Question for turbo or supercharger guys...

[AndyMac]

Starting a TT build, and had a few questions.

1) Which bank runs leaner? Looking for which bank to install my WBO2 and EGT gauges.

2) Are any of the cylinders prone to running lean using the stock fuel rails?

3)Got any pictures of WB/EGT/Boost gauges mounted in cabin?

4)If you're running side feed injectors, what size and where did you locate them? I've been looking at the yellow top Subaru side feeds.

Thanks,
__________________
Andrew MacPherson
My turbo projects
1995 RT/10
1990 300zx ttv8
2002 WRX

 

[Russ M]

Andy,

Just did 2 so here are my .02cents worth of advice.

1) You should be getting an AEM with dual wide band sensors, unless you like replacing expensive motors.
a) EGT gauges are worthless(this is free advice from years and years or racing), you set your tune and be happy with it an EGT gauge tells you nothing new beyond that.
b)Both banks run approximately the same, if your setup provides equal amounts of air, and fuel volume.

2) Not from what we have done, the factory fuel rail is very nice if you have the right delivery/plumbing/injectors/pumps.

3) When you get your AEM unit just get the AEM guage it will let you monitor any parameter the unit has access too. And you install it in the battery voltage gauge spot, fits very nice.

4) The car with the factory rail has 55lb injectors, running roughly 80 psi which makes them more like 70-80lb injectors. Subaru side feeds are what you want, problem is they are not very cheap. In the end on my car I did after market rails because you can get great top feed injectors for $50 each new, or pay $200 each for the side feeds. The fuel rails were only $500 or so, and come with mounting hardware and all.

Good luck on the build.

 

[BOTTLEFED]

here is my Innovate WB installed where the volt gauge was
you can also see my boost gauge on the steering column

You must be registered for see images attach

and Russ is right about the rest
just get a fuel rail. you will need bigger lines and a return system anyway

 

[Vital Velocity]

So what should the fuel pressure be at idle?

 

[plumcrazy]

50 i believe

 

[Vital Velocity]

Thats not good....i believe at idle im 30

 

[Vital Velocity]

33psi at idle....it was tuned by DL?

 

[plumcrazy]

im almost certain doug told me 50-55psi is where it should be. but wait for confirmation from someone else

 

[AndyMac]

Stock fuel pressure with stock rails etc is 55 and should not fluctuate with rpm (ie engine vacuum) since it is a non return style system.(doesn't have a vacuum referenced regulator)

If you have aftermarket rails and a regulator with return line, then you could run a lower fuel pressure if you tuned for it because the vacuum at idle would draw the fuel pressure down 1:1 via the regulator.

 

[Vital Velocity]

Well the AF ratio stays in the very safe area...and the car pulls like a ***** ape/

 

[AndyMac]

Russ M - First off, thanks for your wisdom. Your words carry a lot of weight with me because I have read many of your responses to threads in my search for info.

1) I'm already in the middle of installing a VEC 3 and an AEM is pretty expensive. I have an Autometer WBO2 with gauge and an innovate LC-1. I could monitor both banks if I wanted to, and just might.
a) I guess I never really thought about the EGT gauge that way, but I do my own tuning and am constantly messing around with my project cars.
b) Good to know, although I would have suspected that the fuel rail that gets fed first would be richer.

2) Also good to hear.

3) No AEM for me.

4) 80 PSI? is that with an FMU or regulator?

Just as a side note for some, if you are running 55psi of fuel pressure and 15 psi of boost, your injectors only have 40psi of fuel pressure because intake pressure puts force on the outlet of the injectors. This is where a boost referenced fuel pressure regulator comes in handy, it will compensate for the additional intake manifold pressure. An FMU will also help, but not quite in the same manner.

BOTTLEFED - thanks for the pic and ideas, greatly appreciated.

Thanks guys, love the discussion.

 

[Vital Velocity]

You must be registered for see images attach

Top Left- Boost
Bottom Left- Fuel Pressure
Middle- Wideband

 

[AndyMac]

Vital Velocity - Nice, where did you get the gauge pods? Looks like a GTS, probably don't have gauge pods for the RT/10.

Thanks!

 

[Vital Velocity]

You could always get one and then use some fiberglass to make it fit an rt.

The steering wheel pod should work for you? I put my AF there because if anything goes bad....thats the best gauge (IMO) to tell me to get off the gas!!! lol

 

[AndyMac]

Modifying a GTS gauge pod wouldn't be too bad. Only issue with the column pod is that in my RT/10, it would block the idiot light cluster between the speedo and tach.

Thanks,

 

[Vital Velocity]

Hmmm do you have a pic? never really looked closely at the inside of an rt

 

[AndyMac]

Here is a pic I found on Google.

You must be registered for see images

 

[Vital Velocity]

Hmmm wonder if you could angle the gauge pod so that it sits between the idiot cluster and the speedometer?

 

[Russ M]

Russ M - First off, thanks for your wisdom. Your words carry a lot of weight with me because I have read many of your responses to threads in my search for info.

