Fuel Pressure

[RedDjinn]

As we all know the US guys say get a HPFP asap when modding. Im putting it out there, could our intank pump be the issue? If this is not suppying enough fuel to our HPFP than our HPFP is useless! As we know there are guys here running 220-250kw atw with no fuel presure drop. As soon as we see our fuel presure drop we run out and get HPFP, how many of us have tryed replacing our inboard tank pump first or new high flow fuel filters?

This was bought to thoughts just now recalling the issues with my black car. MPSG had issues with it even after CPe fuel pump and cleaned out my entre fuel supply including fuel.

If not all case's are due to HPFP failure and we have bought HPFP at a $premuim, we could have saved $$ if we knew out inboard pump was a issue..

Thoughts...

[jnt]

Interesting discussion, this could be true as I believe (and I may be wrong) that a drop in, in tank pump that needs no modification to go in has only just come out, I will watch this thread with interest.

I guess a question about the fueling with your black car would be what was the "Target fuel pressure" set at in the tune as opposed to the actual that the pump was achieving?

Cheers.

[SarcasticOne]

the in-tank pump is fine with flow up to ~500whp (on a 3) or ~450 on a 6...
there is plenty of flow, it's maintaining the required pressures where things start getting dicey

[Toddy22587]

the in-tank pump is fine with flow up to ~500whp (on a 3) or ~450 on a 6...
there is plenty of flow, it's maintaining the required pressures where things start getting dicey

I agree with this. I'm also sure i've seen a thread on the US forum about the in tank pump being fine for big HP.

[RedDjinn]

In our cars our HPFP work better with more RPM in most case's our HPFP's are giving enough supply for more power than 250kw atw at high rpms. Its down low where we are at risk, BUT we seem not to have an issue (look at the Golf GTI same pump low rpm issue).. My point is how many of us have looked at in board pumps how many times has it been bought up? We all go OOO i have fuel presure drop at high rpm.. Everyones gone u need HPFP but at 5000rpm+ our pumps are not the issue for 300hp, well not by reports on our pumps


taken from here http://hpfpupgrade.com/Products/Show...sure+Fuel+Pump

[Bakis]

The fact that i've never heard of the In-take fuel pump being mentioned on a Mazdaspeed or MPS forum should be enough of a marker to say its something to keep as stock lol.

[Toddy22587]

The load on the in tank pump would be less at low RPM because your using less fuel so it doesn't have to flow as much. So if it can handle the flow rate at hight RPM then replacing it isn't going to help

---------- Post added at 08:30 PM ---------- Previous post was at 08:27 PM ----------

I have a stage one HPFP sitting here so once i install it i'll log some data to compare fuel pressure.. still waiting for them to send me my 2050psi fuel rail valve

[SarcasticOne]

considering the regularity with which people in the states are hitting and holding 280-300whp from about 3800 rpm through to redline, that graph proves the point that the stock HPFP needs replacing

---------- Post added at 11:38 PM ---------- Previous post was at 11:35 PM ----------

just looked at my dyno graph from last TH dyno day... according to that graph by HPFP, i was borederline my pump giving up from ~2500-4000rpm

[hpfpupgrade]

As we all know the US guys say get a HPFP asap when modding. Im putting it out there, could our intank pump be the issue? If this is not suppying enough fuel to our HPFP than our HPFP is useless! As we know there are guys here running 220-250kw atw with no fuel presure drop. As soon as we see our fuel presure drop we run out and get HPFP, how many of us have tryed replacing our inboard tank pump first or new high flow fuel filters?

This was bought to thoughts just now recalling the issues with my black car. MPSG had issues with it even after CPe fuel pump and cleaned out my entre fuel supply including fuel.

If not all case's are due to HPFP failure and we have bought HPFP at a $premuim, we could have saved $$ if we knew out inboard pump was a issue..

Thoughts...

In tank fuel pumps and filters can become an issue at 45k miles and really become a problem at 80k miles. Not very many people know about the in tank fuel filters, its not just a sock... its a full size fuel filter.

We have seen several high pressure fuel pumps fail because of a worn out pump or plugged fuel filter inside the fuel tank. Keep an eye on these items guys.