[Breakfirstfinishlast]

My friend owns a commercial complex that happens to have a large open parking lot. I was invited to come by later on tonight for a bonfire and to do a little bit of hooning in the lot.


I've heard a little bit about n55s locking up because they were oil starved doing maneuvers like this. I dont plan on doing anything crazy, I just want to have a little bit of fun. Has anyone had problems doing donuts moderately in this car?

I have a lot of eudro racing driving experience, so I understand how to drive a car and how to have mechanical sympathy. I just dont want to completely demolish the engine over doing something dumb.

[Cos270]

Originally Posted by Breakfirstfinishlast

I just dont want to completely demolish the engine over doing something dumb.

Please don't take this as a personal insult/attack, but what you just outlined sounds...dumb. Ergo, I wouldn't risk it.

[Breakfirstfinishlast]

Originally Posted by Cos270

Please don't take this as a personal insult/attack, but what you just outlined sounds...dumb. Ergo, I wouldn't risk it.

Thank you for the constructive input.

[Cos270]

Originally Posted by Breakfirstfinishlast

Thank you for the constructive input.

I'll elaborate. N55 engines in non-M format are fairly well-documented to suffer from oil starvation at high g-loads. Maybe your car is high mileage and a quart low on oil...this little night of fun could wind up costing you a NEW ENGINE if you push it too far. Or, maybe your car is low mileage, and you're running a heavier weight oil and overfilling by 0.5-1 quarts. Well, maybe you'll be fine and nothing will happen. It's impossible to predict, therefore I would not risk destroying my engine because I want to goof off with my friends. The choice is yours, no one is going to be able to definitely tell you what will happen.
For what it's worth, there was a recent thread on here about someone spinning a bearing merging onto the interstate....

[Breakfirstfinishlast]

Its crazy to me that BMW has been having problems building oiling systems for as long as they've been building the straight six. I know that doing donuts isn't something that any car is designed to do, but you'd think that you would want to build an oiling system that is robust enough to save the engine if you do something like accidentally spin out on the highway.

I have had oil starvation issues in my e36 race car almost every single time we've raced it, and thats with a baffled oil pan and all. If its not enough starvation to ruin the bottom end its enough to make the lifters tick badly.

I've seen a few horror stories about the n55, but its really hard to tell exactly how common it is because quite frequently the horror stories are over reported on the internet.

[aerobod]

For the purpose the car was built for (road use with tyres of a similar type as fitted at the factory), there is no issue with the oiling system. R-comp tyres with track use seem to be the weak point, as is the case with most road cars with wet sumps. Best to dry sump it if used beyond it’s designed g-force limits.

Looks like there is a kit for the N55: https://store.vacmotorsports.com/vac...s55-p5446.aspx

[Breakfirstfinishlast]

Originally Posted by aerobod

For the purpose the car was built for (road use with tyres of a similar type as fitted at the factory), there is no issue with the oiling system. R-comp tyres with track use seem to be the weak point, as is the case with most road cars with wet sumps. Best to dry sump it if used beyond it’s designed g-force limits.

Looks like there is a kit for the N55: https://store.vacmotorsports.com/vac...s55-p5446.aspx

This is precisely the type of answer I was looking for! Thank you. It makes sense that they wouldn't build it to sustain high g's.
The question is, what is the g force limit for the m235i oiling system. I thought i'd heard whispers that the s55 is only rated for 1.3g or something like that.

[atek]

As with anything, hoon with care. As I like to put it. I've done a few donuts already with no issues or blown engine. I get sideways and fish tail every so often. I'll race other cars on the highway to absurd speeds when its clear and available. Just have fun, be safe and take care. Don't over do it.

A quick donut or two with proper throttle modulation should be fine, and is plenty fun.

see exhibit a :

https://www.youtube.com/shorts/HruxkyUmsMY

[rtl32]

I've spun off, and witnessed quite a few other N55's spin around for the duration of many sets of tires, and haven't had an issue. All while stage 2+. I also put the full 7 quarts in every oil change.

