Precision Raceworks LIVE BUILD EVENT!

[ccbsecu]

Dammit!!! I would have donated my 135 for this build and supplied most of the parts I already have sourced!!!!

Sleeved block, forged internals, built head, DocRace 6870 kit, LSD, stage 3 clutch and flywheel, axles and solid driveshaft, Diff and subframe bushings, FMIC, etc, etc, etc!!!!

 

[zmon1300]

Don't forget to address PCV and suspension on a 100k mile car!!

 

[PRECISION RACEWORKS]

Update Feb 14th – Happy Valentine’s day to Precision Raceworks Exhaust Arrived!

We are proud to share our decision of which exhaust meets all of our criteria and will share why below. Special thanks to Tiago Vieira and team for getting the exhaust out quickly to make sure it can be here for our aggressive build schedule. Your product was the first to show up at our doorstep!

Exhaust Selected
VRSF 3.5" Street Stainless Steel Catback Exhaust 07-12 BMW 335i/335is

​

So as we mentioned above exhaust is not “Required” to meet our Hp goals so why did we decide to add exhaust to the car and why did we select the VRSF 3.5” kit?​

- First off on a car with 100k miles it is always good to evaluate the exhaust system, depending on if your car is from the north you might have rust and leaks.

- Secondary cats become clogged over time by carbon build up and can reduce flow so a good evaluation of the exhaust should be done.
​

We inspected our exhaust system very well and found there was no rust and inspected the secondary cats (as best as you can) by camera. Everything looked to be in good shape however the factory exhaust system weighs roughly 92lbs while the VRSF 3.5” kit weighs exactly 49lb 4oz. So while our goals do not require upgraded exhaust we do get a more free flowing kit, a more aggressive sound, and a weight reduction of roughly 42lbs. These benefits were enough for us to justify the very well-priced VRSF Street Exhaust kit.

But what about quality? Isn’t that Important?
Absolutly!​

We are known for products of the highest quality and we expect the same from any product we put on our cars!

So what are critical features when selecting exhaust?
​

- 304 or 316 stainless you want low carbon content in your exhaust system or else it will rust (often from the inside out). Many cheap e-bay kits claim to be full stainless and many are however ALL STAINLESS IS NOT EQUAL! A great example of this is Grills, you can buy a cheap bargain brand stainless grill (430 grade) and it will look great and while it is stainless leave it outside for a year or two it will be a rust bucket. Or you can buy a better grill such as a Webber full stainless grill and you can leave it outside for a decade without it rusting. Exhaust is the same as a grill it is exposed to the elements and heat. So make sure you buy an exhaust kit that is 316 stainless or better (smaller the number the better the grade).

o The VRSF kit is 100% 304 stainless so this gets a pass from us
​

- When buying exhaust you are looking to flow more, and while a straight pipe is not always possible you want minimal bends, smooth radius, and no crinkle bends (they create turbulence).

o As you can see in the photo below all bends are smooth mandrel made bends no crinkle bends the angles are not sharp changes. The kit gets a pass for this requirement as well​

- Another important requirements for us is gauge of the metal. Do you want exhaust that lasts if so you need thicker gauge of steel and the industry standard is 18ga. Cheap exhaust kits use thin tubing to save cost on both the product and shipping (free ebay shipping costs someone you know!).

o The VRSF kit measures 1.1mm thick on all pipes measured which equals 18 gauge steel. This matches with the top dollar names on the market which makes this criteria a pass as well

- This last requirement could be a personal preference and we all have a specific “sound” we are looking for when we select an aftermarket exhaust. For us we HATE the raspy bumble bee sound found in many cheap China made exhaust system. Coming from China is not what makes it have this sound but many China brands cut all the corners possible to make it look good but don’t care about the actual end product.

o For this we will let you listen to the exhaust just like we did (we heard it in person as well) and let you make a decision for yourself. But for us the exhaust sounds clean and has a factory performance sound with no drone, rattle, or rasp. PASS!​

Even the packaging for this kit was top notch with expansion foam to ensure tight packaging so no parts rub and get damaged or move excessively during shipment!

