I just got some paxton instructions sent to me (thank you, btw), and the part where it describes the water injection is very, very vague with no pictures really. So I have a few questions.

What does the water injection pump look like? I have a black cylinder about 3.5" in diameter with a bracket on it that has 3 npt fittings coming out of it. Two of the fittings have large hoses(1/4") connected to them, and one has small vacuum line with some fittings on it connected to it. The reason I don't think it is the pump is because it doesn't appear to have a power wire as the instructions say the pump should have.

Also, I don't completely understand how to modify my breather system. I am supposed to remove pvc hose on my T.B., cap it off., runn the hose from the pcv valve to my oil filler cap (which will have a fitting drilled in it) and then also go to my air filter?

thanks.



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89GTA5spd – Came: Completely Stock w/ 3.42’s, rear disks, dual cats, LB9 305, T5, bad paint & interior. I did: Conical K&N w/cust piping, TPIS Airfoil, Ported Plenum/Runners, TB By-pass, Home Made AFPR, MSD Cap/Rotor, Jet Fan Switch, 180 T-stat, , Flowmaster 3” Cat-back, Eibach 1” Drop, KYB’s, Hotchkis STB, BFG 255 Comp T/A’s, AC Plugs, NOS TPI (custom) Kit , Sony CD Deck, Orion Amp, Fosgate 10’s, 1991 GTA interior, new paint. I have but have yet to put on: Alston Bolt on SFC’s, Paxton SN-92. Soon: Mallory Hyfire, Autometer Phantom Elec. FP guage, N20 Guage, Boost Guage, Fuel Pressure Safety Switch, Bottle Blanket. Not So Soon: L98 w/ alum heads. Always a work in progress..

 

I'm doing this from memory so if I'm wrong someone correct me. I'll dig out my old paper work to confirm later.
The one that came with my SN92 kit was a small black cylinder about 1" diameter and about 3" length. with two hose nipples (one for inlet, one for outlet) and two wires (one for +12v, one for ground). basicaly it is an inline windshield washer pump.

Not sure what that would be. Mine had no such beast with it.
Doesn't sound like the pump to me.
The kit also had a T fitting to tap into the hose that comes out of the windshield washer tank to the actual OEM windshield washer pump. It also had two small red check valves to install in the hoses. One goes in the hose going to the windshield washer pump and the other goes in the hose going to the H2O injection pump. They install so that the water can be pumped by each pump to it's proper destination without sucking air in from the outlet of the other pump.
There should also be a pressure switch to turn the H2O injection pump on durring boost conditions.

Remove the crank case breather hose from the throttle body. Cap off the nipple sticking out of the throttle body.

If your engine still has the aluminum tube that the breather hose attaches to that goes to the rubber fitting on the passenger side valve cover, remove it too, but leave the rubber fitting in the valve cover. The Paxton kit comes with a short piece of steel tubing that attaches to the rubber fitting on the valve cover. A small piece of rubber hose (about 3"-5" long × about 3/8" ID) attaches to it. To this piece of hose a Y fitting with one 3/8" nipple & two 1/2" nipples attaches. One of the 1/2" nipples of the Y fitting attaches to a rubber hose about 3'-4' long × 1/2" ID and goes to a nipple on the air cleaner. The last 1/2" nipple of the Y fitting attaches to a piece of rubber hose about 12"-18" long × 1/2" ID. It goes to a Mr Gasket style (or Chrysler OEM style) valve cover breather with a 1/2" nipple on it. This valve cover breather goes in the driver side valve cover (the same valve cover the PCV valve is in). You will have to drill a hole and install a grommet.
You leave the PCV valve and hose connected as it was from the factory. (The valve in the driverside valve cover and hose going to a hose nipple in the intake manifold base for vacuum.)

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z

 

Thank you. I think i have it figured out now. I think what I got is some kind of FMU. I did not get a water injection pump.

I have heard if you run an FMU you don't need the water injection?

I also heard you can just use the windsheild washer pump instead? I don't mind not having that.

I saw a MSD/vortech boost retard device for sale locally for $50 that retards timing acording to how much boost is being made.. can I use this instead? Would it be worth it for the $50?

 

Water injection can be used interchangably with (or in place of) the boost timing retard. Either will reduce or eliminate knock caused by too much timing and/or increased cylinder pressures and heat with fuel that has too low of an octane rating. Neither one will fix or cover for a lean condition, which is what the FMU is designed to help. if your air/fuel mixture is correct without an FMU then you don't need one. There are other ways to increase the fuel side of the mix as well.
If the "cylinder" you described is more "disc" shaped (about 3"-4" round × about 1" thick) then it does sound like an FMU.

[This message has been edited by IROCKZ4me (edited April 20, 2001).]

