SR20 overboosting bad please help!!!

[[email protected]]

Hey guys. I finished my sr swap a few weeks ago. I have been tying up all the loose ends. My problem is i am over boosting bad. I have to control the boost not past 10lbs on the boost gauge with the throttle. If i full throttle it the guage reads over 20lbs. I have been doing research on things to try but i am at a loss now. have any of you had this problem. please help this is one of the only things keeping my sr from being done.

Thanks,
Ryan

[cotbu]

check and verify boost signal line, then verify waste gate works properly, not sticking or a hole in the diaphragm.

[[email protected]]

ok what do you mean by check and verify boost signal line? i am new but i am learning ive been around NA motos forever i am new to the boosted life lol. and how should i check the wastegate

[cotbu]

if your boost signal line is t'd it may have a leak or be clogged
if not t'd it may have a leak or be clogged.
you can check and verify waste gate and signal line with an air compressor.
is your waste gate adjustable?
I'm assuming it's an internal waste gate. So is the flapper working properly and not sticking. Does it swings freely when the actuator arm is disconnected?

[ultimateirving]

I have heard if stock wga not working. Try disconnecting the vacuum line to it. And take it for a run. If it boosts over 7 something is frozen.

[cotbu]

Not true, you probably misunderstood.
with no waste gate reference it will and should boost too about 20psi or until there's enough pressure to force the flapper door open.

with the waste gate arm disconnected, then it shouldn't build more than 7psi

[[email protected]]

ok i just took the wastegate arm off and drove the car. It still overboosts but only to like 12 pounds now. So that means there is something wrong wit the actuator correct? I checked lines nothing is clogged. should i take the actuator appart? and what should i look for inside.

[cotbu]

should i take the actuator appart? and what should i look for inside.
NO

It's probably the turbo not the waste gate if you disconnected the arm, the hole is probably to small to flow enough exhaust for your setup. Did you see if the flapper swings freely? Get back. Otherwise known fixes: EBC and or external gate or port the flapper hole slightly.

To test the waste gate, add compressed air to the port, 7psi should have the arm fully actuated or whatever the actuator is set for. you don't want to add compressed air and have it leak out or blow right through the bladder.

[[email protected]]

yes wastegate door swings freely. and i am going to check the actuator with air now. if it comes down to it. to port it just dremel it out alittle?

[[email protected]]

could it be not pushing enough air because my exhaust is too big. I have 3 inch straight pipe to dual 4 inch tips. The isis blast pipes

[cbcm2435]

are you using a boost controller?

[[email protected]]

I am not using a boost controller at the monent.

[cotbu]

See this is where videos come in handy because if you're just punching it and the boost spikes it's not the same a over boosting. See with the flapper swinging freely and you ease into throttle, then punch it. There is enough exhaust flowing through the flapper to keep you from boosting at all maybe 2-4psi by redline in fourth, usually.
Your exhaust system setup is nothing new or extraordinary.

[cotbu]

I could meet you somewhere like Governors square shopping center on rt40
and Look over your setup real quick.

[Dboyizmlg]

Cotbu is on point!
I just recently had this issue about a week ago! I installed a boost gauge, and I was getting a reading of 18-20psi. I would let off the gas right away of course.
I installed a NEW Hks adjustable wastegate, and problem was fixed!
It seems that the WG goes bad with age, and mileage. I have about 100k on my motor, so yeah.
Also the benefit of the Hks WG is that it's adjustable, so you can set it up to 14psi.
But you should have it around 11psi, safe.

[[email protected]]

Alright here is what I did. I put air to the waste gate and it opens fairly easy. The springs back shut. And when I mean puch I was going along at a normal say 2500 rpm in like 3rd and ease it on itl still boost up to about 20lbs or more. Then do the same but get into it hard this time. Same thing. The one thing I di have is a screamer elbow that atmosphere dumps the wastegate I forgot to mention that earlier. And cotbu I'd be down to set up a time to meet up.

[Mikester]

I installed a NEW Hks adjustable wastegate, and problem was fixed!
It seems that the WG goes bad with age, and mileage. I have about 100k on my motor, so yeah.
Also the benefit of the Hks WG is that it's adjustable, so you can set it up to 14psi.
But you should have it around 11psi, safe.

It's an actuator, not a wastegate. The HKS ones are quite nice.

...screamer pipe...

When you are overboosting, do you feel compressor surge, or get launched back in your seat surprisingly hard (or both)? I had this happen when I was first dialling in my boost controller back in the day- legit overboost- scared me.

I don't think a screamer pipe would cause this; and like cotbu said, your exhaust setup is nothing that will cause an overboost situation. If the wastegate flaps freely with the arm disconnected; and it opens when connected with 7-8psi applied to the actuator, I'd wager you are suffering from an indication problem (bad gauge).

[steve shadows]

Try another boost gauge. Also if you have an HKS did you tighten that sucker up too tight? (i.e. shorten the arm a lot?) I haven't seen 20 psi but then again I have never tried. We always aim for around 16-17 steady PSI max on HKS actuators when tuning (either from remote recommendation or in person). Thanks

[Fre3_World313]

Bringing this thread back.

