Ways to disable turbo ?
 

I'd like to flash back to the stock rom for the purpose of ecutek data logging but not interested in removing the turbo kit(AVO). This would be short term setup specific for capturing some logs.

Anyone have thoughts how to impede the turbos ability to create boost without removing it? I was thinking a small check valve on the BOV vacuum line(full recirculating) so vacuum would hold it open but not sure if no load on the compressor is bad thing as it would probably spin faster than normal at WOT.

Thanks for your thoughts.

I think if you installed a bypass on the wastgate's actuator it would keep it from closing, hense no boost at any load... :D

...it's either that or the wastegate won't open and you'll blow your motor! :bonk:

(someone who actually knows what they're doing should chime in here)

even bypassing the wastegate will still let the car boost to the spring pressure of the wastegate...I think

So if the spring is the wastegate is 5lbs, the lowest you can boost is 5psi

but bump

I'm not sure you'll ever get this to run anywhere near stock even with the turbo disabled. You'll still be running very foreign headers with extra restriction from however you disable the turbo.

What exactly is your purpose here? We may be able to suggest a better alternative if we know what you're truly after.

Can you expand more on why you want to do this? It all sounds like a horrible idea. I am not sure if the MAF placement on the AVO kit will even work with the stock ROM MAF scaling.

Agreed with above. Their would be two ways I can see doing it, both of which likely won't revert the car back to a "stock" engine VE. You could somehow force the wastegate to stay open all the time, but the turbo would still be turning and probably create a little pressure in the intake. You could somehow force the BOV open at all times, then you're venting any air that the turbo builds, but you're also sucking in un-metered air.

This sounds like a bad idea all around... and for what purpose?

I've got an automatic and when I'm driving in traffic I see a little bit of knock under light load at low rpm. ~1300+. If I flog it, no problems. What did it so stock?

"tip in" is how I think people refer to it. There was a member @jamesm who was posting some really interesting information about it but I see he is banned now for some reason?

This isn't the Software tuning section so I don't want to get into it to much but I've driven the car with the turbo and stock rom before but I'm not able to get the IAM to rise to 1 because I can't load it without the boost rising to quickly.

So that's all about the why.


The MAF stays in the stock location wit hthe AVO kit so swapping the MAP to OEM is all I expected to do to keep the ECU happy. I hadn't thought about all the extra restriction on the exhaust side. It probably wouldn't be a valid log anyways if the header and impeller make such a difference in back pressure.

You can either take the spring out of the waste gate (assuming external) so all the exhaust will dump or take off the bov and let the boost leak out. Either way though you won't get proper readings because you will either have an exhaust leak bypassing your O2 or a boost leak bypassing the MAF. You aren't making boost at 1300 rpms so the turbo shouldn't have anything to do with it.

Thanks for the ideas. I realize the whole thought is out there on the edge of "wtf did he just ask" but I regret, just a little, not putting more miles on before the turbo. I only put 1k miles before the turbo kit went on. In retrospect I would have done some logging and gotten more of a feel for what a stock car is like. throttle feel, normal engine sounds etc...

Fiddle with the wastegate (internal) seem like a good idea. Maybe I'll try to pin it open or something.

okay well with an internal wastegate you can disconnect the flapper arm and that will let the boost leak out but still have everything pass by the O2 sensor

I wouldn't do this unless you had to limp the car or something. I would never WOT this disconnected turbo setup.

Sounds like a winner. I didn't really want to take the under tray off to get to the turbo... again.... but probably a good place tackle this. Thanks.

Agreed. I may not need to go WOT to get the IAM number to rise to 1 but I wanted to cover the gamut in the original question.

If he loads up the stock tune I can't see any problem with it. With the waste gate arm disconnected the turbo shouldn't build any boost due to the amount of exhaust flow escaping. Plus I believe he is only testing the lower RPM range.

Even with the wastegate wide open, you could still spool the turbo a little at WOT, especially being AVO (small turbo). Be careful..

