Top Speed
08-19-2009, 03:54 PM
#24
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Here are my "How much HP does it take to go how fast?" and "How fast can I go in each gear?" calculators.
Please keep in mind that it is the HP produced by the engine at the RPM it's spinning at a particular vehicle speed that is the limiting factor--not the peak HP unless the RPM at which peak HP happens, happens to be the speed the engine would be turning at the indicated MPH.
For example, looking the How much HP... chart, you can see that it takes 207 HP to sustain 150 MPH, and if you look at the RPM numbers (in blue in the second column) you will see that with a T3650 in 5th gear the engine wil be turning 4250, 4850, and 5330 RPM for 3.27, 3.73, and 4.10 gears.
Now look at a dyno chart for a stock new-edge GT (mine will work, click here) and you'll see that at 4250 RPM the engine is only putting out 180 HP or so, 27 HP less than needed. At 140 HP the required HP drops to 170, pretty much inline with what would be expected at the 3840 RPM a stock GT would be turning in 5th at 140 MPH.
OTH--a stock GT with 4.10s would be spinning 5160 RPM at 150 (which requires 207 HP) and would likely be producing 215 to 220 HP at 5160 RPM and therefore hit 150 with a bit to spare.
Top speed on our cars is mostly limited by HP, not redline. Even with 4.10s you'd have to be putting out 350 HP or so, at redline, before you'd hit run out of RPMs in 5th--at 180 MPH or so...
Please keep in mind that it is the HP produced by the engine at the RPM it's spinning at a particular vehicle speed that is the limiting factor--not the peak HP unless the RPM at which peak HP happens, happens to be the speed the engine would be turning at the indicated MPH.
For example, looking the How much HP... chart, you can see that it takes 207 HP to sustain 150 MPH, and if you look at the RPM numbers (in blue in the second column) you will see that with a T3650 in 5th gear the engine wil be turning 4250, 4850, and 5330 RPM for 3.27, 3.73, and 4.10 gears.
Now look at a dyno chart for a stock new-edge GT (mine will work, click here) and you'll see that at 4250 RPM the engine is only putting out 180 HP or so, 27 HP less than needed. At 140 HP the required HP drops to 170, pretty much inline with what would be expected at the 3840 RPM a stock GT would be turning in 5th at 140 MPH.
OTH--a stock GT with 4.10s would be spinning 5160 RPM at 150 (which requires 207 HP) and would likely be producing 215 to 220 HP at 5160 RPM and therefore hit 150 with a bit to spare.
Top speed on our cars is mostly limited by HP, not redline. Even with 4.10s you'd have to be putting out 350 HP or so, at redline, before you'd hit run out of RPMs in 5th--at 180 MPH or so...
08-19-2009, 03:56 PM
#25
2nd Gear Member
Join Date: Jun 2009
Location: IA
Posts: 181
agreed... if it's at the track thats one thang but on the street? IDk bout you guys but if ya wanna kill yourself but please don't drive insane around me because I value my life like others out on the road whom you zip by at XXX + speeds. Tho I understand everone needs that feel to see how far they can push it. Watch out for em Cop 'ers tho.
Last edited by BlueMagic; 08-19-2009 at 03:58 PM.
08-19-2009, 07:23 PM
#26
2nd Gear Member
Join Date: Apr 2009
Location: Near China now...
Posts: 314
I've hit 186 (GPS verified) with my old KB setup. 18 psi 550rwhp, 3.55's, 5th gear 5600 rpm and still pulling. I know I can hit 200+ easily in 5th now provided I had 5 miles or so of road to slow down on.
NOTE TO ALL: Please do NOT attempt a high speed runs on any public road. Take them to the Texas mile or Bonneville. Bragging points aint worth your life. There is a reason that magazines dont test cars for top speed anymore.
NOTE TO ALL: Please do NOT attempt a high speed runs on any public road. Take them to the Texas mile or Bonneville. Bragging points aint worth your life. There is a reason that magazines dont test cars for top speed anymore.
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