​

So you can clearly see we made the right choice when we selected which exhaust system to go with. While it might not be “required” to meet our goals here we will benefit from the weight savings and will enjoy the aggressive sound a car with 600-700whp should have.

 

[PRECISION RACEWORKS]

Update Feb 20th – General maintenance day 1

Running a business it is hard to find time to work on side projects such as this car but with March 10th coming up quickly we needed to address some of the maintenance that needed to be taken care of so a couple guys went to the shop today and took care of maintenance on the upcoming build.

1st we had plans of doing walnut blasting this day and wanted to document before and after HP numbers from walnut blasting a 100k+ car. Unfortunately when the intake manifold was removed we found the previous owner had walnut blasting performed fairly recently as there was very little build up on the valves.

During the dyno session we noticed the smell of sulfur (aka rotten egg smell) which is a sign that the catalytic converter is failing. There are a few ways a catalytic converter can fail but we won’t get into those and honestly none are that important as they can’t be repaired anyways only replaced. Lucky for us we already purchased new exhaust that removes the catalytic converters and will be using cat-less downpipes as well.

“Rotten egg Smell Explained”

The smell of rotten eggs is due to a compound called hydrogen sulfide. This comes from the small amount of sulfur that is present in the fuel. Normally the sulfur is converted to sulfur dioxide, which has no odor. When the converter breaks or the filtering layers have worn down inside the converter, the sulfur is not transformed into the odorless form. Therefore a strong rotten egg smell is produced. Another possible cause for this smell may be that the converter is plugged. Unfortunately you cannot repair a converter but need to have it completely replaced. Two other causes of rotten eggs besides a broken catalytic converter include an engine that is running too hot or a broken fuel pressure regulator. You can easily deal with the fuel pressure regulator by replacing the fuel filter.​

Getting started on the work​

We won’t get into the details as this is not intended to be a DIY and there are plenty of DIY’s out there for the work we performed this will just be a couple pictures snapped and a note here and there.

Here we went ahead and tapped the head and blocked the PCV channels in the intake ports. So far this is the only thing we have done in way of “modifying” the car. We decided since we were replacing the valve cover we would go ahead and knock this out. Note the use of antisieze being used here instead of tapping fluid. Grease would of worked as well but we had antizieze handy. The purpose of this is to catch as many of the metal filings as possible so they don’t get into the engine. We also placed a shop rag in the port under the PCV hole to capture more metal shavings and left it there as we sprayed brake clean through the hole after taping to remove any shavings left behind in the hole.​

Noticing the little things​

When you get a new car and do the general maintenance right away you will get a good feel for how the car has been treated. As soon as we removed the oil housing we noticed it had been recently done despite us thinking it was leaking due to an oily mess around it. This was obvious by the condition of the gaskets as they were all nice and pliable, not hard, and easily removed. So it was clear that whoever changed the gaskets didn’t clean up the mess that was made by the old ones leaking. On a positive note we were also able to observe that the mating surfaces were cleaned well and that care was taken to do the job properly. (Many people that do good work are scared to clean with water or even brake cleaner in an engine bay and while it can be done without issue it is a good sign the person is overly cautious despite thinking they are lazy).

When we went to remove the valve cover we noticed that at some point one of the plastic lines had the nipple broken off by someone. This most likely happened when they tried to pull off an old hardened vacuum hose instead of cutting it with a razor as most mechanics would do. Unfortunately they did not replace the part simply did a band-aid fix which we don’t believe in doing. So while it most likely will function perfectly fine the way they repaired things we went ahead and ordered a new line from BMW so we can replace it during the next round of maintenance.

That pretty much sums up the few things that were taken care of this day, we will have one other maintenance day (possibly 2 depending on amount of time we get to focus in a single sitting on the car). We got the leaks (or potential leaks) addressed, got the ports plugged, and got a better idea of how the car was cared for. Plus got to see the Lambo make a little progress as it gets prepared for the ½ mile event coming up.

 

[PRECISION RACEWORKS]

Update March 2nd – VTT TURBOS!!!! / Welding Fabrication

VTTO N54 "GC 2.0" GAME CHANGERS

Requirements​

In our requirements list for this build we mentioned each criterion we were looking for in the turbos we would purchase for our build.

