Thomas Wiborg

Hello,

I have a tune on my 996 Turbo 2001. Around 550hp. New sports catalysator, sports mufflers and K24 upgraded Turbos.
A month ago my intercooler hose popped off during an acceleration.
I drove with the hose off for about 3 weeks before it got replaced.
I have a slight feeling that i dont have the same amount of horsepower now as what I did before it poped off. It shows 0,8 bar of boost, MAYBE 0,9 at max now. Is this normal for a tune with 550?

Or could the ECU been changed after driving 3 weeks with the car without the hose intact? I had some acceleration without the hose on, could this affect the ECU?

Macster

Hard to imagine a tune boosting the 996 Turbo's 420hp to 550hp wouldn't bump the boost up some above 0.9. I've managed to get 0.9 bar boost out of my stock 996 Turbo's engine albeit at around 8K feet above sea level on some highway in Wyoming.

My WAG is there's another hose off or a boost (intake) leak that accounts for the lack of boost and the engine's feeling down on power.

The techs tell me the Turbo intake hoses are tricky to install properly. It is very easy to tear a bit of hose rubber at the edge and bend this back during refitting the hose. This does not necessarily result in an intake leak but it can be the source of a boost leak.

You also have to be a bit concerned about hose integrity making big boost. The hoses are 13 years old and being subjected to boost pressures over standard so there's always the possibility one or more hoses is just leaking.

Thomas Wiborg

So even with the upgrades and K24 turbos it shouldent make 550hp @ 0,9 boost?
I believe its this upgrade http://www.t-t-p.de/english/996turbo.php the Performance upgrade step III.
So you believe, that its some leak or anything like that since its not above 0,9?
Or could it be something else?

What about disconnecting the Battery for an hour?

sanyata

When you say the hose got replaced do you mean a new one was installed or the same hose got reinstalled? The '01 Turbo's had hoses with problems in the clip attachment area and the manufacturer has since upgraded them. If you still have the original hoses you should buy new oem hoses and clips as they are improved upon. You also need to have a good boost leak test done. Good luck!

Macster

I don't know. I'm not an expert on 996 Turbo tunes. All I know is when the subject has come up in the past engines with tunes make more boost than a stock Turbo.

To make more power more fuel has to be burned (or the engine spun to a higher RPM which while the engine generates more HP this does nothing for its output at lower RPMs). To burn more fuel means more air has to be fed to the engine. In a turbo-charged engine the boost level has to go up to fed more air to the engine.

I checked the web site at the link you posted. I see nothing about what if any boost increase there is with the kit.

Ok. While I still believe that 0.9 bar boost is less than my gut says it should be for the advertised amount of HP increase, say the kit only makes 0.9 bar boost and this is sufficient to make the target of 550hp (or 540hp at the link IIRC).

You are still faced with an engine that feels down on power.

The ECU should constantly learn/adapt so I do not believe that the reason is the ECU has just not got around to dealing with the hose being reconnected after a few weeks of use with it disconnected.

However, the ECU does have an aftermarket tune in it or something and who knows what was revised/changed? Maybe the device doesn't have the adaptability/flexibility of the stock setup and has adapted a lower power output tune, maybe to protect the engine from you driving around with the boost hose loose?

Do you have any instructions with the tune? I'm thinking something on how to reset the tune back to its (aftermarket) factory defaults? A battery disconnect perhaps? Or something more involved? If you do not have any instructions perhaps you should contact the company and ask.

You can do the above -- disconnecting the battery for a while is pretty easy to do and as long as you follow proper battery disconnect and reconnect procedures relatively risk free -- or follow whatever lead you want, but I still believe the problem rests with a boost leak/intake leak.

Even with a stock setup the engine needs to have everything in order. With a tune everything takes on a more critical aspect.

Fuel supply (how's the filter?), quality of fuel (fresh, fresh, fresh), air filter (Oiled? then suspect the MAF), plugs. With an engine making that kind of HP over stock plugs won't last nearly as long.

Which reminds me: If you are running the stock MAF it is measuring way more air than it was ever intended to measure. This can have a life shortening effect on the MAF.

DER951

While the hose was off, your engine was not getting as much air as the ECU was reading, so you were probably running very rich. This could have damaged one or both or your cats, which would leave you down on power after reconnecting the inter cooler.

Thomas Wiborg

Hello,

Ive talked to the tuner.
The car should run @ 1,1 - 1,2 bar atleast.
He says it could be the sparks, which after the 3 weeks without the hose intact could have gotten sooted.
He also says it could be the boost valves.

Any idea how I can figure this out without paying alot of money ?

alpine003

You're in the wrong forum. You'll get better answers in the turbo forum.

Imo000

It won't be the soot on the spark plugs. But it could easily be a lot worse. If the engine ran very rich for a long time, the extra fuel can wash the oil from the cylinder walls and cause scoring. Now if the super rich mixture fould the plugs and there was a constant misfire, the scoring can be even worse. Its also possible that none of this happened but to be sure a leakdown test and a borescope would be the best option.

To clear things up with boost. Boost is just the restriction of the air in the intake or exhaust path. Nothing more. If you can get the engine to breath better, the bost will go down but the power will go up. As for measuring boost.....the beauty of it that you'll get the same boost at sea level as at altitude. The wastegate/actuator is set to a certain boost level and it doesn't care what altitude the engine is at.

Capt. Obvious

Something seems fishy here. If a pressure hose popped off, the car would go into limp mode and the car would fall flat on its face, no way in hell could you drive it for three weeks like that. Did the hose come loose and you just had a boost leak for three weeks? Usually even a minor boost leak will cause significant misfires, though.

And why the hell didn't you crawl under your car and fix the damn hose?

Kalashnikov

+1.

If your IC clamp pops off you have NO BOOST at all, and the car would immediately throw a CE and limp. There is no way to miss that you car has a massive boost leak.

Thomas Wiborg

Correct, it wasent all off. It was leaking.
But while it was leaking I drove it untill I got a new hose, about 3 weeks.