ARguide

I'm trying to decide between buying an AutoCal and tune from Blackbear or having a local reputable shop tune my truck on their dyno? I'm clueless as to which is better or if there is any difference. Both offer adjustments in the future at no charge. I kinda like the idea of using the AutoCal. Some advise is appreciated.

I also am trying to decide what to do with exhaust and headers and how helpful it is. I use the truck don't race it. It is a 2002 CC 4x4 8.1 w/ 4.10

And being on a budget what order would you suggest doing these things? Exhaust and Tune, later maybe headers and then Raylar Intake? I doubt I'd go beyond that.

Vindii

If your local guy is familiar with tuning trucks a dyno tune will be the best. BB is very good at tuning trucks and 8.1 motors and the autocal works great.

Tune first. Then get rid of stock muffler. Then headers. Based on cost and gain.

ARguide

Thanks for the help.

Any suggestions on exhaust modifications. I don't want loud, I'd like to hear a nice deep sound but not crazy. How loud is yours? I watched the video and it sounds real good, it's just hard to judge via youtube

I've read so much about the headers and while stainless works looks nice I've seen some guys complain about parts/fit/install.

Vindii

Exhaust mods depend on how you want it to sound. I did a lot of research before doing mine because a lot of people get a bad drone which can be extremely annoying even if its not too loud. Or they are just plain old too loud. The set up I used was recommended by a muffler shop owner on an avalanche forum. Its also basically the same as what Timinator here recommends but he used a single tail pipe. It sounds great to me. You can hear it while running down the freeway but its not loud at all. Very comfortable sound. When it downshifts to pull a hill its definitely louder. But still very good.

I used 2 of these with dual 2.5" tail pipes

https://www.magnaflow.com/products?partNumber=12289

For a little quieter set up he recommended these. Same size but 2.5" openings. Still use dual 2.5" tails.

https://www.magnaflow.com/products?partNumber=12286

The headers fit fine. The pipes on mine didn't line up. But mines a Yukon XL. The issue are pretty minor just annoying for what they cost. They add a lot though.

ARguide

I've read some of the duals vs single debate with regard to HP and torque gains/loss. I have to say I sure don't understand how you can lose by getting better exhaust flow but I'm not a mechanic and I've been primarily running diesels.

So whats the basic thought on single vs duals? Your set up looks good too I might go with the 2.5 just to keep the sound down some.

The other thing I'm interested in was a larger fuel tank. However the only aftermarket solutions are for diesel and not gasoline compatible. Any ideas other than regular pit stops.

Thanks again for the dialogue/help/feedback. It's not easy to find such conservation about the 8.1

ARguide

Local shop Gwatney Performance Innovations

They said they are not optimistic about MPG gains whereas BB said typically they see 1-2MPG increase. They have done a lot of engines and some 8.1's but probably not near as many 8.1's as BB from what I gather. I don't know that for certain but.....

1FastBrick

iTrader: (17)

My understanding is that the exhaust and the Intake are 2 of the limiting factors on these engines.

BB knows what he is doing, That being said he will need accurate data logs from you to dial it in.

MPG gains will depend on how you drive it.

11MPG

Raylar ran the Spintech 8000 Truck/RV muffler on their last project and I have that muffler also on my burb. That dual in / dual out is a good choice but so is the Magnaflow option Vindii suggested. In any case get your intake and exhaust work done "Before" you get it tuned. You'll be shocked. GM left a lot on the table.

Vindii

I would not expect any MPG gains from tuning. Its optimistic at best. If you use the local guy do all your mods first. If you have BB tune it they re-rune for free so it really doesn't matter the order.

My Yukon XL has a secondary fuel tank. Its 12 gallons. Holds a total of 38 gallons. Not sure if that set up could be installed into a pick up truck. You'd have to do some research.

I considered that spintech muff. Wonder how it sounds?

ARguide

Vindii what year model is your yukon?