friendly. Sucks no one has cracked the DME yet. Since the intake and catback do little for power, the only two real power adders are the tune and meth.

I have just the JB4/intake and have run as quick as 12.3, so the car does move, but top end seems just a bit weak to me. I will be adding meth soon. Guessing I’m around 370 SAE at the wheel now and hoping for maybe 410 with WMI and an extra ~4 lbs boost. Pure does have a Stage 1 upgraded turbo for the B58, but it’s only good for ~30 whp. I’m wondering if a catless DP would respond better on the Pure turbo. Could be good for 450-460 at the wheel, all in. There are some guys with mid 11 second 340i’s, running Pure Turbos over at n54tech.

Interested in the throttle closure with dp... where can I find more info?

[XutvJet]

Originally Posted by sev1

Just wanted clarification. Did you mean that the M235 w MPPK has the forged crank or that all M235's have the MPPK and thus the forged crank.

Thank you!

Sorry for the confusion here. The M235 is equipped with the MPPK kit as standard equipment. That's how it gets it's extra power over the standard N55. On top of the factory tune, the N55 in the M235 (and also the M2), uses stronger bearings (crank and rod) and a forged crank. The standard N55 found in other BMW makes use of a cast crank. I can't remember the last time I heard of a N55 crank breaking, but I have heard of a few N55 spinning rod bearings. Since the N55 in M235 has more robust bearings, I'm hopeful the potential for rod bearing failure is lessened. With that said, most of the spun rod bearings I've heard about are on modded cars. If you get detonation really bad, it's possible for the detonation to literally hammer the piston/rod right through the oil film between the rod bearing and crank.

[morphomeman]

We are talking about a use (pre-owned) car, no?
In that case, the probability of finding a 240 one year from now is very low, since few people give up cars after one year, and such cars may be dogs.
So my advice is to keep your eyes open. The number of available low mileage MT 235 or 240 cars is always going to be minuscule (x-cars are all automatic). If you can find a non-modded gem, then go for it and don't waste your time worrying about the difference. Hey, you can always change badges!
And don't buy a modded car. They have usually been driven by lunatics, as I am sure you know.

[B58togo]

Originally Posted by Transfer

Dude needs an M4 or a ZL1 not a 2 series. This is just silly.

What’s silly? Owning a sleeper?

Originally Posted by Jerich0

Interested in the throttle closure with dp... where can I find more info?

Check out n54tech.com

[XutvJet]

Originally Posted by Transfer

Dude needs an M4 or a ZL1 not a 2 series. This is just silly.

Agreed. We all know the inline 6 turbo BMWs are the present day 2JZs, but basically doubling the stock power to 500-600whp will result in a lot of headaches. The motor will probably stay together, but it will have driveability and tuning issues. It's NEVER a mod and forget scenario when you increase power so significantly. Plus, when in the world would you ever use that sort of power? If you want to surprise people, do FBO mods and either buy Xdrive or a set of drag tires. From 0-100mph, not much of anything will be able to hang.

[Luftwaffe1O1]

It really depends on what you plan on doing. Both motors are quite capable, and so far the B58 has shown to be quite mod friendly.

But for longterm some design decisions seem odd about the B58, for instance, I think the timing chain is at the back of the engine, so VANOS issues/timing chain issues are engine out services from what I heard.

If you plan on keeping this car for a while, something to consider down the line.

But raw potential wise, I think the 240 has a bit of an edge over the n55 equipped cars. It also seems to be a but underrated from the factory, as ive read stories of guys with bone stock AWD 240s running mid to lower 12s.

[XutvJet]

Originally Posted by XutvJet

Sorry for the confusion here. The M235 is equipped with the MPPK kit as standard equipment. That's how it gets it's extra power over the standard N55. On top of the factory tune, the N55 in the M235 (and also the M2), uses stronger bearings (crank and rod) and a forged crank. The standard N55 found in other BMW makes use of a cast crank. I can't remember the last time I heard of a N55 crank breaking, but I have heard of a few N55 spinning rod bearings. Since the N55 in M235 has more robust bearings, I'm hopeful the potential for rod bearing failure is lessened. With that said, most of the spun rod bearings I've heard about are on modded cars. If you get detonation really bad, it's possible for the detonation to literally hammer the piston/rod right through the oil film between the rod bearing and crank.

I did a little more research. According to RealOEM parts numbers and cross references:

The M235 has the same forged crank as the M2.

The M235 has the same forged rods and rod bearings as the M2, M3, and M4.

The M235 uses different crank bearings than the M2.

The M235 has the same cylinder head, cams, block, crank girdle, intake manifold, intercooler, and coolant and oil cooling systems as the M2.

The M235 has a different turbo part number than the M2.

The M225 has a different oil pump and pickup and oil pan than the M2. The M2 uses M3/4 equipment.

[Luftwaffe1O1]

Originally Posted by XutvJet

I did a little more research. According to RealOEM parts numbers and cross references:

The M235 has the same forged crank as the M2.

The M235 has the same forged rods and rod bearings as the M2, M3, and M4.

The M235 uses different crank bearings than the M2.

The M235 has the same cylinder head, cams, block, crank girdle, intake manifold, intercooler, and coolant and oil cooling systems as the M2.

The M235 has a different turbo part number than the M2.

The M225 has a different oil pump and pickup and oil pan than the M2. The M2 uses M3/4 equipment.

Does the B58 in the M240i also have unique components compared to the B58 in the 3 series? I haven't looked into this much myself, but I would imagine they might go the extra mile for this as well, especially if they will be potentially updating the M2 powerplant?

[Mr Carrots]

N55 is flash tunerable , B58 is very much not.

If you're staying stock then the B58 would maybe be a better bet, I say maybe because mine died in the first year of ownership and my old N55 was a workhorse

[XutvJet]

Originally Posted by Luftwaffe1O1

Does the B58 in the M240i also have unique components compared to the B58 in the 3 series? I haven't looked into this much myself, but I would imagine they might go the extra mile for this as well, especially if they will be potentially updating the M2 powerplant?

According to realoem, the entire B58 and it's supporting systems in the M240 are the same as the B58 found in the other makes and models. It appears the B58 in the M240 just has a MPPK tune. Nothing more.

[Dylan86]

Do you want best value? If so, a low mileage M235 6MT can be had for a great price in the 14-15MY range.

Or do you want the newest version of the same car, for a lot more $$?

I've lost a lot of money purchasing new or leasing new cars, and it's not worth it to me anymore.. The fad of having a brand new car wears off pretty quickly, imo. The M235 is only down on power by 10% on the high end, and it has a proven powertrain with endless mods available. It's also the best engine in years for carbon buildup and oil consumption, based off of every bit DD I did, prior to buying my own CPO car.

Can't go wrong either way, but price plays a huge factor when comparing the two models. If price is a factor, for you, the M235 is the way to go as the FBO parts are plentiful, and can be had brand-n'used if you're patient. If it's not about price, then sky's the limit, hah