96 Beretta Project

[45es]

I was offered two solutions by aeromotive... Next solution was to take the return from the injectors and feed that to another bypass regulator and create a 7-12 PSI back pressure on the first regulator. I asked him if this would affect the first regulators pressure at all, because if it doesn't then this may be the easiest and cheapest way to go.

I like this option / idea provided the bypass regulator has a high enough duty cycle to allow for operating 100% of the time. The bypass will always be in operation whether the NOS is in use or not. My experience in the past (not with automotive fuel systems) has been, bypass regulators in general can wear quickly if not designed correctly.

Going to a pump system like you described really creates issues for my setup due to working with the stock tank, pickup and baffles right now... A free flowing siphon of 3/8 line will empty the pump chamber quicker than it can fill it up with the current way that tank is baffled... at least when it's got less than 1/2 tank in it... not sure how wll it works when it's full.

Just curious, doesn't your return line at the tank return fuel to the pump chamber as mine does (not the same pump nor tank as yours)?

[3400-95-Modified]

Yes it does return to the pump chamber. IIRC it's just a outlet at the top of the pickup that pours down on top of the pickup assembly.

And in reality the stock bypass regulator (or aftermarket one I'll install) is working 100% of the time anyways... There is always fuel being returned to the tank to regulate the 48-55PSI it's set for so it's always bypassing something. They sell service kits for 22 bux.

I could buy two 13301's and use the low pressure spring included on one of them and the high on the other... Makes it simple and will look better if you ask me because they will match lol.

[45es]

One last thought after I sent my last response. I agree with your thoughts and should work fine. If by chance you do experience any problems associated with the low pressure bypass system, a pair solenoid valves installed could be used to isolate the low pressure system during normal operation. I doubt it will be needed though.

[3400-95-Modified]

Seeing how the nitrous is only used at the strip, I was actually contemplating installing a manual bypass valve so I can enable and disable that low pressure loop instead of the solenoid valves since in all honesty that system never has to be enabled remotely... I still have to turn the bottle on manually.

[1988GTU]

This may be of consideration:

http://www.magnafuel.com/products/efi/regulators/MP-9940-B.htm

Or if you would "Y" off the feed line and use this: http://www.magnafuel.com/products/efi/pumps/MP-4301.htm
Set at the lowest out put (voltage/amps) then use a simple regulator to sustain the PSI you desire as a constant output.

[3400-95-Modified]

yikes... supports 700-1000 HP... that would probably drain my line and kill the walbro pump since It can't keep up. Remember this whole system is working off of factory lines and pickup assembly.

I checked with Aeromotive to verify the dual bypass setup and having the low pressure one on the return side to see if that would affect anything. Once I hear back from them that will make my decision I guess. If that's a no go then stand alone system is really my best and only choice.

[1988GTU]

It would over draw if you applied the level of voltage. Qhy not control it with voltage to drop the psi low enough to use a regulator appropriate?

[3400-95-Modified]

Well lets start with it's a $450 pump, which would still require a regulator on the other side of it... I mean I can get a dual regulator setup for $300 if the secondary loop idea works as Aeromotive suggested, OR I can buy one regulator for the EFI at $150 and a whole secondary fuel system kit with 1gal tank for $430 from nitrous express and not have to worry about affecting my EFI system at all.

[1988GTU]

Your chances of incurring a failure or multiple issues wouldn't be there tho. Less is better. It does come at a price in this case.

[3400-95-Modified]

I just don't see how that configuration is any less complex than the other two suggested... There is always a chance of failure and I feel that running a high volume racing pump off a feed supplied by my Walbro 255 in tank pump while limiting the voltage to that larger pump is just asking for something to go wrong.

The worst I can see happening with the dual loop system is the back pressure on the first loop creating inconsistent pressure or higher pressure when in use... The secondary fuel systems are marketed and sold as a system to ELIMINATE the chance of failure and ensure that each system is properly supplied with fuel and not have one trying to steal from another.

