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Discussion Starter #1
i have a 555 bbc bb2x cnc heads with bs3 with a f3 139 on methanol what spark plugs should this applacation use? like an ngk number or should i be using something different than an ngk?
ignition is a 7531 msd with equivalent coil

what gear shoulds i be using with this combo? car is a back haved car with a 33.5 tall hoosier slick shifting right around 7k.

we are going to build a set of rear fender exit headers for the car can i get away with mild steel being a blower car on methanol or will my exhaust temps be to high? do i need to use stainless?

what size should the headers be? do they need to be steped? i only wanna build these once so what ever will be best is what we will do.

im sure i will have more questions as this goes along so thanks in advance

ken
 

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Discussion Starter #3
the motor for this year isnt going to go over 14-15 lbs this year, do u think it will be enough for just that befor we turn it up.
its all new here sitting in the boxes so ill see if i can return it if i have to.
 

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i have a 555 bbc bb2x cnc heads with bs3 with a f3 139 on methanol what spark plugs should this applacation use? like an ngk number or should i be using something different than an ngk?
ignition is a 7531 msd with equivalent coil

what gear shoulds i be using with this combo? car is a back haved car with a 33.5 tall hoosier slick shifting right around 7k.

we are going to build a set of rear fender exit headers for the car can i get away with mild steel being a blower car on methanol or will my exhaust temps be to high? do i need to use stainless?

what size should the headers be? do they need to be steped? i only wanna build these once so what ever will be best is what we will do.

im sure i will have more questions as this goes along so thanks in advance

ken
A lot of these things go to how much power you are going to make. also 1/4 mile or 1/8

IMO If you keep the boost at/under 20 you will be ok with the 7531 alone. I'm a 7530T (same power at 7531) with no issues keeping it below 20lbs and af ratios in the mid 4's. I make maybe 1600hp.


I'd go with 2 3/8 non stepped. I have dynatech mild steel - stainless are nice but not a must have.

If you pulley it for 50k RPM at 7200 engine and plan on shifting at 7 and going thru at 72, I would think a 4.10 would be pretty close. Again need to know more info.
 

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Chupa Cabra
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A friend runs M5 in his turbo car(94mm) and he uses an MSD 8 box with a grid to control the timing and other stuff. The main thing different about his from others is he is using dual coils to fire the plugs. From the research he did, his set-up the way he has it puts out the same amount of amps as a Mag 22 does.

He ran the car at 3.5:1 AFR year before on 32psi of boost with NGK 10's gapped at .016-.018. Good enough for 151mph with a 275 radial on a hurt motor with bad windage and ring seal problems. This was with just a single coil.

Planning on making a lot more power than last year so the dual coils felt needed as the injectors are getting bigger in preparation to pour the fuel to it he felt he needed more spark even though it worked fine with one coil before.
 

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Discussion Starter #10
its a 1/4 mile car.
let me know any other info you would need to know and ill spit it out trying to learn all i can as this is a whole new ball game for me
 

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Discussion Starter #11
i gess will just see how far the 7531 takes us sence it wont be pushed hard for alittle while we have alot of chassis sorting being a new car, and big learing curve with this all being new to us, afret that im thinking will just go mag and not have to worrie about it
 

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Discussion Starter #12
its a 1/4 mile car and its limited to 16 lbs or so for now so 1200hp or so id gess but idk what to expect to be honest.
and who around the chicagoland area could tune this thing?
 

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A friend runs M5 in his turbo car(94mm) and he uses an MSD 8 box with a grid to control the timing and other stuff. The main thing different about his from others is he is using dual coils to fire the plugs. From the research he did, his set-up the way he has it puts out the same amount of amps as a Mag 22 does.

He ran the car at 3.5:1 AFR year before on 32psi of boost with NGK 10's gapped at .016-.018. Good enough for 151mph with a 275 radial on a hurt motor with bad windage and ring seal problems. This was with just a single coil.

Planning on making a lot more power than last year so the dual coils felt needed as the injectors are getting bigger in preparation to pour the fuel to it he felt he needed more spark even though it worked fine with one coil before.
Dual coils do not multiply. Your friend has split the energy between the 2 coils. Please explain further if I'm wrong?
 

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A lot of these things go to how much power you are going to make. also 1/4 mile or 1/8

IMO If you keep the boost at/under 20 you will be ok with the 7531 alone. I'm a 7530T (same power at 7531) with no issues keeping it below 20lbs and af ratios in the mid 4's. I make maybe 1600hp.


I'd go with 2 3/8 non stepped. I have dynatech mild steel - stainless are nice but not a must have.

If you pulley it for 50k RPM at 7200 engine and plan on shifting at 7 and going thru at 72, I would think a 4.10 would be pretty close. Again need to know more info.
X2 on Greg Kelley's points.
Only I would run a #9 plug, 10 at your level will be to cold and not give you proper reads.

Your ignition will be OK until you decide to step on it. Then it can utilize more ignition especially on alcohol.

If your going to up the power later you may want to build 2 1/2 headers, which is what I run now.

Blessings........Ron
 

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Quick Hijack, I am have pretty much the same set-up except i have the msd 10. Do you need to run a different box for ignition ramps or doesn't the BS3 look after that as well?
 

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Discussion Starter #18
learning alot guys thanks, were gonna use the 7531 for now till we start to bring on the power then will probly go coil on plug of a mag and use the 7531 to control timing ramps.
i was hoping we could use a #9 plug as we have alot of them from the nitrous set up.
and ya eventually it will be making good power so will just build the 2.5's now i gess and not have to worrie about it later.
 

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Discussion Starter #19
what gear should we start off with sence its gona be down on power for now with the big 33.5 tires?
can we use mild steel or does it have to be stainless when we make the 2.5 fender exit headers?
thanks ken
 

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what gear should we start off with sence its gona be down on power for now with the big 33.5 tires?
can we use mild steel or does it have to be stainless when we make the 2.5 fender exit headers?
thanks ken
I made mine out of mild steel, gear it to achieve the rpm you desire just before the finish line.

Blessings........Ron
 
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