Need help

Have a red top sr

Swap was done right, by a good mechanic

He used all the best high quality stuff

I’m over boosting

Over 25lbs...

Fouling plugs..but that’s another story

Have a Greddy BOV. Which whistles not dump. Which is weird

Supposably 300 horse whip

Z32 maf, apexi air filter

T28 turbo and 550cc Bosch injectors

Manual boost controller. Never messed with it.

And air flow converter. Dunno shit bout it lol

I just got it running. So haven’t drove it more than 5 miles. Never been on pavement. I live on gravel.

Someone help me before it sees pavement. And blows shit up. Lol

Drove 800 miles to trailer it home. No s14s in Iowa..

Have a a e m. Fpr.

What do I do to decrease boost. And also.

Fuel pump won’t prime or turn on. Unless I jump the fuel pump relay.

Won’t do shit. Unless JUMPED.

HELP NEEDED. Thanks guys :wavey:

[Blixtin]

Bringing this thread back.

Need help

Have a red top sr

Swap was done right, by a good mechanic

He used all the best high quality stuff

I’m over boosting

Over 25lbs...

Fouling plugs..but that’s another story

Have a Greddy BOV. Which whistles not dump. Which is weird

Supposably 300 horse whip

Z32 maf, apexi air filter

T28 turbo and 550cc Bosch injectors

Manual boost controller. Never messed with it.

And air flow converter. Dunno shit bout it lol

I just got it running. So haven’t drove it more than 5 miles. Never been on pavement. I live on gravel.

Someone help me before it sees pavement. And blows shit up. Lol

Drove 800 miles to trailer it home. No s14s in Iowa..

Have a a e m. Fpr.

What do I do to decrease boost. And also.

Fuel pump won’t prime or turn on. Unless I jump the fuel pump relay.

Won’t do shit. Unless JUMPED.

HELP NEEDED. Thanks guys :wavey:

You are going to get stabbed...you are necro'ing every thread with the same question

Advice is provided in some threads and you keep necro'ing more. I understand the frustration with the car but you should probably take the advice as opposed to necro'ing all of Zilvia

[brndck]

Bringing this thread back.

Need help
:

STOP MAKING NEW POSTS ASKING THE SAME QUESTION WHEN WE ALREADY TOLD YOU WHAT TO DO.

You're going to have to go out and do some actual WORK. Typing the same shit on a keyboard is NOT going to fix your problem.

[Streetdeezie]

So, I have a ka24det. Just threw on the turbo kit. External WG, with manual boost controller set up. I have my MBC screwed all the way out for as LESS boost as possible. It wants to go over 10psi, which is what I want to stay under. This think spikes to 25psi if I got WOT. I have to regulate boost with the pedal! I only can go 65-75% T depending on what gear I’m in. Everything is hooked up correctly. I have trued switching the external WG spring with a 5.5 lb spring to achieve 10-11 psi but the WG just stays open and screams when I try to build boost. I switched back to the spring it came with and that puts me in the situation I am in now. OVER BOOSTING.

[S14rebuild]

So, I have a ka24det. Just threw on the turbo kit. External WG, with manual boost controller set up. I have my MBC screwed all the way out for as LESS boost as possible. It wants to go over 10psi, which is what I want to stay under. This think spikes to 25psi if I got WOT. I have to regulate boost with the pedal! I only can go 65-75% T depending on what gear I’m in. Everything is hooked up correctly. I have trued switching the external WG spring with a 5.5 lb spring to achieve 10-11 psi but the WG just stays open and screams when I try to build boost. I switched back to the spring it came with and that puts me in the situation I am in now. OVER BOOSTING.


This is a joke right?:picardfp:

[Streetdeezie]

This is a joke right?:picardfp:



No I just wrote it there for nothing


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[S14rebuild]

All the info is in the thread u posted on from 2013

But ill feed the noob

Remove mbc

Install independent good vacuum line to bottom port of wastegate

Install know lbs wastegate spring.

Drive car

If it over boost either...manifold design/wastegate placement suxs, wastegate is too small, or wastegate is a peice of shit

If boost hits target psi, and holds steadly thru rps...install mbc per directions

If boost now doesnt hit correct target or over achieves....buy a new boost controller



Anything eles?

[Streetdeezie]

All the info is in the thread u posted on from 2013

But ill feed the noob

Remove mbc

Install independent good vacuum line to bottom port of wastegate

Install know lbs wastegate spring.

Drive car

If it over boost either...manifold design/wastegate placement suxs, wastegate is too small, or wastegate is a peice of shit

If boost hits target psi, and holds steadly thru rps...install mbc per directions

If boost now doesnt hit correct target or over achieves....buy a new boost controller



Anything eles?



That will be all. Thanks. Just got Tapatalk last night, First post to Zilvia as well. And yes it’s old but I knew someone like you would answer.


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