I know EFI is better, but....
#16
Burning Brakes
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Ask to see the dyno showing the 500 RWHP, and see what the fuel ratio's are. That would be, by far, the strongest CIS motor I have ever heard of. From what I have learned along the way, that is a figure taht does not compute, atleast for very long. Just not enough fuel delivery.
Unfortunately, showing a dyno of 500 hp doesn't mean much anymore given tuners who enter BS correction factors. I worked very hard and spent a lot of money to produce a CIS car with 412 rwhp, verified using 2 different dynos. I think 400 - 425 rwhp is most likely a max number for a CIS car.
#17
Burning Brakes
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Ask to see the dyno showing the 500 RWHP, and see what the fuel ratio's are. That would be, by far, the strongest CIS motor I have ever heard of. From what I have learned along the way, that is a figure taht does not compute, atleast for very long. Just not enough fuel delivery.
I understand this to be true as well and that has been my belief.
However, I also understand that Porsche, and many others were getting 500 hp out of these engines in the late 70s and through the 80s etc.. on CIS..
If that's the biggest drawback to getting these kind of numbers then obviously somebody somewhere was doing something to get some fuel delievery... supposedly DP, Andial, Powerhaus and others were getting 500 hp out of no-EFI motors.. or at least that's what they were selling!
Any thoughts?
#18
Burning Brakes
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You're talking about factory race cars now.
If I would have had a big dollar budget, I bet I could have reached 500 hp with my CIS. It would have only lasted 500 miles before a rebuild, but with custom valves, valve train, rods, rod bolts, head studs, fire rings, pistons, turbo, intake, exhaust, intercooler, etc, etc, I bet it would have been possible.
If I would have had a big dollar budget, I bet I could have reached 500 hp with my CIS. It would have only lasted 500 miles before a rebuild, but with custom valves, valve train, rods, rod bolts, head studs, fire rings, pistons, turbo, intake, exhaust, intercooler, etc, etc, I bet it would have been possible.
#19
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The 935 didn't use CIS nor did a majority of the big HP cars. They used hybrids of several system and most were based on MFI. To increase flow all one did was change the pump curving. My point it Porsche never made HUGE power through a fuel head.
As Don has mentioned there is no way Twin plug adds anything HP wise. If it does it is from a more efficient burn and you can gain a little TQ (like under 10 overall) It purpose has never been one to increase HP rather make a complete burn and be able to back off the timing to achieve the same thing yet allow a little more compression. Instead of timing needing to be so far advanced to make sure the flame is complete in the chamber from the spark plug to the other side of the chamber (remember CIS pistons create a swirl effect as the flame iginites) you run less timing because it flashed both halves of the piston. So complete burn is done with less timing. The real gains come from the ignition systems usually used with the TP and the ability to change the curve to be a little more aggressive down low and back off in the mid and top range based on MAP retard.
As Don has mentioned there is no way Twin plug adds anything HP wise. If it does it is from a more efficient burn and you can gain a little TQ (like under 10 overall) It purpose has never been one to increase HP rather make a complete burn and be able to back off the timing to achieve the same thing yet allow a little more compression. Instead of timing needing to be so far advanced to make sure the flame is complete in the chamber from the spark plug to the other side of the chamber (remember CIS pistons create a swirl effect as the flame iginites) you run less timing because it flashed both halves of the piston. So complete burn is done with less timing. The real gains come from the ignition systems usually used with the TP and the ability to change the curve to be a little more aggressive down low and back off in the mid and top range based on MAP retard.
#24
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No there are several systems, one that uses another cap and rotor off of the cam, then many systems that are direct fire and digital. They use a sensor off of the crank, flywheel etc.
#25
Formula One Spin Doctor
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Twin plug = Drivability? If you mean reducing the need for additional spark advance thereby reducing the probability of detonation, then I agree.
If I pulled the wires off either side (top or bottom) off my twin plugged car, there's no way you could tell just driving around.
If I pulled the wires off either side (top or bottom) off my twin plugged car, there's no way you could tell just driving around.
yes , you can use multiple coils or wastespark coils or twin distributors ala 964..
#26
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i am in total agreement with Chuck. Mine has not been on the Dyno but it scares the Hell out of me. Anyway, check out this guy--I have talked to him several times and he is for real. SPEZIALMOTORER
Good Luck
Good Luck