Ok so after having the 7 sit for 3 months it starts right up! I go for a drive and all of a sudden I am hitting 14-16lbs of boost!

Now I ported the wastegate and during the summer the car held a solid 7lbs I added a boost controller and upped it to 10-11. Now with or without the boost controller I boost out of control!?!?

The turbo seals are gone and it smokes a bit of oil....actually a good amount. Ever since I owned it the turbo oil seals were bad

I have haltech with 550/680 (gsl-se injectors)

WE are running 11.5 afr and the car is great when I feather the throttle and keep boost around 7-9lbs, but if I floor it and the boost spikes to 14 the car falls on its face looses 50% power and sometimes wont rev past. At this instance I am in the mid to low tens on AFR.

BUT....I can rev the car out at 9lbs partial throttle and it revs smooth all the way to redline (like 120mph!! haha)

So....what is the problem?

Do I need cold plugs????? ignition is great in low boost but maybe I have spark blowout at high boost?? I have stock new NGKs.

Why would the turbo spool so much?

is it too rich in the higher boost? but still if I lean it out I risk blowing it cause I have actaully hit 1.3 bar today and I let off so who know how high this bastard is boosting.

 

I waited for it to cool down and went and janked on the wastegate arm. It moved. I could get about 1/4 of movement and could hear the wastegate open and close, but I drove it and still was boosting 1 to 1.3 bar.

 

had the same problem with another TII I owned,when i got it someone had everything screwed up...check the twin scroll vac solenoid,vac line ect..maybe hook a vaccum pump up to twin scroll actuator and make sure the valve is still good,mine had nothing to do with wastegate check twin scroll valve under waste gate arm,make sure it even attached Ive also lost the c clip and had the arm fall off...lol

 

FYI,the twin scroll valve controls exaust flow across turbine,to give quicker boost response,if its stuck the wrong way you will hit 14-16lbs,your car falls on its face because you dont have enough fuel to support that much boost, 680's just wont cut it,and the factory unit is very effient over 11lbs anyway hope that helps

 

I removed the twin scroll and plugged the hole where it used to be. This is in a race car that has nothingin the engine bay but the essentials.

thanks for the input though. I am very peturbed that in 80 degree weather it wouldnt go past 7psi but at 40 degrees its boosting through the roof. I mean I really hit 18-19 psi tonitE!!

and I can move the wastegate arm...but its hard to move. maybe the cold weather is effecting the spring rate in the wastegate?


I am gonna lube up the wastegate tomorrow and see whats up.

 

I'm not surprised.


-Ted

 

so is this common?

I really want to find out why its boosting so high even though the wastegate arm is moving.

The nipple on the compressor wheel is slightly loose, maybe i will seal it up and see if boost is bleeding past that.

do internal wastegates have a diaphram?? maybe its torn.


Once I get the boost figured out I can then finish the proper tune.

 

bump

 

is your boost controller still hooked up? if so, run the hose as it was stock.

 

hose is run from the wastegate actuator to the nipple on the compressor side, no boost control as of now.

 

????

 

would lubing up the wastegate arm do anything..

what should i be looking for?

 

Ok. are you constantly overboosting, or just in low temps? If you are constantly overboosting, you have an issue with either no Manifold pressure getting to the WG, or the WG is stuck.


You said your hooked directly from teh compressor to the WG actuator so I would look at the WG or actuator being bad.

 

I hope thats it. I will try to remove the wg and look at the diagphram to see if its torn.

The arm/actuator can be moved so i doubt thats it. I mean going from consistant 7lbs in the summer to 18lbs in the winter is unreal and couldnt be that dependant on temp.

3rd gear holds great at 7lbs untill 4500 rpms then it slams to 1 bar then bam! 1.25 bar!

so weird cause I let of and modulate the throttle to hold it around 8-9 lbs the car Fin flies!

when it stops snowing i will take it off.

 

well, see if the wastegate actuator is actually holding pressure. if it has a hole in it, then it won't move much if at all. if someone has a pump you can pump pressure into it and see if it holds it. you shouldn't hear any leaks, if it does, this may be your problem. Just a suggestion. and boosting larger amounts when it is cold is normal for most turbocharged vehicles, but not that much more.

dpf22

 

come to think of it I was hearing an odd sound when i boosted high levels, to the extent that thought I had a loose coupler on my intercooler. It would boost and hear a whoooosh only at high boost levels, but not the BOV.

How do I pump up the wastegate....like a bike tire pump and connect it like that? and see if it moves or there is a leak?

 

A pressure gauge/pump combo. something like a pressure tester for a coolant system. Ill try to find a pic of one or a link or you could google "vacume/pressure tester gauge" and see from there.

 

Same problem here. Even though I have a straight exhaust and all the usual mods - car experienced no creep with the S5 wastegate - ran about 5 lbs (running on stock spring). I installed an AVC-R and I was able to boost to 10lbs where I wanted it.

One day the car started uncontrollable overboosting. I have disabled the boost controller and for some reason I cannot get the car to act right. I figured I must have fixed a boost leak when I was working on my FMIC - proably why it wasn't creeping.

I have since ported the wastegate but it has absolutely zero efect. Car still boosts uncontrollably - and it sucks.

 

craziness. I am going to try to pressurize the wastegate this weekend. Its so cold here right now the 7 wont start cause I havent adjusted the cold start feature in Haltech.

 

up for any other possibilities

 

any other ideas. I am gonna take of the wastegate this weekend, but right now its about 10 degrees out!

 

Don't be a *****!

 

I am with everyone else.. sounds like a bad wastegate I would just get out there pull it off and check it out thats first if that checks fine. look for vacuum leaks the best way is to get a bottle of soapy water, spray all the couplers, vac lines etc and then start the car and rev it up a touch while under the hood this way u can see if there are any bubbles forming from the spots u sprayed..

 

Overboost is a very simple affair. Only a few things can cause it. In this case here are my theories:

1. Faulty Wastegate or associated lines
2. Not enough wastegate
3. Faulty boost control

All things being equal, if his car ran fine in the summer but is over boosting in the winter, you could probably toss Air Density into the mix (colder air being much denser obviously), but I couldnt predict the amount of creep the difference could induce.

Once you eliminated the boost controller from the mix, you really narrowed down the field.



Rat

 

thanks j-rat, The wastegate was ported to hell so that def isnt it.
Boost controller was removed.

so I will remove the wastegate.

BTW where can I get a new one?

PS- Jrat, I know we where talking about timing split. You mentioned 12 degrees once in boost and carry that out across the board. The stock timing map is not like this at all right? My car is loosing power at higher boost past 10psi. at 10.2:1 AFR (which I will lean out once I resolve the boost problem) It seems to me that the stock map splits in higher rpm/boost as a timing retarding safety feature. You think I will see some benifits from changing the stock timing split.

I want to leave the overall advance/retarding as is for now.