2-Bar Woes

[NAH]

Ok, here's the thing. I have an LS1 supercharged & intercooled setup. It is running very badly with a 2.5-bar MAP sensor & custom OS. I have followed the Custom OS Tutorial & applied all the relevant mods (including the MAP sensor calibration, which reads correct against a barometer - we are approx sea level here in the UK).

It idles ok & pulls away fine but when I floor the accelerator pedal, it coughs & jerks until I back off the throttle . I can accelerate fairly smothly if I go easy on the pedal.

It is pulling timing when the problem occurs (as far as I could see with ScanTool).

I am going to try a few things tomorrow (having read some of the threads in this forum). I have added the GM.DYNCYLAIR_DMA & GM.CYLAIR_DMA PIDS to the dashboard for logging & will do a run before making any mods to the tune file.

Has anyone got any pointers or suggestions (or even had a simialr experience)? Any help gratefully received.

Ta!

[SS2win]

I haven't read the tutorial in a while but when it first came out it recommended you scale the booost tables 300% which I did. Found out very quickly that 300% is an extreme CYA move and it really only needed 15% or so - bad memory. So check your AFR to see where it's at and adjust accordingly. before you try 15% see what 100% or 50% gets you. go slow and be safe.

[onfire]

What's the wideband log when it bucks?

[ringram]

Yes and check what your timing is doing too. It could be burst knock even etc.

[NAH]

What's the wideband log when it bucks?

Erm, don't have one fitted. Was thinking about doing it but only if I really have to. Would you recommend one? (That sounds like a dumb question)!!

[TAQuickness]

MUST HAVE A WB!!!!!

A wideband is a very cheap investment to ensure you tune your motor correctly. You might as well be blind-folded driving your car off a cliff with out one. PM black02ss or visit www.greenlightmotorsports.com to purchase a WB.

[SS2win]

Erm, don't have one fitted.

danger will robinson!!

[ringram]

Yep deffo a sensible idea especially with forced induction. In fact almost mandatory.

[onfire]

MUST HAVE A WB!!!!!

A wideband is a very cheap investment to ensure you tune your motor correctly. You might as well be blind-folded driving your car off a cliff with out one. PM black02ss or visit www.greenlightmotorsports.com to purchase a WB.

I would not drive the car anymore until you have a wideband to tune the VE tables, etc. I like the Innovate LM1 basic. Chad at GreenLight can get you one quick.....and you need one quick!

[NAH]

I have had the original tune done on a dyno, the AFR is not lean. I have sent a mail/PM to black02ss so hopefully can get one soon.