You can still reach him on Facebook through HRI Tuning. I would consult with him before making any changes.

so you want to go through all this hassle because of some knock retard that is probably just noise?

There's nothing "wrong" with running around on an engine with the wastegate wide open, although there's no guarantee that it will make 0 boost under all circumstances. Any car with a vacuum or electric wastegate (BMWs for example) do this from the factory. Those valves are normally open and then are moved to a closed position.

It would have been good if you had a baseline dyno run to see where you car was at before the turbo kit.

Due to the wildy differing quality of gas across the country, within states, and from gas station to gas station, I've seen stock cars where the ecu has pulled power due to knock, which was due to the gas that it was running. So it's very likely that the knock was there before the turbo kit install. At those low of revs, the turbo kit has very little impact on the engine, if almost none.

There is a certain degree, a minor one, of knock the engine seems to live with. If the knock is enough to impact your IAM, then it's likely due to one or more factors.

1. Gas quality - cannot emphasize enough how important good gas is to this motor, FI or stock.

2. Tune - which can pretty much be disregarded, because there isn't much to tune at 1300-1500 rpms.

3. Mechanical factors - often overlooked. If any part of the exhaust is touching somewhere in the engine bay, on either the undertray or where it passes through the front subframe, it will rattle. Even if it's only a light rattle that you cannot hear, the two knock sensors on the motor are pretty sensitive, and they will pick it up as possible knock.

4. High ambient air temperatures - as good as any intercooler is, they cannot do too much cooling when you are sitting at a stoplight or stuck in traffic. Higher air intake temps will result, and this can cause some initial knock.

Agree with avo turbo world guy,

on stock tune the IAM initial value is set to O.7 most aftermarket tunes set the initial IAM to 1 ,

If you want the stock tune iam to 1 just set the initial iam to 1 in the stock tune table and flash that

These motors especially on stock tune will knock in 1500 to 3500 range on anything but the best fuel. at high load low rpm if you get on the throttle agressivly.

I rearly dont understand your logic :iono:

I'm in no way implying the tune or the turbo are causing the knock issue and it really wouldn't surprise me at all if the car did exactly same thing without them.. but I'd just like to know.

The tune is easy to revert, the turbo itself, eeh not so easy.

#3 I did recently notice a rub mark on the bottom of the header where it may be coming in contract with the under tray. I was previously always checking the downstream piping for contact with the frame.

#1 And I've seen it myself how a change from my normal gas station made some real improvement in the logs. That was a surprise.

Dude.. That is a freakin' awesome idea.

I always found lodging something strong in the inlet disabled the turbo. Similar to throwing a stick in someones bicycle spokes.

Trick number 2 for IAM

Vishnu Reset -Trick
Yes you can google it :-)

Basically it will Reset you IAM to 1 if it has dropped due previous knock events (assuming its not knocking at low/steady loads if so you have serious knock problems).

If you do 2 or 3 "vishnu reset" runs ie partial light (20% or so max) steady throttle runs from 2000-5000rpm or so in 2nd or preferably 3rd it will reset your IAM (assuming is not knocking at low/steady loads) if its less than 1. The gear is not really important its the partial steady throttle the longer the run the better. A slight uphill grade can be useful (or you can left foot brake). This works anytime to reset IAM back to 1 (assuming its not knocking at light load) it useful when your chasing knock in an area and want IAM back to 1 without an ECU reset (with initial IAM set to 1)

None of this sounds smart..you have a turbo, take it off.

Do you happen to know the DTC code that needs disabling because the OEM CAT and manifold are now gone?

mate you will have to think up a hard question :D

P0420 cat efficiency

FWIW
On the stock ROM that thing knocked in the sub 2500 rpm range just as much as any "tuned" ROM I've had. IAM started at 1 went as low as 0.73 while not in boost. And I didn't do anything to disable to turbo from making boost other than exercise self control with my right foot and keep an eye on the gauge.
So that's low rpm and very light load creating a lot of Fine knock correction.

I feel bad for making my tuner crazy. There are forces working against me. Time to check all the plumbing again.


Thanks for the tips.