high rpm's for 1/4 mile
Shifting when the power drops off is incorrect. You will go much slower... you need to remember you want to be in the power band as long as possible. When you take into account actual power (mass over time) lower gears will accelerate much more mass faster. On top of that you should want to make sure you dont hit the next gear too low of an RPM. Anyways,
Shift at 8k, stock everything and youll be fine. I do it daily. I will hold the car in 4th till around 8500 if needed to get through the traps on a completely stock engine.
Shift at 8k, stock everything and youll be fine. I do it daily. I will hold the car in 4th till around 8500 if needed to get through the traps on a completely stock engine.
I've said it before and I'll say it again, your posts never cease to amaze me!
Originally Posted by housedj
u will need ARP head bolts cuz the head begins to LIFT over 7850rpm. if you're gonna do cams, get valve springs, valve guides, retainers, lifters, ARP head bolts, & a Cometic head gasket. oh yeah, make sure all your internals are titanium. or you could just do what i'm doing & get a Cosworth built head. Also, Tomei is coming out with some 280 cams that will have 12.2 lift!!!!!!!!! i can't wait to put those in. the Tomei 280 11.8's already make the most power...
Actually, the best shift point between any two gears varies depending on the gear ratios. But always, the best shift point is at the point that allows the greatest average hp to be encountered for each gear. This means one has to consider the power curve where the shift point needs to occur, as well as the power curve where the next gear lands.
It's difficult to illustrate this without a dyno chart and gear ratios handy, but for closer ratios, the optimum shift point usually occurs just after the hp peak. For wider ratios, each gear usually must be held well after the hp peak. Show me a dyno chart, and I'll show you how to calculate your optimum shift points for each gear.
It's difficult to illustrate this without a dyno chart and gear ratios handy, but for closer ratios, the optimum shift point usually occurs just after the hp peak. For wider ratios, each gear usually must be held well after the hp peak. Show me a dyno chart, and I'll show you how to calculate your optimum shift points for each gear.
Originally Posted by Ted B
Actually, the best shift point between any two gears varies depending on the gear ratios. But always, the best shift point is at the point that allows the greatest average hp to be encountered for each gear. This means one has to consider the power curve where the shift point needs to occur, as well as the power curve where the next gear lands.
It's difficult to illustrate this without a dyno chart and gear ratios handy, but for closer ratios, the optimum shift point usually occurs just after the hp peak. For wider ratios, each gear usually must be held well after the hp peak. Show me a dyno chart, and I'll show you how to calculate your optimum shift points for each gear.
It's difficult to illustrate this without a dyno chart and gear ratios handy, but for closer ratios, the optimum shift point usually occurs just after the hp peak. For wider ratios, each gear usually must be held well after the hp peak. Show me a dyno chart, and I'll show you how to calculate your optimum shift points for each gear.
You got half the equation done. The other half is lower gear. Take a 100 TQ car vs a 300 TQ car (All factors the same aside from gearing). Now accelerate with zero slip (clutch, tires, etc) from a dead stop to 30 MPH. Assume the 100 TQ is geared to get to 35 MPH at x RPM and the 300 TQ is geared to hit 100 MPH at the same RPM.... which will get to 30 first? Pretty obvious right... take that same idea and make it alot more complicated but the same equation stands... gearing itself (Lower gears) will make a car accelerate faster to a said speed.... the longer you can hold a gear... even if you are making much less "power" to the ground you are technically accelerating much faster.
If you TRULY want to figure out the exact best shift points you would need to figure out the TRUE power output of the motor through all RPM range. Then take that and multiply it by the final gear ratio... that is the true power to the ground (Obviously we can spin our tires in first but not in 5th). Now my best guess is for pretty much any car, even if it is making much less power on a "dyno sheet" at 9k you are still making more power to the ground technically.
Hope all this makes sense.
Originally Posted by Ted B
Actually, the best shift point between any two gears varies depending on the gear ratios. But always, the best shift point is at the point that allows the greatest average hp to be encountered for each gear. This means one has to consider the power curve where the shift point needs to occur, as well as the power curve where the next gear lands.
It's difficult to illustrate this without a dyno chart and gear ratios handy, but for closer ratios, the optimum shift point usually occurs just after the hp peak. For wider ratios, each gear usually must be held well after the hp peak. Show me a dyno chart, and I'll show you how to calculate your optimum shift points for each gear.
It's difficult to illustrate this without a dyno chart and gear ratios handy, but for closer ratios, the optimum shift point usually occurs just after the hp peak. For wider ratios, each gear usually must be held well after the hp peak. Show me a dyno chart, and I'll show you how to calculate your optimum shift points for each gear.
