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View Full Version : Wastegate crank mod for a few more PSI



-:vw:-
10-03-2011, 05:50 AM
Can the "Wastegate Crank" mod be used on a mostly stock AEB to gain say 2-3 more psi safely? Just curious. Will it go lean or hit limp?

Seerlah
10-03-2011, 06:18 AM
What is the wastegate crank mod? But people either run the N75 race valve (grants 1-2 more psi in many cases), or diode mod then dial up the boost. If this is for your k04'd A4, then bypass the n75, run an mbc, and dial up the boost to maybe 22psi.

-:vw:-
10-03-2011, 06:22 AM
Not for my car. I've read that tightening down on the threaded wastegate actuator rod can increase psi a few pounds. The diode mod will not work on the AEB as there is no MAP sensor.

Seerlah
10-03-2011, 06:37 AM
Whoops. I've never heard of that mod before, but give it a try to see if it will work. Here is a tip to adjust the wastegate without taking the turbo off:

Use an air compressor on the wastegate line to extend the actator arm. This will allow you to get a deep 1/4" socket onto the outer locking nut. The exhaust housing will get in your way if trying to get at it. As for the inner locking nut, get a small open end wrench in there and just go at it till you get it loose (this part will be frustrating) and will be able to dial up the arm with your fingers. I first loosened the outer nut, went at it to get the inner one loose (took me at least 30 min), dialed it up the arm a couple mm, then used the deep socket 1/4" socket (1/4" ratchet with extension) to tighten the outer locking nut. One thing I regret is not placing loctite on the threads, though.

-:vw:-
10-03-2011, 07:31 AM
Hmmm I actually forgot about the J valve... Would it increase on a stock tune in the same manner it increases on a tuned setup. I assume it would... That may be a less labor intensive and sure fire way to achieve this.

biketsai
10-03-2011, 07:37 AM
I don't think the WG mod is what you should do for your turbo. It will cause it to act differently with spool and peak characteristics. Sounds like you just need a MBC

b518
10-03-2011, 07:44 AM
Hope your planning on changing the turbo soon cause it shortens the life definitely...

CCA4
10-03-2011, 07:48 AM
Be wicked careful with a MBC. If you get crazy with the boost you're liable to 'splode your motor.

b518
10-03-2011, 08:03 AM
Be wicked careful with a MBC. If you get crazy with the boost you're liable to 'splode your motor.

This..

Sent from my PC36100 using Tapatalk

-:vw:-
10-03-2011, 08:04 AM
Note that I said "safely" in my first post lol. I'm obviously not trying to do anything here that's going to result in detonation. Just trying to help someone bump up the boost a few PSI on his stock setup without getting rapped $400+ for a very simple chip tune... and more boost then he really wants. Sounds like the J valve is the best and safest way to do this MBC's and diodes are out on the AEB, no MAP sensor.

CCA4
10-03-2011, 08:10 AM
Note that I said "safely" in my first post lol.

Haha just makin sure, some people think its ok

-:vw:-
10-03-2011, 08:15 AM
Not I, that's why I'm here asking ;)

M-Hood
10-03-2011, 08:54 AM
Yes it would work but why go thru all the trouble of removing the turbo and putting it back in just to get 1-2 psi?

-:vw:-
10-03-2011, 09:04 AM
That's why I'm thinking J valve?

ECS Tuning-Audi
10-03-2011, 09:12 AM
Be wicked careful with a MBC. If you get crazy with the boost you're liable to 'splode your motor.

Not completely true, I've pulled the waste gate line off my N75 valve so basically the gate stays closed the whole time. On a stock tune boost has hit about 20+ psi before it cuts out (AEB motor). I'd imagine if you keep smashing the gas while its cutting out you might mess something up. Even then its difficult to do cause it cuts out so bad- almost like a nasty misfire cripples the car. This might be different for chipped cars though.

I even pulled the plugs after and there were no signs of the engine running lean.

Not advising you do this at all or saying wont happen, but there are some fail safes to keep you from grenading your engine.

Jason

-:vw:-
10-03-2011, 09:25 AM
but there are some fail safes to keep you from grenading your engine.

Such as limp mode.

CCA4
10-03-2011, 09:30 AM
Note that I said "safely" in my first post lol.

Haha just makin sure, some people think its ok

M-Hood
10-03-2011, 01:53 PM
Such as limp mode.

