Stillen/GTM Supercharger Pros, Cons, and Questions
 

Since there are still questions.

I think the best way to state it, is that neither kit is designed for heavy duty use. They both will work on the street, but as an "off the shelf, bolt on kit", neither are usable for high performance driving by themselves.

1. neither addresses the heat issues the VQ37VHR already has
2. What additional cooling is recommended with each kit? Fans? Radiator? Oil cooler? Trans cooler? Etc.

Advantages of the GTM kit

1. Supererior powerband. The Rotrex blower, due to design, is slightly more efficient, and will result in superior powerband in comparison to a Paxton blower at the same boost level.
2. The Rotrex blower has its own cooler. This is due to design of the blower; it requires its own fluid.
3. The Rotrex is very quiet.

Disadvantages of the GTM kit

1. Rotrex blowers have a short life. 50k miles or less is typical of the design. Refer to Rotrex kits on over vehicles for the blower's record
2. Rotrex fluid must be regularly changed. This is additional maintenence that the owner MUST do.
3. Once a blower is chosen and purchased, there is VERY little overhead for performance gain.

Unaddressed issues of the GMT kit

1. Oil filter is already relocated. Adding oil cooling via sandwich plate may or may not be possible, and may or may not drop oil pressure to dangerous levels. This is unknown.
2. GTM is implying the kit will be CARB, but have yet to formally announce that they have applied for CARB certification
3. Where is the boost level being measured? What is the max RPM of the chosen blower, and how high does the kit spin the blower? What is the potential room for growth?
4. Sam has stated that there is room for expansion with the kit. How much for each respective blower?

Advantages of the Stillen kit

1. Paxton blowers have a proven track record, and are capable of big power. There is a lot of room for additional power with this kit.
2. *potentially* superior intake manifold design. This remains to be seen, and may not be a true advantage.
3. Oil filter relocation is not required. This leaves room for a sandwich plate to be used in conjunction with an oil cooler. In fact, Stillen's car utilizes their coolers.

Disadvantages of the Stillen kit

1. Paxton blowers are loud.
2. Higher cost

Unaddressed issues of the Stillen kit

1. What blower trims are available? Does the kit use a self-lubricated version of the blower or is it sharing oil with the engine? This will affect both maintenance and room for potential power growth.
2. Where is the boost level being measured? What is the max RPM of the chosen blower, and how high does the kit spin the blower? What is the potential room for growth?
3. Is Stillen applying for CARB?


I would appreciate straight answers from Sam and Josh ONLY. As for anyone else, unless you work for GTM or Stillen, I doubt you'd be able to give any factual information, only opinions.

I'd like to ask that mods/admins please delete any posts that stray off topic from the OP; this thread is for facts only.



****Links****

First user review of the Stillen kit.
https://www.myg37.com/forums/engine-...rn-key-sc.html

More Stillen kit pics
https://www.myg37.com/forums/engine-...-vid-pics.html

GTM in-house install #2
https://www.myg37.com/forums/engine-...instal-ii.html

Stillen SC install by Beshoff
https://www.myg37.com/forums/engine-...m-install.html

GTM in-house install #1
https://www.myg37.com/forums/engine-...e-install.html

GTM SC Announcement
https://www.myg37.com/forums/engine-...s-release.html

Stillen SC Announcement
https://www.myg37.com/forums/engine-...ouncement.html


***CARB EO (Executive Order) Database***

http://www.arb.ca.gov/msprog/aftermk...es/amquery.php To use this link, scroll down, select "Supercharger systems/Supercharger modifications", and hit search.

As of 6/28, both companies have announced that they will be applying for CARB legal status. However, neither have finished the process yet for their respective kits.

1. It's known that the VQ37VHR has heat issues without any sort of forced induction, and increasing horsepower is going to only add to that.

2. Any and all added cooling is recommended with the STILLEN Supercharger system, at minimum an oil cooler kit, for automatic guys, a transmission cooler as well. We've adapted the heat exchanger location to offer tremendous room in conjunction with our oil cooler and trans cooler (as well as power steering cooler for track guys). Air flow was part of the design since day one. We also have a line on an upgraded aftermarket radiator with additional cooling capabilities.


While owned by the same company, let's refer to it as the actual unit it is, a Vortech V-3 SCi Centrifugal Supercharger Unit, for the kit being sent for CARB approval.

