You are correct sir...

The car is knocking a lot up top and we haven't been able to determine the cause yet. We were on the dyno until just about 1am and we decided to call it a night. Taking it back this week.

So far we've done a boost leak test, and we've looked into most of the vacuum lines.

Hopefully I'll have better news soon.

 

I'm assuming you guys have 800cc+ injectors and a fuel pump upgrade of some sort? I've read recently some people having a faulty/weak fuel pump relay that leaves the fuel pump in low power mode which is obviously bad for the top end. Check for boost leaks, Fuel pressure regulator line leaks and all that other stuff too of course. I just upgraded to the 9 heat range (1 colder) HKS plugs in preperation for the bigger turbo as a preventative step, maybe check the plugs to verify they are ok.

Hope you guys figure it out soon!

 

Glad you are being safe and thorough, waiting on results is always better than hearing about a blown engine ...

 

Well, rest assured you have a great tuner on it. If I lived out west, I'd love to have Bryan tune my car.

 

Yup, 1000cc injectors but a stock pump. I have a 255 ready to drop in...but we weren't really having problems with the fuel as Bryan was keeping it in the high 10's without any problems.

We did a boost leak test and fixed a minor problem, plugs seem to be fine, and we checked all of the major vacuum lines. It's hard to speculate what the problem is right now...but the car is really angry with this turbo.

Maybe this is why no one is posting anything about it?

 

Interesting... how do you know it's knocking? Is the car pulling timing? Knock sensor? I hope you guys can track it down!

I actually know of a car running the 3076, bigger front mount, upper IC pipe, an O2 housing/downpipe, and I THINK a testpipe, stock catback, running 20.5psi with NO TUNE, and put down 350whp at 7k rpms.

It still needs a cat back exhaust, cams, bigger injectors, fuel pump, and turn the boost up past 20.5 psi. And a tune of course. The A/F is still somewhere below 10.0, off the chart rich. It's still so rich in the midrange that it breaks up and the dyno looks all jagged.

 

At what rpm do you start to get knock? Do you have cams installed?

 

By angry do you mean its very torquey for not a lot of engine revs ?

Cheers A .

 

Hmmm what PSI are you attempting to run? Honestly I wouldn't go above 22 PSI and 5500 RPM on the stock fuel pump with that turbo but that's just me. You really need a fuel pump to expect to get 500 crank HP at 26 psi in the 6500+ RPM range, the stocker just won't cut it. Also make sure you are tuning on a 1/2 tank or more on fuel, preferably a full tank since I've read issues with starvation since there is no acceleration pushing the fuel to where it normally goes on a Dyno.

So you had knock just out of the blue with 10.8 AFR's or so? Just seems hard to believe unless the timing was too high on the top end. I think mine is around 6 degrees at 3k then climbs to 17 degrees at 7500 on the stock turbo. I've leaned mine out to 11.5 AFR's though and was willing to trade some timing advance for less fuel deposits on my back bumper.

 

I had similar problems with the Dominator 2.0 & Cos Cams. Have Bryan PM me and I might be able to help out some what with getting rid of the knock at the higher RPM levels.

 

Will do.

The main thing that is bothering us right now is that the car is down 40whp from the stock turbo baseline...which is making me think that I got a bad turbo.

Baseline on the stock turbo was 305whp/305wtq...last run on the Garrett was 270whp/260wtq....depressing. On the drive home the car would lurch and felt like it was surging...and this was driving like a grandma and not going past 10psi. Something is definitely wrong somewhere.

 

Bryan could hear the car knocking at about 6k rpm...much easier with an alum. block. That other car is what depresses me the most...we can't even get the car to make more power than the darn stock turbo!

Stock Cams and knock is showing up in the high 5ks and 6k

Angry as in it absolutely refuses to make power and knocks like a door to door salesman.

I'll have to let Bryan chime in on this one...he threw every trick he had at the thing and it just wasn't working.

 

There's definitely something up. Like I said, my friends car is putting down 350whp@7k (on a dynojet I believe) with only 20.5psi and NO tune.

What's your complete mod list? Does Bryan have a chart showing the boost curve? Also, where is the boost being measured (manifold or compressor outlet)?

Was anything else changed during the turbo swap?

If you're making the proper levels of boost, but the power is way down, then I suspect the issue is elsewhere.

Overall, the turbo is relatively simple in operation, and one going bad doesn't really exhibit the symptoms your car is showing that I'm aware of. Maybe there's an exhaust leak between the mani/head or mani/turbo?

Possible issue with MAF sensor? Compressor inlet elbow on correctly with the o-ring?

 

Best of luck, I'm sure you'll figure it out soon.

 

tell bryan to get ahold of me,

we are doing the "official testing" with garrett and I have some tech notes from them... im really anxious to get ours on this week.

cb