Coils

[Lorenzo]

I was hopeing you would have some input as to why some one went to all the trouble to do this. I for one do not know and am puzzeled like yourself.
I found it here . http://www.brengines.com/bridge_racing_performance_engine.htm

 

[BlackICE]

I was hopeing you would have some input as to why some one went to all the trouble to do this. I for one do not know and am puzzeled like yourself.
I found it here . http://www.brengines.com/bridge_racing_performance_engine.htm

Maybe some racing class requires a distributor.

 

[Fubar]

I'm definitely going to do a Motec at some point, I'd just like to drive the car for a little while now. I bet there is 75hp sitting on the table that we can not get to through the stock ECU. Also, the idea of traction control, boost by gear and an automatic bagel slicer is just more than I can bare. Turbo guys would see more benefit as it can retard timing to build boost down low and essentially overcome the only drawback of a turbo system... instant power at any rpm.

 

[kumar]

This wouldn't surprise me at all. It's interesting that so many people have faced "this problem." Why is it so difficult to make a smooth power curve on these engines? The SCT software just doesn't provide the latitude to modify the things we would like to change. Although this issue isn't a direct result of the software's short comings, it is costing me power in other places. I'm not trying to trash SCT, for the Ford ECU, it's the best option. Maybe I should just complain about the ECU.

HP Tuners told me they were working on Ford software about a year ago. I never heard anything.

 

[kumar]

Wait and see how much of a PITA mine ends up being.

 

[B.M.F.]

There is no need for a motec in these cars. A Fast xfi would be sufice or a big stuff 3 which i think is the better option. There are more racers in the country using bs3 and fast than motec combined. there are more road raceguys using motec than any other standalone company in the world. When it comes down to it the tuner is @ the realm of your car blowing up not the efi system. The bs3 and the fast xfi are much much more user friendly aswell. Plus the guy who originally did the first standalone computers in the U.S designed these boxes and wrote the way for stand alone computers here in the U.S He started with Accel dfi, then fast Fuel air spark technology and then Big stuff 3 which is the the fastest efi box in the world Period!!!!

The motec has a always workin traction control and many other really expensive and nice features that many of use would never use. They are 8000 plus you need to have a harness made. which can be another 5000 pretty easy. As far as the traction control Ray's car never used it when he went 249. These cars with a good tire can put down retarded power. All you need is boost by gear and get a tune figured out for it and you will fly.

Just my .02 cents

 

[B.M.F.]

Interesting exercise, but why would I do that when individual coils have more potential?

I wouldn't say they have more potential. The fastest cars in the world have distribitors. I think the coils clutter up the engine compartment and they only fire one at a time, so only having one that does all 8 versus 8 that fire one at a time is really no difference. 8 individual coils will make no more power than 1 coil and a distribitor with 8 wires.

 

[BlackICE]

I wouldn't say they have more potential. The fastest cars in the world have distributors. I think the coils clutter up the engine compartment and they only fire one at a time, so only having one that does all 8 versus 8 that fire one at a time is really no difference. 8 individual coils will make no more power than 1 coil and a distributor with 8 wires.

From a physics standpoint anything one coil and a distributor can do, 8 separate coils can do equally well, or better, because separate coils allow for 8 times more dwell time which increases the spark energy at high RPMs, minimizes cross firing and shorting problems and allows more accurate and specific cylinder timing. The reason the fastest cars may use distributors is that the race class dictated they be used.

 

[B.M.F.]

From a physics standpoint anything one coil and a distributor can do, 8 separate coils can do equally well, or better, because separate coils allow for 8 times more dwell time which increases the spark energy at high RPMs, minimizes cross firing and shorting problems and allows more accurate and specific cylinder timing. The reason the fastest cars may use distributors is that the race class dictated they be used.

Well with all the class stuff that i do and am involved with, there is no rule that says you cant run coil on plug and there are not alot of fast coil on plug cars, one or two. 99% are distribitor cars. Mahovetz is one of them who uses coil on plugs. Threw dyno tests there have been no proven gains from coil packs versus distribitors. Just ones preference i guess. Most coil on plug coils are not able to produce enough power to fire the coil in hi boost apps. and the spark blows out. That is why with the gt (ask Fubar) and many others you have to tightn the spark plug gap up, due to the output of the coil. I Know that i would not want those big red coils on my car that is for sure, especially when one of them and that ford gt valve cover with the distributer(Pic above) with spark plug wires would be enough to make 2000+hp......


Also a ford gt uses the smallest dwell time i have ever seen. 2.0 milosecs. A ls1 gm coil is 7-8 to energize the coil. A ford gt coil is @ peak energy @ 2.0ms about 6-7.5 amps and stock is 1.6ms..... So we run the dwell at 1.6 untill you get to peak torque then we go to 2.0ms.

 

[BlackICE]

I don't disagree that a proper distributor system can work as well, depends on how it is done. The stock system works well for a stock motor, as the boost goes up it has problems. At 7000 RPM the maximum dwell time is only 3.4 msec. using a distributor system and 8 times more, or 27 msec for an 8 coil system, 1 BIG coil, or eight smaller coils, your choice.

