Suburban update and a couple ??s

[1BadAction]

Lowering idle will usually raise MAP. 800 is not high in a BB, there's usually 750 warmed up, if it's OK in gear and not pushing the brake to hard leave it... lower MAP at idle is always better. Sometimes 50 RPM and 5 degrees spark at idle with a cam makes a 10 MAP difference.

Ah, I see, ok. Yes it is pushing the brake pretty hard, that's why I want to drop the idle down a bit.. I only added 4 degrees of spark in the idle tables over stock, I'll drop the speed to 750, and add two more degrees if necessary.

[EagleMark]

You can watch MAP and BPW when adding the spark for idle. If your not getting a smoother idle, not lowering MAP or not making BPW smaller? You've found max spark for idle. You can go to far and cause nothing but heat, then knock off idle...

[Fast355]

Can't you get non ethanol fuel down there for the boat?

Now that weather here has turned from nuclear winter to spring and a dam good one too, 70-80 for over a week! I'm back to MPG testing, so far it is worth the money for premium octane. Last year I did some quick tests with non ethanol and it to was cheaper with added MPG over 87 ethanol on freeway drives. Not sure it would be cheaper MPG in town driving though...

Non ethanol will always put out more WOT HP on dyno... boats have to change props from E fuel to non ethanol...

Funny you mention that both my Hemi and Titan put down the highest power readings running E85. My TPI also loved E85.

[chevmasta]

Funny you mention that both my Hemi and Titan put down the highest power readings running E85. My TPI also loved E85.

Of course it will.

E85 is a completely different animal.

Not to go TOO off topic..............but ethanol uses ~25-30% more fuel vs gasoline. having 10% ethanol fuel (assuming its an actual 10%) would mean a gas mileage percentage change of 2.5-3% right? not that big of deal.

I love E85. There's one station around here for it. I considered running my 520+HP subaru on it but there's only one station. I'd be I would have gained another 50HP on E85 (at the expense of mileage...who cares at that point...non DD)

I guess I don't mind Ethanol fuels. Not every car/truck can be a race car.

[EagleMark]

Funny you mention that both my Hemi and Titan put down the highest power readings running E85. My TPI also loved E85.

I should have been more specific, we were talking of E10 gasoline, not E85 real ethanol.

Hope no one reads this and thinks they can fill up with E85 and go faster (and get way worse fuel milage) without increasing injector size and or pressure. Takes way more E85 fuel to keep up...

[1BadAction]

Well, since we have your attention, chevmaster, thank you for the tuned, smoothed, stock 454 file for comparison. Take a look at what a roller cam and going up nearly 2 points in compression does to the fueling. Stock 454 VE in blue, cammed/compression 454 in black. Keep in mind, mine isn't complete, yet, but it's pretty close from 0-50mph driving the truck normally. Next up is to replace the partially fouled throw away bosch plugs with good ACDelcos, do the first oil change, then some more tuning.

[Fast355]

I should have been more specific, we were talking of E10 gasoline, not E85 real ethanol.

Hope no one reads this and thinks they can fill up with E85 and go faster (and get way worse fuel milage) without increasing injector size and or pressure. Takes way more E85 fuel to keep up...

I was running stock LT4 injectors and stock TPI fuel pressure. No changes to injector flow constants either. Just the commanded air/fuel ratio and that was based off a patch I wrote to use the narrowband 02 sensor feedback for determing alcohol composition.

That being said my MPG wasn't more than 1-2 mpg off running E85 compared to 93 and E85 was much, much cheaper.

[chevmasta]

Well, since we have your attention, chevmaster, thank you for the tuned, smoothed, stock 454 file for comparison. Take a look at what a roller cam and going up nearly 2 points in compression does to the fueling. Stock 454 VE in blue, cammed/compression 454 in black. Keep in mind, mine isn't complete, yet, but it's pretty close from 0-50mph driving the truck normally. Next up is to replace the partially fouled throw away bosch plugs with good ACDelcos, do the first oil change, then some more tuning.

Question,
What is your fuel pressure set at?
what is your BPC set at?

As you can see in MY VE map, I need to raise BPC and re-tune my VE table to lower the values in the maxxed out VE up top.

Don't forget to share your spark table!

[Fast355]

Question,
What is your fuel pressure set at?
what is your BPC set at?

As you can see in MY VE map, I need to raise BPC and re-tune my VE table to lower the values in the maxxed out VE up top.

Don't forget to share your spark table!

If you have it dialed in and running good everywhere except say 3, 500+ WOT just give it a little more PE fuel and be done with it. My TPI was maxed from 90 kpa and 3, 500 rpm through 5,600. It ran great everywhere except was a little leaner WOT than I wanted. Rather than spending hours to retune just give it a little more PE fuel. Really doesn't matter how you get there at WOT as long as you get there.

[1BadAction]

Question,
What is your fuel pressure set at?
what is your BPC set at?

As you can see in MY VE map, I need to raise BPC and re-tune my VE table to lower the values in the maxxed out VE up top.

Don't forget to share your spark table!

everything is stock, truck ran great with the stock 454. I did the rebuild with the Probe forged dome pistons, valve job on the heads, and the roller cam. Then it's suddenly pig rich on a stock tune.

I'm running the stock spark tune now. I will post up when it's done, my GF doesn't drive so I need to get a buddy to drive me around on the back roads so I can do the cruise tuning...

[ony]

teacher her to tune for you, you know at what throttle position it needs change so you would be the best driver?

[EagleMark]

everything is stock, truck ran great with the stock 454. I did the rebuild with the Probe forged dome pistons, valve job on the heads, and the roller cam. Then it's suddenly pig rich on a stock tune.
.

That's about right for idle, but mid range and WOT usually go lean?

I get my kid to drive me once in awhile, he knows the route now and also knows to steady state throttle. It's amazing how much you can do like this, it's like Speed Tuning!

This week I had a Jeep with the ECM mounted under hood so I could not emulate. Wow! Took almost a day to data log, burn chips, adjust, burn chips, tweak, burn chips all of which I could knock out in half hour or so with the AutoProm...

[1BadAction]

That's about right for idle, but mid range and WOT usually go lean?

118ish BLM throughout the cruising and upper RPMs. It was so rich it was black smoking out the pipe like a diesel. BSFC goes down with an increase in compression. I'm something like 20% less fuel in the idle tables, 15% less at cruise and roughly 10% less in the higher load/rpm areas. This is using stoich correct for E10 (14.1 I believe it is, out of town right now with no access to my tune). If I would have left the compression stock I probably would have had to add a bit of fuel.

I'd rather teach the GF to drive (she wants to learn how to work a Left hand drive vehicle anyways) than let her loose on my PC. I'm going to see what happens with the cruise control set. If it's set to say, 50mph, and I bump the timing up in that cell a bit, I should see the TPS go down a hair and the vacuum go up, correct? Tune the 50, 60, 70, and 80mph cells with no load and then with my boat/trailer attached and call it good.

I may end up taking it to a dyno shop down the road from my work on the east coast and do whatever I can't get on the road. That's a nice long drive that'll give me a lot of datalogging time. It's safer than road tuning, and I'm sure he'll have some tips for me also on what to do with the spark under certain conditions.

[1BadAction]

and ditto on the APU. Man am I glad I went that way. Once you know what it'll do and get comfortable with working it, you can get some shit done in a hurry. It's an amazing piece of hardware, impressive what these "dinosaur" ECMs can do when you can work with them.

[EagleMark]

I guess cruise and a trailer for extra load would help, I've been to Florida and never saw a hill...