Write-Up: Northstar Throttle Body Install

N* is online? How's it feel compared to stock TB?

o, i thought you made another attempt today.

Dang..

Keep us updated!

charlieRobinson wrote:

o, i thought you made another attempt today.

Dang..

Keep us updated!

Maybe over winter break or something I'll give it another shot.

Yay!

Looking at the milkshake that came out, I'd drive it for a day or two then change the oil again. That was pretty bad. I did the same thing when I changed my LIM gaskets....filled the oil pan with coolant and started the car I went "OH SHIT". I think I changed my oil 3 or 4 times within the next 2 weeks just to be safe.

Abaddon wrote:

Yay!

Looking at the milkshake that came out, I'd drive it for a day or two then change the oil again. That was pretty bad. I did the same thing when I changed my LIM gaskets....filled the oil pan with coolant and started the car I went "OH SHIT". I think I changed my oil 3 or 4 times within the next 2 weeks just to be safe.

The camera makes it look a lot worse than it was, but I still plan on doing another change soon.

Wooooooo, got it installed today. Took my time, made sure everything was good, and gave the RTV a few hours to set. Started right up and idled decently on stock MAF tune. No coolant leaks period. Going to search around for a 96-99 MAF table to import instead of the LQ4 MAF table. I'll go out and get a scan in a bit no matter what so that in case I can't find the 96-99 table we can just tune it as it is. No check engine light either.

96-99 what? And why?

Abaddon wrote:

96-99 what? And why?

I got one of the OOOLLLDDD Brian Teel adapters that works on the 4 bolt (96-99) northstars. They're the same size as the 3 bolt (00+) except the MAF attaches directly to them instead of being separate. I can still throw in an LQ4 MAF and just gut the MAF that comes with it but I don't need one so I would rather not. I also grabbed a 3 bolt one yesterday to steal the IAC off of it because I broke the one on the 4 bolt.

Here's the log I just did along with my current bin. I would like someone to tell me what I need to adjust instead of adjusting it for me though (please?). My assometer liked the increased throttle response. I couldn't get above ~50% throttle because it would start knocking pretty bad after that. Anything under 50% was pretty solid at 0* KR.

https://www.dropbox.com/s/go4jo2ybr7v0u61/96v5%20%282%29.bin?dl=0 - BIN

For some reason that log is from a few days ago instead of the one I just did, so I removed the link. I found a N* MAF table so I'll import it and drive/restart a few times to get the trims reset.

I have LQ4 and stock MAF tables somewhere in my dropbox. I'll find it and send you a link.

Well, I have the 6L truck MAF tables and they seemed to be a step in the right direction. I can still only get around half throttle or just barely in boost before I start getting bad knock. At around 50% throttle I get around 2* and any more than that it jumps up to 4-5*+. Does this mean I should increase the grams/sec or...?

What are fuel trims doing?

turtleman wrote:

What are fuel trims doing?

If my laptop would actually save one of my logs I could tell you. Going back out in a couple hours to try and get another one.

Alright, here are 2 logs from today. Check around lines 440 on the first one for some heavy knock.

https://www.dropbox.com/s/l5jz1dpmfxwmbww/11222014_145902.csv.csv?dl=0

https://www.dropbox.com/s/kqom6dzl3x4mty3/11222014_193036.csv.csv?dl=0

Your LTFT tendencies are negative so no you wouldn't wanna add to the maf cal table. One thing I see that I don't like is that the o2mv isn't really going where I expect when you go into PE. It sorta hangs out at numbers around 600-750tops and there's frames where it dips down. Overall it doesn't look a ton different than what it shows at stoichiometric. So how old's your o2?
I'm gonna suggest as a test to disable PE (set PE enable to 100% throttle) and log again and carefully get into the throttle watching KR. If you get a harmful amount of KR, back off obviously. I'm curious to see if KR gets better/worse/changes at all. But hold the brake down a bit as you go and get some contiguous data - lots of frames of the same engine conditions. This is kinda what you need to do to fully dial in the tune anyway but again, the o2 has to be providing solid data in the first place.

Also if you eliminate parameters, you'll get a higher frame rate which is good for this sort of thing. Just for now, I'd remove baro kpa, baro v, egr%, egrv, iat, map(inHg), tpv. Make a scanner config just for AFR tuning as it were.

The O2 in the rear manifold is original as far as I know, the one after the cat is pretty much brand new. I'll eliminate the extraneous stuff and get a scan soon.

Alright, with PE set at 100% knock is mostly gone. I can go nearly WOT through all of first (WOT gives me 3-5* of KR), ~75% TP if I'm in second, and ~60% TP if I'm in third. Still having issues with the logs only saving when they feel like it so I'll have to go out and get another one after lunch to see what the fuel trims are doing.

https://www.dropbox.com/s/lo8xruz9xvm5mml/112314.csv?dl=0 - LOG

https://www.dropbox.com/s/yt3qwl7n4indkma/96v6.1.bin?dl=0 - BIN WITH PE ENABLE SET TO 100% TPS

Yeah dude IMO get a new o2 (pre-cat upstream). I'd recommend Denso like zzp says but I've used the usual Bosch without any problems in the past. The downstream one doesn't do anything useful for tuning. An unaltered car can generally slide by ok with a poor o2 sensor but when you have to tune in a new maf sensor and it's not giving good info, you really have nothing. Emissions will let that sensor nearly go dead before it says something's wrong and the PCM doesn't have any really solid way to verify that sensor so it's considered to be a 'trusted' sensor. And it looks like the knock is similar or even attenuated without power enrichment so whatever the PCM is trying to do in fuel trims is not helping.
Just to verify, were you basically KR-free before the maf change or was there anything else changed?

I was pretty much KR free before the new throttle body/MAF. I could stay WOT from 0 all the way to 100+ without seeing a blip, but if I gave it a little gas on the highway in 4th I would see a degree or two. Do you have a part number (front and rear) for the Denso sensors?

Do you think I should just pick up an LQ4 MAF and gut the 96-99 N* MAF since there's tables readily available for it and more people have more experience with it? I'd rather not spend the money on one if I don't have to, especially if I'm going to be getting new O2 sensors.

You have the northstar maf setup with the plastic maf housing that bolts to the tb right? Are you using the maf sensor that came in that housing or did you swap in your L67 maf sensor? I believe it fits in that housing the same. No matter what it's not gonna be dead nuts perfect but I'd think you should be able to use your original maf sensor in that housing with the factory maf cal table and run ok. You need a good o2 to confirm anything one way or another but i'd try that.
I don't remember how much different that earlier northstar maf housing is than the original L67 throttle body maf area but I assume it should only make a small difference. If porting that area completely out of an L67 throttle body doesn't do enough to the maf sensor flow to require a maf calibration tune then I reckon the northstar housing won't.

I'm using the sensor that came with it, but I can try swapping in my original sensor and flashing back to the tune I was running right before I installed the new one. I was also surprised by how much it started knocking.