Write-Up: Northstar Throttle Body Install

A couple pics from mine. I know it no longer looks like this, but this is how the previous guy did it before I dropped the motor into my car:





You can kinda see what they did in these but I don't think I left it this way.

OK, i got the PCV tubed from the blower to the N*. The photos make it quite obvious now that I have the parts all here.

What about the EVAP? I have it currently blocked off on the Gen V. What else do I need to do for the EVAP?
And what is TAC? I didnt get the harness and I have no idea what it does.

God, I hate being such a noob   

The evap line just needs to be connected to any vacuum source. The plastic vac tree on top the blower works fine. Then obviously you just leave the dedicated evap port on the gen5 blocked off.

Don't worry about the tac harness. It is meant to emulate the tp signal so that the pcm sees a tp that more closely represents the amount of actual air going in instead of actual throttle angle. This is so the pcm can anticipate the greater airflow and resulting load calculation better. You can totally work around it in tuning

I have been trying to figure out what tac is! Now I get it - IAC i I EYE - as in Idle Air Control motor.

deekster_caddy wrote:

I have been trying to figure out what tac is! Now I get it - IAC i I EYE - as in Idle Air Control motor.

No. Its to "tell" the PCM actually where the TPS is. The larger throttle blade changes TP angle, therefore confusing a 3800 PCM. The TAC adapter is some sort of inline resistor to correct this issue. You don't need it of you have a Tuner.

http://shop.zzperformance.com/store/p/152-TAC.aspx

The tac harness is actually pretty nice. Not just a resistor. It has an i/o module that looks at the original tp signal and outputs a plotted skew. The biggest difference in real life airflow is in smaller throttle angles. Meaning when you switch to a bigger throttle body you get a little more at wide open with the bigger diameter but you get even more of an increase relatively at part throttle. In other words a 75mm tb gives you a lot more air at only 1% throttle angle than a stock 68mm and the tac harness just lies to the pcm about throttle position so that it matches actual airflow better

where in HPtuners is this changed? And what values should be changed to what?

Thank you

charlieRobinson wrote:

where in HPtuners is this changed? And what values should be changed to what?

Thank you

The biggest thing would probably be PE enable throttle position - you would have it enable a little bit sooner maybe 5% lower. I would do this if you wanna be safe. Personally I think my motor is just fine entering PE a little late in the throttle range (staying at 14.7 a little longer) but every car's different. The rest of it is mostly just see how you like it after the tb install and if any shifts are getting weird on you, start looking at stuff relating throttle/load and shift pressure. I wasn't good at tuning at all when I first installed a northstar so I left it be and had no major issues or complaints. Don't sweat it - you can pretty much throw that tb on and not do anything except import the maf table for the new maf and make sure it's ok with fuel trims.

What he said....MAF table is the biggest thing.

Abaddon wrote:

deekster_caddy wrote:

I have been trying to figure out what tac is! Now I get it - IAC i I EYE - as in Idle Air Control motor.

No. Its to "tell" the PCM actually where the TPS is. The larger throttle blade changes TP angle, therefore confusing a 3800 PCM. The TAC adapter is some sort of inline resistor to correct this issue. You don't need it of you have a Tuner.

http://shop.zzperformance.com/store/p/152-TAC.aspx

Oh, I see. Whoops. I'm out of the loop I guess! I thought somebody was repeatedly making an i - t typo.

The Northstar has two brass cylinder pins at the base. Do I need to just pull them out? Are they reused?

EDIT:

I pulled them out and the adapter now sits flush with the TB. I still think something looks funny. but i will need the hardware to put it all together to be sure.

Looks like I need 3 screws the mount the TB to the adapter plate then 4 screws for the adapter plate to the gen V. Does anyone have the dimensions for the hardware I need?

Youd think zzp would put them inthe kit, but nooooo

That sucks. When I bought my kit, it came with everything needed.
I don't know the dimensions off hand.

I really think you need to call up ZZP.........

matt270avian wrote:

I really think you need to call up ZZP.........

They are definitely making me work for it!

The website even says: (7) M6 stainless bolts

it's supposed to come with the kit but never came with mine!

At least they sent me the gasket for the N* after I asked!

Man...

Really hoping all the parts they gave me for the valvetrain/cam install were correct, cause theyre deep in the engine now and theyre not coming out!

You could just pick up some M6 stainless screws at the local hardware.

AA wrote:

You could just pick up some M6 stainless screws at the local hardware.

After paying a premium for ZZP to put the package together and ship it to me so I dont have to source 1 thing?

NO WAY!   

I found a good deal on everything so I'm starting to piece this kit together. I know I won't see much, but the prices were too good to pass up. I just need the following if anyone could provide it for me.

New MAF tables

New vacuum diagram

How to modify the stock throttle cable bracket - I have no problem buying the ZZP one here.

Go here
http://shop.zzperformance.com/store/p/308-Northstar-Throttle-Body-Installation-Kit.aspx

Down in the "description" box is a link to import the MAF table.

I have no clue on how to modify the cable bracket.....I used the supplied one. The only mod I had to do was round out the cable ends. Ours are barrel shaped, the N* TB uses a round one. VERY easy to do though.

Sorry I should have specified the adapter was for 96-99 N* TBs (it's an old Brian Teel one). Basically this means I can use my stock MAF (still will probably need tune adjustments) or run an inline one off an LQ4. I think I'm going to keep the stock one for now and then step up to the LQ4 later. I'll still grab one tomorrow at the junkyard because they're only $10 and it's a good backup just in case. It also looks like the throttle cables work more nicely with this style compared to the 2000+.

Last questions and I think I'll be good to go.

Has anyone made the wiring adapters or have the just bought the pre-made ones? Since I'm going to be running the stock MAF for now I'll be good to go there, but for the TPS do I just splice the existing connector into the new one or is there some resistors involved? Detailed diagrams would be very nice to have.

I tried starting it after the install. Allow my text to give the best interpretation of what happened. I did not import the new MAF table yet, but I'm willing to bet that would be half the problem with the other half being the ghetto rigged vacuum line.

"brum brum brum.. brum brum... brum... brum..... brum........ brum............ *cough*"

Second try would barely start and then it just coughed again. I figured since I was using the 4 bolt throttle body that shared our MAF that I wouldn't need a massive MAF tune overhall. I'm probably wrong here, aren't I?

I uploaded the new MAF table and it seemed more willing to start, but still wouldn't fire over even if I gave it some gas.

Here's pictures. Ignore the ghetto rigged TPS, it will be fixed later. I tried unplugging the MAF and it made no difference. The car will try and fire over, sometimes even going through a few cycles without dying. No matter how much/little throttle is given it doesn't affect the car's ability to run. Can any of those 3 sensors cause an issue, and are my vacuum lines good enough (let alone routed right) to run? There's a second vacuum port on the TB that I just capped because the stock TB only had the transmission/PCV(?) line and the EVAP(?) line.

Normalled everything up. Since I was using the battery to power the lights it went dead so now the car won't even crank. I swear sometimes.......

And of course the car won't start this morning after a good charge....... Is it possible coolant got into the intake and is causing issues?

I'm willing to bet that the TPS sensor is messing with you somehow....I'd put the DHP into scan mode, and see if the sensor sweep is ok.

You can start and even drive the car with the stock MAF tune on it and the N* installed. It will just run a little rich or lean at different RPMS.