Someone once asked about 2nd gear's top speed
11-14-2005, 06:43 AM
#16
Race Director
Originally Posted by WolfeMacleod
In this post here
Yesterday at PCA Autocross day I learned that my top speed in second gear is approximately 60MPH, with a little room to go, at about 5000rpm.
Just though I'd let him know, if he's still here.
Car is an '88 924S.
Yesterday at PCA Autocross day I learned that my top speed in second gear is approximately 60MPH, with a little room to go, at about 5000rpm.
Just though I'd let him know, if he's still here.
Car is an '88 924S.
With the chip in my car, I can hit 63mph in second with 245/45X16 tires on the rear.
11-14-2005, 11:56 AM
#17
Rennlist Member
Originally Posted by yellowline
It would be interesting to see 0-60 times if 2nd was just a hair longer, say it topped out at 62 or so.
http://www.sportcompactcarweb.com/ed..._technobabble/
11-14-2005, 12:14 PM
#18
Drifting
Wolfe, unless you are using an external source for a speedometer, the wheel speed sensor will still assume stock diameter tires, therefore your spedometer will still show the same linear relationship with the tachometer. If your spedometer indeed showed 60mph at 5000 RPM, then it's time to go sensor hunting.
11-14-2005, 12:26 PM
#19
Race Director
Originally Posted by JustinL
Wolfe, unless you are using an external source for a speedometer, the wheel speed sensor will still assume stock diameter tires, therefore your spedometer will still show the same linear relationship with the tachometer. If your spedometer indeed showed 60mph at 5000 RPM, then it's time to go sensor hunting.
11-14-2005, 02:46 PM
#21
Race Car
Mine eeks past 100km/h right when I shift to third. Then again, mine is a 951, with an unknown transmission in it. Just a thought, some people here are comparing apples to oranges, I saw one guy asking who had a N/A, one with a turbo, etc. The gear ratio's and final drive's are different between the models...
11-14-2005, 03:42 PM
#22
Drifting
Thread Starter
Originally Posted by JustinL
Wolfe, unless you are using an external source for a speedometer, the wheel speed sensor will still assume stock diameter tires, therefore your spedometer will still show the same linear relationship with the tachometer. If your spedometer indeed showed 60mph at 5000 RPM, then it's time to go sensor hunting.
11-14-2005, 04:53 PM
#23
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I don't have a tach so I had to remember when I hit the rev limiter!
I can do 75 mph in 2nd and 110 in 3rd.
I was disappionted because that's not nearly as good as the turbo was (125 in 3rd)
both with stock wheels.
I can do 75 mph in 2nd and 110 in 3rd.
I was disappionted because that's not nearly as good as the turbo was (125 in 3rd)
both with stock wheels.
11-14-2005, 05:39 PM
#24
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Paul (& everyone)- That's a good article- I've tried to use the bicycle gearing analogy to explain car gearing to tons of people. It does leave a little out, however, but this is a HUGE subject w/TONS of variables.
It's true that shorter gearing multiplies more TQ & definately accelerates faster (at ALL speeds throughout a given gear). Of course, just like the article pointed out, at certain speeds, it would actually hurt your time b/c of the exrta shift. Many have used a 3.89 FD in 951S instead of stock 3.38. The 0-60 speed is unchanged @ 5.5 seconds b/c of the early shift into 3rd, but, by the time the 1/4 is reached, it's at 13.9 vs stock 14.2...
0-60 is a horrible indicator of acceratioon performance though- time to speed is very different from time to DISTANCE- the two do not neccessarily correlate. The 1/4 mile is a better test, especially for higher-powered cars. Of course, 0-60 of a given car will correlate almost perfectly w/its 1/4 mile time when it's driven under good circumstances by a professional driver. EX: 951S & it's 0-60 of 5.5 secs & 1/4 mile of 14.2 @ 101 & 0-120 @ 22 secs... Well, many people on this list like to contend that we can't hang w/the V8 crowd off the line, but, on the highway, we can actually catch up & then show them our tailights- this is BS... A 5.5 0-60 correlates almost perfectly to a 14.2 1/4. 1989 911 Turbos hit 0-60 in 5.0 & 1/4 mile of 13.5 w/very tall 4-sp gearing. The E36 M3 from '96 on ran 0-60 in 5.5 but did the 1/4 in 13.9 w/very short 5-sp gearing... The RS6 (manual) beats the AMG E55 to the 1/4 & on to 120, but, E55 is faster 0-150- it's b/c the E55 is so much faster b/t 120 & 150, which is soley b/c of it's gearing in that high-drag speed range. It's very interesting what gearing can do...
