I believe that was one of the things changed after 1999 in the engine. If you read into that PDF file you'll see the first gen of Viggen engines used air injection of some sort. It mentions something about removing that and going to a returnless injection rail. Though I'm not 100% certain and I don't have that file with me. Drat!

The injectors are fairly large, but not excessively so. Most tuners change them before going to 300+ hp. The exact amount of hp they are capable of would depend on a/f ratio. Some people get very high numbers by using water injection, and running leaner. But this is not common practice.

Dubbya~

 

The Bosch EV1E and EV1-6E (as used in the Viggen) fuel injectors are supposed to be producing 176cc/min. The manual does not state however at what fuel rail pressure. But they are good, although a bit thirsty in the application I use them for. 20MPG is considered a luxury for me

.

 

Originally posted by StanleyB:
[qb]20MPG is considered a luxury for me       [/qb][/b]

Must be running very rich! I average over 27 mpg in the city ... and those are US gallons! That's like 33 of your gallons. Goodness!

Also, the CC rating must be at a very low pressure. Shame it doesn't state exactly what pressure.

I think in one of the other threads I figured that, due to the power they are capable of, they needed to be at least like 400 cc/min @ rail pressure. Somewhere in that vicinity anyhow.

So about 400 cc/min is what you're likely looking at. Not too shabby.

Dubbya~

 

If it is 400cc/min, I would guess that would then be around 65PSI rail pressure. Good enough for 300BHP certainly.

 

Thanks for the info boys. I suppose I'll just look under the engine cover to see if it uses an FPR or return line when I get it..

 

Thanks to the pdf adrian sent me I have my answer on the fuel system. It is indeed return based, so a standard FRP can be used for extra measure of fueling protection. Thanks all..

 

Originally posted by StanleyB:
[qb]If it is 400cc/min, I would guess that would then be around 65PSI rail pressure. Good enough for 300BHP certainly. [/qb][/b]

Apologies for being pedantic here ... just trying to make for the most accurate info possible.

I believe the Viggen uses a 3.3 bar fpr stock? (Also a lazy pedant who's too lazy to walk outside and check at the moment, though I may later.)

Unfortunately the testing aparatus is not always anywhere near the kind of pressure you see on the fuel rail. At 3.3 bar it would be running at 48.5 psi above manifold pressure.

At 3.3 bar it has to flow around 400+ cc/min ... but on their testing aparatus it may have only been tested at 1 bar or so.

(The actual rail pressure varies with the manifold pressure to keep the pressure drop, and consequently fuel flow, constant for any given injector duty cycle. That's why I say 48.5 above manifold pressure. At 15 psi of boost, you'd have a rail pressure of 48.5 + 15 = 63.5, while at 10 psi of vacuum you'd have 48.5 - 10 = 38.5.)

Dubbya~

 

Originally posted by Adrian W:
[qb]I believe the Viggen uses a 3.3 bar fpr stock?  (Also a lazy pedant who's too lazy to walk outside and check at the moment, though I may later.)

Unfortunately the testing aparatus is not always anywhere near the kind of pressure you see on the fuel rail.  At 3.3 bar it would be running at 48.5 psi above manifold pressure.  

At 3.3 bar it has to flow around 400+ cc/min ... but on their testing aparatus it may have only been tested at 1 bar or so.

(The actual rail pressure varies with the manifold pressure to keep the pressure drop, and consequently fuel flow, constant for any given injector duty cycle.  That's why I say 48.5 above manifold pressure.  At 15 psi of boost, you'd have a rail pressure of 48.5 + 15 = 63.5, while at 10 psi of vacuum you'd have 48.5 - 10 = 38.5.)

Dubbya~ [/qb][/b]

Viggen has a 3.0 bar FPR for stock.
3.0 bar is achived when the vac line is disconnected from FPR. With 1 bar boost you get 4bar fuel pressure aso.
The stock FPR can be turned into a adjustable one by changing the cover. More pressure can also be added by pinching the cover more. The pinching method is not a easy way to set up pressure accurately.
I have an adjustable FPR cover on my car and it works great.

Remember people that T7 does not work properly with added fuel pressure if the mod is not made to the software also. This is because the ECU will compensate the added pressure by adjusting injector open times. The compensation is done under closed loop, but it affects WOT also!

Also Nordic upgrades the FPR to 3.5bar with all their stage III kits to T7 cars. I have the understanding that with 3.0 bar and stock injectors you will run out of juice at about 300bhp. Ofcourse you can run crazy injector open times, but this is not a recomended solution.
Add fuel pressure is a chep trick to keep you on the safe side. Larger injectors should be introduced above 300bhp.

I dont remember if these are the ones sitting in tha viggen, but
352 cc/min @ 3 bar
Bosch 0280156023 (saab 9-5 2,3t)
Also there are two types of injectors used in viggens. They should flow about the same with stock pressure, but the other ones work better with added fuel pressure.

 

What are some of the common injector upgrades you folks do? I have a set of RC 550's for a bosche style 2 connector. Would these work? How about the common injectors used on LS1 V8's? These are style 3 and relatively cheap with two wire and square plug.