Good Fitment​

While big single turbos can make big power, they come with a few setbacks. One can be good fitment -this is one of the things that discouraged us from going big single turbo. Single turbo kits require many fabricated components leaving several places for potential mistakes, most of which are hard welded and very unforgiving. The GC turbos fit like OEM with no modified lines needed or special routing, the only exception being the compressor outlet of the turbo but Vargas sells the outlet connection so this is not a problem. In our mind keeping things factory location is important when it comes to future maintenance as most components are available off the shelf.

Aftermarket Manifold​

While we want stock location as explained above this is intended to be a vehicle that performs well and utilizes the best product features on the market. Cast manifolds are one of the newest things offered and currently only two suppliers we know of are offering them. We could go into details on the differences between the two but what is important is what we were looking for and why these manifolds are the right choice for us.

The factory manifolds are very restrictive with a bottle neck around 1” in size where the manifold connects to the turbo. Most likely the factory did this to increase velocity making faster spool time for the turbos at factory horsepower. While this faster spool time is great at factory horsepower it becomes an issue at higher levels (we are over doubling the power on this car). By opening up the port we are now able to have less back pressure and a freer flowing exhaust system. With that said we still need and want the same velocity effect the factory had we just want it to match with our new target horsepower.

We talked with Tony at Vargas several times over the past couple months about the new GC 2.0 turbos trying to pull information from him to make the best selection. While we can’t share all the information because we don’t have permission we will say the team at Vargas took the time to do flow testing on the manifolds during design and make sure to increase efficiency without killing spool time due to oversizing the ports.

Horsepower Rating​

While Vargas has made 850whp with this same setup it was done with a fully optimized built motor with custom head work for maximum efficiency. In a stock internals application, the turbos would be capable of around 775-800whp. With our 650ish whp for this car we will do math on 650whp and see how the 20% headroom requirement is met that we were looking for in the initial write up. So 650x1.2 (20% extra) puts us at 780 minimum capability requirement and you can see above there is no issue here. We would actually feel safe taking the turbos up to 700whp without any concern for the turbos longevity. Keep in mind we are tuning for around 650wtq as it will already be pushing the limits of the automatic transmission the actual horsepower numbers will be whatever they end up when we have very nice smooth torque curve maxing around 650wtq.

Turbine Design​

Turbine design is the art of any turbo and VTT made a great turbine for quick spooling and efficient. The turbine is the hardest working component of any system. It’s job see’s the hottest temperatures, is under constant pressure, and is required to transfer this energy through a shaft to the compressor side of the turbo which is under pressure as well (boost). There were some issues because of this in the past as Vargas used the same standards others still use but the reliability just isn’t there with those standards.

Because of this VTT spared no expense and went with a new blade design and uses Inconel 713L for the turbine which retains strength over a high temperature range. Those two differences eliminate the industry-wide TD04HL 9 blade wheel failure problem while improving wheel Aero; even better spool and more flow. We aren’t here to teach about material grades you can find out that information on Wikipedia. This alone was enough of a reason for us to choose Vargas turbos for our build and for version 2.0 we have to agree this is a game changer.

Turbo Inlet Connection​

In our initial requirements list the turbo inlet size of 2” was listed which is not hard to find among turbo manufactures these days. Even stock frame turbos are often modified to have 2” inlets to work with the largest highest flowing inlets on the market. The VTT GC 2.0’s of course have this 2” inlet but also have a ribbed connection to combat the common problem of inlets slipping off. This ensures easy install and removes the issues of clamp placement. So there isn’t much to say about this other than it is a simple yet critical requirement that anyone who has installed inlets on stock frame turbos fully understands.

​

Summary of changes in the GC 2.0 vs original GC turbos​

Key Features of the GC 2.0 reboot are as follows:

• 100% designed, and cast for VTT: this is not a partnership with any other company

• All new castings with VTT logos front and center

• D5S Ni resist material is used throughout the hot side. This includes Turbine housings as well as manifolds.

• All-New Compressor housings with ribbed inlets to ensure a secure fit from inlet to housing.

• Single piece V-band clamp connection from turbine housing to manifold sized to fit Tial Clamps. No more awkward two-piece clamps to install.