There is no limp mode for over boosting on a ndbw car. There is one for the DBW which has a MAP sensor that the ndbw cars dont have.

ECS Tuning-Audi
10-03-2011, 01:55 PM
There is no limp mode for over boosting on a ndbw car. There is one for the DBW which has a MAP sensor that the ndbw cars dont have.

^^ This.

Jason

-:vw:-
10-03-2011, 01:58 PM
but there are some fail safes to keep you from grenading your engine.

Then what are these "fail safes" you speak of?

ECS Tuning-Audi
10-03-2011, 02:03 PM
Then what are these "fail safes" you speak of?

As soon as the ECU recognizes over boost it cuts the ignition. Its like a fuel cut. The car will literally fall on its face. I've read quite a few posts that Mike has made and he seams to know a good amount about this. He might better be able to explain how a MAF works.

Jason

M-Hood
10-03-2011, 02:10 PM
As soon as the ECU recognizes over boost it cuts the ignition. Its like a fuel cut. The car will literally fall on its face. I've read quite a few posts that Mike has made and he seams to know a good amount about this. He might better be able to explain how a MAF works.

Jason

What happens on the DBW cars is that when the ECU sees a actual boost reading that is 300mbar over requested boost the ECU shuts the throttle to 40%. The ECU will also do this throttle shut when the MAF hits it max reading.

ECS Tuning-Audi
10-03-2011, 02:14 PM
What happens on the DBW cars is that when the ECU sees a actual boost reading that is 300mbar over requested boost the ECU shuts the throttle to 40%. The ECU will also do this throttle shut when the MAF hits it max reading.

How about on NDBW cars? As soon as the MAF hits its max reading it just cuts the ignition since the ECU doesn't control the throttle?

Jason

M-Hood
10-03-2011, 02:17 PM
How about on NDBW cars? As soon as the MAF hits its max reading it just cuts the ignition since the ECU doesn't control the throttle?

Jason

No. On the ndbw cars the ECU tends to just dump fuel when it gets a max reading from the MAF sensor.

ECS Tuning-Audi
10-03-2011, 02:26 PM
No. On the ndbw cars the ECU tends to just dump fuel when it gets a max reading from the MAF sensor.

Interesting.

Jason

-:vw:-
10-03-2011, 06:06 PM
No. On the ndbw cars the ECU tends to just dump fuel when it gets a max reading from the MAF sensor.

So it just floods the shit out of it and hopes for the best lol. Brilliant programming.

stofficer2
10-03-2011, 08:27 PM
You can also flip your N75 valve, the line that used to go to the TIP now goes to wastegate, the nipple that went into the TIP now goes to the wastegate line. This will allow you to get an extra 2 psi. I found this out by accident and have been running it like this for months. In low gears (1-2) I only hit 10psi. 3rd and 4 11psi and 5 I have managed to get up to 12 - 13psi. No ignition cuts, misfires or leaning out. (based on VAGCOM's measuring block values.) It convinced me to not chip the car or dick around with a ko4. Save up your money and put a real turbo on it. I miss my vrt, but love quattro :-/
~endrant.

A4Rob
10-03-2011, 08:40 PM
So it just floods the shit out of it and hopes for the best lol. Brilliant programming.

Actually yes. It will avoid it running majorly lean causing damage to the motor.

yoffer
10-04-2011, 12:16 AM
I run a mbc on my 99 aeb and i have it around 11-12 psi and holds about 10psi until redline. Never really had any problems with it, i ditched the vacume hose that came with it (bad idea btw) and used vacume hose from auto parts stores and apparently i have to change the hose out every few months because it becomes dry rotted and starts to crack. Im in the process of finding some better hose that wont crack from the heat lol, But in all honesty, you dont have to go all crazy, this is the mbc that i use (and have always used on friends cars and my previous cars) best one thats on the market imo.
http://cgi.ebay.com/ebaymotors/Universal-Manual-Variable-Boost-Controller-V-2-/370547165110?pt=Motors_Car_Truck_Parts_Accessories&hash=item56465507b6
Its a bleeder type mbc and not a ball/spring unit that sometimes causes spikes. You can say what you want about it being cheap and justifiying spending more money on a "better" one, but ive used this exact mbc for years without hiccups.

