Question about new setup pre and post nozzle

vtec-this · 09-14-2008

i have had various setups over the years on my 2003 mazdaspeed. the engine is a 2.0l dohc with a T25R BB turbo and 9:1 compression. i experimented with individual port injection system last year but ran into some problems with distribution. I ended up just getting a secondary fuel system with additional 4 fuel injectors for a total of 8 combined and ran 15psi (each injector is ~280cc). I never made it to the dyno but i am guesstimating i was around 250WHP. I used a home made afc device running off a gm 3bar map sensor to handle the second set of injectors and clamped MAF voltage at 4.8 to keep the 1st set of 4 injectors from maxing out past 100% duty cycle. (stock boost is 6psi~155whp so an extra 10psi was quite a performance jump)

Since then I ended up selling the majority of my parts as I am poor now. The car went basically back to stock minus the 3" exhaust and home made CAI. Still has small stock intercooler (or interwarmer depending on conditions lol) and overly rich tune.

I still have a shurflo 150psi pump, electronic solenoid, boost sensor, m3 nozzle and associated wiring sitting on my shelf from the old setup.

What I would like to do now is purchase a M1 or M2 nozzle and inject 15-20% meth/80% h20 pre turbo, and then use my m3 nozzle post turbo after the intercooler.

I am wondering if I can run both of the nozzles from the same pump or will I need to upgrade to dual pumps? I am not using a Progressive Controller so I figured the best bet would be to just start with a M1 and spray from 2-3 inches away directly at the compressor turbine.

Any idea when the best time to activate the system would be with pre and post turbo nozzles?

Can anyone give me an example of how much a difference it made injecting pre turbo compared to post turbo?

When I had a single nozzle setup years and years ago I never really noticed any improvement unless I cranked up the boost and put in lots of methenol.

Will a pre turbo nozzle make a noticable amount of additional power without raising the boost pressure?

Sorry for all the questions. Hope that a m1 works out for me, if devils own can verify some of my pre turbo Qs I would love to order M1 and 2-1 line fitting.

also wondering how much of a problem the leakage of fluid from the nozzle after the pump and solenoid have shut, will this be a problem with the pre turbo? do a need a better nozzle to make sure it doesnt leak? I know even when i have almost no line between my solenoid and m3 nozzle i still get some spray in droplet form after the system deactivates, is this a problem with the m1 as well?

GNVYUS 1 · 09-22-2008

Isn't that the stock turbo? Anyways, I believe that turbo is small in size so I'd run an 1gph hour preturbo with 50/50 Meth/Water then at least a 5ghp post turbo.

Have them both turn on around 15psi to help any bogging issues and you'll be fine. I have two separate systems due to a Progressive post 15gph nozzle running straight Meth and a Devils Own 2gph 50/50 preturbo.

09-14-2008	#1 (permalink)
vtec-this Water Injection Year: 2003 Make: MazdaSpeed Model: Protege 2.0l Turbo FSDE Join Date: May 2007 Posts: 15	Question about new setup pre and post nozzle i have had various setups over the years on my 2003 mazdaspeed. the engine is a 2.0l dohc with a T25R BB turbo and 9:1 compression. i experimented with individual port injection system last year but ran into some problems with distribution. I ended up just getting a secondary fuel system with additional 4 fuel injectors for a total of 8 combined and ran 15psi (each injector is ~280cc). I never made it to the dyno but i am guesstimating i was around 250WHP. I used a home made afc device running off a gm 3bar map sensor to handle the second set of injectors and clamped MAF voltage at 4.8 to keep the 1st set of 4 injectors from maxing out past 100% duty cycle. (stock boost is 6psi~155whp so an extra 10psi was quite a performance jump) Since then I ended up selling the majority of my parts as I am poor now. The car went basically back to stock minus the 3" exhaust and home made CAI. Still has small stock intercooler (or interwarmer depending on conditions lol) and overly rich tune. I still have a shurflo 150psi pump, electronic solenoid, boost sensor, m3 nozzle and associated wiring sitting on my shelf from the old setup. What I would like to do now is purchase a M1 or M2 nozzle and inject 15-20% meth/80% h20 pre turbo, and then use my m3 nozzle post turbo after the intercooler. I am wondering if I can run both of the nozzles from the same pump or will I need to upgrade to dual pumps? I am not using a Progressive Controller so I figured the best bet would be to just start with a M1 and spray from 2-3 inches away directly at the compressor turbine. Any idea when the best time to activate the system would be with pre and post turbo nozzles? Can anyone give me an example of how much a difference it made injecting pre turbo compared to post turbo? When I had a single nozzle setup years and years ago I never really noticed any improvement unless I cranked up the boost and put in lots of methenol. Will a pre turbo nozzle make a noticable amount of additional power without raising the boost pressure? Sorry for all the questions. Hope that a m1 works out for me, if devils own can verify some of my pre turbo Qs I would love to order M1 and 2-1 line fitting. also wondering how much of a problem the leakage of fluid from the nozzle after the pump and solenoid have shut, will this be a problem with the pre turbo? do a need a better nozzle to make sure it doesnt leak? I know even when i have almost no line between my solenoid and m3 nozzle i still get some spray in droplet form after the system deactivates, is this a problem with the m1 as well? Last edited by vtec-this; 09-14-2008 at 07:10 AM.

09-22-2008	#2 (permalink)
GNVYUS 1 Water Injection Year: 87 Make: Buick Model: Grand National Join Date: Jun 2008 Posts: 16	Re: Question about new setup pre and post nozzle Isn't that the stock turbo? Anyways, I believe that turbo is small in size so I'd run an 1gph hour preturbo with 50/50 Meth/Water then at least a 5ghp post turbo. Have them both turn on around 15psi to help any bogging issues and you'll be fine. I have two separate systems due to a Progressive post 15gph nozzle running straight Meth and a Devils Own 2gph 50/50 preturbo.