Hydra's voyage into ///M

[questionable]

Originally Posted by lecaf

I totally forgot about your thread. I ended up retrofitting the steering rack as well, and I absolutely LOVE IT! Definitely my favorite mod so far, and as far as the servotronic goes, with a little modification, you can get it working. But even without it, I don't mind

tell me more about how you can get this to work ?

[nacaruh]

Originally Posted by questionable

tell me more about how you can get this to work ?

Pulled from babybmw:

"The servotronic takes a PWM (pulse width modulation) signal at 9v, so theoretically it should be fairly easy to hit maplin and sort out a simple module to allow you to dial in as much assistance as you want."

"Some of the guys who've put M5 racks into their 540i cars have managed to retrofit proper BMW servotronic control by wiring the solenoid into the appropriate module (i can't remember which one it is but it's easy enough to find on google) but that works because servotronic was an option on the 540.
On our cars, only the active steering cars have servotronic, so i'm not sure we'll have the hardware / software options to get it sorted."

So definitely with the proper wiring and coding, it's possible to get this feature working. But tbh, unless you know what you're doing, I don't think it's worth the time and effort. Yes, the steering is a bit stiff on low speeds, but you kinda forget about it as you drive it more.

[ShocknAwe]

I'd love to put a M rack in. How much did you guys end up out of pocket for one if you don't mind me asking?

[nacaruh]

Originally Posted by ShocknAwe

I'd love to put a M rack in. How much did you guys end up out of pocket for one if you don't mind me asking?

From what I've seen, it can range from $500-$1000. I got mine for a very good price, and I just paid for the labor + alignment.

[hydra]

Yeah I got the M3 rack for a pretty good price as well, and I can safely say that it was worth every penny, one of my favorite mods on the car. I never bothered hooking up the Servotronic power-assist, the heavy steering at parking speeds doesn't bother me in the least, but I would imagine an easier way of doing this would be to remove or drill out the oil control valve in the steering rack, which is basically the same thing as 100% Servotronic PWM all the time...

[hydra]

So After going with 650lb Hyperco rear springs with adjustable perches it was quite apparent (surprise surprise) that the 200lb/in Swift Spec-R front springs were too soft, so time to upgrade again! Enter a pair of KW Street Comfort struts with special-ordered 260lb/in linear rate springs... It remains to be seen whether or not I will need a 16mm rear sway bar to re-balance the car after the front coilover upgrade as I like how neutral it is right now. Will report back in a few days I guess...

[hydra]

FWIW, the KW's feel so much better than the Swift/B8 combo I previously had on the car, car even rides better than it did before despite increasing the front spring rate another 30%, so that came as a pleasant surprise..

[hydra]

Put my car on racing scales just now, came in at 2997lbs with 25% in the gas tank, I still have another 16-19kg to shave off via 1M tranny, aluminum recaro side mounts, and a carbonfiber driveshaft although I will gain some of that back when I install the 1M (PPK) auxiliary radiator for greater cooling capacity.

[hydra]

Some pics from last Sunday's M club mini-track meet:

[dane083]

That backdrop is amazing. What a nice plce for some spireted driving.

[hydra]

Here is a video of a 100-200kph pull done in 4th gear on 98RON pump gas ONLY, running 21.x psi on GC Lites in 15C ambient temps on a perfectly flat coastal highway. 100-200 in 6.43s. A 3rd-4th gear pull would have been quicker, but I am unable to get the car to hook in 3rd, even on brand new RE71Rs ...

[Bullitt]

Amazing how you got the 135i's weight down to under 3,000lbs.

What CF hood is that and no aerocatch / hood pins necessary to keep it secure?

[Matticus91]

Holy shit man how have I missed this thread! Awesome build I love what you've done with the car so far. Very impressive.

[hydra]

Put down 665whp on the dyno last week running 22psi on my race gas tune. Have a few more upgrades on the way so lets see if we can crack 700whp next time around

[Matticus91]

Originally Posted by hydra

Put down 665whp on the dyno last week running 22psi on my race gas tune. Have a few more upgrades on the way so lets see if we can crack 700whp next time around

Holy guacamole

That's some nutty power man!!

[hydra]

Originally Posted by Matticus91

Holy guacamole

That's some nutty power man!!

Because if some is good and more is better, then too much is juuust right

[Matticus91]

Cams now????? What range are you aiming for?

[hydra]

Originally Posted by Matticus91

Cams now????? What range are you aiming for?

It remains to be seen what kind of gains these cams will net on the N54, but I will be installing these along with a ported head and an ADE-650 FMIC so will re-dyno once we put the car back together. I'm guessing it should be able to hit 700whp on race gas, will be sure to post an update in due time..

