[DailyN54]

Wanted to get your opinions. I have an 08 335xi I have full bolt ons. I ordered the Hexon R700s + inlets going to order the complete stage 3 kit from Fuel it with JB4 and MHD tuned by Wedge. I want to know do I have to worry about the drive train or trans? Seems like most people who have high horsepower are not AT and "i" not "xi". What hp/tq can the xi handle?

[Beemzilla]

Also curious, similar set up. FBO including RB Evo's. I know a new clutch is on the horizon, but wondering how the transfer case will hold up.

[Give_Em_The_DD]

IMO the trans should be fine, but that will 100% depend on tuning + health of the trans prior.

The weak point of the XI system is: the front diff, front driveshaft, transfer case.

I blew my front diff, twisted my driveshaft and snapped a front axel at the track launching. My setup at the time was standard 15t RBs, and TFT inlets. The car was over 600 wheel torque.

IMO the x drive system is hit or miss. Prior to doing inlets/all the tuning advancement my car was about 470 awhp/520ish torque (RBs and stock inlets) and it was fine. Over 70 track launches (1.5-7 60ft) and the car would run consistently 11.3-4 1/4 mile times @ 121-23 like clockwork.

I will add I have seen XIs blow the front diff at Stock turbo/FBO status. Any questions lemme know.

[FRMTL2_335i]

I know someone that pretty much shredded the front axles and transfer case at the 1/4 mile when he was over 600/600...I guess stay away from sticky pavement lol.

[FRMTL2_335i]

Bahahahah guy just commented above me almost at the same exact time

[DailyN54]

Sounds like the car doesn't like to be launched. I don't do 1/4 mile runs. It will mainly be on the highway doing occasional pulls. This is my daily driver and I want to keep it where I can have it be fun but still reliable. Can the car be converted to a rear wheel drive? I know in other cars the front diff and drive shaft can be removed.

[Give_Em_The_DD]

Originally Posted by DailyN54

Sounds like the car doesn't like to be launched. I don't do 1/4 mile runs. It will mainly be on the highway doing occasional pulls. This is my daily driver and I want to keep it where I can have it be fun but still reliable. Can the car be converted to a rear wheel drive? I know in other cars the front diff and drive shaft can be removed.

Yeah it actually can- there's a thread on that in the XI section of the forum. I'm not sure if 100% of the power goes to the rear though (I am leaning towards no)

[Julian2485]

Originally Posted by Give_Em_The_DD

IMO the trans should be fine, but that will 100% depend on tuning + health of the trans prior.

The weak point of the XI system is: the front diff, front driveshaft, transfer case.

I blew my front diff, twisted my driveshaft and snapped a front axel at the track launching. My setup at the time was standard 15t RBs, and TFT inlets. The car was over 600 wheel torque.

IMO the x drive system is hit or miss. Prior to doing inlets/all the tuning advancement my car was about 470 awhp/520ish torque (RBs and stock inlets) and it was fine. Over 70 track launches (1.5-7 60ft) and the car would run consistently 11.3-4 1/4 mile times @ 121-23 like clockwork.

I will add I have seen XIs blow the front diff at Stock turbo/FBO status. Any questions lemme know.

Why do you think the front diff go bad? I actually had to change mine and I was fbo and probably launched only a hand full of times

[Give_Em_The_DD]

Originally Posted by Julian2485

Why do you think the front diff go bad? I actually had to change mine and I was fbo and probably launched only a hand full of times

IMO mechanically the front diff just wasn't designed to take double/triple power output of stock.

Launching Is the hardest thing you can do to the driveline of the car.

[idspeedskater]

IF you aren't launching then you will probably be okay. My transfer case finally died with 140K miles on it and with 45K miles of that being ST. However, as we've seen with the Xi drive train results may vary

[Julian2485]

If I were to launch now I won't go pass 2k but ever since I changed my front diff I haven't launched lol

[Milan]

Originally Posted by idspeedskater

IF you aren't launching then you will probably be okay. My transfer case finally died with 140K miles on it and with 45K miles of that being ST. However, as we've seen with the Xi drive train results may vary

How much power you making?

I just bought all the stuff for port injection (EOS manifold) so my plan is to finish doing some maintenance and turn it up to 600+ whp

[DailyN54]

So basically no launching or sticky tires and I should be good.

[Give_Em_The_DD]

Originally Posted by DailyN54

So basically no launching or sticky tires and I should be good.

More or less.

For what it's worth, I had pss 245s on my car when it grenaded at the track.

Torque delivery, limiting boost in 1st and maybe 2nd may help too if u were to launch

[idspeedskater]

Originally Posted by Milan

How much power you making?

I just bought all the stuff for port injection (EOS manifold) so my plan is to finish doing some maintenance and turn it up to 600+ whp

Last time I had it on a dyno was on FFTEC's heart breaking mustang dyno and it put about 520awhp with a super conservative tune (21psi peak to run on crap 91 CA gas and 50/50 premix meth).

[cmg5461]

Originally Posted by Give_Em_The_DD

Yeah it actually can- there's a thread on that in the XI section of the forum. I'm not sure if 100% of the power goes to the rear though (I am leaning towards no)

100% power goes to the rear. Transfer case is a pass through to the rear with a clutch engaged front. If the front driveshaft is removed, even with the transfer case locked, 100% torque goes to the rear. Maybe a footpound is lost due to parasitic drag.. if that

[Give_Em_The_DD]

Originally Posted by cmg5461

100% power goes to the rear. Transfer case is a pass through to the rear with a clutch engaged front. If the front driveshaft is removed, even with the transfer case locked, 100% torque goes to the rear. Maybe a footpound is lost due to parasitic drag.. if that

I'm actually glad you said that. I was digging around and came to the same conclusion.

Appreciate it!

[altostratus]

I've got RR600/inlets/outlets/meth and 20's.
But the KM's are low and the 20's are relatively light. So here's hoping

[LaxIan55]

Has anyone looked into building the front diff to handle the power? There is probably a weak link that causes the whole thing to grenade.

[DailyN54]

I dont understand why this car does so poorly when it comes to launching compared to other platforms. It seems like it gets going once rolling but sucks at 1/4 mile.

[PT's_vengeance]

Really glad I finally found something about this. So with pulls it is hit or miss. What about removing the (130mph) speed governor? Would the transfer case and other front drive components be able to handle the higher speeds for a prolonged duration of time?
I always thought that is why the 'xi' would always have the lower speed governor, especially considering my car does have the M sports package.

before someone asks, yes, Autobahn, and tracks

[ripe61]

I have a 2009 BMW 535xi that i just went intercooler + DP + chargepipe on and a stage 2+ on and currently don’t have any transmission tuning, whenever i hit it from anything under 20 the whole car will shake, when DTC is on the limited mode or whatever it doesn’t happen but the transmission will still downshift when i don’t need it to so im going to be getting xHP and seeing if that changes anything. i’m doubtful that xHP will fix the shake but hey who knows