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I figured I should start a build thread since I am actually making some good headway on the build.

Truck is a 1980 C10 single cab short bed. Ive had the truck for about 2 years and this will be its 3rd motor since I've owned it. It started out with a 305/th350c combo and that was switched to a 383 stroker with a XE294H cam and FI Tech fuel injection. I had that for around a year and was a great combo until the efi malfunctioned and ran the motor WFO until it stuck a rod through the side of the block. Now its got a 6.0 lQ4 out of a 2006 Denali. I'm doing a somewhat budget build with a knock off s475. You can see my progress below. Ill try to keep this up to date as I'm going fairly fast on this build.

I plan on putting my wastegate right at the 90 going up to the t6 flange (circled x) and running it into the 5" down pipe. I'm open to new ideas and pointers as this is my first turbo build.

 

Cool truck. Gate placement looks good. Just for future reference most build the hot side with 2" or 2.25" to keep volume down (with a goal of 1k hp or less), but I wouldn't sweat it with your hot side design. I would add a brace to support that heavy S400 if it were mine though. Can you explain the Fitech problem you had?

 

Looks good, I like how you have made the hot side equal length up to the merge. I have often wondered about that as a lot of kits you see built have a short side and a longer side, aka fox mustang kits. I have wondered if it makes much of a difference if they are even especially if the hot side is divided. Should be an awesome ride when you get it going.

 

Making some progress. I do have some injector/Harness questions though.

So I need a new harness. When I bought this LQ4 it was supposed to come with a stand alone harness. Apparently the previous owner did not know what they were doing. Half of the injector wires are gone and he completely removed the plug for the TAC module. So I've been looking at some of the aftermarket standalone DBW harnesses and since I need new injectors anyways I thought I might ask for some advice. I"m running the Holley high ram and it has two different mounting locations for the fuel rails. I'm guessing that would allow me to run the tall or the short injectors. Can someone recommend a harness and injector style that would work well together? I was think something like the Deka 80 injectors. Thoughts?

Motor is a 2006 LQ4 out of a 2006 yukon denali. Running the little john motorsports stage 2 cam package (cam, springs, and push rods)

Fuel system is a aluminum cell with 2 -10 lines feeding 2 AEM 400 LPH fuel pumps to a -8 line with -8 return.

let me know if you need any more info.

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Truck looks great, also interested in the FiTech issue..

 

Turned the key on and the motor ran WFO till it decided to put a window in the engine block. I am by no means bad mouthing FiTECH. I have it on my wifes camaro and its amazing. It very well could have been a mistake made by me or something with the msd box or dizzy. I just chocked it up to the fact that when you mess with stuff like this you always have the possibility of blowing things up. Heck ill prob blow this motor up since I don't know when to leave things alone.

 

That merge is just gorgeous. I tried manifolds like that on my lx and they hit everything and I had to end up using the truck manifolds. It's your show you can do what you want but I would recommend some flex joints; thermal expansion and vibration are real forces.

A 5" downpipe is pretty damn enormous for an S475, 4" would seem to be plenty.

I used a pair of exhaust hangers that were bolted to the frame and welded to the nearby piping to support the weight of the turbo. I'm using small 61mm turbos though, certainly not an S475.
Fuel and injector sizing comes down to two questions: What is the ultimate power you intend to make? Do you intend to use E85?

If you're wanting to make 1000hp and run E85 then I recommend bosch 210lb injectors; they're $40 each on ebay and will NOT be the limiting factor on your setup but are for a full time E85 duty. Do not allow for any choke points in the fuel system, it needs to be -10AN from the pumps to the top of the injectors. In the interest of the amount of fuel you'll be moving, I recommend -10AN for the return as well.

As far as computer, I personally am a fan of the microsquirt. Cheap and effective and very powerful. https://www.diyautotune.com/product/gm-ls-24x-plug-and-play-engine-harness-ultimate-evo/
If you want to set up your own harness it's half that price https://www.ebay.com/i/253373309554?chn=ps
But it will run all the engine parameters and then you have a variety of remaining inputs and outputs for stuff like: alcohol injection, nitrous, 2 step, flex fuel sensor, knock, etc.

 

Hey man, Thank you for the reply this is the kind of input I need. I'm deff going to look into that harness. Does it work with the DBW? Im not against going to a cable throttle body if not.

I was not planning on running E85. I am blessed with a VP by my house that sells race gas so I was thinking of going that route. This will not be a daily driver so running on 97 or higher octane isn't going to be an issue. Do you think that I will be able to get by with the -8 lines and race gas? I wasn't planning on going near the 1000hp mark. More like the 700-800 level.

I have added a flex joint its just under the exhaust wrap now and there is a support on the bottom side of the t6 flange its just hard to see.

 

I’d say you’ll be totally fine with -8 at that power level and not on E85!

 

Also if you could point me to and threads or forums about the microsquirt it would be greatly appreciated.

 

DBW in my opinion is not worth the aggravation; I've been chasing DBW issues on a yukon for a friend. I've replaced the valve, the module, the harness and the pedal sensor; hell no! Microsquirt is all about the drive by cable and those throttle bodies are hella cheap on ebay https://www.ebay.com/itm/92mm-Throt...865019?hash=item3d1c2002fb:g:C4wAAOSwgtJXT6tf
If you're going 800hp on race gas then -10 is still recommended but not as critical and the 80lb injectors will keep you honest.

What you're trying to do is well in line with Denmah (Matt's) builds. Review the sloppy wiki page https://sites.google.com/site/sloppywiki/ and you'll pick up a lot of nuggets on computer systems and tuning.

http://megasquirt.info/

 

Thank you for the link. I cant believe I never stumbled upon that site. It has a ton of good info. I'm not going to get anything done at work today.........

 

So can someone shed some light on the coil packs? I pulled this from the EFI source site and it has me a bit confused. Will this harness work with my LQ4 coils?

The coil drivers have been eliminated from this version and Ignition outputs are logic level only. Non logic level coils can be used with the addition of EFI Source coil driver Part # CI-101.

 

The microsquirt will work with your coils. Many buy it with the un-terminated harness, and graft on the terminals from their existing harness, but they offer a plug and play version as well. The Efisource Ms works very well for a bare bones setup, and they worked with Matt from sloppy so you get that knowledge as well.

 

Would this work better for my end goal or is it just overkill. Im new to all the EFI tuning but I would like to learn more and be able to tune my own truck.

https://www.diyautotune.com/product/ms3pro-drop-on-24x-ls-plug-and-play-harness-w-ecu-evo/

 

Ms3 has many more features, and what's best for you all depends on what you want from it. The microsquirt is bare bones, and its uses a couple of its outputs for the ls so it's somewhat limited as far as things like boost control, fast idle options, anti lag, traction control....ect. if you plan to add or use many of the features then ms3 is the way to go.

 

Not exactly https://www.diyautotune.com/support...ntation/diypnp-v1-5/extra-inputs-and-outputs/
These are the additional inputs and outputs available for the microsquirt.

 

I would pass.

 

I'll look into the MS3. Id like to find one of the packages that comes with everything. Map sensor, injectors, harness, and pcm.

 

http://www.on3performance.com/shop/gm-2-bar-map-sensor-fbody-truck/
https://www.ebay.com/itm/Siemens-De...171426?hash=item3b0bb04362:g:tewAAOSwzE9a6m2g
https://www.efisource.com/wp/shop/microsquirt-for-ls-composite/#ecu