Top speeds?

[porscheboy16]

I tried searching for this info, but I could not find it. What is the top speed per gear for a stock '84 Carrera w/ 915 tranny?

[SpeedracerIndy]

While we're on the subject: What's the top speed of 81-83 EURO SCs? I have heard that RoW 915s had a taller 5th gear. Anyone?

Didn't all Carreras have a top speed of 149mph with the G50 or 915?

[jmarenas]

Had it up to 148mph at 5,000 rpm in 5th last week, 1987 911

[porscheboy16]

Thanks, but I want per gear speeds. For example, 1st is 30, 2nd is 58, 3rd is x, etc. They had it in an old Road and Track (Jan. 1984), but I cannot find mine.

[SpeedracerIndy]

I have my father's 88 Targa factory manual in front of me now and there isn't a table with exact numbers. There is a transmission diagram in the back of it and the best I can do is estimate. It looks like 1st is 40mph, 2nd is 66mph, 3rd is ~100mph, 4th is 125mph, and 5th is ~155mph. I am using 6500 as the redline. Among many other things, it lists the top speed as 149, 0-60 at 6.1sec, and 1/4 mile at 14.4sec.

[djmcmath]

I can concur experientially with CDierks' numbers, at least for the first 4 gears. Haven't made redline in 5th, though, so I can't help you there. However, 1-4 sound just about like what I've obtained on the track.

Dan

[Neilk]

Originally posted by jmarenas
Had it up to 148mph at 5,000 rpm in 5th last week, 1987 911

Is that indicated or measured by a GPS? My mom's old '87 TL targa had an extremely optimistic speedometer. It was off by a good 10-15%.

[Jack Olsen]

Originally posted by CDiercks
While we're on the subject: What's the top speed of 81-83 EURO SCs? I have heard that RoW 915s had a taller 5th gear. Anyone?

The Euro SC came with the 915/62, which was the same as the 915/63, except a shorter 2nd and a taller 5th.

Here's how its gearing works out, assuming 225/50x16 tires:

Originally posted by jmarenas
Had it up to 148mph at 5,000 rpm in 5th last week, 1987 911

Depending on what tires you are running, you were probably going about 141 mph. Still -- be careful out there, man.

[SpeedracerIndy]

Originally posted by JackOlsen
The Euro SC came with the 915/62, which was the same as the 915/63, except a shorter 2nd and a taller 5th.

Here's how its gearing works out, assuming 225/50x16 tires:

Thanks Jack! I've been wondering about that for a while. So... if I'm reading that chart right, if I could get my SC to 7000 RPM in 5th gear, I would be going 170mph!!!! That's scary!

[jmarenas]

running 255-40-17 Rear
205-50-17 Front

Speedline RUF wheels. 148 was NO PROBLEM, Car lowered to 23" top of rear fender, about 3" clearence front to back even.
Look foward to NEW TIRES Goodyear F1 all around to max it out.

[goat]

148!!
That is too scary for me. Plus I think my mirrors would tear off way below that speed. I'll just look at Jacks chart and pretend. Zoom---

[masraum]

Tim, 148 is no problem. I've had my '88 up to somewhere between 6200 and 6300 rpm in 5th which is about 150 - 152. Got to about 145 once with the top off, that was scary! Kept waiting for the back window to stay behind.

[rs911t]

Carquip in Denver has a handy spreadsheet you can download.
http://www.carquip.com/parts/gchart/index.asp

[Jack Olsen]

Originally posted by jmarenas
running 255-40-17 Rear

148 was NO PROBLEM...

I'm not saying the car can't go 148. But at 5000 rpm, with those larger tires, you're still only doing 143.

Look at me, 'only 143,' (This from a guy who's 911 only goes 136.)

[Jack Olsen]

Originally posted by masraum
Tim, 148 is no problem. I've had my '88 up to somewhere between 6200 and 6300 rpm in 5th which is about 150 - 152. Got to about 145 once with the top off, that was scary! Kept waiting for the back window to stay behind.

By my charts, 6200 in 5th should be 175 mph, on 245/45x16 tires.

Am I reading this wrong?

Does anyone have a straightforward chart for the G50/00?

[Adman]

Originally posted by masraum
Tim, 148 is no problem. I've had my '88 up to somewhere between 6200 and 6300 rpm in 5th which is about 150 - 152. Got to about 145 once with the top off, that was scary! Kept waiting for the back window to stay behind.

Steve, I got the same mph to rpm results as you using my GPS.

Tim, your either not using a GPS for speed comfirmation or your tach is quite a bit off. Even if you had 100 hp more than everyone else...with your existing G50 and rear tires your still going to turn the same rpms vs speed as the rest of us. At 150mph GPS my indicated was 165. Consistant with the 10% error from 55mph to red line.

[masraum]

Jack, where are you looking?? Actually your chart is kind of confusing to me, it doesn't seem to jive with my numbers which are from the standard formula

Speed = (RPM*Tire Dia) / (336 * Gear ratio)

Final drive
3.44

88 G50 US
Gear Overall Top Speed in Gear
3.5 12.06 40 @ 6500
2.059 7.09 68 @ 6500
1.41 4.85 99 @ 6500
1.125 3.88 120 @ 6250
.889 3.06 151 @ 6250
.889 3.06 157 @ 6500

And these numbers match my car (the speedo is a tad optomistic, but oddly not as much since I tilted it).

I used the rev-limiter for 1-3rd and the soft redline for 4th and 5th, or if you can hit the rev limiter in 5th you can get 157 in a US model.

88 G50 Euro

3.5 12.06 39.96 @ 6500
2.059 7.09 67.93 @ 6500
1.41 4.85 99.25 @ 6500
1.074 3.70 125.19 @ 6250
0.861 2.97 156.16 @ 6250

[widebody911]

Originally posted by porscheboy16
I tried searching for this info, but I could not find it. What is the top speed per gear for a stock '84 Carrera w/ 915 tranny?

African or European?

[Shadetree930]

I have assumed that Porsche would have engineeered the back glass on the Targa with the ability to stay put at max theoretical speed.

Any facts, concerns or anecdotes about Targas, high speed, and shiny little glass specks on the roadway?

Window going to stay put? Or might I be getting a bill from DOT for roadside cleanup?

[Jack Olsen]

Originally posted by masraum
Jack, where are you looking?? Actually your chart is kind of confusing to me, it doesn't seem to jive with my numbers which are from the standard formula

Speed = (RPM*Tire Dia) / (336 * Gear ratio)

Final drive
3.44

88 G50 US
Gear Overall Top Speed in Gear
3.5 12.06 40 @ 6500
2.059 7.09 68 @ 6500
1.41 4.85 99 @ 6500
1.125 3.88 120 @ 6250
.889 3.06 151 @ 6250
.889 3.06 157 @ 6500

That makes much more sense. I was using an Excel spreadsheet, but I think my setup was all wrong. My apologies about all the above misinformation.

By those numbers, 5000 in 5th isn't close to 148, though. It's 120 -- which makes sense, given the car's top speed.

jmarenas, you're going to have to go back out there again, and try a little harder.