IDLE Vacuum issues - Need Assistance

[GNVYUS 1]

Thanks Steve for the correction, I'll have to find a new calculator. LOL

Brakes Help
In case you're not Hydroboost or Manual
Since you're at 7", which doesn't seem too low for your giant cam considering, you'll need help with your vacuum brakes.

Leed Brake Vac Pump, in my GN sees 23"
Hella 5.0 in my GTO sees 21" and fast.
Both are plumbed to vacuum canisters, so they don't run constantly, with gauges and have a check valve to engine vacuum in case they fail.

 

[BEATAV8]

230/236 on a 113 has 7 degrees of overlap. That is quite a bit.
TA would be able to tell you if there should be more vacuum. My guess would be 10"hg

 

[odise.carr]

Hello All,

I just wanted to give an update on where I'm at on the build.

I've gotten it down to 65-66KPA consistently. I'll layout the method, but would like some feedback.

I did this primarily through timing. I amped up timing to 35 degrees, and played with the VE/AFR tables to get it there. Any more timing, had no benefit on vacuum.

KPA (at IDLE): 66 KPA
IDLE: 950 RPM
AFR: 9.5:1 (E85)
Idle Timing: 35 Degrees
IAC: 3% at operating temp (160 degrees)
11 miles driven on local roads, no faster than 50 mph.

Observation #1:
I did check with a timing light, and it seems to be 5 degrees off - with the timing light showing 31 degrees.

Observation #2
When i give a little gas, say about 1300 RPM, i can get vacuum at about 55kpa.

Observation #3
Doesn't seem to have alot of power under gas... I havn't upped the timing under any load to play with this, but i suspect it may be.

Question #1
Now my timing table, has highest timing in the "idle zone" 1000rpm/65kpa. But, with this setup, should the rest of my combo follow? highest timing, let's say WOT at full boost is set around 18-20 degrees. Should I flow the whole table to 30-25 degrees at WOT/BOOST.

At this time, i have great throttle response, and with this recent change, fuel consumption seems to be a whole lot better. PW is now at .9ms instead of 2.5ms.

Question #2
The 5 degree difference between Holley and my timing light seems to be a real thing? What say you all?

Question #3 (THE NEXT ISSUE?)
The turbo doesn't seem to be spooling any boost until about 3000 rpm (i haven't gone higher than that because i'm still on break-in). I have a fairly big turbo, but it was on the car before switching over to the TA block, it didn't seem to have much of an issue then. curious still if the static/mechanical timing is still off and not allowing the turbo to spool...

 

[GNVYUS 1]

I have Holley HP in my GTO with my custom 12-1 setup so here's how we confirmed timing in the software/engine in these 2 ways....

Might need 2 people here....

1500rpm
Lock it out to 15 degrees in the V6 software, test light, confirm and tweak if needed.

3000rpm
Lock it out to 25, test light, confirm

There's a chance you'll need to tweak the usec delay if its walking up or down on you from your 1500rpm solid timing.

Not sure this helps with a Buick setup but the above is one way Holley can control timing.

 

[THensley]

Question #2
The 5 degree difference between Holley and my timing light seems to be a real thing? What say you all?

I just opened your fill Woo is that different than mine. I use falling on both crank and cam.
Is this a CRUZ startup tune?
1. IDLE Settings .IAC holley 4 Bbl TBI ? don't dose not look correct
2. I use Digital falling and I had to offset my timing 5*to achieve lock timing at 15*.My idle timing is around 30* on E85 my offset timing is +2.5 so my idle timing is 32.5*. -5* off idle will kill power.I use 15* for lock because its the eases number to see on my BHJ balancer and OE timing tab.
3. That is one strange Timing table
My under boost timing is more than 20* with E85 with Iron heads But what I use works for me I would think you have to figure what works for you, But I would not put 30* to start
You have a monster of a cam compared to me and my target idle is 825 with IAC around 16%
Ive reread how cam timing was set.Im quite confused
You have a monster of a cam compared to me.
I don't do KPA some calculators add the 14 some don't
If this is the tune in your car, It would not work in my car.
I know you have come here to ask for help, but I would re visit your tune
I have read its best to use a Gas tune and convert to E85 with the advance table

 

[BEATAV8]

Observation #1:
I did check with a timing light, and it seems to be 5 degrees off - with the timing light showing 31 degrees.

Observation #2
When i give a little gas, say about 1300 RPM, i can get vacuum at about 55kpa.

Observation #3
Doesn't seem to have alot of power under gas... I havn't upped the timing under any load to play with this, but i suspect it may be.

Question #1
Now my timing table, has highest timing in the "idle zone" 1000rpm/65kpa. But, with this setup, should the rest of my combo follow? highest timing, let's say WOT at full boost is set around 18-20 degrees. Should I flow the whole table to 30-25 degrees at WOT/BOOST.

At this time, i have great throttle response, and with this recent change, fuel consumption seems to be a whole lot better. PW is now at .9ms instead of 2.5ms.

Question #2
The 5 degree difference between Holley and my timing light seems to be a real thing? What say you all?

Question #3 (THE NEXT ISSUE?)
The turbo doesn't seem to be spooling any boost until about 3000 rpm (i haven't gone higher than that because i'm still on break-in). I have a fairly big turbo, but it was on the car before switching over to the TA block, it didn't seem to have much of an issue then. curious still if the static/mechanical timing is still off and not allowing the turbo to spool...

The error in timing is the first item to fix. In the ignition settings the angle for tooth #1 needs to be adjusted to make real timing and commanded timing match perfectly.

9.5 AFR (E85) is quite lean for idle. Especially for a cam with overlap. I imagine the headers are probably glowing red at idle.
Around ~8.5 is where I would expect it to be reasonably happy & stable. Maybe a bit richer than that and I'd expect that cam to be lopey even at 950rpm. Typical idle timing should be 20-25 degrees.

Your wide open throttle timing will probably end up being around 15-17 at 200KPa. and 12-14 at 300KPa. AFR about 7.3 at 200KPa and 7.1 at 300KPa.
More timing than that, or any leaner and you will be risking your new build at this stage.

I think you have something amiss and might be trying to tune around it. Probably something simple like an incorrect MAP reading or some sort of leak.
Break out an old school vacuum gauge and see if it agrees with your map sensor reading.

 

[Chuck Leeper]

An observation....
Closed loop set to zero 0-131 KPA/1750 RPM
Learn table restricted to 30% in same area.
What corrections shown above that area seem reasonable.
Why is the correction shut off?

 

[THensley]

my I say because your setup is different than my setup doesn't make it incorrect.
Keep up the good fight you'll get it.