oh got ya. yea i get what you mean about the injectors not all being open at once. but when your at 7000rpm at 80% duty thats got to be alot of fuel flowing through the rail.
And all pointless without maintaining the pressure. As long as your fuel pump can keep up, I can't see it being too much of an issue. I'd say this mod would be great for high power apps, where we both said, a lot of fuel being dumped would need the extra capacity. Otherwise the engine will try sucking the injectors dry. Not sure what a rising rate reg is but a fuel reg to me, increases rail pressure by restriction of the returning, unused fuel going back to the tank.
yea stock fuel reg is rising rate. when you get into boost it restricts fuel back into the tank. this raising pressure
So at the end of the day i just want to know if its a worth while mod??? well your not any worse off anyway
Pretty sure I read that under high boost applications, the pressure in the fuel rail drops enough to lean out cylinders... Having increased fuel capacity in the rail will reduce fuel cavitation and be less likely to run as lean. Not saying the pressure will not drop, but if it does, the larger amount of fuel still present would help to decrease the effects. The 300 degree rails claim: # Has 57% "faster" pressure recovery then a stock fuel rail. The 300 Degree rails maintain pressure longer then a stock fuel rail while regaining fuel pressure quicker with out hindering fuel flow below the delivery rate of the stock fuel pump. (Better than Stock) # Increased fuel velocity when pressure begins to drop which assists in the recovery of fuel pressure. This will be beneficial for those that run Nitorus Oxide Injection systems where the fuel pressure drops to undesirable levels during NOS injection. (Better than Stock and Border) # Fuel injector to main bore alignment is optimized for maximum fuel delivery. (Better than Stock and Border) Now not saying that these rails are equivalent to the 300 degree rails, but they certainly share some similar attributes. Larger fuel entry/exit fittings as the stock feed lines are quite restrictive (See pics) Larger volume of fuel present (Not huge but still an increase - assist in retaining pressure longer?) Larger volume of fuel surrounding the injector (Gotta have a benefit? ) Increased fuel velocity? - I'm assuming that with less restriction, the velocity is increased... Admittedly, this is more beneficial when running NOS, but nice to know you can run NOS with less side effects... Please correct me if I'm wrong...
yer i am about to try this mod, along with twin feed, i dont expect any gains in power at all. mainly just peace of mind, as my car is a drifter, id like to keep as much fuel in the rail at all times, and i also think more fuel in the rail and flowing past the injectors will help cool it down, maybe not at all but cant be worse, my 2c
plus its essentially free, and since im putting a aftermarket plenum on it cant hurt and it more then easy enough
Be sure to use EFI hose - not transmission hose as shown in the posts!! that will certainly fail and you'll have an engine bay fire (seen this all before)
I'm glad I stumbled upon this thread. During my bigger HP build by AMS (which included eveything from turbo's to pistons etc) a new oem fuel rail was installed along with PE850cc injectors and a modded lower plenum. My biggest concern after a few dyno's was fuel flow. After peaking at 491RWHP on pump fuel (94 octane) we saw what appeared to be fluctuations at the higher rpm end of the dyno. Speculation was that perhaps it's a fuel flow issue. I've read plenty that the oem TT fuel pump is more than adequate to provide up to at least 700RWHP or there abouts. Since that was in check, why was I experiencing that higher rpm flutter on the dyno? There was other speculation that perhaps a new fuel pressure regulator might be in order or a new fuel dampener but they appear to also be in check. Now, after reading this thread, perhaps I should focus on the fuel rail instead. While I'm now relatively convinced that a 300* rail is not a good idea given the heat soak potential, I do however like "ezzupturbo"s mod of the oem fuel rail. The heat soak issue is a concern for me as I closely followed my fuel temps (ala my pocket PC and ECUTalk) while I was in Texas last fall. With daytime temps reaching the 100* mark I noticed a substantial rise in fuel temps that I normally don't see in my hometome area. That may be neither here nor there, but my point is, there are noticeable (measurable) differences in fuel temps and by me compounding the issue with the addition of a 300* fuel rail just seems to be a not so good idea. Even though they're reported to have all of these great charatistics that have been thoroughly researched and documented (and posted here several times) it seems odd that the heat soak issue was not comprehensively addressed as intensively in that whole 300* process. Or maybe those bolt insulators were an after thought. In any case, since I'm sporting new oem rails and new injectors, modding my oem rail would seem to be a potential answer to that high rpm flutter I mentioned. I have all of the supporting mods (more have been added over the 2 years since the build) to achieve near 650 rwhp on pump gas but solving that flutter is probably my biggest hurdle. This may indeed be the answer since I've read enough posts here say that this mod would really only benefit those in the higher HP range and with very large injectors - all of which I currently have. I think the only thing I would do differently would be to utilize a double in/out. If I didn't I surely would use something a little more sturdy than the barbed fittings and clamped hose set-up. Since going through all of that trouble to mod the oem rails, I think I'd keep in that mindset and upgrade the inter-connect between the two rails with something a little more robust. At the very least, something that didn;t rely on a hose-clamp type of inter-connect fitting. But that's just me. So indeed, this thread is very enlightening and informative as I prepare for another fun season of zed-ing after the winter snows disappear. I'll be watching this thread as it goes. Many thanks agin to ezzupturbo!!
Thought this might be a suitable companion to this thread since it is also about modding the oem fuel rail. http://www.300zxclub.com/showthread.php?t=124780&highlight=modified+fuel+rail
So you have never had a 300deg rail on this car? and you've never had a parallel fed system, with either a stock or a/m rails. But you did have some kind of problem in 100deg heat with serial fed stock rails on your outrageously 600odd hp zed. And now some how you're convinced that 300deg rails are prone to heat soak, with out having ever used them, is that right?
No, not quite right. My attention to fuel temps came about after the introduction of my Pocket PC and ECUTalk. Months after the fact while on a trip to Texas I noticed the fuel temps were a bit higher than back home. It didn't pose an issue at that time at all or since. However, the mere fact of the fluctuations to fuel temp stayed in my mind. Now that that I see that there's a very strong likelihood of heat soak possible with the 300* rails, I don't think I want to even consider them as a potential candidate for a fuel rail upgrade. I feel I need to do some sort of fuel delivery upgrade and I feel I may be a perfect candidate for the oem upgrade. Lets face it, the $$ saved is a great caveat to begin with. It appears quite conclusive that there's definitely a lacking in the isolation of the 300* rail from the lower plenum in comparison to the oem rail. Just to reiterate, I had NO fuel temp problems in 100* heat. It was an opportunity at the time to see what kind of fuel temps I had. Given those numbers and given that the 300* rails are not as insulated as the oem rails, I don't have to spend a lot of money on the 300* rails just to disprove the heat soak potential. I've seen enough in this thread to be convinced that it wouldn't be a smart move to consider them. I don't have the luxury to buy a product only to find out it won't measure up. The previous posts regarding the 300* insulators on the retaining bolts and the pics of how the rail is all but touching the lower plenum was convincing enough for me. What more does one need to know? Is there any before and after the fact fuel temp numbers for the 300* rail to read up on?
how would running fuel through a small tranny cooler go with fuel temps?? its an idea i was thinking of trying.
Plenty of people run fuel coolers. A friend of mine had a Sigma with a supercharged Holden V6 on Nitrous, and he has a cooler fitted in the return line just before the tank, so the hot fuel from the rails was cooled a bit before mixing with the tank fuel. Even had a little thermo fan fitted to it. I'm not sure where you would go about mounting one an a zed though, but i'm sure it's do-able. Ben
