OBD2 Fuel Pressure Reg, 4bar or 3bar?

[VRTrickster 0]

After converting my rado to OBD2 management a little while ago, which I must say Im very please with!

 

I had the car put on the rollers a couple of weeks ago and it turned out a very healthy figure of 219 bhp 200 lbsft!

 

Its just something the guy said at SRR, that it was running rich, not loads, but enough for him to mention it.

I was wondering if it may have something to do with me running a 4bar rado reg, and not a 3bar Golf one?

 

Am I right in thinking that if I had the car mapped, it wouldnt matter what reg I was running?

 

Calling anyone who knows more about this then I do :)

[Kevin Bacon 5]

OBD2 should be 3 bar, but OBD2 has + / - 25% lambda adjustment, so will take out any excess on part throttle.

 

I suspect your man spotted that it was running rich on open loop (Wide open throttle)? With your head work and cams + 2.9 capacity, it might balance out, or slightly rich as your man mentioned.

 

If it runs OK, I wouldn't worry about it, but yes, when you map it you can choose which regulator to run.

 

3 bar gives a better idle as you can run bigger injector cycles than a 4 bar one.

[VRTrickster 0]

Cheers Cheese, the car does run ok, a bit lumpy on start up, but when she warms up its acceptable.

 

Maybe I should go for a 3bar for a better idle, a friend of mine got in the car and asked why did it feel as though it was going to stall!

I know that it certainly doesnt want to stall now after the conversion, so I put it down to it being a 2.9l V6 with high light cams, alloy flywheel

and uprated engine mounts. :)