Miatapower List Archive

This read-only message was archived from a public mail list.
Mail From: "Todd Paciorek" <(email redacted)>


On the subject of fuel filters - what are the recommendations? I'm sure
my 44k miler has the original filter, so when I change the rail, I'll
certainly change the filter. Is the local auto parts store sufficient,
or are higher performance filters available / suggested?

Todd

-----Original Message-----
From: (email redacted)
[mailto:(email redacted)] On Behalf Of Shiv Pathak
Sent: Wednesday, April 18, 2001 1:07 PM
To: Chris Robertson; (email redacted)
Subject: Re: Cheap dual feed rail :-)


RE: Fuel Filters. I believe the RX-7tt and Miata use the same fuel
filter.
This is why it's vital for RX-7 guys to change filters ever 15-20k
miles,
instead of the usual 30 or 60k miles. The dinosaur-sucking FDs flow
three
times as much fuel at WOT than stock Miatas. I guess the same should
apply
to high boost turbo Miatas.

RE: FPRs. In some cases, running a high flow fuel pump with the stock
regulator can result in not enough fuel being returned back to the tank
under periods of low loads/low fuel consumption. Hence, extra fuel
pressure
during idle and cruise. This is the case with most Subaru FPRS which,
for
some reason, tend to be restrictive on the return side. The Miata FPRs
which don't seem to pose such a problem-- at least with the pumps I've
tried.

RE: Fuel Pumps. There seems to be some variance in what kind of hp
levels
the stock Miata pump can support. On my '94R, the pump proved to be
inadequate over 230 wheel hp. But on Scott M's '94LE, the stock pump
supported up to 280 wheel hp with absolutely consistent fuel pressures.
But
since pump flow is dependant on age, condition, and operating
environment, I
think the safe bet is to upgrade it early.

My 2c...

shiv

----------
>From: Chris Robertson <(email redacted)>
>To: (email redacted)
>Subject: Re: Cheap dual feed rail :-)
>Date: Wed, Apr 18, 2001, 8:17 AM
>

>
> OK, I'll chime in. I think flow (volume per unit of
> time), not pressure, is the key here.
>
> The fuel pump is the first link in the chain. The
> more flow it can pump, obviously the better.
>
> The fuel line from the pump to the rail is the next
> link. The larger the diameter, the greater the flow.
> But a diameter increase will drop pressure. The pump
> needs to be strong enough to produce adequate flow and
> maintain the required pressure. Running a larger
> diameter line isn't difficult at all, but probably is
> not necessary. Plenty of high hp vehicles run 5/16"
> line.
>
> The fuel filter can impede flow. The specs on the
> stock filter are unknown. Using an G3 RX-7 or Supra
> TT filter that is proven to flow adequately enough to
> support 300hp might be a reasonable alternative.
>
> And fuel rail diameter and dynamics have been (and
> still are) discussed.
>
> Fuel pressure and the return line: This is still a
> question in my mind. Is the stock pressure correct
> for larger injectors with much higher flow? It's
> likely just fine, as long as volume is increased over
> stock. Might be worth checking the stock fpr rating
> on the Supra TT.
>
> BTW, stock FPRs are a high quality units. Car
> manufacturers spend a lot on R&D to make a reliable
> FPR. Most aftermarket FPR's do not perform as well or
> reliably as a stock one, although they might look a
> lot more impressive.
>
> Does that help? Best regards,
> Chris Robertson
> Bryan, TX
> 96 M T3
>
>
>
> --- Greg Edgar <(email redacted)> wrote:
>>
>> I do not know the answer to this, but you have to
>> take line pressure into
>> account when determining this. The pumps ability to
>> maintain a certain line
>> pressure will be the determining factor. Since this
>> line pressure is well
>> above the fuel rail pressure post regulator, I
>> suspect this is less of a
>> concern for fuel delivery. This may not be the case
>> for cars running the
>> AFPR as this makes the delta considerable less.
>>
>> Enjoy,
>> Greg
>>
>>
>> >From: "Frank Mowry" <(email redacted)>
>> >Reply-To: "Frank Mowry" <(email redacted)>
>> >To: miata power <(email redacted)>
>> >Subject: Re: Cheap dual feed rail :-)
>> >Date: Wed, 18 Apr 2001 06:45:42 -0400
>> >
>> >
>> >Ralph,
>> >I asked about fuel line size before but no one
>> wanted to answer me.
>> >There's gotta be some smart types that can figure
>> out how much the fuel
>> >line is good for.
>> >
>> >Frank
>> >
>>
>>
> _________________________________________________________________
>> Get your FREE download of MSN Explorer at
>> explorer.msn.com
>>
>
>
> __________________________________________________
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This read-only message was archived from a public mail list.
Mail From: "Shiv Pathak" <(email redacted)>


I think the stock filter is just fine. My only suggestion is to change it
every 20k miles or so. That's probably the safest bet.

