Stock Tune or Other Help

[JimmyJazz]

Hello All

I am very new to the tuning scene. I have a LS1 in a cobra kit car. The problem I have is that it is detting really badly at about 3500rpm. The engine was taken from a Pontiac Firebird with about 30k miles on it but don't know if it had been tuned before.
Is there a stock tune availble to or could I post something up to get a bit of help.
Please bear in mind that I've only had the flashscan a week or so and I am very very green at the moment. I would really like to get it sorted before it does any damage to the engine.

Thanks Alan

[WeathermanShawn]

Hello All

I am very new to the tuning scene. I have a LS1 in a cobra kit car. The problem I have is that it is detting really badly at about 3500rpm. The engine was taken from a Pontiac Firebird with about 30k miles on it but don't know if it had been tuned before.
Is there a stock tune availble to or could I post something up to get a bit of help.
Please bear in mind that I've only had the flashscan a week or so and I am very very green at the moment. I would really like to get it sorted before it does any damage to the engine.

Thanks Alan

Welcome Alan:

Post up a tune. Its easy to get a stock tune. If you post up your tune, we can look at it. Does 'detting' mean knocking?

[JimmyJazz]

Thanks for the reply, it's much appreciated, tune file attched

8281

By detting I mean it's way to far advanced and causing detonation

[joecar]

Hi Alan, welcome to the forum...:cheers:

Also post some logs.

See www.holdencrazy.com for stock tune file.

[JimmyJazz]

Thanks Joe

As I'm very new, can you be a bit more specific as to what you would like to see in the log. ie do I just drive normally?? or different rpm in different gears etc. How long should the log be??
Apologies for being so basic, but I'd like to give you guys the right information

[joecar]

No worries...

Include these engine pids:
VSS
TP
RPM
DYNCYLAIR or DYNCYLAIR_DMA
DYNAIR
MAF (SAE or GM)
MAP (SAE)
IAT
ECT
EQIVRATIO or AFR
SPARKADV
KR
LONGFT1
LONGFT2

Maybe include these also:
DYNAIRTMP_DMA
IBPW1
IBPW2
INJ1DC
INJ2DC

(if you keep the pid channel count to 24 or less (see bottom of PIDs tab), then you will get the fastest sample rate)

[joecar]

Do you have FlashScan V1 or V2...?

Do you have a wideband...?

[joecar]

What condition was the motor...? It may need some top engine cleaner. Or maybe the MAF is dirty (reading low).

Can you audibly hear the detonation, is it light/heavy/prolonged...?

[JimmyJazz]

Do you have FlashScan V1 or V2...?


Flashscan V2

[QUOTE] Do you have a wideband...? [QUOTE]

Sorry no wideband yet, it's on my christmas list though

[QUOTE=joecar;124157]What condition was the motor...? It may need some top engine cleaner. Or maybe the MAF is dirty (reading low).

Motor was is good condition, no smoking, good oil presure no rattles etc[QUOTE]

Can you audibly hear the detonation, is it light/heavy/prolonged...?

I had it on a rolling road last week, just doing a power test as the guys dont really know anything about EFIlive (hopefully we're all going to learn together) when we got to about 3500rpm it was very audible/loud/heavy and prolongled, well for a few seconds anyway, before we backed off so as not to destroy the engine.

[joecar]

To end a quote, place a / in between [ and QUOTE.

Yes, when you get knock back off immediately.

Also check intake manifold for oil ingestion via PCV plumbing (peek with a flashlight thru throttle opening).

[WeathermanShawn]

Alan:

Doing a quick check of your tune..it appears to be a stock tune. I take it you actually downloaded that tune from the PCM?

As Joecar stated, a log always helps. That year's Spark Table is not overly aggressive, but since your MAF and VE Tables are basically stock, the spark load may be putting you into more spark than needed.

To not overly confuse you at this point, do what others are advising first. Check everything mechanically-related. A lot of us ran 'catch-cans' to help prevent excess oil from getting into the CC chambers. It actually helps, as does the engine top-cleaners etc.

Once you check all of that, you might be a good candidate for the Calc. VE Table method of tuning...http://download.efilive.com/Tutorials/PDF/Calc.VE Tuning Tutorial.pdf (http://download.efilive.com/Tutorials/PDF/Calc.VE%20Tuning%20Tutorial.pdf) You are going to need that wideband (before Christmas), so look for a good deal or a decent re-sell. Especially with Knock occurring. Its mandatory.

Good luck..

[JimmyJazz]

Thanks guys for the pointers. I'll check the suggested mechanics and post up a log at the weekend when I have a bit more time.
Once again thank you, you've made a very new person to this feel most welcome and took a little of the total bewilderment out of it.