[hydra]

After a long hiatus, I've decided to create a thread to chronicle all the updates and developments I've put together for my 1er over the past few months. I've given much thought to improving several aspects of our driveline, and came up with several useful observations and - dare I say - new ways of doing things that I figured I would share with the community. So without further ado, here goes:



N53 head + Schrick cams

The biggest bottleneck in the N54 when it comes to making power lies in its cylinder head design. Optimized for peak torque at very low-rpm, it becomes more and more of a restriction as more air is pumped through the motor with increasing piston speeds and pressure ratios. Even porting it for all its worth isn't enough, as the exhaust port outlet is simply too small @32mm ID for a 500cc cylinder, leading to choked flow and excessive pumping losses on the exhaust stroke. The Mitsubishi 4B11 on the other hand (a good example of a modern high-performance 500cc/cyl FI design with similarly sized exhaust valves) runs the equivalent of a 36mm exhaust port, just for the sake of comparison... The intake side isn't all that much better, with a 22.x mm venturi feeding a 31.4mm intake valve, with a horrible short-side radius which really kills high(er) lift flow on the N54 head, far from ideal once Schrick cams come into the picture... So I looked at other BMW NG6 cylinders heads for inspiration. The N52 comes with a very nice CNC ported head, a la S54, but lacks provisions for DI. Now the N53 on the other hand, available in a 90PS/L variant in its ultimate form, runs bigger valves than the N54, and best of all runs the very same DI hardware we do. So I figured surely this was worth a closer look, and went out and procured one to see for myself, and what I found was very encouraging. Pros : +0.6mm intake valves, +1mm exhaust valves, +4mm exhaust ports, 28.x mm venturi on the intake ports (ideal for a 32mm valve), and a nice sharp recessed divider on the intake ports, similar to what you would see on a modern bike engine. Best of all, stock N54 intake manifold bolts right up! Cons: Coolant passages in the deck are different, exhaust manifold flange is different, meaning custom exhaust manifolds are a must, head bolt holes are 1mm too small a la N52, and custom washers for the head bolts need to be made. So it became clear to me that I would have to do whatever it takes to make this work, as the pros easily outweighed the cons in my mind. Of course having a shop complete with machinist and fabricator might have had something to do with it..

Unfortunately, for reasons which escape me, I did not document this process and only have 1x photo of the (as yet unassembled) head before it went on the motor... I will have more in the near future as I am preparing two more of these heads to go out to customers in the US, one of whom will put it on a flowbench to compare with his existing ported N54 head, I am expecting ~23x cfm @ 0.45" lift @ 28" on the intake, and ~185 on the exhaust, so watch this space!

Just for the sake of reference, I have also included a dyno plot of a stock N53, with catless headers, tune, and an N54 intake manifold, notice how it makes almost 100PS/L , and how power keeps rising with rpm while maintaining a very flat torque curve... Food for thought eh?

[hydra]

Custom TT manifolds

Now with the top end of the motor out of the way, and since custom-fabrication was going to be needed anyway, my focus turned to the exhaust manifold(s) and how best to address the matter. I have always been of the opinion that , with all due respect to everybody selling and running them, that ST setups are a vastly inferior choice on the N54 due to several reasons; packaging constraints, incompatibility with the MSD8x DME without additional control boxes, and greater rotational inertia for a given flow capacity being the first to come to mind. Our cars simply were not designed for a single (regular rotation, N55 = reverse rotation) turbocharger setup, and in my experience the closer something is to having OE-like fitment to better, and more reliable the end result is likely to be @ a systems level. So after giving this much though, I decided that the OE shorty manifold design was a very good act to follow, and that I would try and recreate the same geometry using 1.25" Sch 10 304SS elbows whilst maintaining the most compact flow path possible to maintain velocity going into the turbine housing. Here is how it turned out; note the use of fusion welds wherever possible

[hydra]

HP800 Turbos

Now, you may be wondering what turbos are befitting of the setup described above. The answer is a new product I've been developing since Q3 2017, that has taken an inordinate amount of my time, effort, and money to make a reality. Right from the outset, I set out to create what I felt would be the ultimate stock-frame N54 twins, offering the very best construction, aero/adiabatic efficiency, and whp/psi available while keeping the overall package as close to OE-like as possible. Here is how I did it:

-The key to achieving my goals lies in the investment-cast SS turbine housing I designed boasting the highest flowing hotside of any existing stock-frame N54 TT offering as a quick visual comparison of the volute will confirm, with a nozzle area of 6.6cm^2, or ~35% more than stock, and even 10% more than S55 turbos. This is par for the course for native TD04 turbo designs, which usually have housings in the 6-7cm^2 range. Why other upgrade turbo mfgrs keep this information secret or "proprietary" is a mystery to me, maybe they just don't know the answer?
I also opened up the volute radius some 10% over stock to help turn the flow into the turbine, and added a proper cast-in separator between the turbine exducer and the wastegate port to reduce turbulence just like the stock design - something I haven't seen recreated on any other stock-frame N54 upgrade turbo so far. This smacks of poor design and a lack of attention to detail, as it costs nothing to incorporate into a new design.

