Hey everybody. There's this young guy, Matt, that I see at the skatepark quite a bit. He's an awesome skater, stays mellow, and is friendly with everybody there. I pulled up to the park the other day and saw an A4 with a huge ricer wing, white wheels, crappy mesh grill inserts, pillar gauges, fart can muffler, and missing side skirts. Modded Audis are few and far between in my area, so I was intrigued even though I felt the mods were of poor taste. I was even more intrigued when I learned that Matt owns the car.

He came rolling up to me and said "Aww $hit man, what's up? Can you hook up my car and make it fast like yours? (I drive a mildly modded TT, nothing too special... but I did have a 400+ hp Talon for my last car) Anyway, I asked to look at the car and see what he had going on. This is it:

* A/F guage that bounces wildly and stays in the 'rich' section at all times while driving according to Matt
* ricer wing that is bolted thru the trunk, which Matt agrees needs to be removed
* RPMs stay around 800 for about 45 secs after start up, then swing up to about 1300 for about 30 secs, then back down to about 900 and stay there
* no CELs
* boost controller turned all the way down according to Matt
* Apexi turbo timer that he cant figure out how to use
* huge sub box that will rattle your brain

That's the basics I observed in 5 minutes. The car's idling issue confuses me. I read the FAQ/noob section, but failed to see if the car has an SAI that may be causing the issue.

I want to start to help him get it running right. I'm decent at mechanical work, have a VagCom, and can usually figure things out once I get ointed in the right direction.

The first thing I want to do is figure out if the car is chipped or not. He got the car from NYC, with everything done to it already, but doesn't know if it's chipped. I'm not sure if a boost cntroller would turn the boost down past stock levels, or if it just controlls the onset of boost like on a TT. Is there a way to tell if it's chipped? What is the stock boost level compared to a chipped boost level for these cars?

As far as the wing removal is concerned, he's pretty strapped for cash since he's still in high school. He wanted to fix the holes that will be in the trunk. I suggested buying some rubber discs of some sort, painting some bolts the same color as the trunk with some cheap touch up paint, and using the rubber discs as washers to seal the holes that the new bolts would fill.

I also suggested removing the boost controller and A/F gauge and starting those projects over to be sure they are done correclty. If I remove the MBC, what will go in place of it? Can I cap both lines or will it be missing something to prevent it from over boosting?

Sorry it's such a long post, but I feel like it's a cool thing to do for a fellow Audi owner. I was in his place once, as I'm sure many of us were, and I'm trying to pay back the guys who helped me figure out how cars work and understand that the WHOOSH sound between shifts is normal and the car is not going to fall apart

 

whats the year of the car?

idling issue could be a couple of things. old/dirty air filter, bad spark plugs, im pretty sure its something simple though.

Hopefully his stock n75 valve is still connected in his engine. that way when u remove the MBC, you can just plug the n75 right back in.

stock boost is between 6-8lb, chip boost should be 17-21lb.

hope that helps a little.

 

Not sure of the year or the N75. He did say that he was running 19 lbs before, but you know how young guys who don't know cars are... they may embellish just a tad. But if the MBC can't turn the boost up that high then it leads me to believe that he's chipped.

I'll start with the plugs. If anyone cares to share what plug is best and what the gap is, that'd be cool.

 

sounds like a nice thing to do...

id stick with NGK and gap it to .028

good luck


(also i kinda want to see a pic of the car with the big wing haha)

 

* A/F guage that bounces wildly and stays in the 'rich' section at all times while driving according to Matt - most likely a narrowband o2 that isnt accurate at all and can be pulled with no loss.
* ricer wing that is bolted thru the trunk, which Matt agrees needs to be removed - he will either need the holes welded and respray the trunk or replace the trunk.
* RPMs stay around 800 for about 45 secs after start up, then swing up to about 1300 for about 30 secs, then back down to about 900 and stay there see below
* no CELs - if he has a 2000+ A4 it could be the sai pump dying and doesnt set off a cel but still my throw a code in the ecu. Scan the car anyways for any code.
* boost controller turned all the way down according to Matt - judging by what else is on this car, its probably one of those ebay turbosmart knockoffs that dont really work. Just remove it like listed above.
* Apexi turbo timer that he cant figure out how to use - if its installed correctly there isnt much to figure out. You can have it set for auto which determines the time to cool down and can be set from 10sec min to lik 10min max or manual to where you can set it to the same time each time you shut the car down. Im sure he can figure it out with the directions, im sure they are post online if he doesnt have them. You only have like 4 way to move the dial.
* huge sub box that will rattle your brain - pull it if he doesnt like it and he can reinstall it with a new box and or sub later if he chooses.


The first thing I want to do is figure out if the car is chipped or not. He got the car from NYC, with everything done to it already, but doesn't know if it's chipped. I'm not sure if a boost cntroller would turn the boost down past stock levels, or if it just controlls the onset of boost like on a TT. Is there a way to tell if it's chipped? What is the stock boost level compared to a chipped boost level for these cars? He needs a boost gauge NOW (i know you know that). You know the boost levels for chipped cars also. A boost controller works off wastegate pressure. It can only raise it so much over the wastegate psi and only lower it to the wastegate psi spring pressure also. So a good mbc will be able to lower a 1.8t to ~5psi (the spring is 5psi and the rest depends on the mbc) to 12-30psi over the spring psi.

As far as the wing removal is concerned, he's pretty strapped for cash since he's still in high school. He wanted to fix the holes that will be in the trunk. I suggested buying some rubber discs of some sort, painting some bolts the same color as the trunk with some cheap touch up paint, and using the rubber discs as washers to seal the holes that the new bolts would fill. - welding or swapping trunks is the only good way to not have leaks in the trunk

I also suggested removing the boost controller and A/F gauge and starting those projects over to be sure they are done correclty. If I remove the MBC, what will go in place of it? Can I cap both lines or will it be missing something to prevent it from over boosting? he needs a boost controller, a mbc or n75 otherwise he will be set at 5psi

 

thanks Cincy. He's got a boost gauge, and says he peaks around 19, which makes me think he's chipped. I'm pretty sure the A/F gauge is hooked to a factory o2 sensor, but he did say that when he adjusts his boost controller, it reads stoich instead of rich if he turns the boost up. When I saw the gauge, the needle was going crazy, but he said when he's driving it's pretty well steady, but always in the rich sector until he adds boost. I never wasted $ on a A/F gauge, so troubleshooting that is new to me. Same goes for turbo timers... mine were always built in to my remote start.

He's supposed to come over sometime soon so we can VagCom his car and try to make sure it won't blow up. It's got 120,000 on it. He has no idea when the timing belt was done, but says he has people that could do it.

I don't want to invest a lot of time/emotion in this car, but I'd feel like $hit if his belt snapped, the same way I do when I hear about it from other TTers. I'm going to suggest all the maintenance be done since he's already got a few mods done.

 

check his throttle body and hose for the idling issues. may need to be just cleaned out a bit. Mine had a similar problem and that did the trick...
lots of respect for you for helping save a great car!
Lol. get some pics up.

 

^ hey, are you coming to the TireRack in South Bend next Sat for the auto x?