I would do it right the first time. Rails, injectors (750 fuel 1050 ethanol), 340 lph pump on fuel 450 with ethanol, fuel return and FPR. If you will track the car I'd recommend a surge tank. Hunting fuel issues in the dyno will kill all the savings you thought you made.

 

A FRS will also make it easier on the tuner.

Without a FRS you can not have a 1:1 fuel pressure rise.

Now you do not have to have a FRS but in the long run when you decide to crank up the boost you will want a FRS. Do it all at once, take it from someone who has done it in baby steps, it SUCKS having to repeat work due to a small upgrade.

Think about getting on the dyno with 600's and a 255 pump only to find out your injectors are to small. So you upgrade to 1000's now your 255 is not flowing enough regardless of fuel pressure. So you upgrade to a 340, 485 or 525. Now your fuel pressure is all over the place so now you HAVE to do FPR and FRS. If you would of done it to start you would of saved money on parts and dyno time. (This is the extreme but still you get what I mean)

 

I appreciate the input.
When it’s time to build and I’m in this hp range, I’ll be better prepared. The entire engine and trans will come out at that point and I’ll be doing bay work while the drivetrain is getting “fortified” as HKS would put it. I do think I’m going to tackle that aspect of it myself, pulling the drivetrain and shipping it out, the trans to IPT and the engine, maybe Dynosty if they have the time. For now, my power goals will not require these extras though it does make sense to go with the larger injectors & pump for future use understanding that they won’t make tuning more of a *****.

 

I'd still suggest getting the FRS, you will be modifying the basket when doing the pump anyway, also removing rails for the injectors. It's minimal work after that, once you have the FPR in there you can tune at will and NEVER need to touch it again. Getting just the bigger injectors and pump without the FRS is kinda like the same thing as getting too small of a system....in the end you are doing double the work.

 

I got an email back from HKS USA. I asked them about larger fuel rails and a return system, just to see what their point of view is on the matter as I don't recall them suggesting either.
They have no idea what I'm talking about. They asked for their part numbers. I asked that they send my question to the tech dept. The tech dept came back with the same question. Holy ****. Either these things are really unnecessary or they're a bunch of morons or a combination of the 2. I do recall their kit had huge injectors and an unusually small fuel pump, like 190lph. I know I wrote it on this forum somewhere.
I simply asked "is it recommended to use a fuel return system and/or larger fuel rails with either the 110 or 100mm pulley for the gts8555?". What's the problem HKS?
I can't find their fuel kit anymore. Looks like it's been discontinued. Ghee, I wonder why.
118mm or 4.65" is the diameter of the under drive crankshaft pulley. Not sure about the stock diameter. Definitely don't know how to do the math, so I'll plan on the 100mm and see how it tunes.

 

A huge part of it may be that they tune on the F-con and different fuels, I don't even know if people in Japan know what uprev is either lol. Their car has a custom version of the kit, not even a 1:1 with the one they sell. Their air filter sits in the battery box. I think they don't run at max power as far as I can tell, at least I haven't seen it, and I've looked. I mean that screen shot of the it cams says it all, you can just stumble across that info as it seems most Japan companies (or people for that matter) don't care about absolute numbers, just want feel the car perform better.

 

By all means if you want to be the guinea pig let me know if it works so I don't have to get an FRS...but then again I want to hit as close to 500whp which is a TALL order.
I'd also suggest again that you go to factory specs or at least consult with a pro who knows how to read compressor specs, from what I was told the rotrex style superchargers are super sensitive to speed and you don't want to leave power on the table or even worse damage the compressor.

 

For what its worth I use OEM R35 injectors, and then a custom return line setup with an Aeromotive regulator and didnt have any issues using 93 octane with that kit. Iirc I have a 255 or a 340lph pump in there, honestly I forgot exactly what is in there as I put it in a few years ago.
Also, I believe there are a few hanger/basket kits coming out from different companies like Radium / FueledByAi, etc., which will have provisions for return setups so you dont have to do a whole lot of engineering or custom making of parts, so once those come out I suppose the fuel system side of things will be a bit less complicated.

 

What pulley r u using?
Any idea when these kits will be available?
Any updates on your build?

 

I'm using HKS's high boost pulley, all other pulleys are OEM.
And the project was kind of stalled for a bit, had a bunch of personal/work stuff going on and just now am getting through that. So hopefully I can paint it in the next month or so then start tracking it again.

And I am not 100% sure on their release dates or the details but I've just heard grumblings about it. That being said, there are a few other return setups available, they just arent quite as robust as having a nice in tank surge with that return system all self contained. So you still run into fuel slosh issues with just a return line setup on a track car, thats why I had built out a custom in tank surge/return setup.

 

Alright. I’ll ask you what you got to sell for my fat-assed awd 4 door 350z that’s a street light to street light terror when I’m ready to buy all this **** from enju-motha****in-ku.

 

I recommend CZP, they usually have the best prices and often have sales. I bought my kit for $4500 from them.

 

Enjuku's got it for $4,500 right now plus I put aks14 through some **** back when I came hairs away from pulling the trigger on a vortec and other various parts. They're right there with concept z.
Are vendors still ordering these with a 3 month wait?

 

I don't know honestly, when I bought mine it shipped the next day and was here 3 days later. I did see people on IG saying that it was on BO, maybe call around and see who has it in stock.

 

12001-AN008, the V2 8555 system is out of stock at the main HKS warehouse in the US right now. Thats not to say a distributor may have it on the shelf possibly, but if they do not, its gotta go through the main HKS warehouse first.
ETA into the main warehouse in the US is mid/late July according to my rep. Only 1 of the 3 that are incoming are not pre-sold though apparently.

 

So my 8555 leaked it's oil out. It looks like it blew an o-ring after few thousand miles. I've had other issues with the car so the unit is already out of warranty (time since purchase) , when everything else is finally working.

​​​​​​My options are:
- Pray that I can get some help from HKS (unlikely).
- Buy my third HKS supercharger.( Not feeling like I want to support a company that doesn't value it's customer)
-Buy an Rotrex c38-112R and make some custom piping.

I Wonder if anyone has replaced an HKS unit with a C38 Rotrex? Will it fit 😬

 

Ok a little update. I manged to open the supercharger. There wasn't really any tricks in doing so. I was afraid that there might be a thread inside the casing so I was afraid to use to much force. I used screwdrivers to force it open which was stupid. If I would do it again I'd build a custom extractor and press it out. But what's done is done. I don't think I damaged the o-ring sealing surfaces. I'll just put new oil in and wait till it leaks again this fall so I can build a C38R kit during the winter.

 

Whaaaaaaaaaaaaaat? How did this happen? Is the unit toast?

 

I just started the car and it started to pour out oil. Maybe the o-ring was damaged due to heat, but I really haven't even driven it hard for long times except in the dyno. But nothing special that would have made me expect the outcome.

First I'll try to replace the O-ring and see if it holds the HKS traction fluid (liquid gold) inside. If it doesn't I think that's it since I don't have the skills to go further or any intrest to send it Outside EU to get it fixed. In that case I'll start the Rotrex build.

 

Any luck replacing the o-ring? I've got an idea if you haven't tried it yet.
So you say this is your second HKS unit? What happened to your first one?