I wouldn't say it was my brightest decision, but I also wouldn't say I got lucky. Track level R compound tires are a little different than doing circles at 15mph in a lot. I doubt we pull the same Gs as the guys needing/pushing 200 or less TW tires around on the track at their limit with 3 degrees of camber and $6000 brake kits, otherwise everyone and their mom would have a blown engine after every snowstorm

[Breakfirstfinishlast]

Originally Posted by atek

As with anything, hoon with care. As I like to put it. I've done a few donuts already with no issues or blown engine. I get sideways and fish tail every so often. I'll race other cars on the highway to absurd speeds when its clear and available. Just have fun, be safe and take care. Don't over do it.

A quick donut or two with proper throttle modulation should be fine, and is plenty fun.

see exhibit a :

https://www.youtube.com/shorts/HruxkyUmsMY

Thank you for the reply! That was a pretty nice donut in the vid lol.
Where I live, we don't have a lot of big empty roads like that, so there isn't a lot of places for me to do things like that safely. So I jumped on the opportunity to have some fun in his parking lot, where I knew it would be mostly safe and legal.

I ended up going through with it, and I had a lot of fun. This is my first rwd road car. I grew up driving VW's and i've always wanted to learn how to do proper donuts.
No issues to report. The car held up just fine.

[Breakfirstfinishlast]

Originally Posted by rtl32

I've spun off, and witnessed quite a few other N55's spin around for the duration of many sets of tires, and haven't had an issue. All while stage 2+. I also put the full 7 quarts in every oil change.

I wouldn't say it was my brightest decision, but I also wouldn't say I got lucky. Track level R compound tires are a little different than doing circles at 15mph in a lot. I doubt we pull the same Gs as the guys needing/pushing 200 or less TW tires around on the track at their limit with 3 degrees of camber and $6000 brake kits, otherwise everyone and their mom would have a blown engine after every snowstorm

I had a feeling a lot of the folks I saw complain about spinning a rod bearing from doing maneuvers like the ones we're talking about were probably just a quart or so low on oil. I just didn't know what to believe.

Do you race your car or do you do HPDE's? In the racing I do (Champ Car, Lemons, AER) we dont even use, or in some cases, aren't even allowed to use R compound tires. We've still had oiling and fueling issues with long sweepers. Mainly fueling issues. In our race car we even wired in a dual fuel pump set up. Even with it, when we get down to a quarter of a tank we have sputtering problem

[aerobod]

Overfilling beyond the maximum can also cause oil starvation problems under high-g manoeuvres as the crankshaft can thrash the oil if it is too high and aerate it, causing a drop in pressure.

[rtl32]

Originally Posted by Breakfirstfinishlast

I had a feeling a lot of the folks I saw complain about spinning a rod bearing from doing maneuvers like the ones we're talking about were probably just a quart or so low on oil. I just didn't know what to believe.

Do you race your car or do you do HPDE's? In the racing I do (Champ Car, Lemons, AER) we dont even use, or in some cases, aren't even allowed to use R compound tires. We've still had oiling and fueling issues with long sweepers. Mainly fueling issues. In our race car we even wired in a dual fuel pump set up. Even with it, when we get down to a quarter of a tank we have sputtering problem

No racing (just some late night 40 rolls) or HPDEs, but I have also experienced the quarter tank sputter. Also I was always "max" oil level before abusing it the couple of times I did. Those are now considered historic events lol. But when they did happen I made sure the car was well prepared considering what it was about to do. I think the saying is "if you're gonna be stupid you better be tough" so I made sure the car was tough lol.

Always keeping my tank above 3/8 gives me a tad more (much needed) weight above the rear axle and stops that from occurring. I almost never go under that unless I'm putting a tank of 93 through until fumes right before every oil change to keep fuel system clean, in which case I don't drive the car hard anyway since it's on 93 (ew). I think it's probably a fuel tank baffle issue, a sloshing and shifting fuel load under high acceleration when theres a lot of void space, causing the pump to be able to pull air.

I think what a lot of people don't realize with these cars is that fuel pressure doesn't always equate to fuel flow. So they get used to seeing HPFP dips when pushing tunes on stock HPFP and quickly diagnose the fuel system as being inadequate, but then get the same symptoms on a low fuel tank without the HPFP psi dipping and say it can't be the fueling, the pressure is fine. Sure the pressure is fine but it's probably not flowing what is needs. And if we can isolate the problem to low fuel levels independently, it would be foolish to keep ignoring that as the cause.

[Jelly_Belly]

Just add a quart of oil and send it. Making sure to take vids and post em here. You should be fineeeee