Also, TQ peaks at lower rpms & HP at higher. The 951 has 238TQ @ 3500 & 217HP @ 5800 & tops out at ~152 - 157 (depending on magazine) while Turbo S has 258TQ @ 4000 & 247HP @ 6000 & tops out at 162 (consistently)- this 7mph dif is b/c of WHERE the extra 30HP comes in & the rpm the car's running @ 155mph+. Someone here said the 951 redlines 5th @ 157, but, it's definately 167... IF the HP kept increasing linearly w/out too much TQ-drop, 167mph MIGHT be possible...
Last, the amount of HP & TQ & WHERE it all comes in, somewhat affects what the gearing needs to be. I don't know the 944NA's, but, the 951 has decent gearing for it's HP/TQ- even w/simple chips, etc. But, build a 3.1L monster w/500RWHP/TQ & the stock 951 gearing starts to feel pretty short. Turbo's love tall gears- imagine a modded 951 w/Honda CRX gearing... That would just be annoying- just as the turbo spools-up, the boost hits & you'd have to shift... The Viper GTSR had TALL gearing- 6th redlined 300mph... The best Viper upgrade was a shorter FD- the one they used brought 6th to ~240mph & all others by the same percentage- 1st went from 60 to just under 50... STILL VERY tall, but, w/460HP & 500TQ, it makes sense...
Anyway, just food for thought....
Edit:
emw- 125 in 3rd...??? That's over 8000rpm... Either that or a very optimistic speedo... 3rd redlines at 99mph (6400)... Hell, 125 is the perfect shift point for 4th to 5th... Did you do some internal work or something...? you'd HAVE to have mods b/c even with or w/out higher redline, stock 951 could never have the HP to run that far above redline, even if it could keep from exploding...
It's true that shorter gearing multiplies more TQ & definately accelerates faster (at ALL speeds throughout a given gear). Of course, just like the article pointed out, at certain speeds, it would actually hurt your time b/c of the exrta shift. Many have used a 3.89 FD in 951S instead of stock 3.38. The 0-60 speed is unchanged @ 5.5 seconds b/c of the early shift into 3rd, but, by the time the 1/4 is reached, it's at 13.9 vs stock 14.2...
0-60 is a horrible indicator of acceratioon performance though- time to speed is very different from time to DISTANCE- the two do not neccessarily correlate. The 1/4 mile is a better test, especially for higher-powered cars. Of course, 0-60 of a given car will correlate almost perfectly w/its 1/4 mile time when it's driven under good circumstances by a professional driver. EX: 951S & it's 0-60 of 5.5 secs & 1/4 mile of 14.2 @ 101 & 0-120 @ 22 secs... Well, many people on this list like to contend that we can't hang w/the V8 crowd off the line, but, on the highway, we can actually catch up & then show them our tailights- this is BS... A 5.5 0-60 correlates almost perfectly to a 14.2 1/4. 1989 911 Turbos hit 0-60 in 5.0 & 1/4 mile of 13.5 w/very tall 4-sp gearing. The E36 M3 from '96 on ran 0-60 in 5.5 but did the 1/4 in 13.9 w/very short 5-sp gearing... The RS6 (manual) beats the AMG E55 to the 1/4 & on to 120, but, E55 is faster 0-150- it's b/c the E55 is so much faster b/t 120 & 150, which is soley b/c of it's gearing in that high-drag speed range. It's very interesting what gearing can do...
Also, TQ peaks at lower rpms & HP at higher. The 951 has 238TQ @ 3500 & 217HP @ 5800 & tops out at ~152 - 157 (depending on magazine) while Turbo S has 258TQ @ 4000 & 247HP @ 6000 & tops out at 162 (consistently)- this 7mph dif is b/c of WHERE the extra 30HP comes in & the rpm the car's running @ 155mph+. Someone here said the 951 redlines 5th @ 157, but, it's definately 167... IF the HP kept increasing linearly w/out too much TQ-drop, 167mph MIGHT be possible...
