Why is it neccesary to have the 1:1 fpr? If you use stock injectors for primaries wouldn't the stock fpr do the trick? I think I am missing a key point of the fpr. Does the fpr just keep pressure constant in the two rails? I'm going to be using the HKS AIC III, I've seen it setup with no fpr before, but maybe it was because the rails are not in series. Any help on understanding this would be appreciated.

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

you need a 1:1 because you need to keep fuel that comes out of the injectors, at a constant flow rate. You have to remember that fuel is under pressure, and also under boost, you have pressure in the manifold, and pressure acting on the injector outlets. If fuel pressure was constant, then once your boost pressure increases, the increased pressure would start to limit flow from the injector, UNLESS you increase the fuel pressure at the injector, one psi fuel, for one psi boost increase. Hopefully that makes sense.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

It makes sense yeah, what is the best 1:1 to use. The one in corbins setup

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

_____________________________________
Jason ESi-T

04' BMW 325Ci
91' Nissan 240SX
98' Eagle Talon ESi (sold)

The only thing I did was tap the extra fuel rail into the supply line tha goes to the stock fuel rail. I'm using the stock fpr and works fine. No other modification was needed. My fuel gauge read at idle 33-35psi, under boost it goes up to like 50psi.

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

Do you have a 95 fuel rail with its corresponding FPR?

_____________________________________
Jason ESi-T

04' BMW 325Ci
91' Nissan 240SX
98' Eagle Talon ESi (sold)

Yes, I didn't touch the stock fuel system for nothing. I only tap into the supply line. The extra fuel rail I have is from a GST complete with fpr, I added a cap on it. It works as if the fpr is capped at the end.

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

That is what I thought we could do. Do you just have the stock fpr in-line with the stock return? Do you have the rails in parallel then? If you could e-mail me or post how you have yours setup I would appreciate it. It would make this much easier, my setup will be a lot like yours.

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

I got the AIC III from ebay, and all I have to say is e-bay is awesome. You can come around them pretty cheap. Thanks for the help, this setup seems complicated at first, but once you get things figured out its pretty simple. I hope I can get it tuned well.

Edit: I actually have another question. what do I do with the return line that I had setup for the s-fmu. Would I just cap both rails at the ends? If I got rid of the return line, where would the stock fpr go? I had the later model fuel system.

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

Great deal! I also got mine from e-bay. I got the old unit and let me tell you, after I tuned the car, is the best modification to the car ever. You will not believe the advantage with this system. Now just raise the boost, because you have plenty of fuel.

The only thing with my set-up is that I have plenty of fuel, but a small turbo and stock engine. Now I will start saving for new internals and rebuild kit for my 16G. Or should I get a t3/t4?

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

I would just get another t3/t4, or t04e. So just to clarify, what did you do with your return lines, did you have the returnless fuel system?

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

Another issue, is it not possible to place 2 large injectors before the throttle body, much like a wet nitrous system. I cannot see a reason why this can't be done. I figure that the air is moving at such a velocity that the placement of the injectors really does not matter. The fuel in my opinion would get evenly distributed into the manifold with the forced air. Is this possible, or is this just a problem waiting to happen? Could you do this? Wouldn't there have to be an absolutly leak free seal prior to the throttle body.

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

I have the return line system.

If you are going with the 8-injector set-up, there is no need for the other two injectors. You can do it, but thre is no need. Before I finished my set-up, I had one injector in the ic piping before the throttle boby. I had better response with the 8-injector set-up.

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

I'd be a little leary of not using a 1:1 with a boosted app, even though it works. Lets see if I can clarify a bit..

Lets theoretically say you have 400cc injectors, which can spray 400cc's of fuel at 45 psi fuel pressure. Now, when we put boost pressure in the manifold, that pressure acts upon the fuel injector, and lets say we are running 10 psi. So now, the differential pressure accross the injector is 35 psi. You will NOT get 400cc's of fuel now at 35 psi. Maybe thats a better explanation. Using the 034 to add fuel in this situation, helps, because if you don't use a 1:1, you can program in the extra injector pulse width needed to compensate for the pressure differential at the injector, but IMO, I would want a constant pressure/flow rate from the injector using a 1:1 regulator. Its just the *proper* way to do it. I also use an Aeromotive 1:1, its small, extremely good quality, has 2 ports on it, and a top adjustment bolt for your idle fuel pressure. Its pretty cheap too, at around 140-150 bucks. The biggest concern when not using a 1:1, would be using injectors that are not large enough for the application, or just big enough for your power level. If you run injectors that are theoretically *just* large enough when used with a 1:1 regulator, there would NOT be enough fuel flow if you did not use a 1:1.

Lets say you want to run 20 psi of boost, and run a 45 psi idle fuel pressure. Well now, at 20 psi boost, you only have 25 psi of fuel flow coming out your injectors..thats bad, and is why you should use a 1:1 FPR

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

I agree, Matt.

I do think thouch that "customrsturbo" is indicating through his posted fuel pressures that the 95 return lined FPR is boost referenced at about 1:1 ratio. That doesn't really surpris me given those FPR's look very similar, at least to me, to stock turbo fpr's.

