Official HKS/Rotrex Supercharger FYI Thread!
01-02-2012, 08:39 PM
#1
Official HKS/Rotrex Supercharger FYI Thread!
I'm adding info as I go and pics won't be posted until my return on the 13th.. here's what I've got right now.
Physical Differences:
How do you know what unit you have?
Rotrex C30-94 units and HKSGT7404 units look similar in appearance but do have some differences. Rotrex’s have “Rotrex” or “Holset” in the casting while the HKS’ will have “HKS” a long with a “HKS GT Supercharger” label visible on the top of the blower itself. It its believed that the original superchargers came with Rotrex and HKS later developed their own blower, they incorporated the 7404 on the newer kits.
The mounting brackets are different as well. The Rotrex has 4 longer mounting bolts that go through the blower completely while the HKS has only 3 in a triangular fashion and attach to thread wholes on the face of the blower. The idler, bracket pulley from either of the units are interchangeable but the pulley’s don’t look to be.
Rotrex Bracket:
Rotrex Blower:
HKS Bracket:
HKS Blower:
Bracket spacing on the HKS:
Bracket spacing on the Rotrex:
HKS uses a cylindrical container for the HKS Supercharger Fluid and Rotrex uses a square shaped one. The oil cooler hoses also attach differently on the units, the Rotrex has banjo fittings at the 10 and 2 ‘o’ clock postion. The HKS has it’s banjo fittings on the aft of the blower.
Intercooler, Bypass Valves & Chargepipes:
These parts are exactly the same for both kits as I've used the pipes/intercooler from the Rotrex kit on the HKS without any issues whatsoever. If your having an issue with the bypass valve, the OEM kit bypass valve has been discontinued. Other options are available if you wish to use the bypass but it can be converted to a BOV. Sam@GTM recommend the TurboSmart bypass valve for it's efficiency, size, and price. The HKS Race Bypass Valve is available too. The biggest problem with the OEM location is that your limited on space, a HKS SSVQ will not fit in the OEM location so you'd have to put it further down(i.e. right before the intercooler).
Physical Differences:
How do you know what unit you have?
Rotrex C30-94 units and HKSGT7404 units look similar in appearance but do have some differences. Rotrex’s have “Rotrex” or “Holset” in the casting while the HKS’ will have “HKS” a long with a “HKS GT Supercharger” label visible on the top of the blower itself. It its believed that the original superchargers came with Rotrex and HKS later developed their own blower, they incorporated the 7404 on the newer kits.
The mounting brackets are different as well. The Rotrex has 4 longer mounting bolts that go through the blower completely while the HKS has only 3 in a triangular fashion and attach to thread wholes on the face of the blower. The idler, bracket pulley from either of the units are interchangeable but the pulley’s don’t look to be.
Rotrex Bracket:
Rotrex Blower:
HKS Bracket:
HKS Blower:
Bracket spacing on the HKS:
Bracket spacing on the Rotrex:
HKS uses a cylindrical container for the HKS Supercharger Fluid and Rotrex uses a square shaped one. The oil cooler hoses also attach differently on the units, the Rotrex has banjo fittings at the 10 and 2 ‘o’ clock postion. The HKS has it’s banjo fittings on the aft of the blower.
Intercooler, Bypass Valves & Chargepipes:
These parts are exactly the same for both kits as I've used the pipes/intercooler from the Rotrex kit on the HKS without any issues whatsoever. If your having an issue with the bypass valve, the OEM kit bypass valve has been discontinued. Other options are available if you wish to use the bypass but it can be converted to a BOV. Sam@GTM recommend the TurboSmart bypass valve for it's efficiency, size, and price. The HKS Race Bypass Valve is available too. The biggest problem with the OEM location is that your limited on space, a HKS SSVQ will not fit in the OEM location so you'd have to put it further down(i.e. right before the intercooler).
Last edited by Flo-ridaZ33; 01-05-2012 at 09:26 PM.
01-02-2012, 08:39 PM
#2
Operation Differences:
Rotrex’s run a slip system and engage at 5% slippage, the HKS uses a eccentric type and creates boost when your foot is on the gas. They’re relatively quiet units but do have a “sucking” air sound coming from the front of the car so it’s not completely silent as some have said. Oiling is done in a clockwise position:
1. Reservoir
2. Inline filter
3. Blower
4. Oil cooler
Pulleys:
A range of pulleys can be purchased through individual sources. All OEM C38/HKSGT7404's come with 95mm pulleys. There are instances of people using 90mm and 85mm pulleys(I have 90mm pulleys on both superchargers) but most will agree that the 85mm is dangerously close to over spinning the blower unless you have an aftermarket crank pulley(i.e. ATi and Fluidampr) which is larger than the OEM Nissan pulley(albeit not by very much). They're an 8 rib pulley for both set ups but the lip on the inner side of the pulley(side that mates
with the supercharger) has a lip to it and do not work with the HKSGT7404 because its too big. GTM's pulley's are a very nice piece
Pictures of how the kits come:
Rotrex:
HKS:
Installed differences:
Rotrex
HKS
Rotrex’s run a slip system and engage at 5% slippage, the HKS uses a eccentric type and creates boost when your foot is on the gas. They’re relatively quiet units but do have a “sucking” air sound coming from the front of the car so it’s not completely silent as some have said. Oiling is done in a clockwise position:
1. Reservoir
2. Inline filter
3. Blower
4. Oil cooler
Pulleys:
A range of pulleys can be purchased through individual sources. All OEM C38/HKSGT7404's come with 95mm pulleys. There are instances of people using 90mm and 85mm pulleys(I have 90mm pulleys on both superchargers) but most will agree that the 85mm is dangerously close to over spinning the blower unless you have an aftermarket crank pulley(i.e. ATi and Fluidampr) which is larger than the OEM Nissan pulley(albeit not by very much). They're an 8 rib pulley for both set ups but the lip on the inner side of the pulley(side that mates
with the supercharger) has a lip to it and do not work with the HKSGT7404 because its too big. GTM's pulley's are a very nice piece Pictures of how the kits come:
Rotrex:
HKS:
Installed differences:
Rotrex
HKS
Last edited by Flo-ridaZ33; 01-05-2012 at 09:12 PM.
