Can anyone help me with DFI tuning?
Thread Starter
Instructor
Joined: Oct 2001
Posts: 104
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From: Tucson AZ
Can anyone help me with DFI tuning?
I have a 78 vette with a DFI TPI and it just doesnt run the way it should. It pings under acceleration, sometimes will backfire, and generally doesnt make the power it used to. I had to have a new DFI unti installed because the original got fried along with the program shortly after I bought the car. Any thoughts?
Le Mans Master
Joined: Feb 1999
Posts: 5,877
Likes: 1
From: Park Ridge IL
Re: Can anyone help me with DFI tuning? (Dracula383)
I had DFI on my old Superram 383 in my 82. Sounds to me like you're running lean, based on the limited info you provided. If you don't feel confident tuning it yourself, I would recommend finding a local Accel EMIC to tune it for you.
The DFI system isn't hard to tune. I tuned mine and made good power with it, but there's no substitute for putting it on the chassis dyno and wide band O2 to maximize the performance.
To start with you need to do a data logging run to see what your O2 voltage and O2 correction is. It's not the most accurate method, but without a wide band O2, it'll at least give you some kind of idea as to where to start.
I looked around for my old DFI discs, but I can't find them. Since I switched over to the Speedpro SEFI unit, I haven't messed with them, and I don't even have Calmap on my computer anymore. You might want to send an email to Stringray Racing, Rich is still using DFI, and he has a 383, so his Universal File may be a good starting point for you, depending on your injector size.
[Modified by Monty, 10:36 AM 10/11/2001]
The DFI system isn't hard to tune. I tuned mine and made good power with it, but there's no substitute for putting it on the chassis dyno and wide band O2 to maximize the performance.
To start with you need to do a data logging run to see what your O2 voltage and O2 correction is. It's not the most accurate method, but without a wide band O2, it'll at least give you some kind of idea as to where to start.
I looked around for my old DFI discs, but I can't find them. Since I switched over to the Speedpro SEFI unit, I haven't messed with them, and I don't even have Calmap on my computer anymore. You might want to send an email to Stringray Racing, Rich is still using DFI, and he has a 383, so his Universal File may be a good starting point for you, depending on your injector size.
[Modified by Monty, 10:36 AM 10/11/2001]
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Joined: Aug 2001
Posts: 76
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From: Plainfield IL
Re: Can anyone help me with DFI tuning? (Dracula383)
Thats Right a wide band o2 is key in making power.
At first I had some problem tuning mine but then after a few answer questions thanks to some people on this forum. (AKA MONTY).. I was able to tune mine Very close using the o2. Then I went to the track and adjusted my timeing. Finnaly I had a wide band and dyno time and I even gained another 20 horse!
My motor made 450 horse at 6000 and 451 torqu at 4000
I'm proabley at the limit for my heads.. The TFS. But if I could get my hands on some AFR's I'd be a very happy man!
Too bad, if you where by Chicago I could help you out!
Shane
At first I had some problem tuning mine but then after a few answer questions thanks to some people on this forum. (AKA MONTY).. I was able to tune mine Very close using the o2. Then I went to the track and adjusted my timeing. Finnaly I had a wide band and dyno time and I even gained another 20 horse!
My motor made 450 horse at 6000 and 451 torqu at 4000
I'm proabley at the limit for my heads.. The TFS. But if I could get my hands on some AFR's I'd be a very happy man!
Too bad, if you where by Chicago I could help you out!
Shane
