F-Body Europe

Rob Said
"Roy your calculator is great if we were operating in a vacumn, but there is alot more going on than gear ratio/tire diameter/power. "

Touche

Actually Rob your looking at it too hard and trying to read between the lines.

All it is a simple electronic slide rule table for figuring absolute speed . example I drive in 5th gear to 6200 rpms. my speed for that given rpm is 181 mph on paper. But also factor in tach error of plus or minus 100 to 200 rpms from the guage, then you have nice window to work with.

Now if you want to consider elevation ,barometric pSI , tire pressure ,rotaing inertia mass, wind, vehicle height, cd, frontal area plus about 150 other varibles I can do that to. Also If you want to throw a dyno graph in there with 500 rpm increments. I can do that also. But it took some one smarter than me to do it.

Well I've personally have been in Willis's car w/ the auto x-ray and that sucker had 174 and climbing! But I will admit his car felt scary at that speed not stable at all IMO. Mike and I on occasion would bury the pedal on A6 past the 155 range but those speedo's could be off. In my old setup running w/ a 911 we we close to 170. Only reason I knew I went that fast is because I spoke to him after the run. It had a little more left in it but never got to try it again because she died shortly after that.

and i believe that is a must if you are creating a speed calculator. The physics involved is staggering,(and hardly measurable or repeatable between cars or times) that is why nobody this side of NASA and Deep Blue has a calculator with any measurable degree of accuracy. Kinda a we know we arent going to be right, just how less of wrong can we achieve. Finding speedo error is easy. Nothing more than known distance armed with (tire dia/ gear ratio/engine speed/time) finding how bad that error snowballs with speed for each auto is something else entirely. Consider that Schumi and the gang running bass akwards off turn 4 down the front straight in indy is barely tickling 200mph is very telling. They have plenty more giddy-up and exponentially better aero than we do.

The absolute only way to verify is with sometype of closed track and a timing system. So I guess we can agree to disagree on calculators, but if thats all you got, you should feed in as much good data as you can IMO

sorry I stole your thread Da....Rookie
Rob

No big deal. Good info anyway...Mike

All arguing aside, what ever happened to just congratulating someone on a nice picture/achievement? Why does everyone distrust everyone else? It seems like everyone has something to prove as if they know it all and no one else can be right or show something different! All I know is my car bounced off the rev limiter in 5th gear. Now if that is 50 mph or 500mph it doesn't really matter to me, I know I was hauling *ss! It sounded like the t-tops were going to exit the vehicle at any second. I have never seen most of your vehicles, but when you talk about the mods you have and things you have done I believe you because one day I may run into you and if you were lying then you are the one that will look and feel like an *sswhole, not me.

Like I said I am not trying to flame, just voicing my opinion on this matter. Peace

Hey, I know what I've done in my car, and he/she knows what they did in his/her car!! I'm not saying that you have to believe anyone, but you know what I'm sayin'!!

This "brick" here needed 600 hp to hit 200mph check it out.

-----> http://popularmechanics.com/automotive/ ... rint.phtml

wind resistance increases exponentially. Once you get to 100mph things begin to change.

you are missing my point Krazy/Jack/and whoever else is going to try and argue with hard science. I never doubted anyone saw what they saw, and I very well know what the cars do/feel like on the autobahn, I was the second american in Germany to get a 4th gen way back in 94. In 6 years yeah I've buried the speedo a couple times.

It isnt about me being right I'm just one of those people that ask questions and dont just accept things just because. I like to prove it.

In closing I just want to say that the speeds your speedometers/scanners, or that really fast guy with the new nikes running besides you is giving you, is bad data. Are you guys some of the fastest cars prowling? Without a doubt, but I wouldnt bet my life on the numbers your believing.

as a last final parting shot, look in the current issue of GMHTP, you know the guy with 450rwhp who figures he can run 175mph at the top of 5th at 7000rpm even if it did pull 6th (big if, do the math for drag he has to overcome to accelerate) how fast do you believe he can go?

There is also a old GMHTP mag w/ a 383 S/C color burgandy. He had to have 2.73's installed to hit the 200mph barrier. They clocked him on a closed circuit and a highway out in Montana. 600+ rwhp to do it. Only one person here w/ 2.73's but his numbers are not even close.

So the debate is still out.

I'm just arguing hard numbers against "hard science". The fact remains that if you have done it then how can you even start to doubt it? Here is how......

I will add this to the discussion;

1. I have always heard that an LT1 Camaro that went to red line in 5th gear was going 160 mph.

2. I have always thought that red line on an LT1 Camaro was 6,000 (or is it 5,700?)

3. Using Roys gear calculator - 6,000 rpm in 5th gear for my car is 181 mph, and 5,700 rpm in 5th gear is 172 mph. This of course blows my believes out of the water!?!?