1. Vortech blowers have been used all over the place, in a variety of different applications, and have a strong track record, agreed.

2. By custom designing the intake manifold, it allows us to run the Air-to-Water Intercooler, cooling the intake charge at the last possible moment, before entering the engine, rather than allowing the air charge to be heated from the engine bay. This technique is not new, and is utilized on many other applications, including our previous supercharger designs utilizing a roots top-mounted supercharger. By designing the intake, we're able to utilize longer runners, and other features, including a large plenum of air for the engine to draw from, etc.

3. Correct, the Vortech V-3 is a self-contained lubricated supercharger, and does not tap into the vehicles oil system. Also for note, the Water-to-Air intercooler system also has a self-contained coolant system, and does not share the vehicles coolant.


1. Again, Vortech - This system utilizes the V-3, which is noticeably quieter than the V-1 or V-2, and "loud" is extremely subjective. We'll have some additional videos out soon, should help with that distinction.

2. It's an expensive kit to produce.. and we weren't willing to cut costs to provide what we felt an inferior product. And in the grand scheme of things, a turn-key kit for the price we're charging is far less than TT options, less than previous STILLEN systems, and a hell of a bang-for-the-buck in regards to performance delivered. Couple that with the planned CARB approval, ability to upgrade with a simple pulley and a tune (see below for potentials), and we're in talks for a 3 yr / 36,000 mile engine warranty which we've had for previous kits available (to be determined), I'd argue to say the R&D, components, stability from a company in it's 25th year more than provides for the selling price of this kit.


1. The current turn-key kit is providing a V-3 SCi trim blower. As mentioned before, this is a self-lubricating unit, and it contains it's own oil. This is easily changed via a drain cable at the bottom, fill hole at the top, and fluid bottles available. Change intervals are 2,500 miles the first go around, and 7,500 miles after that, basically every other oil change. It's extremely easy to do, and the drain cable Vortech incorporated makes it a snap, checking the oil via the internal dipstick ensures oil level is correct. The V-3 Si trim is also available with the tuner kit, and for those looking for insane power goals, options from there are available as well, all utilizing the existing hardware.

V-3 SCi trim is good to 17psi and 725HP
V-3 Si trim is good to 22psi and 775HP

Only the most extreme cases will exceed the capabilities of even the SCi trim blower, offering extreme upgradability, at minimal cost.

2. I'd have to check and see exactly where we were measuring boost, but we had sensors all over the place, including temperature sensors, etc. Again I don't have RPM numbers on the blower, but since we're running at 8psi with a capability of the blower at 17psi, no where near it's capacity. Potential room for growth dips well beyond the abilities of the stock block, and deep into the capabilities of a built block, especially with the trims available.

3. Yes, STILLEN is applying for CARB.

We have applied and achieved CARB certification for all of the STILLEN superchargers, including the 350Z, G35, FX35, Frontier, Pathfinder, Xterra, Titan, Armada and QX56, and expect no issues with being granted CARB approval on this kit. But as with anything CARB related, nothing is finalized until everything is processed and taken care of.

I hope this helps with some of the questions..

Thank you for the quick response! I believe all of the questions that I had regarding your system at this point were answered.

To sum up the Stillen kit at this point:

-8psi stock (~520hp, less than 50% of max capacity)
-17 psi capability (~725hp, supporting mods and possibly an engine build will be required to get to this level)
-22 psi capability (~775hp) with optional blower.
-self lubricating blower (along with easy access to changing the oil); it does not share engine oil
-self contained system for the air-to-water intercooler; it does not share engine coolant
-will be applying for CARB (yay for us Californians)
-Engine oil cooler compatible, and highly recommended
-no engine oil filter relocation
-Vortech V-3 blowers (used in this kit) are noticeably quieter than the older V-1 and V-2 blowers.

I'd like to add some additional questions.

1. Will Stillen be offering an oversized heat exchanger for the air-to-water intercooler?
2. Is a generic tune being offered with a reflash (I'd venture two options could be stock + SC kit only, and SC kit + Stillen header and Stillen exhaust)? Will you be offering tuning for specific vehicles at an additional cost, to maximize other modifications a given vehicle may have?

Once again, your answers are very much appreciated.

