Thread: Northstar install and other basic build questions.

Hey guys,
So no lie, im an experienced diesel mechanic, but i have little to no experience with the 3800 platform, or any cars for that matter.
To Specify, This is not a "HOW DO I MAKE MY GP FAST" thread. so dont worry about explaining why not to jump to a 3.0 pulley with nothing but a WIZAIR. I have done the research and know exactly what it takes. I am asking (or attempting to ask) more technical questions and hoping for more technical asnwers. I have the knowledge of how things operate and function, but i am looking for some insight from experience, which is what i lack.

Heres where im at:
stock piling parts for a month long build this summer. I have a northstart throttle body and adapter plate, already has a modified bracket for the cables. I also grabbed a miniafc 1.2 for this. i am missing the MAF (i believe lq4 is the one i need) and any other gaskets or hardware that are needed for the install.
I also have an original aeroforce that is currently in the process of being fixed. I havent put too much time into it but from what ive heard i probably wont be able to fix it on my own and will be trading it in to aeroforce for a newer one or for a simple rebuild.

Heres what i want all in one shot:
pulley drop to 3.4 with the normal supporting mods (sparks and tstat) with the N*TB, add headers and down pipe, tuned PCM, custom (ie home made) CAI. then a few electrical things such as cooling fan switch, voltage booster, aeroforce guage. The rest i dont believe should be added to this thread as it will be suspension and more accessory related.

Heres where im running into issues:
MAF tuning and the best way to go about compensating for the larger TB and pulley drop is giving me problems. Im looking for some help from guys who have gone this route before or have more tuning experience and have opinions on the best way to go about tuning the car for the increased air flow. Money is not neccessarily an issue, but i dont want to spend absorbinent amounts of cash for luxury as opposed to funcionality. For example, i know i want to get HP tuners, but i thought i would get the basic "stage 1" upgrades out of the way before i went that route. which is why i got the afc 1.2 for the throttle body. But, i have no instuction manual or set up guide for the afc 1.2 and have no idea what to set the dipswitches to. I understand the concept of the afc 1.2 (i think) where as it is altering the signal from the MAF to make it appear to be the "Stock" signal in order to reach the proper afr.

Heres my questions:

Do i need a tps controller also? I have heard that sending stock tps signal with a larger tb will result in a higher load on the engine that it is not attempting to compensate for, ultimately producing chipped or detonated pistons.
Should i just buy HP tuners now to tune the pcm to the new parts? and if i do will i even need the AFC? also, would HP Tuners or an already tuned PCM be a better choice? Keep in mind that i want to take this car pretty far up the HP ladder, just not this year.
Do i need headers at the same time as the TB upgrade, or will the increase in air flow not put at the limits of the exhaust restriction in the stock headers and dp?
Can i pick up the lq4 MAF at the auto parts store as a cadillac MAF?

Thanks for the help guys. I will be coming back for more abuse and answers in the near future.

Honestly you don't even need to upgrade the throttle body on a basic 3.4 setup, you wont be close to outflowing the stock MAF.

everyone is going to tell you to put headers in. since you said money isn't an issue my personal advice is buy good headers, not cheap ones. everyone will tell you that you won't need any throttle mods and a custom tune is always better than a pretuned pcm.

for a 3.4 pulley all i've ever read that you actually need for sure is at least a downpipe exhaust mod and an open cone intake that i can remember. but a colder tstat, colder plugs, and a tune are usually lumped in depending on who responds and which combo. depending on who you talk to some will say you are wasting money or steps.

3.4 setup is easy to manage for the car from what i understand. i'm getting ready to put in my pulley and i'll be done. so we'll see.

if you go smaller and want to build it up i think you should build or buy a built transmission first before you go smaller than 3.4 size. a smaller pulley is really the only way you are going to get larger horsepower gains (and speed). most the other mods are just to support the different pulley sizes. and stock transmissions are not that great for these cars.

yea, i know that the throttle body might be overkill at this point, and that the next step will have to be transmission upgrades to do it safely, and i already have that in the works, but i figure by putting the N* in now and tuning it in, i will already have the platform and the ability to tune the MAF to whatever flow altering upgrades i add in the future. I know basically how to tune the care up and what a safe order is to do it in, i just need someone who has done throttle body tuning before for a larger TB that can give me some insight on AFR, the AFC tuning, and any other tips or tricks that might be usefull.

SOME cars can run a 3.4 set up on a just a 3" catless down pipe but some cars can like mine lol id go with headers right now dude that will net you a good increase in flow. the N* TB isnt really needed in this set up and you wont get any power from it BUT it will give you a different pedal feel then the stock TB

Put the AFC aside. If you are going with a tuned pcm or getting HPT, you shouldn't need it. There are many guys with tunes that have the base table for that maf. If you send me your email in a pm, I will send you a link to download everything you'd need plus for the tables etc.

Yes on the LQ4, it's a Chevy 6.0 truck maf. If you got the pigtail for it, you would not need an adapter for the electrical. You will need a couple clamps and a rubber coupler to connect the maf to the throttle body.

On buying HPT now, I see it this way. Spend $100 on a pcm to run the car or buy HPT now (save that $100 over the long run) and then you can do all the changes, tweak the car to run better etc. There are many guides (also in that info I'd send you a link on) and helpful guys etc. The changes you will need to make in the beginning are straight forward and will help build tuning confidence.

On all the builds I've done or seen, only one used a TAC module (tps controller). And it didn't seem to make a difference.

Voltage boosting. A cheap diode can bump your voltage.
FREE MOD: Higher voltage! | ZZP News

Headesr, before or after TB upgrade shouldn't matter. Do them before pulley/cam/rockers and you'll be setup for those mods.

Thanks Bill, I was hoping you would stop by. Im sending you a pm shortly regarding lq4 wiring and adapting the electrical circuit. HPT is coming shortly, as soon as my BA tax return gets in...headers will be on that bill also, and probably some new toys...oops, i mean tools....for the home garage.

What is the size of an unported Gen III supercharger inlet? I know they usually get ported to ~75mm, but if it's unported it would still cause a "bottleneck".

With the LQ4 MAF, check the classifieds here I puchased mine from a fellow member doing a demod reasonable. And yes, headers/exhaust work should be done before or same time as mods. If you introduce more air into your motor, you have to free up the path for it to get out.

"yes, headers/exhaust work should be done before or same time as mods. If you introduce more air into your motor, you have to free up the path for it to get out."

Thats what i thought. Just didnt know what the flow limit was on the factory dp and headers.