More Power

My information is that the HKS kit is very tunable. All you have to do is buy the HKS F-Con V pro and the HKS kit is tunable. I got that word directly from HKS and people on this board as well. HKS told me they were more than happy to sell me the F-Con V pro for that very purpose on my 350Z with their supercharger. Last I talked to PumpedVA on this board (and that was a while back), he had bought the HKS F-Con V pro and was setting up to have his 350Z with HKS supercharger tuned with it. There was also talk on this website by some that were so dissatisfied with the way the HKS was running on their 350Zs, they were going to a standalone ems tuning system (not the V pro) and deleting the F-Con S (that comes in the kit as you said) out of the loop entirely.

Even though I personally don't know of any blown engines with HKS, as I said, I was hearing many tuning and drivability problems with HKS last fall till I just gave up on HKS. People pulling the kit off their car. 350Zs running pig rich to the point of fouling plugs almost immediately. Those threads were on this website in the FI forum. Yes, running a little rich is the way to go, but this was causing drivability issues. So yes, those HKS characteristics are engine damage in process IMO. Just a matter of time... I don’t need to wait until the engine blows to verify that 2 plus 2 does, indeed, equal four. And again, no it’s not a blown engine with every car every time. Just saying that every car with kit X hasn’t blown an engine every time in no way reassures me that there is not a real problem that was documented in Sport Z Magazine … by some of the real high level pros out there.

I mean I respect everyone’s opinion and all, but I have given the magazine article where some real high level pros have tested, found this problem with the fuel system that they say is a fact, specifically tested and found part of the solution is the fuel return system, and documented all this and published it in a professional Z car magazine. Now completely contrary to this, even though I respect the opinions expressed here, is the opinion posted here stating a simple “I think” everyone is ok not needing a fuel return system until 450 to 500 wheel HP. Do you have any other evidence to back up your opinion?. Such as the professional, published evidence like I have submitted of rigorous, systematic professional testing, evaluating, documenting and publishing.

Regardless, does anyone think that the return fuel system is not a good idea when there is ample evidence of an inconsistent fuel availability problem? That is far more than a simple lean condition and “significant fuel system” upgrades were found to be need to avoid a problem over the long haul. This is certainly not the first time or the first forced induction car that I have heard of with this situation and a fuel return system turned out to be highly recommended as part of the solution.

Again, to me, it’s simple and I think we’ve both kicked this around enough. If there is any doubt, why take chances with your engine? When a relatively inexpensive part of the solution, in the form of a fuel recirculation system, has been tested and documented and is available on the market in the APS turbo kits? I have been racing for decades and I never needed every engine to be blown every time on every car before I took notice of professional testing, identifications of problems, and recommendations for proven solutions.

But I do agree with the last part of your post that, "Which, will lead me to believe that APS is a company that wants to include everything necessary for the user (besides internals, and drivetrain and etc.)." when going up to the high power levels.

And I also agree that is will be VERY interesting to get these kits on 350Zs and test them in the real world. But to me it also goes back to optimal, perhaps even over engineering for the long term reliability. Bullet proof engineering and reliability is just as important as More Power, though it truly hurts me to admit that anything is as important as More Power, lol.

Maybe some of you with the Turbonetics kit can come to MD and we can put all this to the test at Mason Dixon Dragway on a test and tune day. All in good fun of course. The first er...adult beverages...after it is all over will be on me

Brandon@Forged

Should have clarified, the HKS is not tunable with the F-Con S.

The only experience I have is by seeing what others have done, gq_626, phunk, and others that were over 400rwhp and didn't have a return-style fuel system (i'm not sure about that though, when they switched to one or at what HP level they were at before switching, etc.)

Heh, you know the answer to that. That's like asking if I would take a 650rwhp 350Z or a 1000rwhp 350Z and both would be safe for a daily driver...what would you pick?

Heh, nice pun.