1. We've had extremely successful results with this setup in the past, and in our current testing the temperature drops we're seeing are excellent for the setup, and capable of handling the additional boost and HP requirements for most customers. I can only predict the most extreme setups demanding more than what we've accommodated for, but that remains to be seen with additional testing. It wouldn't be hard to provide for a larger heat exchanger, as we had this one specifically developed to our specifications.

2. Tuning for the current setup (again, the CARB kit, anything is possible..) has been done with a cat-back exhaust, without the use of HFC's or Headers, as both of those would also need to be CARB-certified. Tuning and additional configurations will be available, but obviously not with the CARB-certified kit we are initially launching with.

This does not, however, pertain to the tuning kit which will be available, allowing for someone to incorporate whatever bolt-ons and additional parts and create custom tuning alongside of the STILLEN supercharger system and hard parts available.

Informative
 

Very interesting to know about the life span of the superchargers. For those of us who plan on having their cars for 100k miles I think we can expect much higher costs for service and maintenance.

To sum up the Stillen kit at this point:

-8psi stock on the bolt-on kit(~520hp, less than 50% of max capacity)
-17 psi capability on the standard blower(~725hp, supporting mods and possibly an engine build will be required to get to this level)
-22 psi capability (~775hp) with optional blower.
-self lubricating blower comes with the bolt-on kit, and possibly the optional blower(s) (along with easy access to changing the oil); it does not share engine oil
-self contained system for the air-to-water intercooler; it does not share engine coolant
-will be applying for CARB with the bolt-on kit (yay for us Californians)
-Engine oil cooler compatible, and highly recommended
-no engine oil filter relocation
-Vortech V-3 blowers (used in this kit) are noticeably quieter than the older V-1 and V-2 blowers.
-Heat exchanger options will be available, but will only be needed by the most extreme setups (V-3 Si trim anyone?)
-The base tune for the bolt-on kit assumes the user has a cat-back exhaust, but not HFCs, test pipes, or headers.

I appreciate the prompt answers from Josh and Stillen. Hopefully we'll have some answers from GTM in the next few days.

The VQ37VHR is a hot running engine by design. controlled Heat equals more power,cooling fans don't even come on until temp reaches 101c vs older models 97c. for a daily driven car adding a cooler is not a bad idea. in all our twin turbo installs we had never had an engine over heat or any customer reporting such a problem, Now if you are planing on tracking the car that a different story.

So adding engine, trans cooler is always a good idea since the engine is working harder. Also we will be offering a bigger radiator option very soon. the stock radiator and the a/c condenser is one unit on the G37 and the 370Z so making a bigger radiator is not as simple as the older models .

1-I totally disagree with that statement just like anything else, with the proper maintenance and use you can expect well over 100k miles
out of the Rotrex blower, and with the Rotrex unit utilizing different technology, the traction drives system has greater advantages over the traditional gear transmissions. So with a simple guide lines like changing the traction fluid and not over spinning the blower you can expect a lot of trouble free miles out the Rotrex unit.

Also the Rotrex unit comes with a standard warranty of 3 years unlimited millage witch happen to be the best in the industry right now period, no other company offers that type of warranty on the market right now .

2-Rotrex recommend maintenance intervals for the traction fluid is 2 year or 24k, and there is no other maintenance is required for the system. so i would not say " the Rotrex fluid must be regularly changed "

3-We don't believe in one size fits all, sure it is easier and more profitable to give one blower option that can operate form 1- 22 psi, but there is always a sacrifice doing so. and that is why we choose to offer different stages for different goals .

1-Adding an oil cooler is possible, droping oil press on the VHR engine because of an oil cooler wont be a concern at all. this engine has exceptionally high oil press from the factory.

2- We are doing the carb certification process a little different, We have hired a company that is certified and approved testings facility by CARB to handle the whole process for us, this agency do the same thing for the car manufactures and makes the process quicker and easier on us but of course it costs a lot more.
3-boost is measured at the intake manifold, @ 8 psi we are @ 80000 rpm and still have plenty of room to go
4-we will be sharing the results of our stage 2 and 3 in the coming week or so, stay tuned

Sam

Thanks to the OP, Josh@Stillen and Sam@GTM for this info!!
I think going over the details of both kits will really help members decide which route they'd like to take and settle all their concerns and clear any confusion with factual information straight from the vendor.

Subscribed for future info.

Loving this thread, thanks Mike, Josh & Sam

excelent thread. All potential SC buyers should read this thread.

