Something I really have to think about... I do drive my car on the highway a lot. I like the fact that I can cruise at 65 mph in 6th gear and only be doing 1800 rpm's.






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Depends on where you have to shift with four tens. If your shifting at the stripe there is no point.

Roger

 

I'm just following what most of the big shops have done for gears.

CooBra07 you could step up to 3.73's and it wouldn't make a big difference on your RPM's. A lot of guys on TeamShelby.com recommend gears as a first modification.

 

Be careful, this guy is running 4.10/1 gears and they were too low, he was having to shift into 5th in the 1/4 mile. His solution was to get the tallest MT drag radial tire he could P305/45R18.

He still has to launch at 1800 RPM.

BTW:
He is running 11.43 @ 127.24

http://glasshousefarms.com/cars/GT500Drag/


Just a few random gear related thoughts...

I like being able to drive a 500 horsepower car on the street that is quicker than most and still consistently gets over 22 miles per gallon on the highway.

Since you can exceed every speed limit in the USA in second gear doing 80 MPH with the 3.31/1 gears, lower gears would be more fun on the street. For the 1/4 mile I believe 3.73/1 or 3.90/1 would be the ideal gear ratio. Coincidently, Shelby seems to think the 3.73/1 is ideal.

 

Yeah...If I was contemplating a gear swap I think I would go with the 3.73's instead of the 4.10's.




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That is an awesome looking Shelby ! How much horsepower is he putting out? Do you know what his 60' times are.? He's running 11.43 in 1/4 with the 4.10s....thats makes him 2 tenths quicker than my car and I'm running the 3.31 gears, though he is running 7 mph more...

Something is just not making sense




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You're asking a basic physics question. HP is a simple calculation if you know how much weight was moved over a known distance in a known amount of time. So, to answer your question, a 120 mph trap speed (what you ran) in a 4,000 lb car (your car w/you in it, right?) requires 475 RWHP. Assuming a 15% drivetrain loss, that 475 RWHP equals roughly 560 HP at the flywheel.

On a side note, with proper gearing and traction, your 120 mph trap speed indicates that your GT500 could run 11.30's without adding any more HP.

 

JUST FYI....HAVE FUN
http://www.dragtimes.com/horsepower-...calculator.php

 

I would think it should only take around 500rwhp to get into the mid 11's. A Supercharged GT with between 450-500rwhp and get into the 11's

 

just get it dynoed and you'll have your answer. awesome time btw with the minor bolt one's you have on it now.

 

Hum, according to that calculator 400 extra pounds takes 60 extra horsepower to move to the same 1/4 Mile Time & Trap Speed...

100# = 15 Horsepower

1/4 mile time: 11.43
Trap Speed: 127.24
Weight of vehicle
with driver (pounds): 3600
Horsepower @ flywheel = 527.65 HP

1/4 mile time: 11.43
Trap Speed: 127.24
Weight of vehicle
with driver (pounds): 4000
Horsepower @ flywheel = 586.27 HP

If you compare the cost and effort of dropping 400 or 800 pounds versus adding 200 or more horsepower to these mod motor Mustangs, adding horsepower is clearly the easier way to go...

 

Case in point: my supercharged 07 GT automatic coupe only puts down 351 rwhp, yet goes 12.30's at 111 mph in the 1/4 mile. Another 100 rwhp and mid 11's would be a given.

 

The stage 2 Kit according to Evo w/ 93 octane tune adds 145 RWHP.
Factory RWHP is what 450?
450 + say 120 since you have 91 octane = 570 RWHP.
Remember, you're close to sea level (compared to some) so that helps a bit.
I have the same kit as you do. 3.31 rear is factory and I have 91 only octane.
No dyno sheets right now. Sorry.

 

A GT supercharged is much lighter then a GT 500.

 

ote=o7 tungsten;5676326]just get it dynoed and you'll have your answer. awesome time btw with the minor bolt one's you have on it now.[/quote]


Thanks...the car is fast with just the bolt on's that I have on it now, I think my next mod will be the botton pulley which should give me about 4 more pound of boost.

If I do that I will have to get the car dyno tuned...





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Thanks for that but, I am getting different numbers with this ET Calculator..

Check it out >>>http://www.rpmoutlet.com/dyno.htm


according to the calcualtor im putting out 539rwhp...

your ET Calculator says im putting out 518 FLYWHEEL hp...



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Wow...that translates to some nice hp to the flywheel. I have pretty much the same bolt on parts from their stage 2 JLT combo package...the only thing I don't have is their tune.



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I tried Evo, VMP and Brenspeed tunes and brenspeed by far seem the most responsive. My car came from out east so, it may have been tuned for a different altitude and octane with the Evo/VMP tunes I'm nto sure. The Brenspeed was a mail order update.

Does your supercharger come on about 3000 rpm's when reving in neutral?

Try 570 with the calculater..is it close?

 

I think 540 rwhp is much closer.

The supercharger comes on at around 1500 rpm...Is that to soon???




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1500 if it's in gear with a load (heavy acceleration) then maybe...

ok on 540!

On your clips, are you in 3rd at the 1/4? You get a good launch without wheel spin.