silverboy

I am having my 4.1L GT3RS custom tuned after seeing a AFR of 13.8 (peak). As most of you know 13.8 is quite lean. I'll let you know the results.

TTurbine

Did you upgrade your injectors to the 4.0 RS ones?

Jamie_GT3

Shouldn't need to, flow is fine, they just changed the spray pattern on them a tiny bit... Plenty of headroom as they're the same part number as the turbo's...

Jamie_GT3

Oh and talk to Scott at softtronic. He can do it remotely and log data to get a good street tune as well as one that works on the dyno..

Serge944

Yes, this is not a duty cycle issue. You simply need a tune.

I will also state that with knock sensors, you'll notice huge power loss due to pulling timing if there is a serious tuning issue, before any internal damage.

azmurciev12

good luck!!! looking forward to a perfectly running 4.1L soon.

silverboy

Jamie - I have a AFR peak of 13.8 so I'm pretty paranoid. If I get a better curve then it'll be a bonus right?

Serge - As I said to Jamie my AFR is at 13.8 which is lean so let's see how it goes.

Anton - Thanks for the best wishes. You have the best taste in terms of garage here. Just your 7RS 4.0 and MP412C makes me salivate.

Jamie_GT3

13.8 is a little on the lean side for safety.

Couple things, where was the AFR measured (exhaust tips, with or without cats etc...) and how was it measured?

Do you have a plot vs RPM?

Ideal safe for most NA cars is 12.5 or so, although NA Porsches seem to run in the low 13's...

silverboy

It has free flowing cats and the sensor was placed in the exhaust tip. Yes, I hope to be around 12.5.

I'll get you a proper graph in a few days when it's done.

Cheers and thanks for looking.

hesperus

good luck! can't wait! keep us posted!

though hang on... my E30 M3 was supposed to be in-line for a tune there! you sneaked in!

(just kidding! i haven't had time to attend to my car)