1) I'm already in the middle of installing a VEC 3 and an AEM is pretty expensive. I have an Autometer WBO2 with gauge and an innovate LC-1. I could monitor both banks if I wanted to, and just might.
a) I guess I never really thought about the EGT gauge that way, but I do my own tuning and am constantly messing around with my project cars.
b) Good to know, although I would have suspected that the fuel rail that gets fed first would be richer.

2) Also good to hear.

3) No AEM for me.

4) 80 PSI? is that with an FMU or regulator?

Just as a side note for some, if you are running 55psi of fuel pressure and 15 psi of boost, your injectors only have 40psi of fuel pressure because intake pressure puts force on the outlet of the injectors. This is where a boost referenced fuel pressure regulator comes in handy, it will compensate for the additional intake manifold pressure. An FMU will also help, but not quite in the same manner.

BOTTLEFED - thanks for the pic and ideas, greatly appreciated.

Thanks guys, love the discussion.

Andy,

Sorry I should have been more clear, these cars have reworked fuel systems with returns. You can get away with a fuel system like the paxton kit uses up to a point, but if you saw just how small the factory feed line is (roughly -4) in certain choke points you will understand why I refuse to leave something so cheesy on anything trying to make power.

The fuel pressure is about 65-70 with no vacuum line attached and roughly 80 under 11psi of boost.

 

[treesnake]

Andy,

Sorry I should have been more clear, these cars have reworked fuel systems with returns. You can get away with a fuel system like the paxton kit uses up to a point, but if you saw just how small the factory feed line is (roughly -4) in certain choke points you will understand why I refuse to leave something so cheesy on anything trying to make power.

The fuel pressure is about 65-70 with no vacuum line attached and roughly 80 under 11psi of boost.

I agree. You will need to upgrade the fuel system. I am runing a return system.
I have (2)- 255 Walbro pumps, each with a -6 feed out. They feed into (1) -8 to the front. Splits into (2) -6 in/out of the rails. to the regulator and -6 return. I also have a CRYO2 CO2 inline manifold that sends fuel to the "wet" NOS system.....

 

[plumcrazy]

Tree, its hard to see in my BlackBerry, but I'd get a loop on that driveshaft.

 

[Simms]

Looks like a BRT loop on there.

 

[plumcrazy]

ahhhh, i see it now. its hard to see on a tiny blackberry screen...

 

[coupe]

Sorry I should have been more clear, these cars have reworked fuel systems with returns...if you saw just how small the factore feed line is...

That's what we did.

The factory stuff is tiny so we ditched it. Can't see it in the pic, but where the stock fuel line feeds the intake, we drilled/tapped for a -8AN and used that for a return. On back of the intake, we removed the pipe plugs from each bank and tapped again for double -8AN fittings, which became fuel supply. We used 60# side-feed injectors, got them straight from Roe. Spliced in the new plugs:

You must be registered for see images

Out back, we ran RSI's billet fuel-hanger with three (3) 255 pumps for redundancy:

You must be registered for see images

Those three -6 feeds go to one -10, which has inline filters and goes to the front of the car. Then there's a "Y" to the dual -8 feeds into the back of the cast-in-intake fuel passages.

Base fuel pressure was in the neighborhood of 40psi and cruised around in the 30's. The aeromotive regulator was a 1:1 rising rate, so about 52psi at 12psi boost. Worked like a champ.

Oh.. and we put the O2 sensore in the driver's side pipe after the turbo.

 

[treesnake]

Tree, its hard to see in my BlackBerry, but I'd get a loop on that driveshaft.

Looks like a BRT loop on there.

Yes, that is a BTR driveshaft loop. You can also see the U-bolts for the BTR half shaft loops....

 

[AndyMac]

Russ M - That makes sense. I'm really trying to avoid dropping the tank on my RT since I don't have the fancy access panel like the GTS guys.

Another note about the external fuel rails though, I prefer the look of the stock injectors over the external rail. I can purchase new subaru injectors for 147 cdn each from the dealer, but that is still over 1500 just for injectors! If you shop hard, you can get 4 at a time for 150, which is the route I will go. I don't mind using used injectors, but I know a lot of people don't, and you can't sell a customer used injectors.

treesnake - thanks for your input and picture.

coupe - You know, I was thinking about modifying the intake like you did for dual inlets and a return line, but wasn't sure how easy it would be. Really appreciate your info and pics. That is the setup I would like to pursue.

 

[coupe]

coupe - You know, I was thinking about modifying the intake like you did for dual inlets and a return line, but wasn't sure how easy it would be. Really appreciate your info and pics. That is the setup I would like to pursue.

Works like a champ! However, when tapping for a -8AN return fitting at the factory feed hole, it gets real thin so we actually chose to weld up some aluminum there and then tap it to avoid potential cracks/leaks. Just spot-paint red and you'll hardly notice. And those pipe-plugs at the back are very difficult to remove...must be some real strong glue or epoxy they seal with.

Shout at me if you have any questions.

 

[AndyMac]

Good to know, thanks!