Im new at this what tables/values do I need to change to decrease timing at WOT?

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89 350 TPI,comp cam,edelbrock intake base,SLP headers,highflo cats,flomaster cat back,accel 300+ ign,ported plenum and runners,ported maf,auto w/shiftkit,cold air induction,AFPR,Ed wright chip,3.23 posie best ET 14.011@98.72mph without cam/New best 13.926@98.27mph

 

You want timing vs LV8, or timing vs grms/sec, depends on what software your using, as to the label it's given.
With the MAF systems, it's almost necessary to have a scan tool to see what kind of air flow numbers you have.
Hope, you've done ou homework on tuning, kinda worrisome when someone starts with a guestion like that.

 

heres the deal since I changed the cam .480/.480 lift 210/220dur@.05 LSA112 and added SLP runners my autoXray is showing knock when its in WOT and the ECM is pulling about 12deg out.If I rev it in park the same thing happens.If I adjust the base timing at the distributor from stock 6deg to 0deg their is is only about 3deg pulled out but alot of throttle responce is lost.What to do? Im using winbin and what is LV8=load? Idle and part throttle are fine its just at WOT. Glenn said something about needing less timing at WOT with the stock heads?

[This message has been edited by e-man (edited July 22, 2001).]

[This message has been edited by e-man (edited July 22, 2001).]

 

sorry repost

[This message has been edited by e-man (edited July 22, 2001).]

 

Here's what you'll need to do. Print out your main spark advance table, the one that has axes of RPM and LV8. (BTW, LV8 is a calculated value of the load on the engine, involving airflow, RPM, and some scalar value(s).) Make a run through 1st and 2nd gears, using a scan tool to record the data. At as many data points as possible, make a mark on your table where the RPM and LV8 are. On my 305, it made a sideways bell-shaped curve since the LV8 actually dropped above the torque peak (and it might on yours too). Also notate where you're getting the knock retard and how much. Now you can go back and remove some timing from those cells on the table. Or, you can look up those RPM values in the Power Enrichment spark advance table and remove some from there.

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Greg Westphal
'87 IROC 355TPI/A4

 

I noticed that 165 ecm's have a map sensor. Do you think that the ecm uses this in calculating LV8?

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82' Z-28. 327" w/ flat tops. 216/228/112LS. Pocket ported 041 heads 1.94/1.50 SS valves. World Class T-5 from a 91'. Best run? Runs with 2001 vette to 150mph! Soon to be converted over to TPI w/ supercharger.

 

I noticed that 165 ecm's have a map sensor. Do you think that the ecm uses this in calculating LV8?

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82' Z-28. 327" w/ flat tops. 216/228/112LS. Pocket ported 041 heads 1.94/1.50 SS valves. World Class T-5 from a 91'. Best run? Runs with 2001 vette to 150mph! Soon to be converted over to TPI w/ supercharger.

 

The 165 ECM as used in 3rd-gens doesn't have a MAP sensor, it has a MAF sensor. Since the MAF sensor directly measures airflow, it uses this value in calculating the LV8 value.

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Greg Westphal
'87 IROC 355TPI/A4

 

I know that, but I've noticed that in addition to the MAF there is a MAP sensor also. It is usually on the passenger side. My friends 89 iroc has this. It is bone stock too. I was wondering what it does in a MAF system.

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82' Z-28. 327" w/ flat tops. 216/228/112LS. Pocket ported 041 heads 1.94/1.50 SS valves. World Class T-5 from a 91'. Best run? Runs with 2001 vette to 150mph! Soon to be converted over to TPI w/ supercharger.