Single Turbo DCT E89 Z4

[Drew@Sonic MS]

We've been keeping this project hidden for the last few months. The clutch packs were installed months ago and worked fine on stock turbo power. But before publicizing the success, we wanted to make sure it was capable of handling the expected power levels. Our project E89 Z4 has had upgraded Dodson DCT and a modified Motiv Motorsport 750 Single Turbo kit and am proud to announce that everything is working flawlessly. Although the E89 has much more engine bay space, this kit required a decent amount of modification to work with our cars.

The combination of the upgraded clutch packs and the increased power from the Motiv kit has really transformed the car. Compared to the 1/3 series platforms, I think the E89 is superior with the rear chassis coming from the E46. We're very excited to see how this car performs at Shift S3ctor!

We will have edited videos and pictures in the upcoming weeks. Here's a little teaser of single turbo kit fitted inside the E89.

[jts1981]

That.
Is.
Fucking.
AMAZING!!!!

Can't wait to see the videos! Do you think this will be on Tuned with Matt Farah in the near future???

[nicknaz]

WOW! That sounds great

Any other specs (dyno sheet, timeslips) you can share?

What's the engine and DCT cooling situation look like?

[Drew@Sonic MS]

We are still waiting for the fueling solutions right now to really get it to where we expect it to be. Shift S3ctor will show real world results.

Here's Motiv's dyno for those of you that are interested:


Right now on an OFT map on 91, I'm having trouble getting traction with 295/30 PSS tires. Working on redoing the widebody so we can squeeze a wider tire in the back.

Just easy bolt on stuff for cooling, nothing special - never had issues with limp mode and don't expect to have any from the way I've been driving it.

[nicknaz]

That's so epic!!

Great to see that the DCT with upgraded clutches can handle that much torque

[flpnout]

That's awesome Andrew!! Can't wait to see it in person when it's ready!

[Nkc]

That's a crazy amount of hp and tq. Excellent work. Really want to see how this monster drives.

[Ramjet]

O M G !

[Lurcher]

What a o' crap moment at 3500-4500 rpm the first time you floor it...

[Asbjorn]

Originally Posted by Drew@Sonic MS

Compared to the 1/3 series platforms, I think the E89 is superior with the rear chassis coming from the E46.

First of all, awesome project!

Secondly, do you mind explaining how the rear chassis might be superior vs the 1/3 series platform? I mean besides the 48/52% weight distribution putting extra weight/traction on the rear wheels?

Some background information:

E89:
Central C-link rear axle

An adapted version of the rear axle known from the E85 with the development designation HA 3 is fitted in the E89. Rear axle carrier and thrust strut seems to be the only common parts with E90 and E87, but I may be wrong. The rear suspension on the E85 is taken from the E46 with some minor changes for the roadster. A reinforcement plate was been added then to increase rigidity.

Further text from BMW:

The central link rear axle is an intricately constructed, weight and space saving, multi-link rear axle. The wheels are controlled by two control arms and one semi-trailing arm that is mounted at the central point on the body. The precise interaction between the semi-trailing arm and control arm ensures that the wheels remain in the best possible position with respect to the road surface, thus providing outstanding directional stability. The flexible link bearings ensure exceptional driving stability while cornering, providing the vehicle with excellent rolling and acoustic comfort.

The designation HA 3 does not refer to the three links but rather is a continuation of the development designation at BMW. The central link rear axle optimizes the following properties:

• Directional stability
• Alternating load response
• Self-steering response
• Lane change stability
• Transition response from cornering to straight ahead
• Rolling comfort.

Total toe-in (angle): 18’
Track width: 1562 mm
Camber: -2 20’

Both rear toe and camber is adjustable on HA3.


E82/88
Rear Axle "HA 5"

The rear axle on the E82/88 is of the development designation "HA 5" and was used for the first time on the E90. Currently all E9X vehicles are equipped with a version of this rear axle assembly.