4. Dark Angle has video proof of his car going 187 mph, which was him hitting his red line in 5th gear. I have watched the video and talked to the passenger!

5. Now with my tire ratio it would mean that I would have to hit 6,200 rpm to go 187 mph in 5th gear, using Roys gear/speed calutator.

So here are my questions;

1. Has anyone else heard that red line in 5th gear is 160 mph?

2. What is red line for an LT1 and a LS1?

3. I honestly do not believe that my speedo is off so much that I would gain 20 mph in 300-500 rpm. So how can the gear calculator say I would be doing 20 mph faster than I am guessing? And don't give me the crap about drag because it has nothing to do with the hard numbers I am talking about, as in drag does not effect your speedometer!

4. Are the gear ratios the same for LT1s and LS1s? As in the transmission gears. I know the rear end gears are the same.

5. If so explain to me how Dark Angle is going 187 mph at red line in 5th gear (he may have raised his red line?) But an LS1 is supposedly only going 160 mph, unless you use the gear calculator and then depending on what the red line is either 172 or 181 mph for the LT1. Now I know Dark Angle had after market gauges, but I truly doubt they could be off by that much.?.?

This is not intended to flame anyone, just a few open minded questions. Hell if you read the questions I am actually questioning my one thoughts and believes.

Krazy
Your car is exactly like mine except for year and combo . Our tranny ratios ,axle ratios and tire sizes. are identicle.
The speed calculator shows you what speed you can achieve at a certain rpm. you just have to insure the rpm shown on the guage is actually the rpm your engine is turning.

Roy - that is my point. I would think that even if the tach showed the wrong number, which it did because it bounced off of the rev limiter in 5th gear at just a hair over 5,500 rpm, that the computer would know what the true rpm was and that would mean the cars rev limiter would activate at the same time every time, give or take a 100 rpm or so. Meaning the computer does not read the tach to know when to start the rev limiter it uses the crank/pickup sensor to sense rpm. Not much error there! At this point I just really want to know, was I going 160 mph or was I going more or less? It would be a dream to say I was truly going 181 mph. One of my goals in life is to go a true 200+ mph. May sound stupid to some people, but it is a goal of mine. Call me Stupid or just KRAZY

With the LT1 and stock gearing top speed was achieved in 5th gear because it will not pull 6th gear. Your speed will drop if you shift to 6th at high speed. If that is what you mean.

And if the calculator says you can do 187, than there's no reason to doubt it.

You are correct, my limiter has been raised to 6200 RPM. I HPP3ed it, as well as the speed limiter. When Jr and I did the run, we bounced of the rev limiter in 5th. Your right Rob, shift into 6th and speed and RPM drop to about 160 and 3500RPM. Not enough balls to pull. Like Tracy said, it sounds like a tornado or freight train is going through the car and every window is goign to blow out. But it's a rush.
What HP am I putting out? I don't know. If they numbers from other '01 are good and my mods, I am guessing about 315 - 320 at the rear plus whatever the FTRA gives my at the top end.
There are alot of other variables to look at. for example, road gradient, wind directing, and air temperature. All of these could cause skews in the HP curve that wouldn't show on a dyno.
I like to talk crap, but I don't lie or make other believe things that aren't true about my car. All I can say is I was in 5th gear bounced off a programmed 6200 RPM limiter and my speedo was reading about 187MPH. It was done with the car moving and not strapped to a dyno, I have video and 2 independant people who have been in the car while doing this. One of them being on this board.

So Lets get back to Krazy's question?
Where is the rev limiter and the speed limiter set on a never touched PCM for a 97 LT1?

On a 2001 with the Z rated tires from the factory the Rev limiter is 5500 with a speed limiter set at 162.

5700 rings a bell for me on a LT1, but either way, the rev limiter is less than 5900.

Also stay off the stock limiter. It does limit your revs, but not in the most healthy way.

My SS hits it at about 61/6200 rpm, but I am not the original owner so I don't know if the computer has been tampered with. Now I wish I would have looked but I burried mine several times on the Bahn with no problem, forgot to check the rpm's though. I was to nervous to look down at the gauge...Mike

Is there a speed limiter on the LT1? Now that Dark Angle mentioned it on the LS1 I believe I heard some where that the LT1 has a 160 speed limiter? That could be what I hit. It would make a lot more sense to me because like I stated before my tach showed 5,500ish when it bounced. Using the gear claculator it shows at 5,300 = 160 mpoh, 5,400 = 163 mph and 5,500 = 166 mph. Now giving for tach error I could see a 5,400-5,500 on the tach easily and it actually be 5,300 which equals 160 mph. That would truly make me belive the gear calculator much more because as I stated earlier I just can't believe that I gained 12-21 mph in the short time after my speedo hit the stop needle. Just a thought. Anyone know for sure?

P.S. I find this very informative and apprieciate all of the info you guys are providing. Thanx