a friend of mine said i should install synapse fuel sump kit because im gonna be boosting(28psi) and gonna be making good power(580whp) is this worth buying and can any of you guys explain what this actually does. and my car is tracked on weekly and dd

 

a walbro intank 255hp will be suffecient for that power goal. over 600whp its a good idea to run dual walbros or a better choice is a walbro in tank and a bosch 044 under the hood

 

whats better walbro intank and bosch inline or sumptank w/ a single bosch inline?

 

Depends what your doing with the car. IMO a sumped tank is not nessesary untill your just tracking the car or running a huge weldon or aeromotive. you can modify the stock sump ad come off it with -6an lines which is plenty of line for quite a bit of power.

the walbro intank with the bosch inline is better than just a bosch inline

 

I would use the walbro 255 intank and a bosch inline as mentioned before.

 

What exactly does the Bosch inline do? Won't you only produce as much as fuel the walbro intank can suck to the inline??

 

Nope, the walbro will actually become like a feed pump to the bosch and wont see any of the load or very little of the load and will become a free flowing pump and able to flow tons of fuel. then the bosch which is the better of th two pumps wil become the pressure pump more or less giving you what you need at the rail.

 

I see.... So it's better to run intank w/ inline, than a sump tank w/ a single Bosch.? How much power is this setup good till.

 

Turbo-LS is right. I have been knowing this for a while and the other day i talked to a tuner that said differently(which i will not mention). Which confused me becuase i knew i was right. So i chatted with someone that uses this setup all the time and of course i was right. After about 85psi the walbro is just a feeder. At about 100psi it goes down to about 5psi

I've seen @ 100 base they are good for 750-800hp. I have -6 lines and that's the exact setup i have. I think it's probably the best setup for someone who needs more fuel than what a a single walbro can supply.

 

Why not just run a dual walbro setup ?

 

better yet what injectors does he have? and what pressures can they maintain

 

Because bosch pumps are superior to walbro pumps. they can handle higher pressuers and bosch is bosch. KNown for good stuff. Im not saying the walbros wont work. I run a 255 intank with no problems but im adding a bosch 044 inline once i start crankin the boost up this spring.

the walbro intank and bosch inline is good for probably over 800whp depending on what injectors are being used and the tuner.

 

Thanks for the answers. I'm only askin cuz a local tuner was sayin the same thing "adding a Bosch inline is just a temp fix till u sump your tank"

 

An additional inline pump is a waste of money. Do it right the first time and sump the tank.

 

That's a completly inaccurate statement. Look at the power the OP wants to make. It works and it works well. Adding an inline pump saves you money from not having to do that.

I can promise you that people that did the R&d on this setup would not have said it if it didnt work good. A sumped tank sucks for a dd

he doesnt want a sumped tank for what he's doing. maybe a surge tank but not a sumped

 

I strongly disagree. 2 pumps in line are NOT the correct way to do it.

For 580whp w/ a petroleum based fuel a single walbro should be plenty!

However if it's a matter of ethanol. Sumping the tank or a properly designed surge tank is the way to go.

 

with 2 pumps inline you are able to maintain higher pressures.

For a DD i would surge it before sumping it. When you get low on gas it's not cool That;s what im looking at and for his goal an inline would be perfect. that's just my opinion though and what i;ve been taught and experienced.

 

Yes you can maintain line/rail pressure. However the system will still lack volume as it can only flow as much as the first pump will flow.

A properly sumped tank will daily drive no different then a stock type fuel sending unit set-up.

 

yes it defiantly
i guess that's the key word, properly. But i think it's cheaper to do the inline

 

No, it's a misconception to believe that.. I bet you don't truly daily drive your car with a sumped tank... I already had a few customers with a sumped tank, and even at stock ride height, it was low enough to smack it when they went over some debris on the highway (road kill, etc). I'd never try to drive a sumped Honda fuel tank on a frequently drive street car, unless I want to go 4x4 truckin' and fender gaps the size of my fist.

A single in-tank Walbro @ 70 PSI rail pressure can only flow enough for about 500 WHP... At any higher PSI and the flow plummets drastically. It's not a high pressure pump when working alone.

By adding a Bosch inline, it takes all the pressure away from the Walbro in-tank pump and all the Walbro is doing is just supply fuel at basically 5-10 PSI of pressure at the pump outlet. A Walbro at almost free flow (5-10PSI of pressure) can flow upwards of 700+ WHP and in the neighborhood of 280 LPH.

The Bosch is also working less hard and is not "sucking" fuel anymore.. Fuel gets slightly pushed through the pump by the Walbro so it manages to maintain steady flow for those high fuel pressure setups (80+ PSI rail pressures). The combination of both, is quite popular and easily supports 750+ WHP. Pretty much all other cars, such as a Toyota MR2, or Audi's, etc.. when the stock in-tank pump is really hard to access, runs a similar setup. In fact, most of the factory in-tank pumps can flow A LOT as long as it is not working under higher pressures.

Dual Walbros = combined together it gets a lot more flow at under 70 PSI of fuel pressure

Walbro + Bosch 044 = combined, it flows similar to dual Walbros at above 80PSI of fuel pressure.

Inline pumps are biased on elevated fuel pressures, parallel pump setups are biased for overall volume. With a Honda trying to get 650-700WHP, your fuel pressure will rarely be under 70 PSI because of the boost you'll be running...

 

Good info guys!!!!

 

what size injectors? id2000?