3Bar Vs 4 Bar FPR on S3 8L K04

Post Reply
User avatar
P1LAYA-ZN
Cadet
Posts: 263
Registered for: 9 years 10 months
Car Make: Audi, VW and Toyota
Car Model: S3 8L 20VT & Mk 1 Jetta GLi
Location: Durban

3Bar Vs 4 Bar FPR on S3 8L K04

Post by P1LAYA-ZN »

Good day gents,

So my car just came back from a remap and although I had a 4Bar to fit before tuning, I was told it is not needed and would only make the car overfuel.

How true is this ?

Mods on car are 76mm piping, FMIC, R8 Coils, CAI

On my previous A3 1.8T k03S, after fitting the 4Bar and doing the map, the car ran great, no overfueling issues and was great on fuel economy @ 8.5L/100km. (Before tuning was around 10L/100kms)

I was under the impression, the 4 Bar would give a higher fuel pressure @ the rail and better atomisation of the fuel, hence better efficiency and fuel economy and this seemed true on my A3, so why would it be different on a S3 ?

Would it be related to the injectors on the S3 being bigger?

Surely fueling can be adjusted so that you just get higher pressure @ the same flow with better consumption ?

After the Map I still get around 12L/100 and mostly driving like a granny. I know I would never get 8.5L/100 like my A3 but I'd be happy would even 10L/100.

Any info here would be appreciated.

Thanks.
#Builtnotbought
Image
User avatar
Killerwatt
VWCSA Member
Posts: 4819
Registered for: 15 years 10 months
Car Make: AUDI
Car Model: S3
Membership No: missing
Location: Brakenhurst

Re: 3Bar Vs 4 Bar FPR on S3 8L K04

Post by Killerwatt »

If the map was created for the 3bar regulator then the ecu will adjust the fuel trims to compensate. So it might overfuel a little but not terribly.
In theory you will get better atomisation out of the 4 bar but I doubt it would make any meaningfull difference to the fuel consumption. On the stock k04 023 a 3 bar FPR should keep up.

Having said that, your car does seem heavy on fuel if you are driving it like a granny.
User avatar
madhoshival
Cadet
Posts: 182
Registered for: 8 years 6 months
Car Make: VW
Car Model: 9N3 GTi

Re: 3Bar Vs 4 Bar FPR on S3 8L K04

Post by madhoshival »

I would say if your file is aggressive and you need more fueling, just go for bigger injectors. 4 bar after a while will kill your fuel pump.


Sent from my iPhone using Tapatalk
Image
Post Reply