diy dual feed fuel rail confusion
05-17-2007, 10:33 PM
#23
There are several reasons why the fuel tank gets pressurized. It has a small amount to do with the amount of fuel that is pulled out of the tank, some to do with fuel returning to the tank, but mostly it's just the air in the tank being heated or cooled over a period of time.
Try this. Park your car in the garage overnight. Take the gas cap off in the morning to relieve pressure, then put the cap back on and then go park it in direct sunlight. Go back to the car mid-afternoon 3pm or so when it's been baking in the sun and open the gas cap... WHOOSH! The air in the tank gets hot, expands, and pressurizes the tank.
Try this. Park your car in the garage overnight. Take the gas cap off in the morning to relieve pressure, then put the cap back on and then go park it in direct sunlight. Go back to the car mid-afternoon 3pm or so when it's been baking in the sun and open the gas cap... WHOOSH! The air in the tank gets hot, expands, and pressurizes the tank.
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05-17-2007, 10:58 PM
#24
You might as well incorporate a fuel pressure gauge into the design.
1st Pic: My first design had the gauge mounted directly on a T-fitting inside the engine bay, but I decided I wanted to be able to see it while driving, so I mounted it to the cowl.
2nd Pic: My current design eliminates the first T-fitting the gauge used to be attached to, and instead I'm using just a single 4-way fitting.
3rd Pic: Shows routing of gauge.
4th Pic: Shows view of gauge from drivers eye, easily readable.
1st Pic: My first design had the gauge mounted directly on a T-fitting inside the engine bay, but I decided I wanted to be able to see it while driving, so I mounted it to the cowl.
2nd Pic: My current design eliminates the first T-fitting the gauge used to be attached to, and instead I'm using just a single 4-way fitting.
3rd Pic: Shows routing of gauge.
4th Pic: Shows view of gauge from drivers eye, easily readable.
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05-17-2007, 11:16 PM
#26
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It's not my ******* fault you can't get it up and have to take it out on the interweb.
Latah.
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05-17-2007, 11:18 PM
#28
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if I ban too many, I get ****, if I ban too few, I get ****.
what the **** ever. I wanted to ban this **** days ago when he PM'd me this
but I thought nooooooo people will just bitch because I ban too many people.
what the **** ever. I wanted to ban this **** days ago when he PM'd me this
Originally Posted by speedracerTD04
why can't you just delete that thread that I wrote? if i woulda known it was going to get blown out of context so much I wouldn't ahve done it... at the time i was just weirded out and figured i've seen other problems with girls posted on the bs forum so hey, why not.
if that is to much for you to do then, all i'm asking is that you delete the threads and me from this forum completely
don't think that is too much to ask.
thanks
alex
if that is to much for you to do then, all i'm asking is that you delete the threads and me from this forum completely
don't think that is too much to ask.
thanks
alex
but I thought nooooooo people will just bitch because I ban too many people.
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the best part is he could have at least edited all his posts....He brought it upon himself, in the last week he was posting nothing but nonsense.
05-18-2007, 10:05 AM
#30
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Location: Denver, CO
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Since his weener thread it seemed like every other post he made was, "nobody likes me, the mods hate me, poor me, waaaaaaaaaahhhhhhh." I guess when you're 19 your status on internet forums is pretty important. Maybe he missed the afterschool special on popularity.
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05-18-2007, 10:12 AM
#31
Cpt. Slow
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hey cueball, that sounds like a good idea. I've got my 1.8 injectors now, firesleeve for my coolant lines, and a walbro fuel pump that I was planning on installing all at the same time, along with doing the mod to the fuel rail. this weekend actually. I'm going quad riding saturday, and was going to do it either saturday afternoon/evening, or possibly sunday (little busy with family, but maybe sunday morning?) if not either of those days, I'm taking monday off and I could do it then.
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05-19-2007, 02:11 AM
#36
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Anyone care to explain to me how significant pressure drop can physically occur anywhere in the system? Anyone ever actually measured fuel pressure at the #1 injector and the #4 injector or are we just ASSuming that somehow the fuel system defies the laws of physics and any lean issues on #4 are the result of this? Unless your fuel pump wasn't up to the task I'd think you'd see a global pressure drop before any distribution problems.
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05-19-2007, 10:59 AM
#37
Jwarriner, your arguement is perfectly valid methinks. Other people who have a physics background will tell you it's POSSIBLE that the design of the single-feed rail has the potential for a pressure drop at the far end, being as how that's where the outlet is for the stock FPR. I know nothing of physics.
There are guys who swear they fried the #4 because it was lean. Other guys will swear it was because the lack of coolant flow to the back of the block, hence the need for the famous "coolant reroute". I know of nobody who has equipped a manifold with 4xEGT's and 4xWBO2 gauges to individually measure each cylinder, and then done the before and after DFFR, and then the before and after "coolant reroute" comparison.
The bottom line though, is that for the $8 worth of parts to DIY a dual feed setup to eliminate any possible risk (even if you're not a believer) there's just no reason not to. Again, I know nothing of physics, but for $8 this mod is a no-brainer. There is absolutely no argument NOT to do it. I'll play those odds anyday.
There are guys who swear they fried the #4 because it was lean. Other guys will swear it was because the lack of coolant flow to the back of the block, hence the need for the famous "coolant reroute". I know of nobody who has equipped a manifold with 4xEGT's and 4xWBO2 gauges to individually measure each cylinder, and then done the before and after DFFR, and then the before and after "coolant reroute" comparison.
The bottom line though, is that for the $8 worth of parts to DIY a dual feed setup to eliminate any possible risk (even if you're not a believer) there's just no reason not to. Again, I know nothing of physics, but for $8 this mod is a no-brainer. There is absolutely no argument NOT to do it. I'll play those odds anyday.
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05-20-2007, 12:28 AM
#40
I would guess that it has less to do with it being dual feed and more to do with the size and internal flow of the rail.
Having said that, I've got a dual feed stocker waiting to do into the car.
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