What this all means at the end of the day is lower backpressure and EGT for a given boost level = higher Volumetric Efficiency & reduced pumping losses on the exhaust stroke = more whp/psi = WIN!


- Moving on to the turbine wheel. Right from the beginning I decided that nothing but genuine MHI 12-bladed TD04HL turbine wheels will do, as opposed to the generic chinesium 9-bladed turbine wheels of dubious design and suspect metallurgy. On paper, an increase in blade count means a decrease in the "slip ratio" and an increase in isentropic efficiency. This comes at the theoretical cost of slightly reduced flow area @ the exducer, along with a slight increase in rotational inertia. In practice neither of these disadvantages are realized, since most aftermarket TD04 turbine wheels (that I've seen at least) appear to be of inferior quality and have thicker blades than the native 12-bladed original. Putting theory aside for a moment, every single Mitsubishi Lancer Evolution (a platform we are extremely familiar with) ever produced came factory-fitted with a 12-bladed TD05H(RA) turbine wheel. Keep in mind that this is a platform that is still successfully used in competition to this day, still claiming multiple national rally/AutoX/etc championships all over the world while running the stock turbo. Case in point being my business partner's French Blue Evo VII AutoX monster, a 6-time national AutoX championship winner, which puts out just over 520whp on race gas all while running an FP 71HTA turbo, basically a stock Evo9 TD05 turbo, with an upgraded billet compressor wheel. You may be wondering how any of this is relevant to our discussion, well the TD04HL and TD05H turbine wheels come from the same design family, with the latter being just a 16% scaled-up version of the former. The resulting aerodynamic similitude bodes very well for both performance and durability...


As for the compressor side of things, I went through the trouble of designing a bespoke 7+7 bladed high-trim compressor specifically for this application, using the latest in high specific-speed compressor design techniques whilst juggling the conflicting requirements of maximizing adiabatic efficiency while maintaining a wide map width @ high pressure ratios for surge protection. I also had it anodized in blue for extra style points lol. Note that your generic chinesium 11-blade GTX clones don't take any of this into account, (assuming they are even accurate copies of original design to begin with) as all native GTX applications use surge-ported covers... Speaking of covers, I specced a native TD04 compressor cover which offers the correct diffuser radius and volute area. A TD03-style compressor cover is simply too small to properly support the compressor wheel in question, at the cost of decreased adiabatic efficiency and flow potential.

The end result of all this is a design capable of up to 74lb/min of flow before overspeed. This means that more flow is very well possible, but then adiabatic efficiency (and durability obviously) plummet. This means that a genuine 800bhp SAE should not be asking too much , provided the use of a high-enough octane fuel of course (race gas, E85, etc)... The difference with the other TT offerings out there being that this figure will be attainable at a lower boost level, with resultant benefits to EGTs, IATs, engine, and turbocharger durability.

As for construction, it goes without saying that these use full native TD04 CHRAs and are VSR balanced @ up to 150k RPM on a UK-made Turbo Technics V3 balancer, with individual balancing reports with each serialized CHRA for additional quality assurance.

In closing let me reiterate that I am not claiming to have reinvented the wheel here. After all, the turbocharger was patented in 1905, and pretty much everything done since has more or less been just detail design changes to the original idea. What I did was merely to piece together what, in my opinion were, the optimal combination of components to suit a high performance stock-frame TT N54 setup, and I am quite certain these will make the most whp/psi of any TT option out there, and quite possibly more than most ST kits as well...

[hydra]

Stainless Steel Turbo Heatshield & Outlet


In the interests of minimizing radiant heat within the engine bay, since I no longer have the OE double-walled manifolds, I set about designing a 0.6mm thick mirror-polished (on the inside surface) stainless steel heatshield to box in as much of the hotparts as practical, and also wrapped the downpipes for good measure to further help keep underhood temps down. I made a pilot batch of 10 of these heatshields if anyone is interested, fits right on top of the OE solenoid heatshield bracket - PM for details..

Also designed my own outlet, with full flow 1.75" ID connections, with a good shallow-angle merge into a 2.5" ID, and wrapped the whole thing in gold foil for good measure. Fits very well onto the car, and will never burn up due to being very far from any major heat sources.