bpgreen20

I just received my dynosheet from Turbo Tech. What do you guys think? This is all new to me so I'm hoping for opinions and or education from you guys. The blue is the stock condition, the red is the final tune. They weren't comfortable with the green with a stock engine so I think they backed out some timing. 6lbs of boost.

Brian


[IMG]local://upfiles/32842/DF3D000A773646B79CFF4EBD45BF9B59.jpg[/IMG]

chevykiller

You need a better tune...period. Look at your a/f on the stock pull. Your a/f is all over the place on the 'tuned' pulls. This is a dangerous tune at the 400HP+ mark. It is also a factor of why your power is so erratic and you need to get the power band much smoother accross rpm. You want to get rid of the 'dips and valleys' throughout power band.

Mark

QuickShortBus

+1 You need a better tune, I assume this must be the Granatelli turbo kit that you had installed. If this is the kind of tune that is going out with the GMS kits I feel sorry for the guys wasting their money and makes me that much happier I went with PowerHouse.

Edit: That is also extremely lean, I wouldn't get into boost at all until you have it retuned.

bpgreen20

Thanks guys. You are exactly the two guys I was hoping would respond.

Turbo Tech said they didn't measure the a/f on the stock pull which would explain why it is completely flat. I was however a little skeptical about the dips and valleys on the runfile #10 which is the final tune. I am at a disadvantage because I am clearly uneducated, but it appears that I need to become educated quickly.

Shortbus - How did you know it was the GMS kit?
In your opinion what is an acceptable air fuel mixture?
I'm hoping I haven't wasted my money and just need some fine tuning. I'm told that the components of the kit are high quality.

Chevy killer - What about the curves tells you that this is a dangerous tune?
Is there an acceptable tolerance to the peaks and valleys on the power band? One of the guys at Turbo Tech said that the peaks and valleys were "the nature of boost" This didn't sound right to me, but not being educated, it's difficult to argue, which is why I'm here asking for your help.

I've read alot of post from both of you and don't doubt your knowlege, but I need to educate myself before I go back to the shop to ask for revisions to the tune.

Do either of you have an dyno sheet that I could bring with me as an example of what I should be able to expect given the dollars I have spent?


Thanks for your help.
Brian

QuickShortBus

Well since Turbo Tech is the company that co-developed the kit with GMS it was pretty easy to figure that part out. To feel safe I would want to see no leaner than 11.5:1 with a stock motor and a little richer isn't going to hurt anything. I agree that for the most part this is a high quality kit, I'm not crazy about the aluminum piping and if this is the kind of tune everyone will be getting then they will still need to have a custom tune done which costs more $$$$. Your AFR should stay very flat once boost comes in.

bpgreen20

Man you are on the ball. I thought I knew a secret on the source of the GMS kit.

I don't have a problem with a custom tune, I just need to know what to ask for and how to tell whether or not I've gotten it once I've asked for it. So if I'm understanding this correctly my AFR is ranging from 17:1 to a low of 11.5:1 and you are saying I shouldn't exceed 11.5:1?

When you say very flat what do you mean? Is there an acceptable level of variance?

I have a high opinion of George at Turbo Tech and I received alot of positive reccomendations before I decided to go there. My biggest problem is I don't really know WTF I'm doing.

Sleeper05

then "peak" of leaning in the A/F at the beginning is normal and due to momentary increase in airflow when the pedal is actually first floored. the "flat" line that shortbus refers to comes after it has quickly settled down. with boost, it should be around 11.5:1, but less than 12:1, with variance NO MORE THAN .1-.2 from that number anywhere above 3000rpm or so. yours has peaks and valleys at least 3-4 times that, and that can be of concern, and puts unneccessary random stress on the motor in the process

bpgreen20

Thanks Sleeper!

Keep it coming guys! I'm going to leave the office at 4:00 to go ak them some questions. The more info I can gather for them to respond to the better.

That's two people who have said that the AFR should be 11.5:1 or less. I'm assuming that leaner that that will cause the motor to run too hot. Is this the danger?

Thanks again for all your help.
Brian

QuickShortBus

The only problem I see with the kit coming with this tune is, you are paying for a complete kit including tune but then to have a safe tune you have to spend additional money for a custom tune. If you buy a kit complete with tune the tune should be better than this.

If the AFR is measured at the tailpipe then it will read a little leaner and if you have cats on the car still then the AFR at the tailpipe would be useless.

When I say the AFR should be no leaner than 11.5:1, I mean when it is under boost. You wouldn't want it that rich when the turbo isn't making boost. I would say when under boost an acceptable level of variance would be +/- .3-.5 points. The lean spike at the begining of the pull is cause for concern also. Obviously the pull will start leaner because you aren't making boost and it should be leaner at that time but as soon as boost starts to come in you should see the AFR richen up and reach a nice flat AFR within about 500-800 RPMs without spiking lean even more so if it is spiking 17:1.

chevykiller

The truth is you want to be as close to 11.5 as possible and the main point we are all bringing up is that it shouldn't fluctuate more than slightly. Your a/f reading is making drastic dips and they should only be marginal. The kit you have is fine but as with any forced induction, the tune is essential and most important. The 'dips and valleys' yes are a fact. You will be hard pressed to get a steady curve. But what sleeper and I are saying is your dips are significant. To put it in easy terms, your curve should have slight 'jagged edges' here and there and not 'dips' and 'ups' and downs'. I know this sounds childish but hopefully this gives you a visual.

I'm going to almost bet you are going to need to work on your fuel system. My guess is for a custom tune to work properly with your set-up, you are going to need to get more fuel into the car. You are probably going to need bigger injectors and a bigger pump or BAP (Boost-a-pump) I would also recommend fuel rails for your car as well.

The bottom line is that where your car is now is LEAN. Not a good thing. I would stay out of the boost as much as possible until you get more consistent numbers.

Here is 2 dyno charts from my car. One is my street tune and it shows the a/f (notice how steady compared to yours) The other is an old race tune and on bothg charts, notice my lines?? Yes, there's fluctuation but nowhere near as drastic as yours. Hope this helps explain it...

Mark

[IMG]local://upfiles/24802/10154C748C534899BE6A68D0F94C5A43.jpg[/IMG]

[IMG]local://upfiles/24802/A43ADD216D094A0EBFF0C0BE1098D21C.jpg[/IMG]