More Power

I don't know, for an absolute fact, when gq_626 switched to a fuel return system but it was listed on his 350Z on the video as one of his mods when he was racing the Subaru turbo. And I am pretty sure he was at 416 wheel hp at that time. I am pretty darn sure that he has been listing the fuel return system at the 416 wheel or similar HP. Now don't quote me on that, because I am not absolutely sure in all honesty. Again I haven't gone back and done a big search. I can't speak for him on when and what power level exactly he went to the fuel return system, though. Not with absolute certainy. I know that he has certainly made many very positive posts about the the APS fuel system compared to the other kits out there.

And as far as Phunk is concerned, here is a fairly recent post by him regarding the APS fuel system and what he thinks of the need for the APS fuel return system:

"When doing my fuel system R&D on the 350z I realized that APS did their job... they didnt just slap a kit together... they tested their product and vehicle to find out what it really needs other then a turbo stuck on a manifold. We were bench testing the components of the fuel system and sliced up a pump assembly to verify its inner workings and thats when I said... gee... all the people with this AAM return fuel kit are never gonna get to use more than one side of their gas tank with this stupid plug that replaces the fuel pressure regulator... you need the fuel returned to that location to power the siphon jet... so then I say hey I think APS has their installation instructions on the website lets see what they did with their fuel return... we were assuming it was going to be rigged as well... well nope, we found the page and i said to myself "****... these guys werent ****in around, they bothered to actually find out that their fuel system is functioning correctly'

i said in a post a while ago that the APS kit will give 350z's the HP that other kit owners will blow their engine trying to obtain. Crank trigger interferance and dropping fuel pressure when your gauge says you have 1/4 tank is whats going to kill other guys every time." That is a direct quote of Phunk.

Pay particular attention to that last 2 sentence paragraph. Yes it does not flat out say that it is dangerous to run forced induction without a fuel return system in our 350Zs, but it sure as heck makes clear what he thinks of the engineering and the fuel return system in the APS kit, IMO. A pretty good endorsement and he has made many positive statements like that.

Brandon@Forged

Well there you go.

MIAPLAYA

iTrader: (3)

Let me respond to a few posts:

First I completely respect the crew chiefs and everyone else with a large amount of knowledge with engines. But lets be honest, this isn't Turbonetics first time around the block. The majority of the kits they produced in the past were for Nissan motors and the head of design has been building, boosting, and racing Nissan engines since I was in middle school. I'm not saying the crew chief is wrong but I think Turbonetics has thought about this once or twice. If Turboentics thought that the kit or engine would fail without a external regulator they would not have taken any chances. The fact is they have logged thousands of miles with their kit on an otherwise bone stock motor and have not had a single problem to date. And I'm not talking dyno or baby miles. As you can see from my video (that was liek 2 weeks post install) they have flogged and otherwise tortued their motor from day one with the kit. They've taken it on road trips of over 4 hours and flogged it the whole way. Its now coming up on a year that they have had this kit installed in their car and I honestly believe they have tested every possible scenario this car could say from drag racing, to drifting, to cruising (raod trip style), to rush hour traffic, off boost testing, etc. My point here is there was going to be a problem a la fuel system they would have found it by now. The miles have not been good to their test car. As a matter of fact the testing is the reason they decided to add the Walbro. They felt the stock fuel pump was just not suffcient and added a Walbro and tuned for it to ensure there were no issues.

As for the CAS wire issue: Turbonetics wa made aware of this via Performance Motorsports (the 1000+ HP Z) that uses their turbos and has a very strong relationship with them. To date Brad has called Nissan Tech directly to discuss this and there may be a TSB as a result. Even if there is not Turbonetics is working on including a solution for this with their kit as I type. I'm sure they will be testing this themselves to try to replicate the issue as well since it has only ACTUALLY been recorded once or twice. Regardless of that fact Turbonetics had no problem immediately beginning investigation and working on a solution. I will call Brad either today or tomorrow and see what kind of update there is.


