hi everybody

just about o rebuild my engine just do put a T04S on it with 550cc and RC's 1300cc injecotrs to get about 400rwhp out of the enginge

now had a walbro 255lph pump in, that is going to be at is peak whit 400rwhp, so thinking about the walbros new 400lph...

my idea was to run standard fuellines and fpr, as much stock as possible.. or will the pump produce to much pressure so the lines and fpr will be to limiting for the setup??

a friend gets 400hp in engine, out of stock injectors and stock fuellines and a 255lph pump... is the differense so mutch that its nessacary to change anything?
the fuelfilter is upgraded already, since I know that was somewaht limiting already at 350 hp in the enginge with BPU


/niklas
sweden

 

stock lines and rails are good for about 500 horsepower to the wheels, as far as the pump goes, you get what you pay for and the new walbros are the cheapest and highest output rated pumps on the market currently.

most people run a bosch 044 or a supra tt pump as those 2 are the most reliable.

 

never had any problems with my 255 pump.. and going to put it to the test in a real pumptesting bench before installing it

so stock fuellines and rails are good, how abot stock fuelpressure regulator? will it be able to keep the pressure down with the higher flow?

 

i wouldn't run the stock FPR for anything over about 350. as for the pump, i wouldn't run the walbro over 400.

 

No the walbro 255 is not going to run over 400hp, that's why I was thinking of walbro's new 400lph pump... That I will be running!

 

You should be good with the new walbro 400 pump, I think there are some other members on here who are now using it. I use the aeromotive 340lph pump that I installed right before the walbro 400 came out or I would have got it. I think you will also need 1680s and 550s for 400 hp, that's what I had with about 400 hp. And I good fuel pump rewire with a relay. I read someone had 700 hp still with the stock hard lines up to the firewall, I have 528 hp and still stock hard lines and stock fuel filter, no problem.

 

i'd be more curious which will heat up the fuel more. more is usually better when fuel is concerned but to an extent.

does it flow consistently?
do i really need that much volume?
is it reliable?
will it generate alot of heat cycling all that fuel around through smaller diameter piping that wasn't made for the pump?
will i need battery cable wiring for the pump to keep it from blowing out at inoportune times?

 

A Denso Supra pump will handle 400whp no problem. I am running SaRD 280lph pump which is essentially the same.

With your power goals, why not put a quality piece in there?

http://www.rotaryextreme.com/fdindex.html

 

oki good will replace original FPR to a aftermarket to be sure about fuelpressure

but will be running 550 and 1300, a buddy of mine here in sweden has 550 and 850 running 400 hp in the engine on that setup with singelturbo... so let's se how far the 1300's will do...
according to Howard Colemans thread about fuel o singelturbos, https://www.rx7club.com/showthread.p...fuel+calculate
I calculated that at 10 ARF and about 85-90% injectionduty it would be good for just over 400 at the wheels...
Wanna se how that translates to the reality =) perhaps stock fuelrails will be somewhat of a bottleneck?

but since the auhoritys in this country wanna check our cars every year for trafficsafty it's even accually illegal to even change the IC and do BPU upgrades... so dont wanna ha all flashing new fuelrails and whatnot to make them even harder.. just hope that d HKS cast manifold and my T04S will be out of sight whit the big airpump in the way!

rewire is done a long time ago for the walbro 255 already so that's no problem, the fuelfilter is changed to aftermarket freeflowing and put in an other place, just so its more easy to get to

 

Stock fuel rails will be good. There is no way someone can have that much hp with stock injectors, and you definitely don't want to run 10 afr which also requires a lot more fuel, too rich and makes you loose a lot of power.

 

350rwhp is what his dynosheet tells us... so about 400 in the engine

and acording to http://rx7.com/cgi-local/3rdgencalc.cgi
standars injectors on 95% will do 401 hk on the flywheel

and 550 + 1300 injectors at 95% will make about 470 flywheel hp's.. that would be aruond 400 at the wheels right?
theese number are very close to what I've been calculation from Howards thread I linkes in earlier

and I just said 10AFR since Howard calculates on that just to have enough fuel... ofcourse I wont fun with 10 afr.. when calculation its just a safty to always have to much fuel than you need

 

Ops! Of course I mean 85% on 550 + 1300 will do around 470 on the flywheel according to calculations and rotaryperformance calcylator...

 

Tom94Rx-7,
When you say stock fuel rails will be fine, do you mean running through original supply line, or using supply and retun in parallel (1 supply 1 return or 2 supply 1 return using vent line) ?

 

For the HP he is going for the stock rails and line are fine. 1 supply and 1 return.

 

Thanks

 

I use the stock supply fuel line all the way up to the secondary fuel rail for 1680s, except with fpd elimination. All stock fuel line setup from the firewall back to the pump. Aeromotive fpr.