1985 Monte Carlo SS known as Barney

[ScotI]

Originally Posted by SSLance

No, we had a custom cam ground for it the same time we put the Fastburn heads on 3 years ago.

It's still pretty mild though, pulls 21" of vacuum at idle.

Ok. I've been reading/following since the thread started & went back through recently looking to see what engine changes were made along the way. I knew the heads were different & the carb updated but I didn't recall the cam change. Sounds nice. Not too much but you definitely know its there. Curious on the specs w/that quality of vacuum so I'll keep reviewing the thread.

[SSLance]

Comp Custom cam specs are as follows:
3014 lobe on a 110 intake center line
3015 lobe on a 118 exhaust center line

4 degrees advancement in the cam and timing chain in the “straight up” position.

Lobe specs are below – lift with 1.5 rocker.
Lobe - Dur - @.050 - .200 - lift -- 106 -- 110 -- 1.5 Rocker
3014 – 268 – 218 – 143 -- .356 -- .058 -- .047 -- .534
3015 -- 274 – 224 – 149 -- .358 -- .068 -- .055 -- .537

[sls1025]

Great work Lance!

[SSLance]

So after a quick trip out of town for a week or so, I've been driving this thing around a bit more, tweaking on the tune and basically just enjoying it. For a lot of people it would be great just like it is. It's super responsive, starts idles and drives like a new car and makes a lot more power in the upper RPM range than before. But I'm not like most people and have been working with Andrew to clean up a few small areas of concern.

One is a low voltage symptom that happens with all the high draw accessories are on at the same time and the idle is slow. Andrew came up with the idea of adding a low voltage idle ramp table and it worked like a champ.



Basically the Alternator is underdriven and at the base 750 RPM idle it won't produce enough amps to keep the volts up above the minimum threshold of 12.0v the Holley ECU needs. So as the volts start to drop, the ECU starts to add idle RPM to compensate.

I've driven it around twice now on super hot days with the AC blower cranked and it works pretty good as long as I remember to push the clutch in before the trans drags the engine down below the threshold RPM when pulling up to a stoplight. It's pretty fun to watch it work.

The other thing we are working on is a chug at lower RPM high load scenario like 1500 RPM in 6th gear on the highway. It's not bad and in reality was always like this (even worse) with the carb but he thinks we can clean it up even more. I learned how to take and send datalogs and sent him several couple of days ago so he can see exactly what is going on during the chug.

Other than that...Barney finally got some Arizona Copper Tags yesterday so he's officially an Arizonian now...

[hackster]

Bad ass dude!!!

This, this right here is the difference between 99% of the project cars out there and the ones that are really tuned and work properly.

Nice work Lance.

Sean

[ScotI]

Originally Posted by SSLance

So after a quick trip out of town for a week or so, I've been driving this thing around a bit more, tweaking on the tune and basically just enjoying it. For a lot of people it would be great just like it is. It's super responsive, starts idles and drives like a new car and makes a lot more power in the upper RPM range than before. But I'm not like most people and have been working with Andrew to clean up a few small areas of concern.

One is a low voltage symptom that happens with all the high draw accessories are on at the same time and the idle is slow. Andrew came up with the idea of adding a low voltage idle ramp table and it worked like a champ.

Basically the Alternator is underdriven and at the base 750 RPM idle it won't produce enough amps to keep the volts up above the minimum threshold of 12.0v the Holley ECU needs. So as the volts start to drop, the ECU starts to add idle RPM to compensate.

I've driven it around twice now on super hot days with the AC blower cranked and it works pretty good as long as I remember to push the clutch in before the trans drags the engine down below the threshold RPM when pulling up to a stoplight. It's pretty fun to watch it work.

The other thing we are working on is a chug at lower RPM high load scenario like 1500 RPM in 6th gear on the highway. It's not bad and in reality was always like this (even worse) with the carb but he thinks we can clean it up even more. I learned how to take and send datalogs and sent him several couple of days ago so he can see exactly what is going on during the chug.

Other than that...Barney finally got some Arizona Copper Tags yesterday so he's officially an Arizonian now...

So radiator cooling fans, fuel pump, A/C blower motor @ high speed, ECU/IGN & tunes as power draws @ idle?
What alternator are you using?

[SSLance]

Originally Posted by ScotI

So radiator cooling fans, fuel pump, A/C blower motor @ high speed, ECU/IGN & tunes as power draws @ idle?
What alternator are you using?

I have a 140 amp CS style alternator but with underdrive pulleys. The blower motor is what puts it over the edge, itll drop the voltage by about 1v when turned on high (the only position the switch works on).

There are several areas that could be used to address my issue but pressing a couple keyboard buttons was the easiest.

Adding a couple hundred RPMs puts the voltage right up where it needs to be on full draw.

[SSLance]

Originally Posted by hackster

Bad ass dude!!!

This, this right here is the difference between 99% of the project cars out there and the ones that are really tuned and work properly.

Nice work Lance.

Sean

Thanks Sean, its by no means at your build level but I'm trying. I do love it when a detailed plan works out though, I worked on this plan for a long time...

[ScotI]

Please keep the FI updates coming as the info is appreciated. Curious of the impact it will have on your fuel use vs the carb. When is your next dyno session?

[SSLance]

Originally Posted by ScotI

Please keep the FI updates coming as the info is appreciated. Curious of the impact it will have on your fuel use vs the carb. When is your next dyno session?

I'll be sure to share what I find as I go along. At this point I really don't plan on taking it to a dyno...I don't need to see a number and I'm fairly certain we are getting the majority of what we can out of this engine like it is. I'd rather be safe with it than tune for maximum power at WOT and take the chance of leaning it out and hurting it. It's got plenty of power for what I need it to do.

I'm about a half tank into it so far with a good mixture of highway and street stop n go driving. I want to run it down pretty low before filling so I can test the corner pickups to see if and or when it starts to fuel starve...so it may bea bit still before I get to check the mileage.