lsxperformance

iTrader: (2)

Ya I may do a little more work to it I've considered to get a Holley flange and weld it on and use a standard 90mm DBW t body. Maybe some port matching. And I'll be welding an bungs onto the intake for the pcv system and adding a catch can setup. The engine currently is consuming 2qts every 2500miles on a 7qt system. It's a major issue and a big priority to get it resolved! I could bypass the system and vent it but I'd like to retain its functionality, for ring seal etc.

Here is a few plugs.. I just changed them last week to a copper style ngk and will continue to monitor them thru the build, I have no clue on mileage of these plugs. They were in it when I bought it and I had only put about 6-7k miles on it since purchase.

lsxperformance

iTrader: (2)

When I was shopping there was one available in Colorado but they wanted double the cash as what I paid. I also didn't want the up keep, and added costs associated with a diesel. I have been a diesel mechanic for the majority of my career so I've grown quite familiar with injector installs, and high pressure oil system controls etc the late model diesels use. Honestly I just didn't want to deal with it. So I looked for a big gas guzzler, and it isn't that terrible on mileage compared to my 6.0lq9 Denali considering its roughly an extra 130cubes to feed. It currently gets as is stock with a flow master 13 highway, 6 pulling enclosed, 8pulling open trailer with a f body. Vs the Denali 6.0 that got 7pulling enclosed, 10-11 pulling open, and about 16mpg unloaded but that was tuned cam, heads intake truck.

lsxperformance

iTrader: (2)

Thanks man! I did look into the truck versions with the 8.1 but they were considerably more beat than the Yukon was. I don't do a lot of hard labor with my vehicles like some folks do. I have two young kids so the roof DVDs entertainment system was a huge must, along with the head phones so I don't have to listen to "Frozen" on long drives. The mid row captains seating is nice and keeps them separated so they don't beat on each other going down the road. Iam an XM subscriber and spend a fair amount of time on the road a year towing so this makes since. I get customer vehicles from all over the mid west as part of a convenience for them so they don't have to deal with it, it does help with the selling of jobs that are a long ways away. I really don't mind it either I enjoy getting out of the house and seeing the country we live in!

My Yukon has an 80e in it I do believe there is a lot of torque management in them for whatever reason and that will be addressed when we tune it. As far as engine tuning they don't really respond the greatest from what I'm told anyhow, the induction system is VERY restrictive and needs to be opened up to really get its full potential from really anything. I did consider ditching the oe setup and going with a dart dual plane carb intake with an elbow but decided to modify and keep the long runner setup the factory intake uses for more torque and keep on the path of tow rig.

Yes I've heard of Raylar, and had talked to them on the phone. After I did some shopping around I opted out of the products they carry. It's out of my budget, I'd rather put the high dollar parts on my race truck. They do seem to make a lot of nice things for them tho and it's great there is a go to if needed.

lsxperformance

iTrader: (2)

I'm guessing the 17/8 header, is the best fit for the truck. I am going to have to make the rest of the system they don't build direct fits for the Yukon you have to gm cut the existing setup and fab your own connecting mid pipes. I will be deleting the cats from the system and I like the chambered mufflers from stainless works sound I may possibly build a complete system for it when I get caught up here in the shop. I don't want an obnoxious sounding truck my gues is if this thing is able to breathe better it's going to get extremely loud.

1FastBrick

iTrader: (17)

My understanding is the TQ management on the 8.1/4L80E Suvs is because of the low end torque of the 8.1L will tear up the 4L80E.

I believe the truck version 8.1L/Allison has a higher rating because it has less TQ management in it. I believe starting with the engine parameters from Truck and tuning from there will be a good start.

A friend of mine has an 8.1L truck and is running it on E85 with a flex fuel sensor.

I recently found a 8.1L intake sitting in a core Bin at the junkyard. I plan on modifying it soon. We are also going to swap to a 4 bolt 90mm style flange. This is what we bought. ---> Race Proven Motors Store - Flange - LSX 92mm Throttle Body Flange

lsxperformance

iTrader: (2)

Do you really think it would tear it up tho? Didn't they run duramaxes with an 80e? The flex fuel thing probly isn't a bad idea it being iron headed and from what I hear they don't like timing much because the chamber shape. I found a company that is in Florida that has a Cnc program and am debating having them Cnc a set of stock castings. But I haven't spoke to them about it yet. I'm jealous you found an intake for free I wasn't that lucky but I still picked one up at a decent price. I hear running the 90mm t body isn't worth the work if the factory heads are still used in un ported form. But that's what I hear... Seems there is very little information on them.

Anyhow here is a pic of the chambers, looks like top notch work. I'd like to see some flow numbers and prices on this before I pull the trigger.

1FastBrick

iTrader: (17)

Not sure on a factory Dmax 4L80E combo.

Damn, those do look nice. Would be interested in if you get more info.

The intake wasn't free, I had to pay for it like any other part despite being in the scrap bin. But, the cheapest one we were able to find used was $200. So it made sense to buy it.

Same with the Hotchkis Sway bar kit I found on a tahoe...

lsxperformance

iTrader: (2)

Right not bad and at a fraction of the price of the darts or raylars not sure what the gains would be but I feel it's needed to make the most from the setup. The ports are decent looking too. I'll keep you posted and pm you numbers when I get them.

chpspecial

iTrader: (1)

the DMax vans with the 4l80e where also derated just like the 8.1l/4l80e vans/suvs.

Julian's vanjina was also derated compared to similar year truck with the lly or lbz

chpspecial

iTrader: (1)

Definitely look into e85, it was a vast improvement when I did it. My truck suffered from pinging due to oil consumption and the iron heads, after the e85, the truck felt much better, picked up much better throttle response, and the butt-dyno-meter says it is making better power. The engine would also fall on its face just past 4200rpm, but with e85, the truck pull fantastic to each shift point just past 5200rpm.