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spencerxog
12-08-2014, 03:04 PM
So this may be a stupid post but I'm still new to this crap, I have an 98 a4 1.8t aeb, with new air intake, stage 1, and exhaust on the way, the stage 1 I'm pretty sure is stand alone, I bought the car like that and I spike around 13 psi, just bought a new forge splitter valve and some may say get a different one but that's what I want, what are some mods that would substantially increase boost before getting a bigger turbo.

viceprp
12-08-2014, 03:09 PM
I wouldn't go over 18. After that youre just blowing hot air.

BlueBoostedAudi
12-08-2014, 03:13 PM
what are some mods that would substantially increase boost before getting a bigger turbo.

A boost controller and boost gauge

spencerxog
12-08-2014, 03:20 PM
I have a boost gauge that's how I know what psi I'm at and I heard mbc's are not good or at least make you go into lymph mode, what else do you think would help me reach around 18? And what about getting a hair bigger turbo instead... money is tight and I'm a noob.. I was looking at some ebay turbos

thedownwardsprl
12-08-2014, 03:25 PM
Apr tune is good. ..don't Mbc and over do it. A little boost you can use an upgraded n75 valve. Like the n75 h or j. But only do it with a tune

ray4624
12-08-2014, 03:26 PM
well there is no way your stage 1 is "stand alone." That would mean someone spent thousands on a computer system to run on a stock turbo.
Check for boost leaks and make sure everything is sound.
If you aren't getting the boost you want then you need a different tune.
Most "stage 1" tunes are from 15-18 psi. My aeb tune was about 16-17 psi.

thedownwardsprl
12-08-2014, 03:26 PM
A more reliable diverted valve is good. Forge is good. U can change the spring in those for pressure setting.

thedownwardsprl
12-08-2014, 03:27 PM
If you run a mbc after the n75 you can keep it from spiking too high and go into limp mode

GrapeBandit
12-08-2014, 03:32 PM
stand alone MBC doesnt throw you into limp mode...I run stand alone MBC on my aeb engine. stand alone MBC is better for me, but not for everyone. I like instant boost and the fact that boost barely tapers down at high rpms.

spencerxog
12-08-2014, 03:35 PM
Sweet thanks for the help, and it says stage 1 aeb on it in sharpy so I mean idk, I have a large exhaust Leak I have only my down pipe with cat converter because I'm peicing together my exhaust but as soon as I get a hold of an air compressor I will defiantly check for boost leaks

demonmk2
12-08-2014, 03:36 PM
upgrade your intercooler but don't get crazy with it

demonmk2
12-08-2014, 03:37 PM
check your evap ( pcv ) it can cause lose of pressure under boost.

spencerxog
12-08-2014, 03:38 PM
I'm gonna try getting a MBC today... any recommendations to which one I get

spencerxog
12-08-2014, 03:39 PM
What do you mean by evap pcv? Doesn't seem specific to me I replaced my crankcase valve not too long ago but as soon as I get an air compressor, I will defiantly know if I have any leaks

GrapeBandit
12-08-2014, 03:40 PM
I'm gonna try getting a MBC today... any recommendations to which one I get

any B&S MBC will work good. you dont need anything fancy or expensive. ebay or amazon for voodoo boost controller. thats the one I run. $20 shipped, you cant beat it

ray4624
12-08-2014, 03:56 PM
any B&S MBC will work good. you dont need anything fancy or expensive. ebay or amazon for voodoo boost controller. thats the one I run. $20 shipped, you cant beat it

X2 I have a cheap "boost valve" and it works great.
Just make sure it's not a bleeder style as those have mixed results on out cars.


Sent from my iPhone using Tapatalk

ricekikr
12-08-2014, 04:45 PM
What tune do you have. I wouldn't touch the boost til you know which tune it is.

Increasing boost without a known tune, a wideband or at the very bare minimum vagcom to monitor knock is one way of letting a motor go boom.

Davdraco1
12-08-2014, 06:19 PM
Apr tune is good. ..don't Mbc and over do it. A little boost you can use an upgraded n75 valve. Like the n75 h or j. But only do it with a tune

Changing the n75 will only cause your at to not know how to handle the boost. Keep the proper n75 that the tune calls for. Plenty of stage 2 and stage 2 plus tunes use the factory n75.

thedownwardsprl
12-08-2014, 06:45 PM
I agree with ya dav to the fullest extent. The Ecu is still regulated at a certain boost level b4 limp mode. But you have certain individual that think they can pump 30 lbs out of an aeband it works once. Bit just from experience the tune gives alot of width on boost range versus the stock tune. Like the ecs race valve gives abnormal jerky boost should at low rpm...not good. But an mbc is just as bad stand alone. All I'm saying is to use the mbc in parallel to the upgraded n75 to make sure you don't have exceeding boost spikes

demonmk2
12-09-2014, 05:52 AM
I'm gonna try getting a MBC today... any recommendations to which one I get
G2

Davdraco1
12-09-2014, 10:31 AM
Using them both will work. I've just read where people use a race n75 and the boost comes on so strong it feels faster but then you ECU opens the WG to try and control it and it just that back and forth building boost not building it and so on. Makes the car slower bc your on/off so much

Mad Cow
12-09-2014, 11:50 AM
Changing the n75 was a hacky fix from back when there weren't any affordable or good tunes, there's absolutely no reason to do it now. All it does is respond faster to its input duty cycle, which gives you more boost until the ECU realizes what's going and and tries to tone it down. And like others have said an MBC in place of the n75 is a terrible idea too, especially when you don't even have the slightest clue about your AFRs, knock, or even what kind of tune you have. For all you know your tune could have bypassed knock detection (yes some self-proclaimed tuners actually do that, even to this day), it's unlikely but you never know. An MBC should only be used in parallel to protect against overboost. Blindly "tuning" with an MBC like some people are suggesting is a great way to melt a piston or throw a rod.

Davdraco1
12-09-2014, 12:15 PM
Honestly, just drive the car. The difference between 13 psi and 18 psi on a ko3 is kinda useless. Yes, the car will be more peppy, but your not shaving a second with more boost. If you had a bigger/better flowing turbo, you would notice a difference. Have fun with it!

demonmk2
12-09-2014, 02:44 PM
on aeb tunes from experience n75 race valves are useless.
use the n75 valve for the car, your tune should be optimized for it.

Fischerryan
12-10-2014, 03:21 AM
I have a large exhaust Leak
That's not helping, and will lower back pressure which will lower your boost.

I just replaced my K03 with another K03s. Mine crapped out, but I also found that after replacing it, it wasn't boosting to it's intended potential. I have a APR StgII, test pipe, K&N filter, Higher flow injectors... and she boosts the prescribed 20-22 psi per APR specs. I did the spring mod on the turbo before installing the new KO3, but found out the spring rate was too high and I was boosting 30 psi which was awesome, but made me very uncomfortable so I cut it off. The K03s is small, but it does well for a bit more boost and you can find them on the cheap. Got mind from a german car used parts company, and it included a warranty, good price, completely cleaned and checked over/tested. They ship, too.

Davdraco1
12-10-2014, 05:04 AM
Back pressure on turbo cars is bad. The turbo itself cause back pressure from the turbine housing you want as free of flowing as you can after the turbo so all the exhaust gasses can get out as quickly as possible so you can get more in and keep it spooling.

Fischerryan
12-11-2014, 04:34 AM
True, true