8100 Tuner

[Adger Smith]

Who is the "Go To Source or Guy" for Tuner or ECU for a 8100 in a 3500 Chevy
Interested in:
1. Some increase in pulling power for LQ 44 ft trailer
2. A slight increase in un loaded gas mileage would be nice.
3. Getting the trans into higher gear at lower Rpm/Speed.
I've been doing searches on the net, but can't believe all the sales pitch and propaganda.
What does the "Racers Brain Trust" have to say??
(Geared & tire sized to run 2100-2200 RPM at 65 MPH)

[Tom Meyer]

Excessive Autosports In SD [605-275-3966] did a wheel dyno tune on my 2002 suburban 8.1. Gas mileage was no better towing, but picketed up almost 45 in toque and 35 hp. There was a noticeable difference in towing. They do mail order stuff also. There is also a intake mod that will make more power, got the intake done just have not switch it out yet. Tom

[SSDiv6]

https://www.raylarengineering.com/computer-tuning.html

[Alan Roehrich]

Adger,
I did not see this earlier, sorry. I strongly suggest you search the DuraMax and Silverado forums. Black Bear has a pretty good reputation for tuning. The stock tune is abysmal. However, you have to be careful with tuned trucks, they'll usually require 89, 91, or 93 octane. The factory tune has very low timing, and delayed fuel and timing response. The most effective tunes will resolve that, and they'll reduce the torque limiting to some degree. You'll want to make sure that they don't go too far on reducing the torque limiting. But some significant reduction in torque limiting can be helpful, as it prevents having to re-open the throttle, and re-advance the timing, and add fuel again after every shift.



You might want to reduce the thermostat temp to 180 to help prevent detonation. I put MSD wires and Champion double platinum plugs in my 8.1, and I run Royal Purple 20W50, my truck is 2WD, so I can run a PF932 filter. The switch to Royal Purple 20W50 reduced the temperature, and also stopped the oil consumption and plug deposits. You can dump the catalytic converters, and replace that monster muffler and gain some there. The muffler has a limited life span, and when it goes, the guts fly apart and make an awful racket.



Eventually, my truck will get a lot more modifications. There's a lot to be had with an 8.1, if you want it and want to do the work.

[SSDiv6]

Adger,

As Alan stated, be careful with the torque limiting.
I have learned that the limiting was done to also extend the life of the transmission.

I own a 2002 Silverado LS Dually, 2WD. I purchased the Moroso wires and used NGK plugs and also use the Wix 51515XP oil filter since it is a 2WD. Switched to Mobil 1 Truck & SUV Synthetic oil and the oil consumption also dropped. With the larger oil filter, you have to add an additional quart of oil. If you truck is a 4x4, you cannot use the larger oil filter.

[Tom Meyer]

We also dumped the converters, and went with magna flow muffler, it is a little noisy. There are no rear O2 sensors so not a big deal. Been told fuel curve was changed to make the cats live from the factory. We have the 4l85e trans and drop the fluid every oil change. Never had a over heat problem and have well over 200 plus on the clock. We run 87 fuel and thats what it was tuned on. Tom

[Alan Roehrich]

I'll be honest, I'm not a Raylar fan in the least. They LOVE your money, their prices are high, and I've seen evidence of them not being real careful about their tune, and hurting stuff. The best thing that they have, that no one else seems to, is the heads that they paid Darin Morgan to design. And honestly, not too many people need those to tow with.


Eventually, if things improve, my plan is to make my truck, an 03 3500 LT crew cab, capable of truly hauling a 53' living quarters trailer. We'll be reworking an intake, going to a 105MM throttle body, porting the heads, installing real headers, changing cams (Billy Godbold has something for it), and I'm working with Yella Terra to develop a bolt on shaft rocker set up to make the valvetrain adjustable. I've invested in bigger better brakes, and 19.5" aluminum wheels, and the appropriate tires. I'm keeping my 20 year old monster.

[Tom Meyer]

The intake manifold has the real restriction, when you look down in the intake divider floor there is a hole that is no bigger opening than the throttle body. Air going into the engine goes threw the throttle body to a hole that drops down to lower level a goes to the intake runners. The intake air changes directions many times before it gets to the intake valve. By removing the floor it becomes a big open plenum with long intake runners. In order to remove the floor you have to cut the bottom of the intake off then weld it back on. It is not a Saturday afternoon job. I got another intake from junk yard to modify but have yet to bolt it on. At that point another trip to the dyno to see the difference. Tom

[Alan Roehrich]

Originally Posted by Tom Meyer

The intake manifold has the real restriction, when you look down in the intake divider floor there is a hole that is no bigger opening than the throttle body. Air going into the engine goes threw the throttle body to a hole that drops down to lower level a goes to the intake runners. The intake air changes directions many times before it gets to the intake valve. By removing the floor it becomes a big open plenum with long intake runners. In order to remove the floor you have to cut the bottom of the intake off then weld it back on. It is not a Saturday afternoon job. I got another intake from junk yard to modify but have yet to bolt it on. At that point another trip to the dyno to see the difference. Tom

It needs more than the plenum opened. For the engine to make good power at an RPM high enough for it to accelerate through the gears, it needs at least a 100MM throttle body, and all of the restriction removed behind it. The plenum is currently a reservoir for air, that empties rather quickly, and cannot be refilled quickly enough. Ideally, the throttle body needs to be moved back about an inch. Widen the inlet substantially, then use a throttle body spacer to mount a minimum 100MM throttle body. You can then change the duct from the air cleaner to have a larger radius, and eliminate the big restriction required to clear the shroud.


Removing the baffles, and opening up the plenum can be a double edged sword. If enough restriction is not removed, air will enter the plenum and slow rapidly, so the back half of the intake can be starved for air, you get uneven air distribution.


The runners are a bit long, even for the goal GM had of maximizing torque, even at near off idle RPM.



Also, if you move the PCV inlet and put some baffling in it, you'll get rid of a lot of the oil consumption, while also helping the crankcase breathe a bit.


I've worked with a few people who have modified the intake, with mixed results. A good example is a video Richard Holdner just put up on youtube. In looking at the intake, there were several things NOT done. The first is how the larger throttle body was installed and located. Too far forward, and too restricted. I do not think radically shortening the intake runners will work well on a tow vehicle. But porting them will.


I actually bought a spare 8.1 and an Allison from a friend of Adger's, I'm going to work on it fairly soon, and develop some packages.

[kirk]

ARP does make a conversion rocker arm stud for the 8100 , to install conventional BBC rocker arms or any aftermarket roller rockers.