Fuel pressure reg mounting

[benracin]

Where have you guys mounted your fuel pressure regulator? I've got the holly one that has two out puts and I'm not quite sure where to put it. One person awhile ago told me to yank the hood latch, install some hood pins and put it there. Is it legal to get rid of the hood latch though?

[paulydee]

I don't have an adjustable pressure regulator but I would think that at the firewall near the secondary fuel rail would be ideal. As far as the hood latch, I seem to recall that it can be removed but I am going from memory, not the GCR.

[joeg]

You can remove the stock hood latch.

[benracin]

It's kind of a wacky spot since about 3 inches down from the top of the fire wall there's a 1/2" seam sticking out. Maybe I can make a couple cuts and flatten a portion of it out to make the regulator fit.

[lateapex911]

There is an L shaped bracket to the right of the hood latch, and it has a nut welded to it...all you need is a 10mm short bolt, and a simple plate that mounts to the regulator. Seemed like an easy spot to me. I can send a digital pic next week, packing for the Glen now...

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[Eagle7]

I put mine on the driver's side strut tower.

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Marty Doane
ITS RX-7 #13
CenDiv WMR

[ddewhurst]

***there's a 1/2" seam sticking out. Maybe I can make a couple cuts and flatten a portion of it out to make the regulator fit.***

Ben, just because I toasted my car don't mean I ain't keepen an eye on you. http://ITForum.ImprovedTouring.com/wink.gif Rules my man, rules. Ya been telling me how yer refurbing the car to be legal & ya can't just go cutting & flatening my man. Between the carb & the incoming fuel line use some rubber hose on each end & a couple tie raps. The second out put is a great place to attach a T & one side of the T is for a pressure gauge & the other side of the T is for a fuel sample little shut off valve (hardware store stuff) & line.

By the way my full time job is finding another chassis. Rusted out pieces of $hit in the Northern Midwest. Anyone have a GOOD 1st gen RX-7 chassis just waiting to be used ? I can see it now as it's going. $5OO for the chassis & $1,000 to ship it to Wisconsin. That is a http://ITForum.ImprovedTouring.com/frown.gif (cost) & a http://ITForum.ImprovedTouring.com/smile.gif (no rust)

Have Fun http://ITForum.ImprovedTouring.com/wink.gif
David
[email protected]
1-414-453-0929

[Eagle7]

If I remember correctly, this Ben has a 2nd gen (FI). I think that would mean the regulator has two inputs (not outputs), meant to come from multiple fuel rails. I plumbed my rails in series (like the factory plumbing) and plugged the second regulator input, since I don't think there's any danger of the fuel lines being undersized for the HP of this car.

------------------
Marty Doane
ITS RX-7 #13
CenDiv WMR

[ddewhurst]

Marty, there are two racing Ben's that frequent this site with bensomething names. http://ITForum.ImprovedTouring.com/smile.gif benracin the one I know from Minnesota with a 1st gen & a benspeed with a 2nd gen.

I think http://ITForum.ImprovedTouring.com/wink.gif
David

ps: I ben wrong before.

[benracin]

So David, is your regulator just hanging by fuel hose?

Oh yeah, it's an 83 ITA 1st gen car. Sorry!

[This message has been edited by benracin (edited July 22, 2005).]

[ddewhurst]

***is your regulator just hanging by fuel hose?***

Ben, I wouldn't call it hanging. There is a short length of rubber fuel hose from the in steel line to a 90* fitting at the bottom of the regulator. The piece of rubber fuel hose connected to one of the regulator out ports is slightly longer but the whole deal is not floppy. Then there is a good tie rap connected to the 2nd outlet T fitting (the T fitting for the pressure gauge/fuel sample port) to the 90* bracket that the clutch line/hose is connected to. With my blueprinted carb I have never had a fuel issue of any sort. No pause in left handers or anything.

Have Fun http://ITForum.ImprovedTouring.com/wink.gif
David

[benracin]

Sounds awesome David. I like the simplicity of it. Now I just need to wire the spark plug in the exhaust so that I can shoot flames and we're on to something.

[Eagle7]

Originally posted by ddewhurst:
Marty, there are two racing Ben's that frequent this site with bensomething names. http://ITForum.ImprovedTouring.com/smile.gif benracin the one I know from Minnesota with a 1st gen & a benspeed with a 2nd gen.

I think http://ITForum.ImprovedTouring.com/wink.gif
David

ps: I ben wrong before.
Sorry, guess I had them reversed.

[ddewhurst]

Marty, if we do something sooner or later we are bound to make an error. If we do nothing we will never make an error. I can handle an error or two per week. http://ITForum.ImprovedTouring.com/smile.gif

When these two Ben's post I always do a double take before I respond. I responded to benspeed once thinking I was responding to benracin. http://ITForum.ImprovedTouring.com/biggrin.gif

Have Fun http://ITForum.ImprovedTouring.com/wink.gif
David

[tom_sprecher]

I know this is an old thread and not specific to mounting the regulator but what fuel pressure are you guys running on a 1st Gen?

Thanks,

[Boswoj]

Originally posted by tom_sprecher@Sep 8 2005, 03:26 PM
I know this is an old thread and not specific to mounting the regulator but what fuel pressure are you guys running on a 1st Gen?