Oil Pan Starvation: This one still boggles me. While I agree a fin cooled oil pan will lower oil temps long term I have yet to see any evidence whatsoever of NEEDINg to have a baffled one due to oil starvation. As a matter of fact in Sharif's latest post in which he inspected his bearings he found ZERO evidence of an oil problem. And we are not talking a few miles here. Sharif ran his car hard for every one of his thousands of miles DAILY and never experienced a problem. Furthermore on the subject of Sharif he is a prime example of a non-full return fuel system boosted Z who has never had a problem. Not only that but he is running much higher boost out of the box many others have and again..no issues.

MIAPLAYA

iTrader: (3)

I agree the APS fuel system is nice. But lets also remember that its not the full fuel return system that is seems to be. It does not compare to the AAM fuel system in any way shape or from. The APS kit uses a regulator at the pump with the return line routed directly back into the tank. Although this is a simple method to install a true full return system would have the fuel running forward to the injectors and have a return line from the rails back to the tank a la AAM, CJM... As for longevity without one, I think Sharif and some others have already shown that its not an issue. Although for further evidence I submit myself. I plan to run on the base kit setup for AT LEAST the next year. My car currently has close to a thousand miles with the Turbonetics kit on an otherwise stock motor and there have been no issues to date. In a year or so I do plan to pull a replace my stock motor with a built one to include the AAM fuel system as I will be gunning for the 600s RWHP. Furthermore Brad from Turbonetics own G35 will be going under the knife in the coming months with a built motor and either a 62-1 or T66. I am not sure what fuel system he is going to run but suffice to say it should be interesting.

More Power

Phunk compared the APS fuel return to the AAM system in my prior post quote and it was not the APS system he found to be lacking, LOL.

Sharif lists a fuel return system as one of his modifications that he does run with.

Here is a post that Sharif made in reply to a post I made about the need to upgrade the fuel systems in the other kits and the need for a fuel return system:

My post minus parts unrelated to this issue and minus some redundant points:

Read Sport Z magazine, latest issue, and what the 350Z Grand Am crew chief says.... They say the fuel system has to be upgraded correctly for any power much over 300 engine HP or so in order to be safe LONG TERM. Weak kits are therefore not safer just because they are weak. They also talk about the absolute necessity for a fuel return/recirculation system for ANY forced induction 350Z at any power levels for long term reliability. Only APS and UR have this type of heavy duty fuel system including fuel recirculation system in their standard forced induction kits.... But if you are afraid of too much power, you can always take a better engineered kit like APS and tune it for less boost and less power. You can't take these other kits with dangerously weak fuel systems and tune in better engineering unless you start tossing out pieces of their kit and modifying with better parts. Which has been done successfully by some on this board.

Believe what you want, I have heard from too many of the top import engine builders in the U.S. that the fuel systems on most of the forced induction kits for the 350Z are very much inadequate and unsafe for our 350Zs. The fact that they put out less power is another turnoff, not a virtue IMO.

SHARIF'S REPLY TO MY POST:

"More power is right. The PE and Greddy kits have a sevearly inadequate fuel system out of the box."

Now since Sharif is running the Greddy kit that he speaks of above, it is pretty plain that his thoughts and experience prove that you do very much need to improve the Greddy kit fuel system to run safely with it.

Another post by Sharif on that same thread and these same issues:

"Well, the APS kit is pretty nicely tuned out of the box. And it certainly is the safest kit out there, in the way it address a complete fuel and engine mangangement setup." APS does recommend dyno tuning their kit after “out of the box” install to get even more precise tuning.

Sharif has made many many posts saying that APS fuel system and fuel return system are highly desirable and needed.

Regarding the comment that APS fuel return in the standard kit is not the holy grail of all fuel return systems: APS has stated that at some very high power level, you do need to upgrade their strong fuel return system in their kit. Seems like it was 700 or 800 HP or something - I don't quite remember or care cause it's not a power level I'm going to anytime soon and not a power level we are discussing here. The point is that the APS fuel return is much more than rock solid at the standard power levels of the kit and good for well up into the levels after you have to build up the bottom of the engine. But, yes, at some point most every fuel system needs upgrading. To have included that stratospheric level of fuel system in the standard kit would have much increased the price of the kit needlessly compared to the needs of the vast majority of their kit’s buyers. APS has provisions for an even better fuel return system for people that do want that kind of power and want to pay more for it. But, yes, if you want to turn your 350Z into a NHRA Top Fuel Dragster, this is not the thread for you, ha.

