cammed vz ss idle trouble

[h41ry]

hey guys i have a vz ss with an ls1 and comp cams 227/235 113lsa
the tune was done by oztrack a few months ago but im not to happy wit the idle. sounds great as it warms up but at operating temp doesnt really sound like it has a cam in it. i have attached a copy of the tune file if anyone can have a look and tell me if they can fault it that would be great
19601

[krisr]

You're idling with 27 degrees of timing at idle. You're not using the base spark tables because of the thresholds set with B5916/B5917. If you want it to idle with a hint of cam lower your idle timing until you get the quality you want. My VZ with the 224/230 cam uses 21 degrees of timing which for me was a good compromise between quality and cam lope.

[joecar]

B5916: 1.19 %TP
B5917: 249 mph

If operating point is below both of these then base spark tables are used, otherwise HO/LO tables are used, right...?

So to me it looks like he is using base spark when TP drops below 1.19%, and HO/LO tables when TP goes above 1.19% (i.e. he's using TP only)... which in itself is odd when vehicle is moving, change of spark table as TP crosses 1.19%.

or did I miss something obvious...?

[krisr]

Ahh yeah of course. That'll learn me to quickly glance at something when tired LOL.

113lsa will also tame down your idle some too.

[h41ry]

You're idling with 27 degrees of timing at idle. You're not using the base spark tables because of the thresholds set with B5916/B5917. If you want it to idle with a hint of cam lower your idle timing until you get the quality you want. My VZ with the 224/230 cam uses 21 degrees of timing which for me was a good compromise between quality and cam lope.


B5916: 1.19 %TP
B5917: 249 mph

If operating point is below both of these then base spark tables are used, otherwise HO/LO tables are used, right...?

So to me it looks like he is using base spark when TP drops below 1.19%, and HO/LO tables when TP goes above 1.19% (i.e. he's using TP only)... which in itself is odd when vehicle is moving, change of spark table as TP crosses 1.19%.

or did I miss something obvious...?


Ahh yeah of course. That'll learn me to quickly glance at something when tired LOL.

113lsa will also tame down your idle some too.

i have looked at the above and have made changes but still no difference. i know the cam is 113lsa but it should still have some lope in it i have heard smaller cams sound bigger than this. it also doesnt feel right when sitting in the car it feels a bit rough and not the rough that that you get from a cam. as i said it sounds great when its cold and i do understand there will be more lope while cold but when its warm you wouldnt really think it has va cam at all. here is a log file that was used when the tune was done if it means anything.
also if there is anyone local to brisbane southside that could go over the software with me that would be great as i do plan on a possible cam upgrade if i carnt get this right and i also have a nitrous kit ready for it to. i do have a pretty good understanding of the software just would be nice to have someone that could give me a few tips without having to spend a day digging through the forum to find what im looking for

[auspeed]

To toughen idle you normally, reduce spark timing, change target idle speed up or down depending on cam size & leanout the mixture a little in the VE table.

Im sure Steve would do it for you if you asked.

[h41ry]

To toughen idle you normally, reduce spark timing, change target idle speed up or down depending on cam size & leanout the mixture a little in the VE table.

Im sure Steve would do it for you if you asked.

I would have thought the same and I also expected better after sales support
I had to fix a few things myself such as hanging idle on startup, stalling and had to take some timing out as it was showing 4deg of knock retard at 6000rpm not sure if it was false knock but not a risk in willing to take due to lack of support

I will try what you have mentioned but staring to lean towards a bigger cam

[statesman]

How much did you pay for that tune?

[h41ry]

How much did you pay for that tune?

I would rather not say I already made the mistake of mentioning the shop

[krisr]

LOL, he's not got the best rap that bloke.

[Tre-Cool]

take 5 degrees out of the timing map for base idle spark.

see how that goes, if it's still a bit tame then bump up the under/over idle spark error correction.


also 29 degrees seems a bit high in the main spark map even if you have already taken some out

[GTS 383]

hey guys i have a vz ss with an ls1 and comp cams 227/235 113lsa
the tune was done by oztrack a few months ago but im not to happy wit the idle. sounds great as it warms up but at operating temp doesnt really sound like it has a cam in it. i have attached a copy of the tune file if anyone can have a look and tell me if they can fault it that would be great
19601

G'day mate,
Are you sure you've got one of oztracks tunes? Living in Australia your thread caught my eye so I had a quick look at your tune johncam8. Both spark tables Hi and Lo are identical. As knock is detected spark advance is reduced toward the low table (depending on other settings it will land somewhere in between Hi & Lo) but as your Lo table is identical to your Hi table your advance has nowhere to go. This effectively makes the knock sensors ineffective. I can't understand why a professional commercial operation would do that. Is it some sort of mail order tune?
Peter

[joecar]

G'day mate,
Are you sure you've got one of oztracks tunes? Living in Australia your thread caught my eye so I had a quick look at your tune johncam8. Both spark tables Hi and Lo are identical. As knock is detected spark advance is reduced toward the low table (depending on other settings it will land somewhere in between Hi & Lo) but as your Lo table is identical to your Hi table your advance has nowhere to go. This effectively makes the knock sensors ineffective. I can't understand why a professional commercial operation would do that. Is it some sort of mail order tune?
PeterWouldn't the ECM immediately subtract the KR value from the current running timing, and at the same time (or shortly thereafter) position running timing somewhere between HO and LO tables (which in this case are identical)...?

[GTS 383]

Wouldn't the ECM immediately subtract the KR value from the current running timing, and at the same time (or shortly thereafter) position running timing somewhere between HO and LO tables (which in this case are identical)...?

Hi Joecar,
I've never tested for that scenario. It would barely be a blip I guess on Scan Tool, subtracting and then immediately reinstating advance for lack of any other instruction. Or would the recovery rate table get tangled up in it?