crappy e36

[frcefed]

Well, ive got a few questions and need some help making my e36 cool. First, the rear suspension feels really soft and loose, as in the bushings feel weak, where should I go to find either better bushings or control arms?

Second, I put some h&r lowering springs in all the way around but the rear sits just as high as it did before?! Why is that? Haha I hate how high it sits in the rear.

Third, is anyone running a 7200rpm limit? I want to but I'm worried that the m50 w/vanos can't handle it with drifting seeing as I'm @ rev limit literally all day on track days.

[B C]

cool pic

 

Check for chassis stress cracks around the rear subframe mounting points

 

 

 

 

As for raising the rev limit to 7200:

 

When you search around the M50 family of engines doesn't take well to high revs without substantial modifications.

 

Engine harmonics potentially killing the crankshaft (requires proper harmonic damper at minimum)

Hydraulic lifters

Soft valve springs

Cylinder head flow

Oil pump flow

 

7200 rpm probably isnt high enough to worry so much about the items listed above but with any engine, theres the additional ring/cylinder wear from high piston velocities.

Mean Piston Speed  
------------------ ------
Under 3,500 ft/min  Good reliability
3,500-4,000 ft/min   Stressful, needs good design
Over 4,000 ft/min    Very short life 

 

http://www.unofficialbmw.com/all/engine/all_redline_rpm_vs_reliability.html

 

Piston velocity pertains to ring and cylinder wear and has a linear relationship with rpm.

A stock M50 with 6500 rpm redline  has a mean piston velocity of 3257 ft/min

raising the redline to 7200 moves it to 3607 ft/min. . 

Unfortunately the inertial loads in an engine that cause rod/main bearing wear and crankshaft/connecting rod failures increase with the square of  rpm.
So while 6500rpm to 7200rpm may not seem like a lot, the stress on engine components is 49% higher at 7200rpm vs 6500rpm. 

For full throttle rage drifting purposes this will probably list the engines life in hours instead of miles. 

in my opinion, the additional performance had from the extra 700rpm is not worth the decreased engine life. You may be able to bounce the car off the limiter for a few years worth of drift events  at the stock limit whereas you may be lucky to get through 1 season at 7200.

 

More time enjoying the car is always good.

[KaiserRolls]

Is it the TMS chip?

The dinan one in my m50 is like 6800 limit. And I rarely visit that. And my motor has a lot of miles on it.

[frcefed]

That doesn't look like my subframe mount but I dont see any cracks.

Is it the TMS chip?

The dinan one in my m50 is like 6800 limit. And I rarely visit that. And my motor has a lot of miles on it.

I probably wont put a chip in. Ha

[jc43089]

I would skip the chip and then not worry about bouncing the limiter all day.  Here are a couple pics that you can see the subframe mounts.  I welded in AKG reinforcments for the RTAB pockets and OE for the 4 subframe mounts.  Rough looking welds, I did it with flux core, I have a gas bottle now and will go over it again before I paint everything.

 

 

 

[patsbimmer1]

Step 1: Do burnouts

Step 2: go sideways

Step 3: look cool

Burnouts = cool

[Morzada]

I doubt you need better bushings. You probably just need new bushings.

Likely candidates are rear trailing arm bushings. How does the tail feel coming off an exit ramp fast? If it feels like oversteer or crabbing, the RTABs need to go.

Rear upper shock mounts often go bad, but I don't know that they'd make your suspension feel soft.

Another likely one is the front control arm bushings. If the steering isn't precise these are candidates. Really the entire front control arms are probably due (ball joints and whatnot). Finally, in the front look to the outer tie rods and an alignment.

Good luck.

[Morzada]

RM European or Pelican for parts (or Tisher (GetBMWParts) for OEM)

[jc43089]

^ What Morzada said, if the front feels loose check the control arm bushings.  Replace them with centered M3 bushings, exactly the same but more rubber area holding them together, symptoms are jiggling in the wheel during coasting or accelerating but it will go away when you tap the brakes, and loose feeling in the front end.  Easy and cheap replacement.

[frcefed]

I just had an alignment done (that helped a lot with the front) the front tie rod ends feel super tight. I checked all of the mounts for the rear subframe and there are no visible cracks. So m3 rear control arm bushings seem like a good choice, are they available from pelican?

Sidenote: the m50 stumble at low rpms has never been solved, has it? I had an m50 in an e34 chassis a while back and never found a cure after replacing o2 sensors, cleaning the icv and so on I'm already at my witts end with this m50 stumble and I haven't even done anything, haha I didn't even want an e36 chassis but it was a last minute thing so I guess I'm just gonna roll with it now.

