Quote:
Originally Posted by DavidVizard-GFN
My intake restricted dirt car motor makes right around 370 on our DTS engine dyno and about 330 at the wheels on a Dynojet chassis dyno. (I say 'about' because I did not have time to dig around all the power curves to find the exact numbers but these are close enough). I am using 1 5/8th headers.
Fuel idea is good - it would be interesting to dyno both. The alcohol content is slower to evaporate than typical gasoline front ends. You might want to try blowing down some 93 octane and then add 15% ethanol so that you have in effect brewed your own E85.
DV
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We use a mustang dyno and the power numbers are typically lower than a dyno jet. 72% is what they use for a converstion factor. For now we will be stuck with the large headers but may try them later in the year. E85 is cheating in our class. We tryed 3 fuels right from the pump (except 110 sunoco) The power was almost identical (+/-2 hp) and with the cost of fuel going up e10 makes the most economical sence. The other fact is with a limited engine the true compression is lower because of the lack of cylinder filling so we can get away with lower octane fuel. The new engine is a 377 and has 6.125 rods with honda journals(used nascar rods), the stock forged crank was turned down to 1.88 on the journals. The bob weight is 1581 grams. I wonder what advantages the light weight and reduced journal size will have on horsepower. The heads are some used sprintcar early bowties with titanium valves and I am hoping the by reducing spring pressure we can gain back some more fiction losses. The biggest limitation are the stock cast intake and rochester 2gc (approx 480cfm @ 3.0hg) So not only is there a large restiction the intake also limits air flow. Finally we are only allowed 9 to 1 which is which is just one more bite out of our horsepower cookie. I still wonder what horse power gains could be made with a cam ground spec to crutch the intake. Right now we typically run a 1.6 on the intake and 1.5 on the exhaust and it shows a bump of 5lbs of torque across our very flat curve.
Thanks again for writting the article it has helped alot.
John Ebke