 

I might add that Paxton's water injection system is referred to by Paxton as their "Detonation Suppression System". Them's fancy words for an extremely cheap, plastic $9 Anco brand windshield washer pump that Paxton uses for their water injection.

I never measured the pressure output of one of these pumps because they wouldn't last past one month when I initially installed my Paxton about three years ago. But suffice it to say that it probably cannot produce over 5 psig pressure. Can you imagine the lack of atomization through the water injection nozzle at this low a pressure?

That being said, what do you think happens when the blower has compressed the air intake charge beyond the pressure of the water? Well, the water stops flowing and as boost pressure increases further, the water is forced back into its reservoir!! I use a 100-psig Carroll water injection pump. Talk about a super-fine atomization pattern!! (I accidentally sprayed myself in the face checking this out!)

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Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
Former Paxton (6-psig): 12.57 @ 111 mph.
Former Paxton (6-psig) & former 50-hp nitrous: 12.04 @ 114 mph.
Current ATI D1SC (Initially 10-psig): Projecting high 11's.
Future ATI D1SC (15-psig): Gotta catch them pesky 26-psig boosted TTA's!!

http://willie.camaro-firebird.org/

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

[This message has been edited by Willie (edited April 21, 2001).]

 

The Cylinder is more of a disk shape than a cylinder, but all the math I have taken has convinced me anything with any type of height is a cylinder. I think I'll just buy that boost retard thing for now (it looks real easy to hook up and is designed to connect directly to a GM wiring harness) and use that until i can figure out a way to use the water injection.

I am not sure how the FMU works, but it looks like it taps into the fuel lines somehow and also gets a vacuum signal from the plenum?

 

I have a paxton sn2000 with the modified impeller. I have the water injection unit on my kit. My pump stopped working a few months ago, Paxton wanted 175$ for a new pump! I went up to shucks, got a windshield washer pump for ten bucks! Works great now! I do have to agree with Willie, that's why i added a crane hi6s boost retard onto my system. However, when i am in the boost frequently, i do notice my water needs to be refilled frequently.

 

That sounds like a good idea to me. An adjustable boost biased timing retard will allow you to dial in the best timing for any given condition. A bad tank of gas is easy to compensate for. Then when you have a tank of good gas you can just turn up the wick on the timing.

yep, pretty much. The FMU goes inline in the fuel return line.
It increases fuel pressure in the fuel rail by "pinching off" the return. The small hose taps into manifold vacuum/pressure and when under boost the FMU will increase fuel pressure a certain amount per pound of boost. Many FMUs are adjustable as to how much fuel pressure increase you get per pound of boost, some are not adjustable.
FMUs increase the amount of fuel that any given size of injectors can supply. My personal preference is no to use an FMU but to use injectors rated for the fuel flow actually needed and tune from there.

 

Thanks for the help! I started installing the S/C today. I got it all on except for the crankcase ventilation and water injection/fmu/boost retard. The install was fairly strait-forward... but man was the alternator a PITA to install. I have no clue as to whether the S/C works or not yet, since I don't have the belts for it. Tommorow a friend is taking me to the parts store to pick some up so I can test it.

Suprisingly, I got almost every small piece I needed, even though the seller had no clue if it was complete or not. I only was short one small bolt (for S/C idler pulley) and the small bracket that mounts to the intake manifold engine hoist bolt(tommorow i'll pick something up at the hardware store and drill it to fit).

I ended up ditching my Cruise control instead of re-locating it because I didn't feel like drilling more holes in my engine compartment and the vacuum connector off of my plenum that connects to it broke a few weeks ago, so it didn't work anyway.

Tommorow I am going to go pick up the boost retard, and play with that.

I don't think i am going to use the FMU. Maybe i'll try it later.

When you use water injection on these things, what do you put in the windsheild wiper fluid resivoir.. windshield washer fluid?!?

I'll try to post some pictures as soon as I develop the role I am taking.


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89GTA5spd – Came: Completely Stock w/ 3.42’s, rear disks, dual cats, LB9 305, T5, bad paint & interior. I did: Conical K&N w/cust piping, TPIS Airfoil, Ported Plenum/Runners, TB By-pass, Home Made AFPR, MSD Cap/Rotor, Jet Fan Switch, 180 T-stat, , Flowmaster 3” Cat-back, Eibach 1” Drop, KYB’s, Hotchkis STB, BFG 255 Comp T/A’s, AC Plugs, NOS TPI (custom) Kit , Sony CD Deck, Orion Amp, Fosgate 10’s, 1991 GTA interior, new paint. I have but have yet to put on: Alston Bolt on SFC’s, Paxton SN-92. Soon: Mallory Hyfire, Autometer Phantom Elec. FP guage, N20 Guage, Boost Guage, Fuel Pressure Safety Switch, Bottle Blanket. Not So Soon: L98 w/ alum heads. Always a work in progress..