_____________________________________
Jason ESi-T

04' BMW 325Ci
91' Nissan 240SX
98' Eagle Talon ESi (sold)

Yeah, the stock regulator is 1:1. I guess what I think is interesting about it is that it seems to work as well in boost as it does in vaccuum. I wonder how much boost it can take before it bursts or looses pressure control.


95 Eclipse RS : 5 speed
15.7 @ 87.9mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

I know that stock 4g63 guys have issues with their stock fpr's not able to maintain pressures, especially static, when using a high pressure fuel pump. That's one of the main reasons they have to upgrade.

_____________________________________
Jason ESi-T

04' BMW 325Ci
91' Nissan 240SX
98' Eagle Talon ESi (sold)

Yeah, I guess thats what I am trying to get at, is that I would not trust the stock FPR in a boosted application, even though it may *work*. Its not like it costs an arm and a leg for good, reliable, well made FPR such as the Aeromotive, and that alone can give you peace of mind..ehh that's just me though

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

I understand the point that you all want to make. As for now I haven't had any problem with my set-up. Even, it was too easy to make the 8-injector setup with the less money spend and I'm running rich for safe issues. I am even running on the stock fuel pressure and haven't had any problems. I drive the car daily and boosting even 15psi in some ocasions two to three times a day. I just try to take an idea from the theory and an put it to practice. If I had the money I will replace the entire fuel system, bottom end, etc. But as a family man, other expenses are more important. I just try to have fun with this hobby & my kids, and try different ideas with the less money involved. This is why I'm planning on only buying just low compression pistons and use the stock rods. I have read some post and people had done it, even running 20 psi. I know this will be bad idea for some of you, but $ is limited. Also, you have to know when to reach to a point and don't push the envelope when pushing your engine. I hope nobody gets offended, this is not my intention and I am not mad at anybody. I just try to be different and try my own methods based on this forum with a lot of information and everybody experience.

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

^^ wouldnt a turbododge t03 fit your setup better? i mean, iirc, it has hte same flange as your teo4h

2005 Legacy GT Ltd, Garnet Red Pearl
speak softly and spool a big turbo

Yes I thought of that, but I got a 16g for free. I will have to work on another turbo manifold and downpipe. So I'm still don't know wich one. Either one is a good choice. Obviusly, the t3 will fit with no other modification. So I will see what happends.

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

Sorry to bring this bck up, but what did you do with a return line for the secondary fuel rail? Does it have a return, did you just t-off of the factory supply line? Thanks.

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

No, I just put a cap on the return port and don't put any vaccum line neither. The fpr from the secoundary fuel rail will work now as a cap only. Or you can fabricate the cap, for me is not necessary.

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

Be careful with the stock rods brother, the highest I have heard them lasting is 13-14psi. You may also want to look at the cost of just buying the rods the first time vs. the cost of tearing the engine down again to rebuild it when they fail... not a sermon, just a thought...

Yeah, I know. You know what, I'm still not making my mind on this issue. I will make the desicion when a get the money in my hand. But thanks anyway

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

I think I am going to attempt using just two injectors before the TB. They will be 550cc injectors, so plenty of fuel. Do you think this will be a problem, or will I be fine with this setup. I plan to just weld in two injector bosses not directly at each other, but close for better atomization, would it work ok?

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

Would two injectors right before the TB give you equal fuel distribution? The intake manifold is meant to flow air not and air/fuel mix. You might not get the best distribution and you might get some fuel puddling and evaporating effects during transition periods. People do it, but it doesn't sound like a great idea to me.

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire

Thats what I'm not sure about, supposedly you get better atomization if you place the injectors before the throttle body, it gives more time for the air and fuel to mix, but our manifolds are not designed to carry gas. I have seen this done before, and it seems to work for most who try it. Basically what it comes down to is money, I have everything i need to do just 2 injectors, and I also have everything I need to do 4 injectors, except drilling the mani. So at this point is seems a lot easier to drill the intake pipe than the mani. Either way I just need to get my car in running condition, I can probably do the 8-injector setup in a few months, but I need something to just get me running for a bit. I know customrsturbo said he had a single injector in the intake stream and didn't have problems, just not as responsive which seems kinda obvious.

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

Drilling the intake is not a big deal. The important part is marking the drill places and aligning the injector tubing. The intake layer is less than a 1/4" thick and been aluminum is easy to drill. It will give you greater response installing the injectors in the intake. I had some backfiring thru the intake when too much fuel was injected with only one injector on the ic piping. To keep driving your car, buy a second lower intake to work on it and then make the swap. Beleive in yourself

1995 Eclipse RS-T
GT35R, SPEC Stage 5 clutch
E85 Fuel(Helping the Ecosystem)
MS, v3.0, 029t
10.87 @ 135

I think I will most likely just drill the mani, I guess I got time to do it, my car isn't back together yet, any special technique to drilling. Should I make a jig, or just something to keep the drill straight, and what is the best kind of bit to use, and what size of bit is needed for the injector bosses?

Work in progress
98 GS t3/t04e, hrc Sidemount, tial 38mm, HKS ssq bov, clutchmaster stage 4, wiseco pistons, Eagle rods, Apexi TT, HKS EVC II, Phantom grip lsd, 3in turbo back, Eibach pro-kit, Defi D-gauge EGT,boost, autometer fuel pressure
8-inj setup in the works, HKS AIC III and 450cc injectors

use a punch to gently make dent so the bit will not wander when you start to drill.