Hello

I recently purchased a Bosch Fuel Pump for my Fuel injected 4port bridge project. Its 6Bar and 235l/h so far as i know. The inlet on the back of the pump is quite large. (around 14mm, just over 1/2 inch). Ive got a reducer which drops it to the size of my feed in the fuel tank (8mm) and the rest of my lines. Is this alright or must i run the huge feed into the tank? Ive made a quick diagram in paint to help . Please have a look and give feedback.

Option 1:



Option 2:





Thanks

 

It's the other way around. It can only push as much as it can pull. The stock NA line is a bit too small for your application. Going to 3/8" for all of your fuel lines would be better. This includes the pickup in the tank and the return.

 

Well what I did was remove the return line. I then used the current main line as my return and increased the size of the pipe entering the tank as the return to match. I then replaced the main line with 8mm hoses from the tank to the fuel rails. The thing is that the part where the hose attaches to the fuel rails has the same diameter as the pickup line at the tank. So i thought that there was no point upgrading the pickup at the tank as it would just bottle neck at the fuel rails. Its so confusing because the line which the hose attaches to always has a smaller diameter. Unless I run a large line that splits into two smaller lines to fit to the two fuel rails to allow higher flow. The main line im using now is 0.31 Inches, dont know if that helps, mm vs inches doesnt help matters . When you say 3/8" its around 9.5mm. I guess that would make the pipe which it goes onto 8mm Inner diameter which is probably right. But then i still have the problem of it bottle necking at the fuel rails unless my splitting up idea will work?

 

Is that 3/8" outer diameter or inner diameter? Because my main line does look like it may have been upgraded at some point and I have noted that the lines i'm running are the same size as the lines on the 13b Series 4 turbo that i'm having rebuilt. If its big enough for turbo engine shouldn't it be big enough for N/A?

 

Any help? Are Turbo stock fuel lines big enough for NA bridgeport?

 

https://www.rx7club.com/showpost.php...0&postcount=61

Have a look!

EFI Hardware RX-7 Specific surgetank
Genuine Bosch 044
Genuine Carter Gold P4794 6-8psi 72gph
3/8 main fuel line
m14x1.5 1/2 fitting in feed side of 044
m12x1.5 to something, and something to 3/8 fitting for feed line
sard rising rate fuel reg

This is really how you want it, tried and tested!

 

http://img.photobucket.com/albums/v2...urgesystem.jpg




You want the feed to the efi pump to be as practically large as possible. Mine is 1/2 ~12.7mm fuel hose to a 1Litre tank, there is no flow restriction in the path to the efi pump.

My lift pump is a little overkill, as it can nearly match the flow of the main efi pump

Other guys have used the stock mazda pump to fill the surgetank and make more power than I hope to!

 

OK thanks looks like a nice setup. Is the surge tank vital? Because I don't feel like ordering more stuff from australia right now . But thanks for the pics now I can see that my lines are too small. Have to go sort this out all over again. And I have to take fuel tank out again . That thing was fighting me last time.

 

It's 3/8" InnerDiameter....the stock line is 5/16"...

 

Ok so If i run a surge tank I need a second pump?. I still have the problem of my fuel rails. Im using the efi hardware twin throttle bodies. Ordered them from tweakit. And the nipples on the fuel rails are too small for 3/8" lines. It has two fuel rails and I was planning on running the line through the one and into the other in series and then to the regulator. But then I can't use 3/8" line as it will bottle-neck at the rails. So I need to find out if I can use a T-joint or something similar to split the 3/8" line into 2 smaller 8mm lines (nipples on fuel rails are for 8mm hose) to fit onto the rails which then rejoin after the rails back into 3/8" which goes to the regulator. Will this work?

Here are the throttle Bodies:



Jobro can you please tell me the importance of the surge tank because ill order one tonight from tweakit if i need it.

Thanks

 

Yes a surge tank is essential. This is my setup. Im using the stock fuel filter before the Carter and a 1/2" Volvo filter before the Bosch as an extra precaution. There is also an EFI filter before the fuel rail.

 

I'd recommend an EFI filter before the fuel rail. Only a low pressure filter is needed before the lift pump. There is a Volvo filter with 1/2" inlet and outlet that works great.

 

OK thanks a lot for the help. Looks like i've got some work ahead of me before the engine arrives.

 

If your fuel rail suits 5/16 then just use 5/16 lines for both FEED and RETURN

YES the surge tank is 100% necessary, unless you want to baffle your fuel tank, but personally I would use both, or just a surge tank.

Personally I just use a Ryco Z200(~$12AUD) filter before my carter lift pump. Minimal restriction, and any fuel in the system has been filtered once which is fine. Trying to get a cheap filter in 1/2' or 3/8' bullshit and starts costing $ in the 50s to 200s.


www.kpperformance.com.au sell the surgetanks for like $99.

Carter Gold is worth about $110 I think.

Then you will be needing 1/4 BSP (I think thats it) fittings for the carter which have 5/16 hose barbs on them.

I should have done another 5/16 line practically. So just do what suits what you already have. The factory FC turbo uses 5/16 feed and return lines!


!EDIT! Obviously I didn't look hard enough, what are those 1/2' filters worth REVHED?

 

Pretty cheap. Under $20 if I remember correctly.

I agree, 5/16 is plenty. I simply swapped my return line for another feed line so they're both 5/16.

 

I sugested 3/8" line because I bought a 25' roll of aluminum line for 20 bucks, that's enough to run supply and return lines. It's also easy to bend and bulb flare the ends for good clamping on the rubber hoses. sSince the States is still using Standard and not Metric measurements, it does get confusing on a worldwide forum. I'm also and old fart and refuse to learn the metric system.

The stock 2nd gen lines are approximately 5/16" for both the NA and Turbos. If you do run a larger supply to the fuel rails, you can run a parallel set up instead of the standard series one ReTed, on this forum, has a website with the parallel system laid out for the TII. It could be adapted to the Teak-It kit fairly easily. Apparently the parallel system helps eliminate the secondary fuel leaning in the rear rotor on high hp engines.

 

What they want for steel fuel line isn't much more expensive than that.

Legally in my country we MUST use thick walled steel lines. It is not difficult to get this stuff, just goto a brake specialist and they will be able to order you in 3m of the stuff. They gave me very fair prices. The car length of 3/8 would have come to about $30.

 

Where did you guys pick up your lift pumps? I parted with my stock pump long ago, unfortunately, so I need to purchase something for my surge setup.

 

Anyone? I'm confused after looking at the Summit catalog and seeing "8psi" next to most of their selection of Carter pumps...and I'm not really sure if the lift pump is supposed to be high pressure or?

 

I used a 6-8psi 72gph lift pump!

I have a stock s2 pump you can have on the cheap too :P

 

Pesonally use this one

http://store.summitracing.com/partde...5&autoview=sku

or this one

http://store.summitracing.com/partde...5&autoview=sku

but i used this one and it works fine

http://store.summitracing.com/partde...5&autoview=sku

 

72gph is 280L/hr with is a LOT of petrol, I highly doubt you would be able to run that dry

 

Thanks Jobro. I knew the volume would be okay but I'm thinkin, wow, the fuel pressure in my rails is like, 40psi, and is that going to conflict with the lift pump in any way, you know?

I'll pick up something from Summit -- it's just a few miles from my house .

 

Nope. You're going for free flow rates here. Pressure doesn't matter as the surge tank won't be under pressure.

 

http://www.geocities.com/hrayhouston/antisurgetank.html .... props for creativity on a budget...