It is designed as a multi-link independent rear suspension axle with 5 different link arms. The designation "HA 5" does not refer to the five links but rather represents the consecutive development designation used at BMW.

The use of five links enables free selection of the pivot axle for the design layout. This means that the movement of the wheel in interaction with the suspension can be optimized without compromise under braking, acceleration and lateral forces. This largely determines all important variables such as toe, camber, brake support (anti-dive) angle, roll center and roll center change rate.

The large rear axle carrier is connected directly to the rigid frame side member, allowing it to transmit the applied crash forces more favorably. The semi-trailing arm features crash beading (in the semi-trailing arm of the HA 5 rear axle) to ensure the fuel tank is not damaged.

The braking support (anti-dive) realized on the E82 as on E9X vehicles represents an optimum compromise between comfort, safety and driving dynamics requirements.

The placement of the mounting points considerably lower stress and strain on the body and the option of designing the rear axle bearing mounts relatively soft. This arrangement and the double flexible mounting, provide outstanding insulation against road noise and tire rolling noise.

The rear axle carrier and the links are made from high strength steel. The wheel carrier is cast from GGG 40. Both toe and camber adjusting screws exist.

Minor differences exist between the HA 5 versions being used on the E9X and E82/88 variants. The rear axle of the E82 is fitted with modified wheel hubs. As a result, the rear track width of the E82 has been widened by 20mm in comparison to the E9X. The exposed wheel housings combined with the wider track width at the rear to emphasize this vehicle's rear-wheel drive.

Advantages with HA 5 compared to HA 3 - kinematics

The very small positive kingpin offset guarantees less sensitivity to longitudinal forces even in connection with wide tires.
The relatively large caster ensures a defined degree of lateral force understeering and therefore improves vehicle handling/stabilization and offers faster response.
The change in toe as part of the suspension action enables outstanding directional stability with a relatively short wheelbase and exceptional self-steering characteristics while cornering.
The change in camber as part of the suspension action is selected in order to establish an optimum camber with respect to the road surface while cornering.
The long toe link has a positive effect on the toe-in characteristics over the spring travel range.
A low roll center has a particularly beneficial effect on the rolling motion.
The "propping" effect while cornering has been largely minimized by improving the roll center change rate.

Total toe-in (angle): ?
Track width: 1532 mm
Camber: ?

F80
Also HA 5

Same five-link rear axle as for E9x. Components and bearings redesigned for increased requirements. All trailing arms and the wheel carrier are made using forged aluminum. 3kg unsprung mass saved compared to E9x. Spring strut also designed in aluminum. The rear axle support is fixed to the body without a bearing (bolted on for optimized wheel guiding and directional stability / less comfort). Diagonal struts added to achieve a direct transmission of the longitudinal forces applied during braking.

Total toe-in (angle): ?
Track width: 1603 mm
Camber: ?

[Drew@Sonic MS]

The E36/E46 rear end is well-known to be extremely well designed - numerous articles about that, you can do a quick google search.

I'm by no means a technical expert but just from experience on working on numerous 1/3-series, the difference is noticeably there.

[Drew@Sonic MS]

Uploaded some pictures from HRE's photoshoot.

Jake@Motiv is sending the rest of the fueling system today so hopefully we can show some results the following week!

[BMWZ4RIDER]

That's a Beauty.

[Alext]

Can't wait for the vids!

I'm no expert either but I can confirm that the e89 feels a LOT more planted that the 135i that I had.

[Pejsen]

Very cool indeed!

[flpnout]

I'm liking the new shoes better than the previous ones! Your Z4 looks fantastic. Take me for a ride soon!

[Drew@Sonic MS]

Fueling solution is finally done! Should have everything good to go by next week.

Cris, already on another set of shoes... BBS Motorsport haha.

[VMRWheels]

Beautiful ride

[Hujan]

Form and function. This might be the perfect Z4. Love it!

[jts1981]

Any updates?

[jts1981]

Any updates or vids?

[ttuner]

yes, updates. My favorite Z out there right now...