To sum up both kits:

-Additional cooling is recommended for both kits, especially under heavy duty
-Either kit will take you to 500+hp at the crank


To sum up the GTM kit at this point:

-Expected life is 100k+ miles
-Rotrex fluid is changed every 24k miles or 2 years
-GTM kit utilizies different size blowers for different power goals; once you choose a blower, it is implied that you are fairly committed to a given level of power (there is still a overhead to get more power via pulley swap, but it is not stated how much.)
-Utilizing different blowers will generally give a superior power curve at a given level of boost
-GTM kit is compatible with oil coolers
-GTM kit will be applying for CARB, possibly on multiple stages, through a third party.
-oil filter is relocated
-utilizes a air-to-air intercooler
-Stage 1 kit is 8 psi, measured at the manifold (post-intercooler)
-quiet blower


To sum up the Stillen kit at this point:

-8psi stock on the bolt-on kit(~520hp, less than 50% of max capacity)
-17 psi capability on the standard blower(~725hp, supporting mods and possibly an engine build will be required to get to this level)
-22 psi capability (~775hp) with optional blower.
-self lubricating blower comes with the bolt-on kit, and possibly the optional blower(s) (along with easy access to changing the oil); it does not share engine oil
-Vortech blower's oil is changed at 2500 miles, and then every 7500 miles after the initial change.
-Stillen kit utilizies different size pulleys and reflash to determine power level. Additional blowers are available for extreme power setups.
-self contained system for the air-to-water intercooler; it does not share engine coolant
-will be applying for CARB with the bolt-on kit (yay for us Californians)
-Engine oil cooler compatible, and highly recommended
-no engine oil filter relocation
-Vortech V-3 blowers (used in this kit) are noticeably quieter than the older V-1 and V-2 blowers.
-Heat exchanger options will be available, but will only be needed by the most extreme setups (V-3 Si trim anyone?)
-The base tune for the bolt-on kit assumes the user has a cat-back exhaust, but not HFCs, test pipes, or headers.


Advantages (based on my observations)

Initial cost (kit only) - GTM
-GTM's initial cost is $900 lower with pre-order
Powerband out of the box - GTM
-Rotrex blower is more efficient, and blower is chosen based on buyer's desire. However, it is important to note that the Stillen kit utilizies a Air-to-water cooler, and the water can be chilled (via ice) to increase power for short durations.
Ease of expansion for additional power - Stillen
-All that is required is a pulley swap and reflash. GTM's kit ultimately limits you if you choose a smaller blower out of the box.
Ease of installation - Tie
-this may change after install instructions are released
California users - Tie
-Both kits will be applying for CARB
Maintenance - GTM
-24k or 2 years, whichever comes first. Vortech blower in the Stillen kit requires a change at 2500, and then every 7500


At this point, I'd like to see compressor maps for the respective blower options for both kits.


OP's choice: Stillen, ever so slightly, because there is a LOT of expansion room. Changing the heat exchanger to a larger one is not much harder than putting in a bigger intercooler, (and does not come with the corresponding loss in response). Additionally, all that is required for more power is a pulley swap and tune. I realize the GTM kit is the same, but for the base kit, the Stillen blower has much more capacity for expansion. Sam@GTM, please correct me if I'm mistaken on this end. However, the quietness of the Rotrex is VERY appealing to me. If I am supercharged, I don't want people to know that I am, especially LEOs. It remains to be seen how quiet the Vortech V-3 blower is, and it MAY be quiet enough to have potential as a sleeper mod. Last but not least, additional maintenence is not a concern for me. I'd likely be changing the Vortech blower's oil with every oil change anyway.

Map for the Rotrex compressors:

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Mike, I know you've clung to this point that it would be necessary to go with a larger heat exchanger with higher boost/HP applications. I'd like to clarify this.

I'm in no way saying this is the case, it's very possible the Air-to-Water intercooler and heat exchanger that's on the car (which is very large) will be more than enough to handle even extremely high horsepower numbers.

I was simply stating that if in fact there needed to be a larger heat exchanger, that wouldn't be a problem, just a matter of mounting a larger one.

This setup should be MORE than enough to handle your S/C goals.. FYI

Josh, do you have any pictures of the heat exchanger/coolant cooler?

nice info all. thanks mike for keeping it on point