Cheers,
shiv

----------
>From: "Todd Paciorek" <(email redacted)>
>To: "'Shiv Pathak'" <(email redacted)>, "'Chris Robertson'"
<(email redacted)>, <(email redacted)>
>Subject: Fuel Filters WAS:RE: Cheap dual feed rail :-)
>Date: Wed, Apr 18, 2001, 10:18 AM
>

> On the subject of fuel filters - what are the recommendations? I'm sure
> my 44k miler has the original filter, so when I change the rail, I'll
> certainly change the filter. Is the local auto parts store sufficient,
> or are higher performance filters available / suggested?
>
> Todd
>
> -----Original Message-----
> From: (email redacted)
> [mailto:(email redacted)] On Behalf Of Shiv Pathak
> Sent: Wednesday, April 18, 2001 1:07 PM
> To: Chris Robertson; (email redacted)
> Subject: Re: Cheap dual feed rail :-)
>
>
> RE: Fuel Filters. I believe the RX-7tt and Miata use the same fuel
> filter.
> This is why it's vital for RX-7 guys to change filters ever 15-20k
> miles,
> instead of the usual 30 or 60k miles. The dinosaur-sucking FDs flow
> three
> times as much fuel at WOT than stock Miatas. I guess the same should
> apply
> to high boost turbo Miatas.
>
> RE: FPRs. In some cases, running a high flow fuel pump with the stock
> regulator can result in not enough fuel being returned back to the tank
> under periods of low loads/low fuel consumption. Hence, extra fuel
> pressure
> during idle and cruise. This is the case with most Subaru FPRS which,
> for
> some reason, tend to be restrictive on the return side. The Miata FPRs
> which don't seem to pose such a problem-- at least with the pumps I've
> tried.
>
> RE: Fuel Pumps. There seems to be some variance in what kind of hp
> levels
> the stock Miata pump can support. On my '94R, the pump proved to be
> inadequate over 230 wheel hp. But on Scott M's '94LE, the stock pump
> supported up to 280 wheel hp with absolutely consistent fuel pressures.
> But
> since pump flow is dependant on age, condition, and operating
> environment, I
> think the safe bet is to upgrade it early.
>
> My 2c...
>
> shiv
>
> ----------
>>From: Chris Robertson <(email redacted)>
>>To: (email redacted)
>>Subject: Re: Cheap dual feed rail :-)
>>Date: Wed, Apr 18, 2001, 8:17 AM
>>
>
>>
>> OK, I'll chime in. I think flow (volume per unit of
>> time), not pressure, is the key here.
>>
>> The fuel pump is the first link in the chain. The
>> more flow it can pump, obviously the better.
>>
>> The fuel line from the pump to the rail is the next
>> link. The larger the diameter, the greater the flow.
>> But a diameter increase will drop pressure. The pump
>> needs to be strong enough to produce adequate flow and
>> maintain the required pressure. Running a larger
>> diameter line isn't difficult at all, but probably is
>> not necessary. Plenty of high hp vehicles run 5/16"
>> line.
>>
>> The fuel filter can impede flow. The specs on the
>> stock filter are unknown. Using an G3 RX-7 or Supra
>> TT filter that is proven to flow adequately enough to
>> support 300hp might be a reasonable alternative.
>>
>> And fuel rail diameter and dynamics have been (and
>> still are) discussed.
>>
>> Fuel pressure and the return line: This is still a
>> question in my mind. Is the stock pressure correct
>> for larger injectors with much higher flow? It's
>> likely just fine, as long as volume is increased over
>> stock. Might be worth checking the stock fpr rating
>> on the Supra TT.
>>
>> BTW, stock FPRs are a high quality units. Car
>> manufacturers spend a lot on R&D to make a reliable
>> FPR. Most aftermarket FPR's do not perform as well or
>> reliably as a stock one, although they might look a
>> lot more impressive.
>>
>> Does that help? Best regards,
>> Chris Robertson
>> Bryan, TX
>> 96 M T3
>>
>>
>>
>> --- Greg Edgar <(email redacted)> wrote:
>>>
>>> I do not know the answer to this, but you have to
>>> take line pressure into
>>> account when determining this. The pumps ability to
>>> maintain a certain line
>>> pressure will be the determining factor. Since this
>>> line pressure is well
>>> above the fuel rail pressure post regulator, I
>>> suspect this is less of a
>>> concern for fuel delivery. This may not be the case
>>> for cars running the
>>> AFPR as this makes the delta considerable less.
>>>
>>> Enjoy,
>>> Greg
>>>
>>>
>>> >From: "Frank Mowry" <(email redacted)>
>>> >Reply-To: "Frank Mowry" <(email redacted)>
>>> >To: miata power <(email redacted)>
>>> >Subject: Re: Cheap dual feed rail :-)
>>> >Date: Wed, 18 Apr 2001 06:45:42 -0400
>>> >
>>> >
>>> >Ralph,
>>> >I asked about fuel line size before but no one
>>> wanted to answer me.
>>> >There's gotta be some smart types that can figure
>>> out how much the fuel
>>> >line is good for.
>>> >
>>> >Frank
>>> >
>>>
>>>
>> _________________________________________________________________
>>> Get your FREE download of MSN Explorer at
>>> explorer.msn.com
>>>
>>
>>
>> __________________________________________________
>> Do You Yahoo!?
>> Yahoo! Auctions - buy the things you want at great prices
>> auctions.yahoo.com/
>