• The single biggest improvement is the casting of proprietary turbine wheels in Garrett GT28 profile with a TD04HL shaft to fit the existing GC family bearing housing. Wheels are cast from Inconel 713L. This eliminates the industry-wide TD04HL 9 blade wheel failure problem while improving wheel Aero; even better spool and more flow.

• Full sized GC’s, and GC Lites still available

• Rebooted pricing. With all these improvements the GC line up price still dropped

What didn’t we get that we wanted out of these turbos?​

The only requirement we had and did not get out of the turbos was a V-band connection at the turbo outlet. This isn’t really “necessary” and there currently is not anyone offering this style connection on the outlets. So to be fair it wouldn’t be a negative to the market only a negative to our requirements which can be asking more than actually needed at times.

But where there is a will there is a way to get everything you want. We reached out to Tony before purchasing our set of turbos and while reluctant, he agreed to let us take apart his turbos and chop them up while still honoring warranty on them! Now I wouldn’t expect him to do that for everyone as most people don’t have fabrication equipment or experience in house to tackle these sorts of things. But Tony said “You know what, you guys do great work in everything else you do… go for it, I trust you will take the same care we do when modifying and assembling them”. Who knows maybe VTT will start offering a V-bad turbo outlet as an option or a standard? That would be up to them we were just grateful we could modify them without sacrifice of warranty and suggest if you intend to do what we did that you contact VTT and talk it over in-depth with them first!

Getting started on V-band Conversion
Well the turbos showed up at 7pm and we opened things up and got excited Tony threw a set of V-band fittings they had for outlets (o-ring in face) in the box in case they would be useful. A couple of us looked at each other and said why wait. Quickly we loaded up some tools and drove to our old location as we haven’t moved the fabrication equipment yet. We devised a game plan to weld up the ring groove and just machine the face to save time and give an OEM flange face for our outlets to sit against. Well that turned into a disaster… We forgot the welding torch/leads/pedal are in the big toolbox we already moved so we went and grabbed a TIG from someone’s house nearby and tried it out. Needless to say, the welds didn’t come out very good, we didn’t need much from them but when machined they looked horrible. See pics below for a good laugh of what thinking you are going to knock something out in an hour or so turns out like.

ewww... LOL don't have pic after machining will have to upload later...​

We revisited the turbos again the next day with our equipment and flanges we machined from scratch and things went much better. As you can see the flanges look just like the factory flanges except the ID is larger to match the exact size VTT designed the ID to be.

Next we took a couple measurements to decide where we wanted to cut and weld the new flanges on. Cut the turbo housing using a band saw carefully (as seen here) and precisely measured the height needed one more time for the flanges and cut them to their final length.

Then it was time to fire up the TIG, line things up, and finish up the job so here are a few more pics of how things turned out once complete. Nothing major here if you are setup with the right tools for the job but we were happy with the end result.

Overall Summary​

Our experience with VTT was excellent, communication was spot on, and they allowed us to modify their product to be everything we dreamed of in a set of twins.

Really not sure what else there is to say at this point other than we couldn’t be any happier with how every aspect of our selection has turned out. Great work VTT team!

 

[pysical]

+1 for VTT.

 

[PRECISION RACEWORKS]

Update March 5th – Fuel supply

Precision Raceworks Stage 3 Pump Kit
High Voltage secondary pump driver & Fuel Filter Assembly

​

When building a high horsepower car fueling is one of the most important things to get right. Luckily with modern cars we have fuel pressure sensors and computers that adjust pulse to injectors based on pressure. This is great for a safety net but when you are trying to make higher horsepower like we are you want solid fuel pressures and not just pressure but volume.
This kit we are running will support much higher horsepower cars but with the kit being our product (some parts aren’t even public yet) it would be foolish not to run a fuel system that will be solid throughout the RPM range with no sacrifice or risk of running short on fuel supply.

Pump Fuel Flow​

Historically everyone has supplied data of pump fuel flow out of the pump. The problem here is the output from the tank does not connect to the pump itself it connects to the factory fuel filter/regulator assembly. This assembly happens to be the restriction in the system it is such a restriction that the stage 3 bucketless systems do not benefit like they should. We will get to the solution for this issue a little further down but for now we want to discuss why we selected a bucket system over bucketless.

This is one of the restrictions in the filter assembly and it is no secret as you see here in a photo Fuel-it took yet it is still commonly ignored. Thanks Fuel-it for making a good explanation photo!

Bucket vs Bucketless​

This car will be a daily driver so it will see low fuel conditions, it will most likely get driven somewhat hard on the streets and through the curves at less than ideal fuel levels. Because of this a bucketed fuel pump is the best option as it keeps the car from having any fuel starvation issues due to slosh and most importantly keeps pump temperatures down by having the pumps always submerged in fuel.

High flow Fuel Filter/Regulator Assembly​

The Factory fuel filter assembly restricts flow greatly limiting you to maximum of 1.8gpm at 72psi this is a problem when you are looking for steady pressures and is a bottle neck to all fuel pumps above stage 2. To put things in perspective a stage 3 bucket pump flows around 2.1gpm and a stage 3 bucketless flows around 2.3gpm this means removing this restriction would be roughly a 15% gain for a bucketed stage 3 pump and roughly a 20% gain for a stage 3 bucketless! Best of all on a car with 100,000 miles the fuel filter is long overdue for being replaced anyways!

​

But wait there’s more!​

So above if you noticed the math the factory venturi in the bucket consumes .2gpm that’s why there is an increase when it is ditched with a bucketless system. Did you know there is a 2nd venturi that you can’t ditch located on the fuel filter side? It pumps fuel from the driver’s side up over the driveshaft hump and to the passenger side so you can use your full tank of gas. This venturi happens to also consume .2gpm but since it can’t be removed we have to get the gas over somehow we decided to take the waste off the built in adjustable regulator and use it to drive the venturi. Now we gained .2gpm for doing nothing but moving plumbing around a little.
One of the biggest perks to our fuel filter/regulator assembly is true AN fitting output from the filter. We actually designed it so you can pick your fuel line size anything from -4 to -12 will work with our kit. It is as easy as unscrewing the drop in XRP racing 10 micron fuel filter and screwing in another XRP filter with the output size of your choice.

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High Voltage Pump Driver​

Now to be honest this is in no way needed for a build around the 700whp mark but we have been kicking around the idea of changing out the transmission in the future and making more power. So since we haven’t released this at all to the public we won’t post any information or numbers. Just know this driver will work with any existing dual pump setup on the market and take your fuel supply to the next level without even smelling fuel!

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Fuel Line​

We selected an -8AN fuel filter to screw into the Fuel Filter/Regulator Assembly which gives us a true -8AN fuel connection for our fuel line. With this we have a single -8AN line the runs to the front of the car with no additional connections or potential leak points. This setup will support much higher horsepower but will ensure that we have zero dips in fuel pressure. Best of all since the regulator is built into the fuel filter assembly we don’t have to run a second line back to the tank!

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Summery​

This fuel setup is overkill for the car we are building, a simple stage 3 bucketed setup would supply the fuel needed for our horsepower goals. It would keep all reliability of a OEM designed fuel system for low fuel conditions while providing more fuel then the filter/regulator assembly can handle. Matched with upgraded fuel lines 650-700whp would not be a problem and fuel pressures would stay solid.

 

[PRECISION RACEWORKS]

Update 2 March 5th – Flex Fuel

Motiv Motorsports & MHD Flex Fuel!
We are proud to say that we will be one of the first Flex N54’s ​

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The MOTIV Flex Fuel Box will allow you to finally have full Flex Fuel capability in conjunction with the MHD Flex Fuel module. Every necessary table will interpolate between a pump gas and full e85 map without touching a thing. Fill up and go regardless of the mix. Thanks to a collaboration between the incredible guys at MHD, Jake Yamona and MOTIV we can now have true Flex Fuel.

Why Flex Fuel is important to our build​

Flex Fuel isn’t complicated we can’t write a super long review on this like we can turbos and fuel systems etc. But Flex fuel is a very important part to our build because as we stated this is being built to be a daily driver. Just like we want safety in our fuel supply with a bucket system we want FLEXability it our fuel type.

With an Ethanol sensor you can fill up with 93, e85, e100, whatever you please and instead of having to keep up with your exact blend and flash new maps so the car runs right. Or even more important so you don’t damage the motor because it thinks you are running a higher octane gas then you are. The Ethanol sensor tied into the DME allows the computer to constantly adjust your tune based on the ethanol content.

This is great because on a daily driver you don’t know if you are always going to have access to E85. Or maybe the wife is going to drive the car for the day and you don’t want to have to change the flash in case she fills up with the wrong gas.

Is Flex a requirement? Can you live without it and be just fine? Absolutely but for the small cost it is a wonderful insurance policy for your motor. Best of all the car will perform it’s best no matter the fuel you put in the tank because now it is smart and can make necessary adjustments to perform how it should at the given ethanol levels.

 

[Jake@MHD]

Going to be a very exciting day! Following

 

[pysical]

@PRECISION RACEWORKS

When does your driver side FPR kit come out for sale? Any group buys or anything for this? Maybe some sort of bundle with the lines as well? Looking to provide fuel to my 750hp build. Currently only have the S3 bucket pump.

 

[devildog0905]

so excited to see the results of the Flex Fuel kit!!!

 

[PRECISION RACEWORKS]

@PRECISION RACEWORKS

When does your driver side FPR kit come out for sale? Any group buys or anything for this? Maybe some sort of bundle with the lines as well? Looking to provide fuel to my 750hp build. Currently only have the S3 bucket pump.

We do not currently have a release date this is the first unit we had machined for testing of design and fitment. With the build going on we can't make the few minor tweaks we would like to make before production. Best guess we will have inventory here in 8 weeks or so.

 

[doublespaces]

 

[PRECISION RACEWORKS]

Update March 7th – Wavetrac LSD arrived!

From the factory the 335i came with an open differential what this means all power is sent to the wheel with the least amount of traction anytime traction is not equal across both wheels. This isn’t good for many reasons but for us the biggest reason is we need as much traction as possible for the increase in horsepower.

Limited-slip differentials such as the Wavetrac we selected limit the tendency of sending the power to the wheel with the least traction. These differentials send power to both wheels at the same time when traveling straight. If a wheel experiences some loss in traction and begins to spin faster the differential directs the torque to the other wheel which still has traction which reduces the work load from the spinning wheel allowing it to regain traction. Simply put limited-slip differentials send power from the wheel that’s slipping to the wheel that isn’t.

So why did we pick the Wavetrac over say the MFactory? (give you a hint it wasn’t cost)​

To best understand how the Wavetrac is truly different from the other gear differentials on the market, you first have to understand the primary problem that the Wavetrac solves. Loss of Drive in Zero Load Conditions

Zero Axel-Load​

Zero axle-load is a condition that occurs during normal driving, but creates the most noticeable problems when driving in extreme conditions. Zero or near-zero axle-load is the condition that exists when there is ‘no-load’ applied through the drive train, when one drive wheel is nearly or completely lifted (often in aggressive cornering). It also occurs during the transition from engine driving a vehicle to engine braking and back, even with both drive wheels firmly on the ground. (Or during wheel hop - hint hint)

​

How does this loss of drive hurt you?​

1) If you lift a wheel, all gear diffs except Wavetrac, will NOT power the other wheel with traction.
2) During the transition from accel to decel, all gear diffs except Wavetrac, do nothing.

Why does this happen?​

• All gear LSDs (including Torsen, Truetrac, Quaife, Mfactory, Peloquin, OBX, etc.) work in basically the same manner: They divide the drive torque between the two axles, applying drive to each side, up to the available grip of each tire. The amount of drive torque one wheel can get over the other is described as the bias ratio, a measure of the torque split across the axle.
• Standard, open differentials have a bias ratio of 1:1. They can only apply as much drive torque as there is available traction at one wheel. When one wheel loses grip, the total available drive is lost as well (at a 1:1 ratio). All your power goes out the slipping wheel - along the path of least resistance.
• Torque biasing differentials offer increased bias ratios over open differentials. For example, if a diff has a bias ratio of 2.5:1, then it can apply drive torque to the wheel with the most traction (gripping wheel) at 2.5 times the traction limit of the wheel with the least traction (slipping wheel). This is a significant improvement over an open diff… most of the time.
• The problem is that when one tire has LITTLE or NO grip (zero axle-load), the other wheel gets ZERO DRIVE, because (basic math here): 2.5 x 0 = 0.
• Lift a wheel (or substantially unload a wheel) and you get zero axle-load on that side - that means that during the time the wheel is unloaded, the typical diff will NOT power the wheel that’s still on the ground. No matter how high the bias ratio, you get no power to the ground.
• During the transition from accel to decel, where you have near zero torque on the axle, even if the wheels are on the ground, the typical diff is unable to begin applying drive torque until AFTER the zero torque condition is over. While this condition is generally short-lived, the fact that most diffs can do nothing during that time means that there will be a delay once the zero torque condition stops - creating a reaction time in the driveline.
• The innovative, patent-pending, Wavetrac device in the center of the diff responds during these exact conditions when zero or near-zero axle-load occurs. At or near zero axle-load, the axles (and therefore each side gear in the diff) start to turn at different speeds. This speed differential causes the Wavetrac device to step into action:
• Precisely engineered wave profiles are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart.
• Very quickly, this creates enough internal load within the Wavetrac to STOP the zero axle-load condition.
• The zero axle-load condition is halted, and the drive torque is applied to the wheel on the ground (the gripping wheel)… keeping the power down.
• Some gear differentials rely solely on preload springs to combat loss of drive. The drawback is that you can’t add enough preload to prevent loss of drive without creating tremendous handling and wear problems at the same time. So, to avoid these problems, the preload from ordinary spring packs must be reduced to a level that renders them ineffective at preventing loss of drive. The Wavetrac is the only differential that can automatically add more load internally when it’s required.
• In the case where both wheels are on the ground during zero axle load, such as during a transition to deceleration, the Wavetrac device is able to prepare the drive train for when the zero torque condition stops, eliminating the delay seen with ordinary gear diffs.
• What this means for you as a driver is that power is delivered to the gripping wheels for more time and in a more constant manner – making you faster and improving stability.

The Wavetrac truly is different - and its innovative features can make a real difference in your car’s performance.

Now for the short version of why we went Wavetrac​

So no other LSD on the market has the ability to drive torque to the traction wheel in a zero load condition except Wavetrac (that is the big difference with them an all other brands available. This is very important in competition environments where every 10th of a second matters. But we are building a daily driver that is to be fast and reliable and really don’t care about those extra 10th of a seconds we are leaving on the table. That’s right requirement 2 is reliability…

Wheel Hop is a common problem that we try to combat in the 335/135/535 platforms we won’t get into details on what causes wheel hop you can read that on your own elsewhere. What is important is we do our best to not only combat wheel hop but to also prevent damage if it does occur.

When wheel hop does occur the unloaded wheel spins up quickly while in the air only a short period and then comes back in contact with the ground transferring all inertia and torque to the wheel and more importantly to the drive axel. When this happens often the axel of the car breaks and can cause additional damage or loss of control of the car. Often these situations are pretty controlled and at lower speeds but with higher horsepower cars the speed at which this situation can occur increases. Best case you end up breaking a part and stranded waiting on a tow truck. This alone is enough to warrant the slight cost increase of the Wavetrac over other brands available on the market.

 

[NoQuarter]

Nice write-up on the LSD. Some quality effort went into creating such a short yet informative article.

When a real LSD is installed, do we need to account for the electronic LSD that still thinks it is running the show?

 

[doublespaces]

Nice write-up on the LSD. Some quality effort went into creating such a short yet informative article.

When a real LSD is installed, do we need to account for the electronic LSD that still thinks it is running the show?

It needs disabled is my understanding.

 

[Jake@MHD]

It needs disabled is my understanding.

I wouldn't say it "needs" to be, but certainly can be.

 

[NoQuarter]

I wouldn't say it "needs" to be, but certainly can be.

Is this a change via NCSExpert?

 

[veer90]

Is this a change via NCSExpert?

Yes, but I haven't done it yet and the car drives fine as a daily and on an autocross course

Is it a huge difference?

 

[doublespaces]

I had this done by @Levanime but I think he prefers to work on the 'bigger' stuff.