What your suggesting I've never seen attempted anywhere online so it's a shot in the dark on if it would even work, never mind how reliable it ends up being. I have my doubts because in all honesty there is nothing in that pump to prevent it from being overpowered by 55PSI of pressure from the first pump, it has no way to isolate the two separate systems.

[1988GTU]

I cringe at the loop system you are entertaining. If you impede flow of the factory used return line in any way, it can make the feed psi be manic no matter how much checks and balances you put in its system.

I am almost certain that regulating volts to the pump I linked should not pose any issues. Def contact there cs for clarification.
However, that other link I posted shows a dual feed regulator thats capable of maintaining pressures indifferent of each other, thats what I think im seeing.

[3400-95-Modified]

I cringe at the loop system you are entertaining. If you impede flow of the factory used return line in any way, it can make the feed psi be manic no matter how much checks and balances you put in its system.

This is exactly why I questioned that suggestion made by Aeromotive to see what their response is on how their regulators would respond to a back pressure on the return.

And that regulator has a range of 35-85psi... It can't do indifferent pressures. The 2 port and 4 port options are just giving you more feeds for each item, One carb and two stages of nitrous for example. Some EFI regulators only have one inlet and one return meaning you would run the feed to your rail first then go to the regulator like stock... Ones that have the two port options give you the ability to setup a semi-returnless fuel setup and have the feed go to the regulator first and the return back to the tank and you just feed the second inlet to your rail. Then your rail will sit at the set pressure but it will use all the fuel delivered to it and not have any just passing through.

If aeromotive comes back with their solution being a bad idea then I will probably go for the NX tank solution. I'm just not a fan of trying to steal feed fuel for this setup... Which is the only reason why I was entertaining the return line since it would be excess fuel that's not being used that I'm taking. And in reality if the back pressure causes the first loop to read higher than originally set without it, then you can probably just adjust it down to compensate so when both are active they stay pretty stable. The secondary regulator would not see a VAC signal it would be static pressure so at least the return restriction would never change during operation and the worst it can do is spike my main pressure when enabled resulting in a rich condition.

[3400-95-Modified]

I re-sealed the firewall with the Napa sealant, did two thin coats this time so no areas cracked on me. I then sprayed over that coating with the Leak Seal stuff from rustolieum... Seems to work good. That also dried up nicely and didn't stay a tacky mess like some rubberized undercoatings do. I still need to clean up and spray the rest of the bay with the bed liner I got.









Here is the older fresh air vent cover in place as well...

[3400-95-Modified]

Also got my two cam choices from Ben yesterday...
Current cam specs adv dur 216/240 @ .050 .517/.568 lift 112LSA I believe it's a 113 ICL but not sure.

This is the best I can come up with without XFI lobes. XFi is 10 hp more in the mid range and 8 up top running less duration and more lift with a faster ramp up rate. The springs necessary are nitrided so that aspect would be better for longevity. The stiffer spring will probably stretch your double roller....ROFL not. Bearings might be an issue but I haven't heard of it. Lasted a year in a racing engine without an issue but thats not the same type application.

Xtreme Energy version Advertised by comp as 276/294 adv 224/242 @ .050 .536/.576 lift 113 ICL 115 LSA.
XFI version Advertised by comp as 268/286 adv 218/236 @ .050 .570/.579 lift 109 ICL 114 LSA.

XFI cam would require new PAC springs which are stiffer than what I have, and also need new seats and seals as well as machining the head spring pockets to allow them to be installed at the proper height for close valve preload.

I'm leaning towards the Xtreme Energy just because that will reuse the same springs I have and I haven't seen any long term ill effects form them. Heavier springs could cause premature cam bearing wear, lifter bleed down, or other unknown issues. And its only 10 more hp across the mid range and 8 on top... I can probably get that another way for less money and not as much fear of longevity issues, or just live without it since I'm sure it will already be better than what I have.

[ericjon262]

I don't know nitrous systems well, but why can't you just run 43 psi like your injectors, with a tighter orifice in the nozzles?