m50b25 non-vanos questions... fuel efficiency?

[pr0craztinazn]

how do you like that setup? i would imagine that it would still be pretty quick and fun to drive right? i just bought an 87 325e which is geared similar and i like the way it pulls, but just wish it were a little faster.

my current dilemma is what to do with the motor. ive been leaning toward putting a 731 head on my rebuilt m20b27 and use 1.3 motronic with all i related parts needed, but i realized today that the cost and amount of work is almost the same as doing a m50 swap. so now i need to look into building a m50 and decide what i would want to do with it, and how much it would cost.

i am also leaning toward no boost, and just making a really efficient N/A motor. the car is just going to be a spirited daily driver, not a track rat. the hassle of making euro itb's clear the vanos solenoid is enough to make me go non-vanos. to me itbs = throttle response, and that makes your car feel more responsive/faster even though your not making any more power.

It responds way faster and smoother than my eta ever did (with the Mark D chip or when it was stock), although the eta had a smidge more torque from a standstill. If you want a little faster, the NV will do it. I keep finding exhaust leaks pre-o2 sensor due to hitting all sorts of stuff while driving in DC (terrible roads are terrible), so it should feel faster whenever it's all sealed up. I don't regret my swap at all; it's fast enough to get into trouble, but economical enough that I could idle around in 5th gear at 35mph in medium highway traffic like I did with my eta without lugging.

[pantelones]

So are you guys saying that a NV is bad for boosting?

to my knowledge, its not bad to boost a m50 nv, but its not that bad to boost a vanos motor which will make more torque than a nv. the easy way out is just to avoid the "problem" all together and get rid of it. the only difference between boosting a nv vs. a vanos is having a proper tune to effectively use the vanos to your advantage, and not cause a headache. i believe that you need a stand alone or piggy back to run boost+vanos right? the extra rotating mass of the nv rods and crank play a roll in some peoples decision, but a m52 short block with the nv m50 head will solve that weight weenie issue. in the end it really doesn’t matter what motor your boosting, its just if you can FULLY comprehend how your motor works and how boost is going to affect it. or loads of cash works as well...

someone with actual hands on knowledge correct me if im wrong...

[GunMetalGrey]

So are you guys saying that a NV is bad for boosting?

[e30_325es]

I was getting ~25mpg highway with an s50/zf/2.93lsd and schrick cams, high comp pistons, trm tune. ~20 average and ~18 on it alot.

[nwe30]

im getting 15mpg right now with a 4.10 lsd. WTF. and i've been trying to drive alot more economically.

[CorvallisBMW]

No reason you shouldn't get 30mpg highway, unless you're running a 4.44 diff

[highoutput]

Wow, I'm seriously doing something wrong. I recently finished my M50 Vanos swap, and my car gets noticibly BAD gas mileage. I'm talking 20 on the highway....thats not "official" yet, but it seems that way, and its not far off either way. I've done the math, just roughly, not exact.
I DO have S50 cams and a Turner tune......but christ I never thought I'd miss my M10 for any reason at all, lol

[pantelones]

Mixed highway and city + 3.25 diff + Getrag 260 + M50NV = 27mpg mixed

how do you like that setup? i would imagine that it would still be pretty quick and fun to drive right? i just bought an 87 325e which is geared similar and i like the way it pulls, but just wish it were a little faster.

my current dilemma is what to do with the motor. ive been leaning toward putting a 731 head on my rebuilt m20b27 and use 1.3 motronic with all i related parts needed, but i realized today that the cost and amount of work is almost the same as doing a m50 swap. so now i need to look into building a m50 and decide what i would want to do with it, and how much it would cost.

i am also leaning toward no boost, and just making a really efficient N/A motor. the car is just going to be a spirited daily driver, not a track rat. the hassle of making euro itb's clear the vanos solenoid is enough to make me go non-vanos. to me itbs = throttle response, and that makes your car feel more responsive/faster even though your not making any more power.

[Wh33lhop]

Best I've gotten with a G260/3.73 is 26mpg on the way to the picnic (cruising 75-90ish). I get about 19mpg mixed, but I drive like a lunatic.

Don't pick an NV over a VANOS to boost, that issue has been debated many times and basically there are no major upsides to the NV besides not having VANOS (cylinder walls are a few thou thicker if anything, the rods are beefier but unnecessarily so = extra reciprocating mass, double valve springs are unnecessary, etc). And this is coming from a NV owner.

[pr0craztinazn]

Mixed highway and city + 3.25 diff + Getrag 260 + M50NV = 27mpg mixed, and my DME has no speed sensor reference signal, so it is throwing codes and supposedly has the limp mode reduced redline because I have been too lazy to fix it. Keep in mind I get those #s including sitting in traffic for an hour during my commute each day, 5 days a week. If I drive like a douchebag, I get 22mpg, while all highway is just short of 31. The Vanos versions will net you some additional low end and better MPG, but its doable from a NV with the right gearing.

[pantelones]

M50nv isnt the best/cheapest option to turbo at all.

Go vanos M50. This is coming from a guy with a non-vanos.

really? from what i have been reading the non-vanos is better suited for boost. care to share why you would have rather gone with a vanos m50?

M50B25nv/G260/o3.73 I get about 23.5mpg combo, I once did 27.6 doing 55mph on a long highway trip, and I get around 15mpg at the track.

thanks for sharing. 23.5mpg doenst sound that bad with a 3.73

Vanos will net you better fuel efficiency than non-vanos. It simply uses cam timing to optimize engine torque, meaning you can rev the engine less. Less revs/less TB opening = better fuel efficiency

hmm, well if its better to use the m50tu for a turbo build then i guess ill be gaining some mpg's while i raise the funds for a turbo. but then i probably wont go through the hassle of making itb's work since ill have to make them clear the vanos solenoid.

[CorvallisBMW]

Vanos will net you better fuel efficiency than non-vanos. It simply uses cam timing to optimize engine torque, meaning you can rev the engine less. Less revs/less TB opening = better fuel efficiency

[Fusion]

M50B25nv/G260/o3.73 I get about 23.5mpg combo, I once did 27.6 doing 55mph on a long highway trip, and I get around 15mpg at the track.

[Tchao]

M50nv isnt the best/cheapest option to turbo at all.

Go vanos M50. This is coming from a guy with a non-vanos.

[pantelones]

ive been searching forums for the past 8 months and ive come to realize that its better to just ask your question and hope someone is nice enough to share their knowledge. obviously you can find things that are more common relatively easily, but for some, like a step by step how to on an abs delete, it comes up with 15 post asking if their is any info on a abs delete and everyone tells them to search, but there is no/very vague info on the forum about an abs delete.

anyways, yeah a really low ring and pin like you said wouldn’t be a bad idea, but would that only benefit on the highway, or city too? and for the itb's i would be making a plenum and using a miller MAF. i could use the euro intake and a MAF, but id rather just make one since i have the resources to do so.