M-Hood
10-04-2011, 01:00 AM
I run a mbc on my 99 aeb and i have it around 11-12 psi and holds about 10psi until redline. Never really had any problems with it, i ditched the vacume hose that came with it (bad idea btw) and used vacume hose from auto parts stores and apparently i have to change the hose out every few months because it becomes dry rotted and starts to crack. Im in the process of finding some better hose that wont crack from the heat lol, But in all honesty, you dont have to go all crazy, this is the mbc that i use (and have always used on friends cars and my previous cars) best one thats on the market imo.
http://cgi.ebay.com/ebaymotors/Universal-Manual-Variable-Boost-Controller-V-2-/370547165110?pt=Motors_Car_Truck_Parts_Accessories&hash=item56465507b6
Its a bleeder type mbc and not a ball/spring unit that sometimes causes spikes. You can say what you want about it being cheap and justifiying spending more money on a "better" one, but ive used this exact mbc for years without hiccups.

Just pick up some normal rubber hose from the auto parts store.


So it just floods the shit out of it and hopes for the best lol. Brilliant programming.

Well what do you want for a ECU that doesn't use the 02 sensor during WOT. That means once the MAF hits its max reading the ECU has nothing to really tell it how much air is coming in or where the AFR is at. So it pretty much just dumps fuel based on the RPM and throttle position.

-:vw:-
10-04-2011, 05:41 AM
I run a mbc on my 99 aeb and i have it around 11-12 psi and holds about 10psi until redline. Never really had any problems with it,

Completely stock other than the MBC?


You can also flip your N75 valve, the line that used to go to the TIP now goes to wastegate, the nipple that went into the TIP now goes to the wastegate line. This will allow you to get an extra 2 psi. I found this out by accident and have been running it like this for months. In low gears (1-2) I only hit 10psi. 3rd and 4 11psi and 5 I have managed to get up to 12 - 13psi. No ignition cuts, misfires or leaning out. (based on VAGCOM's measuring block values.) It convinced me to not chip the car or dick around with a ko4. Save up your money and put a real turbo on it. I miss my vrt, but love quattro :-/
~endrant.

This sounds like witchery to me lol. Can anyone confirm this?


Actually yes. It will avoid it running majorly lean causing damage to the motor.

True.


Well what do you want for a ECU that doesn't use the 02 sensor during WOT. That means once the MAF hits its max reading the ECU has nothing to really tell it how much air is coming in or where the AFR is at. So it pretty much just dumps fuel based on the RPM and throttle position.

True.

Did I get everyone =). Thanks guys.

CCA4
10-04-2011, 06:23 AM
This sounds like witchery to me lol. Can anyone confirm this?

I accidentally put my N75 in sideways after I installed my Samco TIP and the car ran like dogshit lol. No CEL but i couldn't boost above about 3psi. I don't remember which side was where but now I've got a piece of vac line looped between the WG and Turbo sides of the N75 and I'm running about 12psi with a Forge bleeder MBC. I also realize that my input to this thread is not really useful since I'm not AEB. I'll go stand over here now ->

-:vw:-
10-04-2011, 06:26 AM
Ya... that MAP sensor is everything... Your opinion means nothing here =P

CCA4
10-04-2011, 06:35 AM
Your opinion means nothing here =P

http://th790.photobucket.com/albums/yy190/waruXmono/th_forever-alone.jpg

kmodel46
04-18-2013, 09:25 PM
Ive read this thread and now am a little confused. I am running a 1997 a4 1.8t with the AEB and was told by a friend that is big into german cars that I can still install a diode in the MAF wiring the same as the MAP. From what Im reading I can get away with using my MBC to boost say 17lbs and the car is able to adjust for this? I'm new to the audi scene. Ran several turbo hondas and nissans but never anything this advanced.[confused]

M-Hood
04-19-2013, 06:32 AM
Ive read this thread and now am a little confused. I am running a 1997 a4 1.8t with the AEB and was told by a friend that is big into german cars that I can still install a diode in the MAF wiring the same as the MAP. From what Im reading I can get away with using my MBC to boost say 17lbs and the car is able to adjust for this? I'm new to the audi scene. Ran several turbo hondas and nissans but never anything this advanced.[confused]


Yes the car will adjust for the change in boost because of the MAF, no point in putting a diode on the MAF wire since it isn't going to change anything. Point of putting it on the MAP sensor is because when it reaches 5ohm's the ECU shuts the throttle and that does not happen when your AEB MAF maxes out.