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If Im running 30 deg with a rons mfi terminator and I want to change to a gas dominator with vp115, do you think I will need to change de timing on the engine? How much?
Do you think I will have problems with temperature?
The engine is a 557ci BBF with 14.5cr 810hp with SCJ.
 

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Timing -- start where you have it and then start increasing it until the mph falls off. Then back off a couple degrees.

Temp -- yes it won't cool down as quickly running gas and you'll need to run the water temp much cooler than with alcohol.

If bracket racing, gas is affected more with environment changes Vs alcohol.
 

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scj heads oem style i run 35 degrees of timing on gas and alky,, like the alky better ,, more consistant
 

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If Im running 30 deg with a rons mfi terminator and I want to change to a gas dominator with vp115, do you think I will need to change de timing on the engine? How much?
Do you think I will have problems with temperature?
The engine is a 557ci BBF with 14.5cr 810hp with SCJ.
Why are you changing, just curious? Would never go back to gas for bracket racing,
 
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Discussion Starter #9
Why are you changing, just curious? Would never go back to gas for bracket racing,
I bought an used alcohol system and the car has been very inconsistent and not doing the ETs I thought the car should do,
I think it may be this or the converter,so I want to try my old gas carburator and discard the alcohol system first.
The car is running [email protected]/8 and [email protected]/4 2300lb w/driver, 32 tires and 4.56 gears, with 200hp less made almost the same times.
 

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Was the alcohol system you bought matched and properly tuned to the engine it was on? Where are you getting the 200 less number from? Actual dyno? Running a given et with a car takes a given amount of hp. If you change the hp, the et will change. If you have a combo that's making 200 hp less running the same et, and nothing has changed but the hp as you state, then you didn't loose that much hp...that's what you had to begin with, or the combo is completely wrong and not working efficiently together. But regardless, a 200 hp change WILL make a difference in et, ideal combo or not...my guess is the alky system was WAY off for what your engine wanted, as was timing. My car, a dragster, running a 665" BBC, is faster on alky than it was on gas. And it was built for gas.....when I got the new system, it had a baseline for my stuff, but I've had to significantly richen it to make it happy. I'm just playing with timing now, but will likely have to adjust fuel again once I get the timing right....and everything I do the car continues to get faster....

Something had to be wrong with your setup, because most bracket cars will either run the same or slightly quicker on alky than gas....Some may slow slightly depending on the combo. The big thing here is you stated it was not very consistent. That's the biggest advantage to running alky, is it take a much larger swing in weather conditions for it to cause a change in performance. But just like with gas, if the tune is wrong, the car will not be consistent. So based on that, your tune was off by a large margin. Just because a system may have ran well on one engine doesn't mean it will run well on another, especially if they are different combos.....
 

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Discussion Starter #11
Was the alcohol system you bought matched and properly tuned to the engine it was on? Where are you getting the 200 less number from? Actual dyno? Running a given et with a car takes a given amount of hp. If you change the hp, the et will change. If you have a combo that's making 200 hp less running the same et, and nothing has changed but the hp as you state, then you didn't loose that much hp...that's what you had to begin with, or the combo is completely wrong and not working efficiently together. But regardless, a 200 hp change WILL make a difference in et, ideal combo or not...my guess is the alky system was WAY off for what your engine wanted, as was timing. My car, a dragster, running a 665" BBC, is faster on alky than it was on gas. And it was built for gas.....when I got the new system, it had a baseline for my stuff, but I've had to significantly richen it to make it happy. I'm just playing with timing now, but will likely have to adjust fuel again once I get the timing right....and everything I do the car continues to get faster....

Something had to be wrong with your setup, because most bracket cars will either run the same or slightly quicker on alky than gas....Some may slow slightly depending on the combo. The big thing here is you stated it was not very consistent. That's the biggest advantage to running alky, is it take a much larger swing in weather conditions for it to cause a change in performance. But just like with gas, if the tune is wrong, the car will not be consistent. So based on that, your tune was off by a large margin. Just because a system may have ran well on one engine doesn't mean it will run well on another, especially if they are different combos.....
The person who sold me the system said he was using it on a 598ci I think, is a 1060 terminator with a 0-1/2 twing gear pump, according to killerrons this pump is for 650-1050hp.
The engine when we bought it new was a 521bbf from ford motorsports, they didnt gave us a dyno sheet but in every website I see that engine the infosays [email protected] and [email protected], this setup was used with a gas dominator and vp c12 fuel and running [email protected]/8
About a year ago we send the engine to the shop and now it is a 559 and the dyno showed [email protected] and [email protected] with the alcohol system. I also send the converter to hughes for a refresh and to adjust it for the new engine but they said that the converter was ok for the new numbers, but with the 600hp the converter stalled at 5500 and now it stalls at 6300 at least(took the chip off and tried it with the transbrake)
The person who built the engine told me not to run more than 6500rpm(using 6300rpm chip now), the problem is my rpm at the start is 4500(Ive been trying between 4000 and 4500) and the car almost immediately reach 6300.
A few weeks ago I change the 4.56 to a 4.11 but the racetrack havent open yet.
One day at the track I made 4 passes, 1.- 6.33, 2.- 6.19, 3.- 6.32, 4.- 6.15 and is very frustrating to be .001 at the tree and run a 6.32 with a 6.20 index, and then run a 6.15 with a 6.31 index
 

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I'd say your issues aren't due to the alky, but maybe a converter/gearing issue. Don't run your engine above 6500 rpm? That doesn't make sense. If your converter is stalling at or above 6300 then it's too loose for the combo.
 

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Your conv is not right for your application. You've gained nearly 200 lb/ft of torque increasing the displacement and adding alcohol. THAT is going to cause the conv to stall at a higher RPM. Alcohol, by itself, in most every case, increases torque.

If it were mine, I'd opt for a different conv builder and shoot for a 5200 to 5500 max stall.

The gear change to 4.11's is very well likely going to cause the existing conv to stall even more.

Tell us what is the water temp you are staging at (with alky).

Here are proven techniques that I developed for my alky burner (injected) 406 small block, that made it consistent as hell and others adopted and had equal success:

-) water pump on when the engine is running (critical)
-) starting line / staging water temp 175-180* ..... (alky likes heat)
-) use the elec fan to only modulate the water temp
-) need to see a 10 to 15* increase in water temp at the end of the run. This indicates that the WOT jetting is near perfect, not too fat and not too lean. **Note, if you aren't running a high-speed lean out, you ought to invest in one. I had one on my car.

Hope this helps --
 
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