01-02-2012, 08:40 PM
#3
Oiling systems:
Oil is a HUGE deal on these particular units. Their oiling systems are the same but the oil is very different and are blower specific. Every unit consists of:
• Blower unit
• Supercharger oil cooler
• Inline filter
• Reservoir
• Supercharger Oil(HKS for HKS and SX100 for Rotrex)
Rotrex requires oil changes at 80,000km/50,000mi, 2 years or which ever is first. Active does their service on HKS kits at 100,000km/62,000mi so I'm going to use this as a benchmark for the HKS kit. Oil is NOT interchangeable, I’ve received the same information from both URD(Underdog Racing), Kraftwerk, and Active Autowerke (which uses both units on a multitude of BMW’s). The oiling compounds are different and if you ever used HKS fluid in a Rotrex(same principle applies the other way too) and something goes wrong… the warranty is void on the blower and your going to fork out $2-3K for a new kit as units are not available for purchase individually. I’m sure if you were in a pinch you could but they very adamant about not mixing fluids.
HKS Traction fluid P/N:
G08834-K00020-00
GTM and Active carry the oil but.... it's hard to come by and still is on order:
http://www.gtmotorsports.com/product...1&cat=0&page=1
http://store.activeautowerke.com/hks...fluid-p66.aspx
Rortrex Fluid can be had in different places:
http://www.urdusa.com/Forced-Inducti...duct_info.html
http://store.activeautowerke.com/rot...fluid-p65.aspx
http://www.kraftwerksusa.com/product...p?productId=37
I just recently bought fluid and filters through URDUSA.com, they had it in stock and it was at my house in 3 days.
Oil is a HUGE deal on these particular units. Their oiling systems are the same but the oil is very different and are blower specific. Every unit consists of:
• Blower unit
• Supercharger oil cooler
• Inline filter
• Reservoir
• Supercharger Oil(HKS for HKS and SX100 for Rotrex)
Rotrex requires oil changes at 80,000km/50,000mi, 2 years or which ever is first. Active does their service on HKS kits at 100,000km/62,000mi so I'm going to use this as a benchmark for the HKS kit. Oil is NOT interchangeable, I’ve received the same information from both URD(Underdog Racing), Kraftwerk, and Active Autowerke (which uses both units on a multitude of BMW’s). The oiling compounds are different and if you ever used HKS fluid in a Rotrex(same principle applies the other way too) and something goes wrong… the warranty is void on the blower and your going to fork out $2-3K for a new kit as units are not available for purchase individually. I’m sure if you were in a pinch you could but they very adamant about not mixing fluids.
HKS Traction fluid P/N:
G08834-K00020-00
GTM and Active carry the oil but.... it's hard to come by and still is on order:
http://www.gtmotorsports.com/product...1&cat=0&page=1
http://store.activeautowerke.com/hks...fluid-p66.aspx
Rortrex Fluid can be had in different places:
http://www.urdusa.com/Forced-Inducti...duct_info.html
http://store.activeautowerke.com/rot...fluid-p65.aspx
http://www.kraftwerksusa.com/product...p?productId=37
I just recently bought fluid and filters through URDUSA.com, they had it in stock and it was at my house in 3 days.
Last edited by Flo-ridaZ33; 01-05-2012 at 08:34 PM.
01-06-2012, 12:42 PM
#15
No such thing as a noob question in regards to Rotrex/HKS. The HKS units seem to make "better" power because of how they create boost. Rotrex has more support and blower options. HKS has 2 units that are available for purchase... a 8550 and a 7404. Active Autowerke uses both in their kits but uses 8550's for the newer kits(E92 M3) and use Rotrex for the older kits because of physical size issues. The Rotrex's have several units per range(C15,C30,C38). I believe the HKS is better but that is relative, both units are export(HKS Japan-Rotrex UK) but more people are using the Rotrex due to their support.
01-06-2012, 03:41 PM
#17
Good set of info, regarding the way it makes boost where did you get the info from? By looking at the way boost is built on the 7040 on the HKS VQ kit and comparing that to the 8550 on the AA e90 kit, they seem to be employing different means eventhough they are both HKS unit. My guess based on ctran77's HKS kit, which is also using an 8550, is that the compressor desgined has changed post 2008 and is now more similar to the rotrex, but I'm just guessing here. Do you have pictures comparing the impeller?
01-06-2012, 07:25 PM
#18
Good set of info, regarding the way it makes boost where did you get the info from? By looking at the way boost is built on the 7040 on the HKS VQ kit and comparing that to the 8550 on the AA e90 kit, they seem to be employing different means eventhough they are both HKS unit. My guess based on ctran77's HKS kit, which is also using an 8550, is that the compressor desgined has changed post 2008 and is now more similar to the rotrex, but I'm just guessing here. Do you have pictures comparing the impeller?
Look at the bypass location on this pic of kit above... I'm going to include upgrades in one of the reserved area's.
01-07-2012, 10:17 AM
#20
This is what I was referring to. Take a look at the behavior of the 8550 and the 7040 from the old HKS kit. On a side note, it's interesting that they advertise that the vq kit comes with the 8550 as oppose to the 7040.
http://www.hks-power.co.jp/products/...rformance.html
http://www.hks-power.co.jp/products/...rformance.html