Top Speed: 4.055 vs 3.555 Mirage final drive swap...

[7milesout]

No spotter.

[Wallythacker]

No spotter.

Ok. You have your reasons I'm sure. I just don't want to see a friend I haven't met yet get jammed up.

Here's a page that might be of use. Calculates all sorts of goodies for you.

https://businesspath.com/business_pa.../rpm-calc.html

[7milesout]

It is between 2 exits. I'm going to drive it the first time at normal speeds and check it out. Turn around, drive it going back at test speeds. Turn around, drive it back at test speeds going away. And if I'm feeling lucky, 1 more time as I turn around to go home. I'll have waze and a really good radar detector keeping lookout for me.

[Top_Fuel]

Once you are caught going 93.1 MPH or faster, its: $10,000 Ticket, 30 day license suspension...

That's un-American!

[7milesout]

Well, let me just say: I would NEVER EVER purposely go even 1 mph above the speed limit. It is most definitely imminent death to myself and everyone around if I ever did.

Secondly, let's just say that my research *activity* is complete. Now the documentation portion of the research has to be completed. I don't want to speculate, just yet.

But I will say this: My results will not be official. There were too many variables (wind & traffic mainly) and not enough flat asphalt. However, the results shall be a really close measurement. To circle back, there was WAY MORE traffic than I expected. But not enough to totally prevent research. I just had to look for openings in the lab, so to speak.

It will be tomorrow before I post numbers. Let me say that, I felt a bit guilty as I left the testing & research facility. As maybe about 5 or 6 speeders (how dare they) were receiving awards. Yeah yeah, I know what you all are going to say, that I wasn't speeding, I was doing research. While true, I'm going to go out on a limb and say that those speeders weren't doing nearly as much "research" as I was doing. And yet they got rewarded, and I didn't. In reality, it actually didn't feel fair. In my 20's, I might have thought, "ha ha, screw them!" But now in my 100's, I'm a bit more prehistoric in my thinking. (Perhaps not THAT prehistoric, or I wouldn't have done this research).

Maybe I made more provisions for reward prevention? It helps to be prepared. I have "research" video too. Maybe we should discuss whether it gets posted or not. I'm thinking ... not. At least one interesting thing. While researching, something on the car had a very loud buzzing. It was fairly loud. It would buzz and go. Something, like a mirror housing would hit a resonant frequency via the force of the wind. Scared me the first time.

I donated an entire tank of gas to this effort. It was worth the time away from home as the rattlesnake-in-law (and her sister, the aunt-in-law) were at my house.

[7milesout]

Well, I got kind of screwed on the video. The only drawback to this dash camera I have is the battery dies after about 36 hours (sitting). And it defaults to 1/10/2018 or so when the car starts. And I didn't notice it had done that before doing this research. So, I lost a portion of the research, somehow, due to this date default.

DATA:

I believe the top speed of a nominally running 4.055 geared 5MT Mirage to be ... 110 mph. Faster than I expected. Germans beware. These N.A. Mirages are BUILT like racecars (especially the blue ones)! foama may want to slip a 4.055 ratio into his to be the SpaceStar big dawg on the Autobahn.

• In one direction I was able to top out at 107 mph.
• The other direction I was able to hit 113 mph.
• 4th gear I was able to pull 6,600 rpm. And it might have went a bit higher, but I shifted to 5th to protect.
• 5th gear will add a few mph over 4th gear.
• 5th gear I hit ~5,750 rpm when hitting 113 mph. Which makes the speed per gear graphs not very accurate.
• Something on the car made a buzz (that came and mostly went) in the 100+ mph speeds. Sounded like maybe the left mirror housing.

Those of you who are planning to use a Mirage as a getaway car, I wouldn't even bother with 5th gear. Unless you find yourself on a long desolate interstate or desert run with no traffic. 4th gear is only maybe 4 or 5 mph slower. And is the "gear of choice" for best performance at 65 mph and above.

It topped out and I let off before the bunny slope just ahead.


So yeah, I felt a little guilty for the speeders who were "rewarded" by the Georgia State Patrol, who were not likely doing nearly as much research as I.

[Wallythacker]

I congratulate you on Nobel level research and applaud the fact you didn't win a participation Trophy from Georgia's finest. (They are the finest right?) I suspected our crazy little beasts had serious legs but I never realized we could chase McLaren F1's down on the Autobahn.

Extrapolating 113 mph @5750 rpm gives us 148 mph @ 7,500 rpm or 177 mph @9,000 rpm. But what could possibly allow our little 78 hp engines the ability to turn ever higher rpm when they are running out of power? More power? Watson, I have it. A turbo. Better yet, a supercharger for immediate response. Who needs lag when the F40 pilot just had the nerve to high beam you in the left lane?

We're going to experience 4x the drag if we double our speed so we'll only experience 2x the drag if we merely go 50% faster, from 113 mph to 170 mph. Doubling the hp should in theory allow the higher speed, but.... to be safe we'll quadruple our HP as well. Now we're looking at 300 hp required. Didn't I just see a u tube vid recently with a turbo Mirage pulling the mid 200's HP not long ago? That might be enough power if we add some aero tweaks and lose some weight.

We haven't even slipped the Euro differential in yet. We get a nice 14% drop in rpm or a boost in top end speed just from that! So our wundercar with mid 200's HP and 3.555 ratio should see us moving along at about 168 mph @ 7,500 rpm. Not too shabby. Can the engine take the stress of 7,500 rpm? I recall reading someone had on many occasions spun the engine that high without damage. How the limiter didn't kick in amazes me.

7, seriously, thanks. I've always wanted to build a killer super oddball car. The Mirage fits the bill. I have the time and skills, the big variable is health. If it continues to improve I just might be able to build something interesting.

[25Plus]

I did only 2 or 3 tests with my Space Star 1.2 with 3.55 final drive and manual transmission. It reached without problems 183 km/h/114 mph (GPS, about 190 km/h on the speed indicator) on a flat freeway and another time it hit 195 km/h on the speed indicator several times on a hilly freeway (5th gear). Of course this was no speeding in Germany.

[7milesout]

Unpossible I says!

[inuvik]

I did only 2 or 3 tests with my Space Star 1.2 with 3.55 final drive and manual transmission. It reached without problems 183 km/h/114 mph (GPS, about 190 km/h on the speed indicator) on a flat freeway and another time it hit 195 km/h on the speed indicator several times on a hilly freeway (5th gear). Of course this was no speeding in Germany.

I'm eager to see some video "research" with these scenarios!