Speed vs. RPM table for all gears with both stock and Stillen rear ratios

[BlackICE]

The tire diameter was worked out using actual data logs from the Mojave mile. My rev limited is set to 7000 RPM and using that and my Driftbox data I determined the effective tire diameter (at high speed) of a GY tire to be only 27.92" not the published 28.9 number. I hit the rev limiter in 5th at 194.3 MPH. I held it there too long, more than 1.5 seconds, because I thought I could break 200 in the gear. Another owner with the very similar setup did, but he was running Hoosier. Tire slippage of 3.5% under the load could account for some or all of the discrepancy. Another reason why stock speedos may read low.

The stock rev limiter is set 6600, however many aftermarket tunes use 7000, or 7200 and some even 7500 with built motors. I think Ray's is over 8000!

Note that if you are using tires other than the stock GY your diameter thus speed will probably be different.

 

[Apollo]

Cool Clinton,
Looks pretty accurate.
Can I get you to email this to me?
TC

 

[BlackICE]

Cool Clinton,
Looks pretty accurate.
Can I get you to email this to me?
TC

I sent you the xls file.

 

[Apollo]

Thank you!:thumbsup

 

[ChipBeck]

Stock gearing, 7200 RPM in 5th gear = 232.0 MPH. Come to Papa!!

Chip

 

[BlackICE]

Stock gearing, 7200 RPM in 5th gear = 232.0 MPH. Come to Papa!!

Chip

Chip, I hope you hit the rev limiter in 5th in TX. :wink

I did at Mojave, but had the 3.90 gears had to shift into 6th.

 

[Mullet]

I'm not sure the stock graph is correct. I have run 226 at the Texas Mile in 5th (I have never used 6th at the Mile) and my redline is set at 6500.

Stock size Hoosiers.

 

[soroush]

I'm not sure the stock graph is correct. I have run 226 at the Texas Mile in 5th (I have never used 6th at the Mile) and my redline is set at 6500.

Stock size Hoosiers.

must have been that 10mph tail wind that day:lol

you probably have the rev limiter at 7000

 

[RALPHIE]

At Rally IV at Goliad (with an FRPP pulley and tune) the rev limiter on 1st and 2nd was around 6,500-6,600 rpm, but in 3rd and 4th, I was able to get to 7,000 rpm without hitting the limit. Just some info....

 

[PL510*Jeff]

Stock gearing, 7200 RPM in 5th gear = 232.0 MPH. Come to Papa!!

Chip

That's a 10-4 big guy, with a little tire growth it could be a 233.

 

[BlackICE]

I'm not sure the stock graph is correct. I have run 226 at the Texas Mile in 5th (I have never used 6th at the Mile) and my redline is set at 6500.

Stock size Hoosiers.

Sandman did a 205 run with the same 3.9 gears, but with Hoosiers not GY. So I would say that Hoosiers run bigger at the mile. I will have to double check is what his rev limiter was set to, either 7000, or 7200. In either case Hoosiers are bigger.

Ralphie I don't understand how the car has different rev limits for different gears. What you must have observed is the lag time of the tach in the lower gears, not what the engine was really doing. The tach needle moves real fast in the lower gears. :lol

I never even look at the tach, but installed a shift light instead.

 

[B.M.F.]

I see a new 60-130 option. second gear start, 4200rpms to 9000rpms NO SHIFTS:biggrin Anyone interested in hearing a GT @ 9grand:rofl

I have the data spread sheet from ford on gearing and rpms saved in my computer, Its on here too i believe, so I kinda new this option already.

Some ones gotta do something, Peter's Lambo just went 3.61 on the street 60-130. 2.77 100-150. 1400hp in 3rd and 1550 in 4th. Damm that's fast.

 

[soroush]

I see a new 60-130 option. second gear start, 4200rpms to 9000rpms NO SHIFTS:biggrin Anyone interested in hearing a GT @ 9grand:rofl

I have the data spread sheet from ford on gearing and rpms saved in my computer, Its on here too i believe, so I kinda new this option already.

Some ones gotta do something, Peter's Lambo just went 3.61 on the street 60-130. 2.77 100-150. 1400hp in 3rd and 1550 in 4th. Damm that's fast.

I would imagin if you can pull it off, one gear 60-130 with big power over 1000 to the wheels and stick you can get sub 3 sec times.

 

[B.M.F.]

Also I went 192 on chassis dyno (Dynojet 248) in 4th with pirelli 355-25-21 tires @ 7200rpm. So it looks like about 4mph off @ that speed with pirelli's versus stock tirs and im suprised the stock tires don't grow that much. You can see my tires grow on the chassis dyno.

Soroush I ordered a 4.350 stroke crank for more Stroke. 374cubes of mod motor is coming, then it will have more torque down low also.

 

[RALPHIE]

...Ralphie I don't understand how the car has different rev limits for different gears. What you must have observed is the lag time of the tach in the lower gears, not what the engine was really doing. The tach needle moves real fast in the lower gears. :lol....

I don't pretend to understand it either, but the data seems to fit your table, as I was clocked at 179.984 at Goliad (OEM rear end ratio; fairly new GY rears), and stayed in 4th gear through the timing lights. And I know that the rev limit in 1st and 2nd is at 6,500 rpm, as I've often hit those if not watching my tach shift points. We've also been told that the FRPP pulley and tune doesn't modify the speed limiter, but it seems to play with the rev limiter.

 

[Mullet]

must have been that 10mph tail wind that day:lol

you probably have the rev limiter at 7000

stop it. there was no tailwind that day. what about the 223 the day I beat you at the last Mile....was there a tailwind?

Dynos on my car show 6500 and the software says 6500.

 

[skyrex]

Interesting graph and it makes sense. I have a 7,200 limiter and on one of my 231+ I hit it shortly before the finish so 232 sounds about right for the end of 5th. On the other 231+I went to 6th earlier to try something different. (the one on the video)

So I gearing wise I can get to 282 in 6th?? That is crazy. I guess I am asking that on a long enough road (like Bonneville which I would never do) the car can do 282?? Ice I would like that file as well please.

 

[dbk]

Here is the speeds in gears chart. I extended the lines to reflect higher than factory rev limiters. It's about right. Whenever Ray has blasted down the runway it's always in 5th all the way into the 260s.

 

[HHGT]

Mach 1 !!!

So what would it take to do Mach 1 in the GT?

How much HP?
What gears?
How long of a road?
Which Tires?
Can the windshield take the speed?
Aerodynamics & Downforce compliant?

And, will Ray be the first to do it?

 

[Kingman]

So what would it take to do Mach 1 it?

So Sammy........you planning on being the Chuck Yeager of the Forum::driving: