VTT CNC Modular Billet Valve Cover & Dual Catch Can setup (review)

[berns]

With the constant beating I subject my N54 to, I was having some PCV issues and was tired of filthy valves and warping stock plastic valve covers. We all know the N54 runs hot, but for anyone that does road racing / time attack, you know it is a f%^*ing oven under the hood. I suspect the heat and abuse only accelerates the wear of the OEM valve cover.

I was intrigued with the VTT kit and while this setup isn't cheap, you really have to consider the cost of parts and labor on stock valve covers over the life of your car, plus walnut blasting! So, I'm glad I no longer have to worry about this part of the motor.

VTT Modular BILLET CNC Valve Cover

VTT is proud to announce a ground-up system designed to give the end-user complete control over their valve cover/ PCV set up. Tired of being told you will run two -10 lines from your VC to your Catch Can? So were we. Now you can run them any way you want, including complete VTA, oil cap

vargasturbo.com

The VTT Valve Cover fits perfectly. Not a single issue. It is a seriously beautiful piece. I went with the Billet version over the cast one for weight savings, as this is a time attack car and every pound counts!

Both Tony & @Chris@VargasTurboTech were awesome to deal with. They provided instructions on routing the lines and valves, and everything came ready to install. Tapping and plugging the head ports was a bit nerve racking, but it's really not a big deal once you get going. Just take your time and be gentle!

Each catch can has a window to check consumption, and they both have easy to access drains on the bottom. I know VTT sells a small petcock valve that you can fit to the bottom of the cans and that'd make emptying them way easier. Definitely going to order some!

After 6+ track days, I've had zero issues, and I don't expect any will turn up. Can't recommend this piece enough! Sorry for the not-so-pretty engine bay, it's a track car after all.

And a bonus shot of the valve cover in action!

 

[MDORPHN]

Bern -

Off topic, but what size sneakers are you running? Thanks.

Neil

 

[berns]

Bern -

Off topic, but what size sneakers are you running? Thanks.

Neil

I'm a size 10 in vans, 9.5 in adidas.

wheels are Titan7 18x10 +25 with 275/35/18 Nexen SUR4G. 10mm spacer up front and 15mm out back. Keep in mind, it's not a real 1M so my rear hubs are different than yours. Not sure if that means you'd have more or less room in the rear.

Just picked up a set of 18x10 +19 Fikse, running a 5mm spacer up front to clear the lower coilover perch and 10mm out back because I like to look cool!

Going to pull the front helper spring out soon to see if that'll work with enough preload so I can get some more room inboard. Ideal setup for this car will be 18x10.5 all around with 295/30 Advan A052. A052 is the mandatory street class tire for GTA now, so that's the goal for later this year.

 

[Chris@VargasTurboTech]

Beautiful!

 

[doublespaces]

Looks good, do you have the CES kit?

 

[berns]

Looks good, do you have the CES kit?

I do. I'll make a separate thread for it soon, or you can see detailed photos and some words here: https://www.spoolstreet.com/threads/135i-build-track-toy-with-a-license-plate.4522/page-4#post-89174

Here's a track video from the weekend. Car rips.

 

[Payam@BMS]

Great video and time! 1.53 is very quick at buttonwillow cw13 config.

How do you like the ST compared to the twins for track days? What size turbo did you end up going with?

 

[berns]

Great video and time! 1.53 is very quick at buttonwillow cw13 config.

How do you like the ST compared to the twins for track days? What size turbo did you end up going with?

yeah, feels good putting down GT3 RS times in my street car on 200tw tires
Running a Garrett GTX3076R Gen2, T4 divided 1.06a/r. I love this turbo for this application. So responsive and power / boost never fall off.
Took some adjusting to get used to the new delivery and personality of the N54, but now it feels properly suited to track duty, where the stock twins felt like they wanted to call an Uber home after the first hot lap. The instant torque and wheezy powerband with stock turbos is really not ideal for a road course. I couldn’t be happier with the single. Was very nervous I’d upset the balance of the car but it is perfect. Previously I was hitting 124mph at the fastest part of the track, and now I’m hitting 130mph. The best part, though, is the impact on temps. IATs skyrocket with twins, and in-turn, so do oil temps and water temps. Zero heat issues now, with amazing recovery. Car never gets hot and power is consistent all day.

 

[Payam@BMS]

yeah, feels good putting down GT3 RS times in my street car on 200tw tires
Running a Garrett GTX3076R Gen2, T4 divided 1.06a/r. I love this turbo for this application. So responsive and power / boost never fall off.
Took some adjusting to get used to the new delivery and personality of the N54, but now it feels properly suited to track duty, where the stock twins felt like they wanted to call an Uber home after the first hot lap. The instant torque and wheezy powerband with stock turbos is really not ideal for a road course. I couldn’t be happier with the single. Was very nervous I’d upset the balance of the car but it is perfect. Previously I was hitting 124mph at the fastest part of the track, and now I’m hitting 130mph. The best part, though, is the impact on temps. IATs skyrocket with twins, and in-turn, so do oil temps and water temps. Zero heat issues now, with amazing recovery. Car never gets hot and power is consistent all day.

That's so awesome to hear! What boost are you running at the circuit? All your points are valid and important esp for the road course stuff.
The single is really fantastic as long as you're in the correct gear

 

[berns]

That's so awesome to hear! What boost are you running at the circuit? All your points are valid and important esp for the road course stuff.
The single is really fantastic as long as you're in the correct gear

Only running about 16-17psi. Stock (new) HPFP, new Index 12s, Fuel-It Stage 2 with lines and e-content analyzer, tuned by Wedge on MHD, running e30.
Honestly, you can still easily pass in 6th gear on the freeway from low RPM with the GTX3076. It's a great fit for this motor. Would really love to see someone go with a v-band manifold and test the new G30-770 from Garrett.

 

[Payam@BMS]

Only running about 16-17psi. Stock (new) HPFP, new Index 12s, Fuel-It Stage 2 with lines and e-content analyzer, tuned by Wedge on MHD, running e30.
Honestly, you can still easily pass in 6th gear on the freeway from low RPM with the GTX3076. It's a great fit for this motor. Would really love to see someone go with a v-band manifold and test the new G30-770 from Garrett.

Oh wow, still baby boost but that should be good for 450whp! Yes, that's the beauty of twin scroll. Even with my larger turbos I've tested, it's all felt the same down low. It wont be the same with a single scroll Vband, I promise.

 

[berns]

Oh wow, still baby boost but that should be good for 450whp! Yes, that's the beauty of twin scroll. Even with my larger turbos I've tested, it's all felt the same down low. It wont be the same with a single scroll Vband, I promise.

Baby boost is awesome. Also, car made 520whp before the HPFP crashed on 17.5psi and E40... So it should be around 500whp on this setting.

 

[Payam@BMS]

Baby boost is awesome. Also, car made 520whp before the HPFP crashed on 17.5psi and E40... So it should be around 500whp on this setting.

Woah that is awesome for that low boost!

 

[berns]

Woah that is awesome for that low boost!

You can see where HPFP crashed around 6k. All fixed now with a new pump and tuning adjustments. Will have to get back on the dyno to see where we're at on E30.

 

[Payam@BMS]

You can see where HPFP crashed around 6k. All fixed now with a new pump and tuning adjustments. Will have to get back on the dyno to see where we're at on E30.

Haha, yep that little dip in powerband. That's the beauty with single turbos, less heat and lower boost you can run less ethanol and make a nice amount of power

 

[miller335i]

Hi All. Just had a Vargas CNC non-cast Valve cover (like above) installed. 25k on new crate engine. Single Mishi catch can on the cold side. Engine never smoked before. RB drain lines, nothing else done, and it smokes at idle, catch can is clean. After driving for e few minutes no smoke at idle. Let the car cool down and start it, smoke is back. Again no smoke before the VC change. I know the new VC does not have the internal parts that the stock one does. How can I get it to stop smoking? I believe i need more vacuum. But then again I am a noob so...

 

[The Convert]

Hi All. Just had a Vargas CNC non-cast Valve cover (like above) installed. 25k on new crate engine. Single Mishi catch can on the cold side. Engine never smoked before. RB drain lines, nothing else done, and it smokes at idle, catch can is clean. After driving for e few minutes no smoke at idle. Let the car cool down and start it, smoke is back. Again no smoke before the VC change. I know the new VC does not have the internal parts that the stock one does. How can I get it to stop smoking? I believe i need more vacuum. But then again I am a noob so...

Need a lot more info about your crankcase ventilation setup to answer that since you eliminated the stock system.

 

[doublespaces]

Hi All. Just had a Vargas CNC non-cast Valve cover (like above) installed. 25k on new crate engine. Single Mishi catch can on the cold side. Engine never smoked before. RB drain lines, nothing else done, and it smokes at idle, catch can is clean. After driving for e few minutes no smoke at idle. Let the car cool down and start it, smoke is back. Again no smoke before the VC change. I know the new VC does not have the internal parts that the stock one does. How can I get it to stop smoking? I believe i need more vacuum. But then again I am a noob so...

How is the mishimoto catch can attached to the valve cover, directly or with some valves?

Are the head ports blocked which go from the valve cover area into your intake runners? What does a cylinder compression test show? Which turbos? How long since they were serviced?

I've heard of multiple instances where smoking issues were resolved by putting the PCV system back on. Not because you actually require the PCV system, but because the turbos did. A problem with their draining capabilities meant they depended on the crank case vacuum to be drained properly, aka a vacuum assisted drain of sorts. When you delete the PCV system you end up with no pressure or positive pressure which is a fairly drastic swing in conditions from what they were operating under.

 

[berns]

I guarantee the number of N54 owners who just blatantly ditch their stock valve covers, plug their head ports and run some catch can setup, have not measured the vacuum in their crankcase.

I swapped from a stock valve cover and PCV setup, with the exception of a BMS CC, to the VTT billet valve cover, vac relief valve (spring cut), dual CC setup with the VTT-supplied check valves to both cans.