MIAPLAYA

iTrader: (3)

Well if you read the post by phunk more carefully you'll see he was referring to the way in which they handled the actual return system and the FPR. Not the entire kit itself. And sure the APs kit is good for that if you add the six extra injectors to the plenum. But that does not make it a true return system like the AAM. Sharif has stated many times that he only had the Walbro pump added to the Greddy kit. He was installing the AAM fuel system on his built motor.

Here you go


He is referring to hpw APS has modified the stock FPR location to ensure you use both sides of the tank. It still does not make it a full return system like phunks or AAMs. When the fuel is returned from the last portion of the fuel rail back to the tank THAT is a full return solution. APS does not do this.


And my point is that yes the Greddy fuel system is inadequte (Hello it doesnt even come with a pump) but that doesn't mean that EVERY kit is. Somehow even without a return people with HKS, Vortech, ATI, SFR, Stillen, Turbonetics, etc seem to keep their car running. If thats your opnion that EVERY kit needs a return system, hey more power to you. But that doesn't mean its fact. And it certainly doesn't mean that every kit that doesn't have one is garbage. Certainly you can't argue with the constant power output and reliability of the Vortech, Stillen, HKS kits...and all with no reutrn.

MIAPLAYA

iTrader: (3)

Oh heres Sharifs sig pic with mod listing. Note it says currenty installing and has the AAM fuel system there

More Power

As I posted previously, Shariff, a.k.a. gq_626, very clearly posted within the recent video, when he raced the Subaru turbo, that one of his modifications on his 350Z with Greddy TT is the "AAM Return Fuel System w Upgraded Fuel Rail". That video is still on this website. And his having this modification on his 350Z is very clearly listed at the end of the video. That is per his own video, regardless, though it does not really matter either way because just because every engine has not blown with a fuel return system in no way proves that there is not the problem as documented in the published Sport Z Magazine article I gave.

More Power

You say "hello" the Greddy is obviously inadequate because it doesn't even come with a fuel pump. Then you turn around and keep redundantly saying that the Greddy's that haven't blown engines prove that you don't need the things I and the Grand Am crew chief in Sport Z say the kits need. So you are saying the Greddy is INadequate as is, then you say the Greddy IS adequate becasue not all engines with the Greddy have blown up. That doesn't make sense. But it does prove, as I say, that just becasue every engine has not blown up, does not mean that significant upgrades are not needed as supported by the rigorously tested material I quoted from Sport Z mag. You said this yourself and make my point quite well. Again, not just my opinion given as fact. My opinon is supported by the published material I referenced. Not just the "I think" "you don't need a fuel return system until x HP level" as you have given. You are covering the same old ground and not in a straight forward way.

From the other post I gave from Sharif, "And it (APS) certainly is the safest kit out there, in the way it addresses a complete fuel and engine management setup", and other posts he has made, it is clear to objective people that it is far more than just the Greddy not having the fuel pump that makes Sharif admire the APS fuel system and fuel return system. Re read the post. When I make the case that a fuel return system is very much needed in the kits, Sharif's reply was, "More Power is right". Clear, concise, and unmistakable agreement by Sharif regarding my main points. That is clear I think to objective people. The person you are holding up as proof clearly, unmistakably agreed with me. Listen to him.

So, yes, as I posted very thoroughly several times, as the crew chief published, and as Sharif agreed, I obviously do think a fuel return system is very much needed to make any 350Z FI kit very safe and effective. And again, I do not need every car to blow up every time to make me understand the professional testing and evalunation materail I touted in Sport Z magazine is right on the money. Sharif posted on 12 Greddy's alone that he knows of that have blown up, but I have already posted this and your posts are becoming redundant back to not getting this. There HAS been a lot of engine trouble with other kits as I posted. But again, now we are covering old ground once again. Which is pointless.

