I went to get the car tuned today, but we ended up cutting the session short to be resumed at another time.

The problem was at the top end (above 6.5k) RPM... the boost dropped significantly. All the way down to .3 bars (~4.3lbs). Normally the boost dropps down to just above .5 bars (~7.25lbs).

We checked to see if the blow-off valve was leaking.. nothing there.
I checked all the piping that i could reach without taking the bumper off... all were tight. I don't think its piping because the car ran great in idle.

(BTW, we richened up the idle and the car is running great - so thats good news.)

So now im not sure what the problem is. Worst case scneario would be a damaged turbo. That would be odd though seeing how everything was running great until today.

I'm thinking it maybe the weather. It was about 92 degrees out today. This is the hottest its been in a long time. Once it gets cool again tonight, i'll do some pulls and see if the boost holds.
In the meantime - any other thoughts of what it may be?

-hS

 

Check your catalytic converter... it's likely the culprit

 

I agree, check the cat. How much boost did it make and at what point did it start falling off. How much power did it make at these boost levels? Did you get a dyno chart? Scott

 

It made boost, up to the amount the boost level was set at. As we increased the controller it made that much boost, but above 6000 rpm the boost quickly began to drop... coming down to .3 bars no matter where the boost controller was set.

I have a high flow cat right now... i'll take it off tommorow and do some quick runs to see if the boost can hold without it. If thats the case i'll just get a straight mid-pipe.

No power results or dyno chart. We were still street tuning it, and haven't put it on the dyno.

Also...
Scott, As you suggested i need to order some plugs. I'll give you a call on monday.

-hS

 

I have the same problem with my car the problem is a high exhaust back pressure tends to open the wastegate at high RPM .

 

Here's a video clip taken tonight. It was about 71 degrees out, nice and cool. The weather made no difference... with the same results as this morning
http://www.youtube.com/watch?v=zPDqsLn3gJQ


As you can see it rises to where the boost controller is set (.5-.6 bars) - but then drops at the higher rpm back down to .3 bars.

Tommorow i'll pull the high-flow cat off, and do some more pulls.
Is there any danger (other than the extreme illegality of driving with no cat), i need to be aware of. I was thinking with no cat... there will be alot more air-flow, and hence the car will run leaner (Danger Danger) - any thoughts on this?

-hS

 

It won't run leaner unless you start boosting higher. The turbo will spool MUCH faster. When I removed my cat and put in a 3" pipe, it just about negated all the benefits of moving the wastegate signal line from behind the throttle body to the turbo outlet (fix #2).

 

Update, Just removed the Cat, and ran it again.
On low and high boost, the car was able to hold .48 bars (7lbs).

I believe thats what the greddy turbo was set to do. So now i'm thinking that was probably the problem. I'll post a video of the gauges later tonight.

-hS

 

U mean the high flow cat pose such a large bottleneck?

 

The cat is probably beginning to fail.

 

Today We ran it on low boost (.6 bars) and high boost (.8 bars).
The recording was done on the higher level. You can see it holds boost much better now.
http://www.youtube.com/watch?v=nkmFN4yGHbQ


What i want to know is... how are some people with the greddy kit able to hold .68 bars (10lbs) of boost to redline???

-hS

 

you are just getting started, slow down grasshopper....

one step at a time. fix one problem then move to the next..

beers

 

Correcto Mundo. I'll wait for "someone" to release a bigger turbo for the greddy kit, until then... i'll enjoy my 7lbs.

-hS

 

wo wo wo.

i dont think you are done. . .

read maddogs thread... but fix one problem at a time....

beers

 

I thought maddogs thread was about the emanage. I'm already off that party bus.

-hS

 

hey i don't know if you're still having problem with the boost drop.... i have couple questions and suggestions here. first take a look at the connection from the pipes to the intercooler.. my it might be leaking a little just tighten all the clamps.. hopefully that will do the trick. and here is my question here. what size and type exhaust system you're running. and also what type of cat.. im pretty sure its your pipe more and also check on your boost control hose... it could also cause the problem... chinky

 

if your problem was the cat, and i am sure it was... a lot of the problems with the greedy still apply.... you cannot read to much.... the emanage is just one problem...

research is your friend... i know this and i dont have a turbo...


beers

 

I don't know of anyone holding 10psi all the way to redline!

I experimented with some springs, but I found that tightening the wastegate actuator all the way down helped hold another 1-2psi in the high end.

 

What brand high-flow cat were you running Big-O??

 

Living down the street from Rotary Performance definetely has its benefits...

I took the cat to them on Monday, and let Chris take a look at it. It was pretty clear the cat saw an excessive amount of fuel. These cats are designed to handle a very, very high heat level... but i dont think it had a chance with my myseterious e-manage which delivered unkown amounts of fuel across the board. Now with the interceptor-x that shouldn't be a problem anymore.

The whole reason to getting the Supercat in the firstplace was to avoid the CEL. Since the CEL isn't an issue anymore (its always on with the interceptor), i didn't need a Cat over a Midpipe.

RP was really good about the service. They went ahead and cut the Catalytic Converter off and replaced it with a resonator. I just tested it out, and the car is now holding around .43 bars of boost.

BTW, its really hard to type a post with the ***** in Miseterwilson007's signature line staring at you. MMMMMM, boobies

So comparing driving the car with CAT completely off, and driving with the RP midpipe/Greddy Exhaust - i only lose about .5 bars. Pretty good IMO.

-hS

 

took me twice as long as usual to read your post because i had to keep glancing up at the movement i was seeign in the peripheral. then id stare a moment and start over

 

BTW, its really hard to type a post with the ***** in Miseterwilson007's signature line staring at you. MMMMMM, boobies

So comparing driving the car with CAT completely off, and driving with the RP midpipe/Greddy Exhaust - i only lose about .5 bars. Pretty good IMO.

-hS[/QUOTE]


The point of his signature is that she breathes underwater.

Next thing I note is that you only lose 7 psi???????????

 

OOPS, i meant .05

 

I just had to take the cat off, and put it on again... forgot to reinstall the gasket ring. Oops.

Its pretty easy to do once you get used to it. To take it off and on... it only took about an hour. While i was down there i also cleaned my exhaust piping

-hS