[Beisofmarko]

Hey,

I have early 2006 RWD E92 335i n54 6MT with stage2 turbos, inlets, fbo and
running custom e45 tune at 25+ psi, power is somewhere 5xx hp i'd guess.

My problem is that i have traction issues and not sure what causes them
and what would be easiest / right way to improve them.
If i do a wide open throttle pull on 3rd or even on 4th, it will try to spin
other wheel across whole rpm range even at 100+ mph.
Then again sometimes it hooks like crazy on second gear and leaves
me thinking if theres something wrong with the suspension or something that might cause the loss of traction, anyway it's sketchy to the point
where i'm scared to floor for long time as the traction light starts to blink like crazy.
Drag tires are not really option for me and wider rears could help but i still believe
theres something else, maybe i need LSD

I'm pretty sure theres something wrong since i don't believe i should be facing
such problems yet with the power levels and setup i run?
I have brand new michelin pilot sport 4 s 265/30/19 tires at the rear
and alignment was done last week and everything is under "standards"
except rear cambers being slighty more straight (-1.41 degrees).
I also have eibach lowering springs and adjustable koni yellows.

Anyway i was not sure under what category i should make this post
so hopefully this is the right place and i appreaciate all the help and tips
that might help my case!

[Aceway]

How old are your rear control arms? I have a single turbo E92 and I recently replaced the guide rod, upper control arm, toe arm, and lower control arm bushing. My upper/lower control arm bushings were completely shot, the others probably didn't need to be replaced. I noticed big improvements in third and fourth gear traction. Don't really do a lot of second gear pulls so can't say much on that.

I also run 285/35/18 in the rear. LSD is definitely coming in the future though. Seems inevitable once you crank up the power all the way lol.

[Bimmer_Engineer]

Would you consider an n52 swap?

[Beisofmarko]

Originally Posted by Aceway

How old are your rear control arms? I have a single turbo E92 and I recently replaced the guide rod, upper control arm, toe arm, and lower control arm bushing. My upper/lower control arm bushings were completely shot, the others probably didn't need to be replaced. I noticed big improvements in third and fourth gear traction. Don't really do a lot of second gear pulls so can't say much on that.

I also run 285/35/18 in the rear. LSD is definitely coming in the future though. Seems inevitable once you crank up the power all the way lol.

I have not changed any control arms at rear during my 6 years of owning the car,
however car came clean from yearly inspection like every year but who knows
how closely the inspector checked them Might be worth to inspect myself.

Your tire setup sounds more ideal with wider tire and higher sidewall,
i tried to invest in good brand tires since i'm lowered and running 19's so space is quite limited.

A Quaife LSD might be in the future plans anyway but trying to rule out any other faults before that.

Would uneven roads at higher speed pulls could be part cause for blinking traction?
Maybe i should look if adjusting rebound on the koni yellows would change something.

Thanks!

[Aceway]

Originally Posted by Beisofmarko

Would uneven roads at higher speed pulls could be part cause for blinking traction?

Yeah especially with the open diff. There's this straightaway near my house that is really bumpy in the beginning. Second gear pull the driverside rear tires would spin out on the bumpy stretch and my car would veer left suddenly as the rpms shot up.

[jwalker87]

Agree with Aceway that, while I don't know your mileage, if it's a 2006, then all the rear suspension rubber is probably at (or past) end of life, especially for getting maximum performance. Replace the rear control arms, toe arms, and the bushings on the lower control arm.

I would also recommend addressing the rear subframe bushings, either M3 bushings (costly in parts and labor) or aftermarket inserts for your current bushings.

Also, yes, LSD. All of these cars should have come with one from the factory, but gotta cut costs somehow...

[Beisofmarko]

Originally Posted by jwalker87

Agree with Aceway that, while I don't know your mileage, if it's a 2006, then all the rear suspension rubber is probably at (or past) end of life, especially for getting maximum performance. Replace the rear control arms, toe arms, and the bushings on the lower control arm.

I would also recommend addressing the rear subframe bushings, either M3 bushings (costly in parts and labor) or aftermarket inserts for your current bushings.

Also, yes, LSD. All of these cars should have come with one from the factory, but gotta cut costs somehow...

Forgot to mention, 110k miles. Might need to dig into those then.
I'll try to get car on lift next week and do some visual/pry bar inspection first.

[zomski101]

What is your tire pressure? What are the temps?
Are you sure you're losing traction or does the rear end feel like it shimming from side to side? If it does I would recommend the BMS diff brace.

[rick100]

Originally Posted by Beisofmarko

Hey,

I have early 2006 RWD E92 335i n54 6MT with stage2 turbos, inlets, fbo and
running custom e45 tune at 25+ psi, power is somewhere 5xx hp i'd guess.