You disagree and that's fine. But again, I have at least documented professionally published information to back up my opinion. Your position is only backed up with your "I think" "you don't need a fuel return system till 450 to 500 wheel HP". Your argument is not with me. Your argument is with the crew shief of the Grand Am team as submitted in the reference as tested and published in Sport Z. He has rigouously tested and published in Sport Z mag to support his claims. What credentials equivalent to his and what knowledge and testing do you base your opinion to the contrary upon other than "I think"? So it is not just my opinion given as fact. I have supported it with references. It is you that have given your opinion as if it were fact. Unsupported by any more than "I think".

Just like it is very clear from the post I gave and other posts by Phunk, the admiration he has for the APS fuel system and need for a return fuel line. Re read, it clear and unmistakable. You can nit pick it any way you want, but the points will be obvious and unmistakable to any objective reader.

Whether of not you think the APS fuel return system is better than some separate aftermarket fuel returns is not what we are discussing here or relevant to me. As I posted several times, I want a good fuel system with a fuel return system present and fully integrated into the forced induction kit I buy. So your touting a separate after market fuel return sytem does not address the issue I raised. You are making an unsupported claim that one does not need a fuel return sytem in the standard kits, but oh, just in case one does need such a fuel return system, you like a different separate aftermarket fuel return system better. Plenty of posts by Phunk and others have noted that the APS fuel return system is more than adequate to way more power than the power levels we are talking about. That is what we are discussing and is relevant. This is also the same old ground so there is no need to continue. People can make their own decisions at this point. As I already posted, some people had rather buy a basic kit and mix and match upgrades. And that's cool if they want it that way. Some of us want it covered in the standard kit. Your reply is that a fuel return is not needed at all until 450 to 500 wheel HP. Let's stay on issue, but I also think we've covered the issue at this point.

At this point your posts are merely re covering the same old ground again. So If I reply, I have to cover the same old ground as well. People can make up their own minds at this point.

More Power

In my earlier post, the sentence, "That is per his own video, regardless, though it does not really matter either way because just because every engine has not blown with a fuel return system," there is a typo and it should read just because every engine has not blown withOUT a fuel return system. The whole sentence shoud read, "That is per his own video, regardless, though it does not really matter either way because just because every engine has not blown withOUT a fuel return system, in no way proves that there is not the problem as documented in the published Sport Z Magazine article I gave.

MIAPLAYA

iTrader: (3)

Well that was some redundant reply. You bascially said the same thing in every paragraph. My thoughts on the fuel system are not based on what I think. They are based on what I have seen in my own eyes. I have SEEN three Zs including my own without a return system making big power with no issues. My Z has 1k miles and yeah thats not a lot. The other Z has about 14000 miles and that is significant. The last Z I could not tell you the mileage but the owner had the kit on his car for about 7 months solid before it was wrecked and it was his daily driver. Again thats not my "theory" thats waht I have seen. Sharif is another example. His video may say he has the fuel system but he doesn't. You can believe what you want on that I could care less. As for my saying the Greddy fuel system in inadequate it IS. Sharif does not have the standard Greddy fuel kit. Sharif added a Walbro fuel pump. That by itself makes the kit at lot better. He also uses the timing harness to pull timing thus making it sufficient for what he was doing. In the end of you are willing to believe everything you read thats fine. I know what I have SEEN and EXPERIENCED with my own eyes. Not just on my car but on three all of which have been unmercifully flogged and there have been no issues to date.

JimRHIT

iTrader: (6)

Ok, it is 100% obvious you two do not agree on this. Please stop restating this. Everyone that has read this now knows of morepower's theory, as well as miaplayas beliefs.

Let us now take this information and form our own judgements. I thank you both for your extensive posting, researching, and now arguing. It has been a very informative thread here, but if this keeps up we will end up in a dickswinging contest, and we all know I'll win that j/k

later guys,
jim