Thanks,

59879


I'm running the Mallory unit - real nice looking, expensive, billet, expensive.... you get the picture. It has a provision for releasing the overpressure back to a return line to the tank that I liked, so I spent the extra bucks. Works good, just wish it was a little less pricey. Did I mentioned it seemed a bit expensive? B)

[lateapex911]

It depends...what carb are you running?

[tom_sprecher]

Sorry for the delay, I forgot I asked this question. The stock carb.

[tom_sprecher]

Anybody have any input as to what fuel pressure to run on the Nikki carb?

TIA

[dickita15]

from what I have seen the answer varies from 3 to 6 psi depending on who set up the carb, if the number is too high the floats are overcome and the car floods. usually when you get back on the gas the motor stumbles. If the pressure is to low you lose top end power.

[Marcus Miller]

will depend somewhat on jetting, but I'm under 3 Psi in my pro7.

Marcus (Pressure regulator mounted to shock tower)

[Andy Bettencourt]

Can't speak to the carbs but I think a couple hours on the dyno would be worth you while. On 2nd gen cars, we have optimized anywhere from 38 to 52lbs - depending on the car...weird I know but trial and error will yeild the best results for your own application.

We mount on the drivers-side inner strut tower.

AB

[bldn10]

Andy, this issue has come up before but I do not recall ever seeing a consensus. W/ you being a power that be and all, and using an after market regulator, what is your opinion? The question is whether the GCR allows you to modify or remove the stock regulator on a 2nd Gen. if you use an after market one. It don't say it. One person even suggested a custom fuel rail. How can that be legal? I realize that the stock regulator needs to be eliminated for the new one to work properly, and that the rules allow an after market one, but IMO that does not mean you can mess w/ the stock one. How is Flat Out dealing w/ this?

[Andy Bettencourt]

"Power that be"... :lol: :lol: How about 'tiny voice in the distance'...

Here is how I look at it:

The configuration of the S4 cars (injectors, CPU, etc) is such that they seem to like higher FP than stock. An in-line FPR will override the stock one so no mods are neccessary to get to where you need to be.

The S5 cars are different IMHO. We have seen the most power at LOWER FP that stock, so you must disable the stock FPR in order to make the aftermarket unit effective.

And I know you know all of this...so to answer your question:

If protested based on the literal wording of the GCR, I would defend myself by arguing that since an aftermarket FPR is allowed, it is inferred that the stock one may be disabled. I would point to the brake proportioning valve allowance as supporting evidence. It doesn't say you can disable the stock unit, so the limited effect a aftermarket BPV would have makes it illogical to think it can't be disabled.

As far as fuel rails, etc...some people take very liberal interpretation of the 'fuel lines are free" allowance - not us - we see them as two distinct pieces but I could see someone arguing it.

All of this is IMHO of course. Agree - disagree? Miller? Darin? Gulick? Amy?

AB

[lateapex911]

"Inferring" ...is logical, but, the old "It doesn't say you can.." thing comes into play.

I bet the rulesmakers need a little clarification on that one....

[Eagle7]

Originally posted by Andy Bettencourt@Sep 29 2005, 02:27 PM
... since an aftermarket FPR is allowed, it is inferred that the stock one may be disabled. ... As far as fuel rails, etc...some people take very liberal interpretation of the 'fuel lines are free" allowance - not us - we see them as two distinct pieces but I could see someone arguing it.

61471

I look at this as "if it says you can, you bloody well can" (haven't heard that in a while). Since the S5 FPR is integral with one of the fuel rails, you have to modify that fuel rail in some way if you are disabling the FPR. But you can't modify it in such a way that it performs an illegal function.

[bldn10]

"Relative" power.

"The configuration of the S4 cars (injectors, CPU, etc) is such that they seem to like higher FP than stock. An in-line FPR will override the stock one so no mods are neccessary to get to where you need to be.

The S5 cars are different IMHO. We have seen the most power at LOWER FP that stock, so you must disable the stock FPR in order to make the aftermarket unit effective."

Oh Lord, now I'm confused. I thought the stock FPR operated by bleeding off pressure through the return line. Thus, if you boost pressure upstream and leave the stock FPR in place, it will bleed off that increased pressure. Conversely, if the upstream pressure is reduced, the stock FPR will never come into play. I.e. I understand exactly opposite of what you describe. You are more apt to be right but why?

"I would defend myself by arguing that since an aftermarket FPR is allowed, it is inferred that the stock one may be disabled."

Geez, that opens up a whole lot of options, doesn't it?

"I would point to the brake proportioning valve allowance as supporting evidence. It doesn't say you can disable the stock unit, so the limited effect a aftermarket BPV would have makes it illogical to think it can't be disabled."

To my knowledge I've never had a car w/ the BPV disabled. How can you tell?

[Eagle7]

Think of it like a garden hose with a hole (think injector) in it, but the end open (think return line). The water system (think fuel pump) can deliver lots of pressure, but with the end of the hose open, there's lots of flow but very little pressure in the hose, and not much leaks out the hole. You put your thumb (think pressure regulator) over the end of the hose - the pressure goes up and lots more water squirts out the hole. Your thumb isn't strong enough to withstand all the pressure the water system can deliver, so water starts streaming past it, increasing the return line flow and limiting the pressure at the hole. You put both thumbs on the end of the hose (think additional FPR) - now two thumbs are stronger than one so you can build up more pressure before the water streams past it. But your second thumb doesn't make the first one weaker, so it can't reduce the pressure at the hole.

The only reasonable location to plumb an additional FPR is in the return line after the injectors, and it can only increase the FP, not reduce it.