Ignition map
Thread Starter
5th Gear
Joined: Sep 2002
Posts: 5
Likes: 0
From: Goteborg, Sweden
Ignition map
I've switched from custom chip to a fully programmable aftermarket DFI and WB. I will soon install my Vortech s-trim and H2O injection. I've been looking for information/leads how to a design a good start-up ignition map but have ended up with nothing (yet). Still stock bottom L98 (cr 10:1) so I guess not more than 8psi, camshaft is designed for peak hp's at 5500 rpm (approx. 220/230'/0.500/0.500 LSA 114'), other mods in the signature. Any information on this topic is appreciated!
Melting Slicks
Joined: Apr 2001
Posts: 2,094
Likes: 217
From: Ca.
Re: Ignition map (bogo783)
First off-welcome to the forum! And just curious-Goteborg? Where's that?
OK, onto your question now....The aftermarket manufacturer of your DFI should have "start up" tables for fuel, spark etc. Otherwise start with the spark table now in it-and just have to tune from there. Your dfi has knock retard? That would keep it safe. I've ended up down as low as 18deg at wot at certain loads, and just backed the idle/low load timing from 23deg to 15deg in some spots to pass smog! A lot depends on heads/porting also. Your cam specs are real close to mine-do you have to deal with smog checks where you are? Also-does your dfi use the wide band in its program to adjust wot f/a ratios? That'd be too cool!
OK, onto your question now....The aftermarket manufacturer of your DFI should have "start up" tables for fuel, spark etc. Otherwise start with the spark table now in it-and just have to tune from there. Your dfi has knock retard? That would keep it safe. I've ended up down as low as 18deg at wot at certain loads, and just backed the idle/low load timing from 23deg to 15deg in some spots to pass smog! A lot depends on heads/porting also. Your cam specs are real close to mine-do you have to deal with smog checks where you are? Also-does your dfi use the wide band in its program to adjust wot f/a ratios? That'd be too cool!
Thread Starter
5th Gear
Joined: Sep 2002
Posts: 5
Likes: 0
From: Goteborg, Sweden
Re: Ignition map (drive it)
Thanks! Well they did provide me with a "safe" start-up map. This is the spark advance at WOT and load 150 (max load, +50kPa MAP):
rpm Total SA
900 12
1500 16
2000 19
2500 22
3000 25
3500 28
4000 28
4500 28
5000 29
5500 31
6000 32
The WB is only used during tuning: I put target AFR's in each cell of the fuel/air map, driving the car at a certain load and rpm during two seconds enable the computer to home in and lock on the right AFR (and yes, at WOT as well). No knock retard in the DFI but I've kept the sensor in the block and use some electronics to drive a small lamp and a buzzer. In addition I hope my EGT probe will give me some help as well.
By the way, Goteborg is the second largest city in Sweden and unfortunately we have a very seroius smog check every year.
rpm Total SA
900 12
1500 16
2000 19
2500 22
3000 25
3500 28
4000 28
4500 28
5000 29
5500 31
6000 32
The WB is only used during tuning: I put target AFR's in each cell of the fuel/air map, driving the car at a certain load and rpm during two seconds enable the computer to home in and lock on the right AFR (and yes, at WOT as well). No knock retard in the DFI but I've kept the sensor in the block and use some electronics to drive a small lamp and a buzzer. In addition I hope my EGT probe will give me some help as well.
By the way, Goteborg is the second largest city in Sweden and unfortunately we have a very seroius smog check every year.
Drifting
Joined: Jul 2001
Posts: 1,897
Likes: 0
From: La Fontaine Indiana
Re: Ignition map (bogo783)
Accel offers a ESC as a option for the DFI unit I don't remember what the cost was but I have one installed on my car. This will protect your engine if you have the map wrong I would suggest you get one. The kit comes with harness knock sensor everthing for the install. With only 8lb. boost you could run stock timing with intercooled procharger but I don't know if you can get away with that on your setup. Have you thought about intercooling.
Thread Starter
5th Gear
Joined: Sep 2002
Posts: 5
Likes: 0
From: Goteborg, Sweden
Re: Ignition map (black bart)
I will use a ESC module + knock sensor from a pre -90 corvette together with an electronic circuit to indicate detonation. I think the Accell DFI (or is it FAST?) use the same principle (using a stock ESC). I've found a really simple circuit from the SyTy board (like $5 in components) that seems to work quite well. Yes, I've considered intercooling but as indicated in my previous message I have a "slight problem" with smog control (I have to make my engine bay appear stock during inspection=removing the supercharger, brackets etc). I am however thinking about the Vortech Aftercooler, it seems quite easy to fit in the engine bay (at least compared to air/air intercoolers).
I agree with you regarding the ignition timing, I'm planning to use my stock ignition map up to vacuum, above vacuum I will try to "reverse/mirror" the stock map ( maybe a little vague but I hope you understand). Any comments?
I agree with you regarding the ignition timing, I'm planning to use my stock ignition map up to vacuum, above vacuum I will try to "reverse/mirror" the stock map ( maybe a little vague but I hope you understand). Any comments?