My problem is that i have traction issues and not sure what causes them
and what would be easiest / right way to improve them.
If i do a wide open throttle pull on 3rd or even on 4th, it will try to spin
other wheel across whole rpm range even at 100+ mph.
Then again sometimes it hooks like crazy on second gear and leaves
me thinking if theres something wrong with the suspension or something that might cause the loss of traction, anyway it's sketchy to the point
where i'm scared to floor for long time as the traction light starts to blink like crazy.
Drag tires are not really option for me and wider rears could help but i still believe
theres something else, maybe i need LSD

I'm pretty sure theres something wrong since i don't believe i should be facing
such problems yet with the power levels and setup i run?
I have brand new michelin pilot sport 4 s 265/30/19 tires at the rear
and alignment was done last week and everything is under "standards"
except rear cambers being slighty more straight (-1.41 degrees).
I also have eibach lowering springs and adjustable koni yellows.

Anyway i was not sure under what category i should make this post
so hopefully this is the right place and i appreaciate all the help and tips
that might help my case!

you have to much power . So proper wheels and lsd are probably your best bet. You gotta pay to play

There is a reason cars with that much power comes with LSD and better tires from factory. Even then , a lot of them still have a little bit of those issues

You probably not gonna like this idea, but if it is your daily and you are not competing in drag races , the easiest way would be to lower the HP to go with ur current set up

Like I said many times , I rather take a 350 whp car with a proper set up than a 500 whp that its all over the place

[Beisofmarko]

Originally Posted by zomski101

What is your tire pressure? What are the temps?
Are you sure you're losing traction or does the rear end feel like it shimming from side to side? If it does I would recommend the BMS diff brace.

Tire pressures are currently: Front 2.8bar / 40.6psi and Rear 3bar / 43.5psi, sizes are 235/35/19 F and 265/30/19 R
Outside temperatures have been somewhere plus/minus 20Celcius / 68 fahrenheit.

If i dont deactivate DTC fully, it will blink at dash at 3rd and 4th WOT and looking back to some datalogs
there seems to be minor spiking at rpm's as they rise indicating some loss of traction?
However i'd say it might feel like shimming abit from side to side abit aswell if theres a minor turn on the road but i'm not sure.

Thanks!

Originally Posted by rick100

you have to much power . So proper wheels and lsd are probably your best bet. You gotta pay to play

There is a reason cars with that much power comes with LSD and better tires from factory. Even then , a lot of them still have a little bit of those issues

You probably not gonna like this idea, but if it is your daily and you are not competing in drag races , the easiest way would be to lower the HP to go with ur current set up

Like I said many times , I rather take a 350 whp car with a proper set up than a 500 whp that its all over the place

I understand, this is why i'm trying to figure out what i should focus at upgrading next.
E9x just being so restricted when it comes to wider wheels, especially when you are lowered and drag tires such as slicks / semi slicks
are not allowed on public roads here i'm pretty sure. However an LSD is option that i could do for sure in the future.

[Vivek.]

Replacing rear bushings as mentioned should help. However at your HP levels you're gonna need an LSD to properly put down power. After that, a 200tw tire wouldn't hurt and would keep you street legal.

[Emilime75]

That's a lot of tire air pressure, why so high? Lowering it would aid in traction.

Don't know what width and offset your rear wheels are, but you could've gone wider with your tires. I'm on a 19x10 +40 with 275/30 PS4S. I probably could be gone to a 285.

You mention Koni yellows, how old(in miles) are they? And you haven't tried adjusting them? Too stiff and traction will break easier over bumps.

TLDR: soften tire air pressure and shocks before you start throwing parts at it. Do inspect all of your suspension bits. Get an LSD.

[Kevinl]

A diff lock down made the biggest difference so far for me car was hairy to drive before now it spins less and when it does spin there is very little drama

[jwalker87]

The side-to-side movement is the rear subframe bushing compliance. I have a 2008 335i with about 450hp (crank, limited by clutch currently) and 115k miles. I just refreshed the entire suspension and did the inserts and it made a world of difference.

Check out this video; side-by-side comparison of stock subframe bushins to ones with inserts at 8:45

[iqraceworks]

I replaced all of the subframe bushings in my 07' 335i with that Whiteline hard poly bushings. Made a big difference in traction, and how well the car hooks up.

[Beisofmarko]

Thanks for the replies guys, gives me a good base to begin with, good stuff

Originally Posted by Emilime75

Don't know what width and offset your rear wheels are, but you could've gone wider with your tires. I'm on a 19x10 +40 with 275/30 PS4S. I probably could be gone to a 285.

You mention Koni yellows, how old(in miles) are they? And you haven't tried adjusting them? Too stiff and traction will break easier over bumps.

TLDR: soften tire air pressure and shocks before you start throwing parts at it. Do inspect all of your suspension bits. Get an LSD.

9.5" et30 rears so not much room for wider tires with these current wheels.
Koni's are 2 years old maybe 10k miles on them, i only adjusted them once i put them on
to some standard setting that was on the manual, but haven't tweaked them after.