[KaiserRolls]

Did it only stumble when cold? Coolant temp sensor issue?

[Earl]

Check over the boots on your coils too. If they have any small cracks or splits it can cause a misfire. You should also do a akoke test to find any vacuum leaks. I have a slight miss only at idle and need to smoke test my e34.

For fromt control arm bushings I would highly recommend the treehouse racing eyeball arms but if this is low budget, offset m3 mounts would be great. If this is a drift car, I would recommend poly rear subframe bushings. The rubber might still have too much give when throwing it sideways. You can get sets through AKG Motorsports, Bimmerworld, or Turner Motorsports. I always order all of my OEM parts through ECS Tuning. They always seem to have the lowest price to me and I have had excellent interaction with their customer service. Some people have had issues in the past but I have never had anything less than great service.

[jc43089]

The m3 bushings for the front control arms are an upgrade (more rubber, they are available with centered hole, and offset hole.  I'm not sure if the offset to increase caster would help you or not.)

 

I don't know if the rears are different, I have UUC poly rear trailing arm bushings and they stiffened the rear up nicely, I did not lube them properly the first time and they squeaked fyi.

[frcefed]

Did it only stumble when cold? Coolant temp sensor issue?

It stumbles all the time, hot or cold, just around 2-4k rpms. Besides that it runs perfectly other than the burning bleach smell when I floor it.... Ha the cluster claims its at 44k for mileage, not sure if I believe it.

[patsbimmer1]

You might want to consider e46 control arms as an upgrade.  From what I understand they will give you a little more at full lock.

[Rowleym]

You might want to consider e46 control arms as an upgrade.  From what I understand they will give you a little more at full lock.

They give you added track width mainly I believe. This, plus an SLR half kit(or some rack spacers) will give you lots of lock. Don't just replace the stock arms. 

Also, No need to up the rev limit with a stock motor. Keep it at 6800 or whatever, and don't be afraid the bang the hell out of it. 7k won't hurt a properly maintained m50.. 

[frcefed]

They give you added track width mainly I believe. This, plus an SLR half kit(or some rack spacers) will give you lots of lock. Don't just replace the stock arms. 

Also, No need to up the rev limit with a stock motor. Keep it at 6800 or whatever, and don't be afraid the bang the hell out of it. 7k won't hurt a properly maintained m50..

What is an slr half kit?

[Earl]

The e46 arms give you mad tyte camber=P You do need e90 tie rods though to make up the added width. There is a lot you can do to get more lock in the front. There are tons of threads on driftworks and such from UK guys building e36 drift cars. 

[frcefed]

The e46 arms give you mad tyte camber=P You do need e90 tie rods though to make up the added width. There is a lot you can do to get more lock in the front. There are tons of threads on driftworks and such from UK guys building e36 drift cars.

Well I am a sucker for camber, especially when my e34 pillowball mounts are maxed out at like 2.8 degrees:(

[Rowleym]

The e46 arms give you mad tyte camber=P You do need e90 tie rods though to make up the added width. There is a lot you can do to get more lock in the front. There are tons of threads on driftworks and such from UK guys building e36 drift cars.

Well I am a sucker for camber, especially when my e34 pillowball mounts are maxed out at like 2.8 degrees:(

With e46 arms you will probably put the camber adjustments max positive. Nearly.

[frcefed]

With e46 arms you will probably put the camber adjustments max positive. Nearly.

I dont have pillowball mounts on my e36 yet. Haha

[patsbimmer1]

http://www.driftworks.com/forum/technical/161071-e30-e36-lock-increase-guide-my-try-photos.html

 

Some more info on the swap.

[frcefed]

Nice! Yeah I'm definitely doing the e46 swap...

Soo I've noticed my rear tires toe in and my tires are wearing ridiculously fast.. anyone know why?

[Morzada]

Soo I've noticed my rear tires toe in and my tires are wearing ridiculously fast.. anyone know why?

Given that this thread started with a question about your rear suspension, I'm going to go out on a limb and say that your RTABs are shot.

[frcefed]

Given that this thread started with a question about your rear suspension, I'm going to go out on a limb and say that your RTABs are shot.

Why would that make the tires toe in? Wouldnt that force them back so they toe out?

[frcefed]

Well I did some research and my rtabs have to be shot but $280 for solid ones from turner seems like a lot.