Low side is VC--->CC-->Check Valve-->Throttle Body
High side is VC-->Check Valve-->VTA

Low Side sees a lot of accumulation
High side sees almost none

After a pull the car stank like oil, and on the dyno there was a ton of white smoke at high rpm off throttle.
It gets frustrating to see people seek help and the only responses are usually "turbo(s) probably blown." "check your compression."
The shitty thing is that too much vacuum can cause and then exacerbate turbo and motor issues, so PCV system should be the first thing, as confirming it's function is pretty easy with the right tools.

Crankcase vacuum should be around -17 milibar on the N54 at idle. I'd never measured mine, or even knew this. Oops.
Readings at idle were over -50mb with the current setup. Meaning the check valve isn't working properly and this system needs tweaking. I removed the spring/diaphragm in the vac relief valve on the valve cover and we were now at -12mb. Basically added a giant leak on the valve cover. Sure enough, smoke and smell was gone.

For this system to work well and keep the motor happy, you have to know where you're at, run a proper PCV valve. The only way to do this without trying is to just run a simple VTA setup with the head ports plugged, but that's not how the motor was designed and people will say what they want about turbo health, etc..

 

[doublespaces]

I guarantee the number of N54 owners who just blatantly ditch their stock valve covers, plug their head ports and run some catch can setup, have not measured the vacuum in their crankcase.

I swapped from a stock valve cover and PCV setup, with the exception of a BMS CC, to the VTT billet valve cover, vac relief valve (spring cut), dual CC setup with the VTT-supplied check valves to both cans.

Low side is VC--->CC-->Check Valve-->Throttle Body
High side is VC-->Check Valve-->VTA

Low Side sees a lot of accumulation
High side sees almost none

After a pull the car stank like oil, and on the dyno there was a ton of white smoke at high rpm off throttle.
It gets frustrating to see people seek help and the only responses are usually "turbo(s) probably blown." "check your compression."
The shitty thing is that too much vacuum can cause and then exacerbate turbo and motor issues, so PCV system should be the first thing, as confirming it's function is pretty easy with the right tools.

Crankcase vacuum should be around -17 milibar on the N54 at idle. I'd never measured mine, or even knew this. Oops.
Readings at idle were over -50mb with the current setup. Meaning the check valve isn't working properly and this system needs tweaking. I removed the spring/diaphragm in the vac relief valve on the valve cover and we were now at -12mb. Basically added a giant leak on the valve cover. Sure enough, smoke and smell was gone.

For this system to work well and keep the motor happy, you have to know where you're at, run a proper PCV valve. The only way to do this without trying is to just run a simple VTA setup with the head ports plugged, but that's not how the motor was designed and people will say what they want about turbo health, etc..

Since I'm the only one who has mentioned checking their compression, allow me to explain.

What you're describing speaks to solving the smoking problem given your specific circumstances and I have no doubt that you solved that problem as you say. Additionally, my question about the compression was to get an idea of the general health of his engine as blowby becomes a more important variable on engines with higher mileage and (overly) sensitive crank case vacuum levels.

With that said, the configuration you have is not a common one, most people aren't running the vacuum clamp nor an aftermarket valve cover. For the average individual, the most common way to have this over vacuum situation is to accidentally delete the flapper valve and replace it with a normal check valve. This causes the seal howling situation. As for why it smokes, I'd imagine there are many reasons but I can't give personal insight on that as I never made that mistake nor do the turbos I have begin smoking when outside a narrow vacuum window.

Deleting the pcv system is not only common, but you do not need it in the first place. If you have smoking symptoms and other oddities by 'properly' removing the PCV system which were resolved by subsequently putting the PCV system back on, personally I'd immediately consider the source of the smoke as a potential issue. By covering up the problem with more or less vacuum, that doesn't necessarily mean there is a problem with the pcv delete concept on this or any other engine, rather it highlights an incompatibility with the different components installed on the vehicle, just need to determine exactly which one that is.

If you have twins, I'd recommend keeping the pcv system installed, it's quite clear they do not adapt well for varying vacuum levels. They are quite sensitive, this seems to differ by brand and condition which makes it particularly frustrating to account for and dial in. A quick search of n54 and smoking won't prove but it would illustrate this trend, almost all reported cases are twins. In my humble opinion, this is a limitation of the turbo selection, not the pcv configuration.

If you see this occurring on a big single converted car, the turbo is likely unhealthy or they have an oil drain issue, with the turbo mounted too low being the most common reason. Personally I never have any smoking issues with or without a pcv system with a bottom mounted 6266. The turbo seems to drain well in a variety of crank case pressure levels as I've subjected it to various conditions.

If you have smoke and burned oil smells from a PCV delete system, that would be due to the decision to VTA which creates the situation you've described and is unsurprising. Those fumes must be evacuated to the intake pipe/cone or routed under the car or into the exhaust. Several folks consider VTA and PCV deletion the same thing, as they are commonly associated but are different.

All engines benefit from a degree of crank case vacuum, but there's no evidence I've seen that our engine, turbos aside, is special and needs vacuum for proper operation. People can talk about the rings sealing, etc etc but it's far more likely issues will arise from pushing the engine to 200-300% of its original power or from neglect. If someone has actual evidence of engine problems from a PCV delete I'd genuinely like to see the details.