The FGT is hampered by the coils being mounted inside the valve covers, limiting the size and cooling of the coils. So even if the stock ECU could drive the coils harder, they would most likely have a short lifespan due to heat failure. Aren't the LS coil much bigger and mount externally ?

BTW, can the dwell time be adjusted in the stock ECU. I don't see that option in my SCT software?

 

[B.M.F.]

I have some video's i will get and post of the coils. There is no reason to run them over 2.0ms as they are fully charged @ that point and after that they will overheat.
Idk about dwell setting in the factory pcm or if you could change it. I do know that Diablo can add features to the programmin. I have a Stand alone computer on my car firing the factory coils, so i can adjust dwell with rpm. I know the factory coils are good to about 38lbs of boost and 1450rwhp. Idk after that power level.

 

[2112]

Great thread. Just subscribing so I don't miss anything.

 

[BlackICE]

I have some video's i will get and post of the coils. There is no reason to run them over 2.0ms as they are fully charged @ that point and after that they will overheat.
Idk about dwell setting in the factory pcm or if you could change it. I do know that Diablo can add features to the programmin. I have a Stand alone computer on my car firing the factory coils, so i can adjust dwell with rpm. I know the factory coils are good to about 38lbs of boost and 1450rwhp. Idk after that power level.

What gap were you using at 39lbs with the stock coils? When you measures the current, is that peak current on the coil's primary side after being fully charged?

 

[BlackICE]

Most likely the stock ECU is using coil drivers similar to this one.

http://www.st.com/stonline/products/literature/ds/9671/vb325sp.pdf

This particular one has a maximum current limit of 10 amps, but the current limit decays with both temperature and dwell time. To get higher spark voltage and or energy, one either has to replace the ECU or at least add something after the stock ECU coil drivers.

 

[Fast Freddy]

any update to this info here for us? are the factory coils still the best or should i get aftermarket coils? i am gonna be buying new coils next week and would like to know which i should get....

 

[BlackICE]

any update to this info here for us? are the factory coils still the best or should i get aftermarket coils? i am gonna be buying new coils next week and would like to know which i should get....

I would talk to Torrie.

I haven't read about anything that is much better than OEM that will fit inside of the valve covers and due to heat, a limitation in power input to the coils. To do better you would have to modify the tune to get rid of bad coil detection by OBDII and then either mount better external coils that won't overheat and drive them harder, or over drive the OEM coils sparingly (like only under boost at high RPM) and hope they live long enough.

The GM coils are inductive spark and have built in drivers to make it easier to drive. You still may have a black box modify the dwell settings to the GM coils.

This is on my list of things to do, but I work at glacier speeds. Two approachs come to mind. External GM LS1 truck coils mounted on top of the valve covers, UGLY, or using an 8 channel CDI and take a risk of over driving the OEM coils. Both would require a tune to turn off some OBDII features.

 

[Fast Freddy]

I would talk to Torrie.

I haven't read about anything that is much better than OEM that will fit inside of the valve covers and due to heat, a limitation in power input to the coils. To do better you would have to modify the tune to get rid of bad coil detection by OBDII and then either mount better external coils that won't overheat and drive them harder, or over drive the OEM coils sparingly (like only under boost at high RPM) and hope they live long enough.

The GM coils are inductive spark and have built in drivers to make it easier to drive. You still may have a black box modify the dwell settings to the GM coils.

This is on my list of things to do, but I work at glacier speeds. Two approachs come to mind. External GM LS1 truck coils mounted on top of the valve covers, UGLY, or using an 8 channel CDI and take a risk of over driving the OEM coils. Both would require a tune to turn off some OBDII features.

whatever coil advice i receive here needs to work with my SCT. i assume that your advice does?

 

[BlackICE]

whatever coil advice i receive here needs to work with my SCT. i assume that your advice does?

I got some SCT code that is supposed to turn off the OBDII coil test, but I haven't try it yet. If it works then and you are willing to build/buy a black box (don't know if they exist) to run the GM coils or run a CDI (they exist) then an upgraded ignition can be done with the stock ECU and SCT tuner.

I want to test a CDI running a 8 coils on the workbench to see if anything blows up. I suspect that it might. I have read horror stories about many of the multi-channel after market CDI boxes. Most only can do 4 to 6 coils max so you would need 2 of them. I think Fubar is running an 8 M&W but I think he is using Motec ECU. The only other 8 channel I have found was AEM's Twin Fire. Many posts about them burning out quickly.

 

[tmcphail]

That came from me, and it should work for you in that manner.

 

[B.M.F.]

I have coils and these are the only coils I know made that will actually produce more amps before the coil is fully charge in the dwell time given by the factory. Most coils need more dwell to make them hotter and a Ford Mod coil cannot be charged more then 2.0 secs of dwell time. Also there is NO Software to change the dwell time in any oem ford computer. You would need a stand alone computer todo so. I am ready to start testing these coils and they will also need a coil cover spacer as the ends are angled up a little bit. After testing I will be making those aswell.