Last, the amount of HP & TQ & WHERE it all comes in, somewhat affects what the gearing needs to be. I don't know the 944NA's, but, the 951 has decent gearing for it's HP/TQ- even w/simple chips, etc. But, build a 3.1L monster w/500RWHP/TQ & the stock 951 gearing starts to feel pretty short. Turbo's love tall gears- imagine a modded 951 w/Honda CRX gearing... That would just be annoying- just as the turbo spools-up, the boost hits & you'd have to shift... The Viper GTSR had TALL gearing- 6th redlined 300mph... The best Viper upgrade was a shorter FD- the one they used brought 6th to ~240mph & all others by the same percentage- 1st went from 60 to just under 50... STILL VERY tall, but, w/460HP & 500TQ, it makes sense...
Anyway, just food for thought....
Edit:
emw- 125 in 3rd...??? That's over 8000rpm... Either that or a very optimistic speedo... 3rd redlines at 99mph (6400)... Hell, 125 is the perfect shift point for 4th to 5th... Did you do some internal work or something...? you'd HAVE to have mods b/c even with or w/out higher redline, stock 951 could never have the HP to run that far above redline, even if it could keep from exploding...
11-14-2005, 07:53 PM
#25
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read my sig.
I just tested my 924 today to make sure I wasn't confusing 2nd with 3rd etc,
but I wasn't 75 in 2nd 110 in 3rd
I remember that I could do somewhere in the 140 range in 4th with the turbo, and hit about 165 before the hg blew.
I just tested my 924 today to make sure I wasn't confusing 2nd with 3rd etc,
but I wasn't 75 in 2nd 110 in 3rd
I remember that I could do somewhere in the 140 range in 4th with the turbo, and hit about 165 before the hg blew.
11-14-2005, 10:51 PM
#27
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M758...
You have a N/A? I got my truck to 97 today in 4th, no telling if I was redlining, as I couldn't hear my motor. It just seems that a 944 no matter what kind, would be faster then my truck. I pushed her to 55 today in second, and 77 in 3rd, and like I said, 97 in 4th, but had to slow down to stop.
I thought the gearbox's in the 944's were same in all, except for probably gear hardness and what not. Like I said, a guy with a yellow 944 told me he was just getting out of 3rd at 100-105. I'd suspect 2nd gear on a 944 to be anywhere from 55-63.
You have a N/A? I got my truck to 97 today in 4th, no telling if I was redlining, as I couldn't hear my motor. It just seems that a 944 no matter what kind, would be faster then my truck. I pushed her to 55 today in second, and 77 in 3rd, and like I said, 97 in 4th, but had to slow down to stop.
I thought the gearbox's in the 944's were same in all, except for probably gear hardness and what not. Like I said, a guy with a yellow 944 told me he was just getting out of 3rd at 100-105. I'd suspect 2nd gear on a 944 to be anywhere from 55-63.
11-14-2005, 11:33 PM
#29
Drifting
Thread Starter
Ok, I just got back in the car today for the first time since Saturday. Looking at the tach, I can see I estimated low on the RMP's. It was definately more in the 6000 - 6500 range.
11-15-2005, 07:21 AM
#30
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emw- when I said internal mods, I meant more like dif pistons... something to allow higher redline & keep things in your engine from blowing up... 140 in 4th is very acceptable- I've acccidentally hit the rev limiter in 4th a few times, right after getting the car, although that's pretty stupid since the shift point should be well under 130 since one has run out of TQ long ago & even HP starts to dip above 6000... Anyway, 6400 rpm in 4th = 134, but, 6500 rpm = 136. You'd hit 140 by 6700 & I know plenty of these cars, w/chips, turbo, etc, are capable of accelerating to 7000, so, that makes plenty of sense... 8000 seems pretty damn high though, but, when going by factory speedo, tach, etc, it's anybody's guess... I've told people here several times how my speedo is perfect all the way from ~30mph to 127, by radar signs, but, somehow, at 80mph in 5th, the tach is off by ~300rpms... It matches up perfectly at 60mph & is back on perfectly by 100mph, but, somehow, in this range, it tapers off.... who knows...? Doesn't much matter... attaining certain speeds in certain gears doesn't help anyone's performance... I've always wanted a taller 5th, but, that's more for quieter cruising & possible higher top speed (secondary) after I've done enough mods...