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Yan Yan is offline
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Question 60/100 mph in 6.7 = Good time for a 951?

Hi there,

I recently bought a 1986 951:
90 000 original miles
Stroker kit (2.8L conversion)
Manual boost controller, running around 15 PSI

Today, I decided to test its acceleration times on the nearest SAFE highway. Here are the conditions:
87 Octane gas
One passenger with me
25 C (or 77 F) on a sunny day
Launches were made at 60 mph in fourth gear
3 trials, the exposed times are the averages
The tires are 225/50 to the rear and 205/55 to the front

Here are the times, I know that with these tires the speedo is wrong, the speeds are the exposed speeds on the speedo:
60-100 mph in 6.7 seconds
60-125 mph in 12.9 seconds

Are these good times? Which cars are comparable with theses?

Thanks alot guys
Yan

Old 05-25-2001, 12:36 PM
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sound like correct tires to me...
Old 05-25-2001, 12:59 PM
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looks maybe a bit slow for the variables you indicate, but not sure. sure about one thing, however: you should not be running 87 octane at 15 psi! the factory recommends 92 and that's for a stock 951. running higher boost (not sure how 2.8 stroker would factor in) dictates you use at least 92 or you're risking detonation. hey, even using 92 octane you can detonate at 15 psi.

Old 05-25-2001, 01:03 PM
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I agree with Blackfoot the buy the good gas for a turbo. The tires are stock on the car so the speedo should be as accurate as the rest of ours.
Old 05-25-2001, 01:24 PM
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Can running at 87 Octane be bad for the engine @ 15 psi with a stroker kit?

Thanks!
Old 05-25-2001, 01:58 PM
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Yan thats like mixing water and gas together in a NA 944. It will damage your fuel injectors and build up a lot of carbon scorring in your fuel system. You MUST use 92 octane especially for a turbocharged 944.



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Old 05-25-2001, 02:31 PM
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Try it in 3rd gear. Floor it at 50, so the boost if full by the time you get to 60. Your tires do not give you the correct speed. With mine, a 225/60 gives the correct speed.

Going to redo mine once my ignition system arrives. Mine is modified.

My speed with 225/50 tires is 7% off on the high side.

[This message has been edited by Lawrence Coppari (edited 05-25-2001).]
Old 05-25-2001, 02:35 PM
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WOW!! 125mph? I'm scared to drive my 944 100mph.


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Old 05-25-2001, 02:47 PM
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Quote:
Originally posted by Yan:
Can running at 87 Octane be bad for the engine @ 15 psi with a stroker kit?

Thanks!
the stroker kits i'm aware of for porsche (like the devek one for porsche 928) raise compression ratio, so that's even more reason to run 92+. how long have you been running 87 with your setup?

who makes the stroker kit you installed? how costly was it? also interested to hear the comparison of pre and post-stroker.

Old 05-25-2001, 02:52 PM
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If I were you, I'd use higher octane gas.
Old 05-25-2001, 03:39 PM
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Like everyone says, don't use anything lower than 92 octane in your car. 15psi and being a stroker motor that it more sensitive to boost will end up detonating.
Old 05-26-2001, 02:17 AM
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Hey Yan, are you the same guy with the "My 951" webpage? I think I have a "speed tale" on your page.

Small world.
Old 05-26-2001, 10:49 AM
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Looking back at my records the 60-100 in THIRD gear takes 5.9 seconds on my 2.5L with 225-60 tires front and back. With 225-50, it will take less time. The test was done at 70 F at full boost. Thus spoolup time is eliminated. Engine is not stock.

I am thinking a 2.8L should be faster than the numbers you show. For starters, you ought to use high octane fuel. You are losing performance by not using it.

I plan to retest as soon as I install Jacobs ignition. Will do a comparison to see if what is advertised is true. System puts 60K across sparkplugs and refires as necessary. There will have to be improvement because system is costly.
Old 05-27-2001, 08:04 AM
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Yan, you MUST run higher octane gas with the turbo. I'm using 93 octane and ran the following VERY ROUGH estimates using a hand-held timer:

trial 1 60-100: 5.7 sec
trial 2 60-100: 6.0 sec
trial 3 60-100: 5.9 sec
trial 4 60-100: 5.9 sec
Old 05-28-2001, 03:53 PM
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CJFusco, yes I am the same Yan as on the web page in question! I'm presently rebuilding it but the old speed tales will remain on it.

Ouch, 60-100 mph times of less than 6 seconds! What are your modifications guys? Considering my modifications, what time should I be running? I'll retest my times with 92 octane gas on a colder day and let you know about the results! My friend told me that I could have blown my head gaskets by running 87 octane gas, is that true?

Thanks alot
Old 05-29-2001, 05:41 AM
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Yan,

If you are only using 87 octane gas, you are probably detonating. If so, the knock sensor will trigger a timing retard in 3 degree increments, putting you down on power. Get better gas.
Old 05-29-2001, 08:16 AM
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Quote:
Looking back at my records the 60-100 in THIRD gear takes 5.9 seconds on my 2.5L with 225-60 tires front and back
Quote:
Yan, you MUST run higher octane gas with the turbo. I'm using 93 octane and ran the following VERY ROUGH estimates using a hand-held timer:
trial 1 60-100: 5.7 sec
trial 2 60-100: 6.0 sec
trial 3 60-100: 5.9 sec
trial 4 60-100: 5.9 sec
Quote:
looks maybe a bit slow for the variables you indicate
Guys, what are your modifications? Because a 60-100 mph time of 5.9 seconds is incredible. Here are some results that I took from Car and Driver and Road and Track magazines:

Porsche 911 Carrera 1995: 8,1 sec
Porsche Boxster 1997: 10,7 sec
Ruf Porsche CTR2: 4,3 sec
Toyota Supra Twin Turbo: 7,3 sec
Mitsubishi 3000GT VR-4: 8,5 sec
Chevrolet Corvette C5 1997: 6,5 sec
Acura NSX-T 1997: 6,7 sec
Bmw M-Roadster 1997: 8,5 sec
Ford Mustang GT 1996: 9,4 sec

Are our cars really THAT great 60-100 mph runners?
Old 09-03-2001, 03:33 PM
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I don't know about 60-100, but I have the UK magazine's "Auto" tests for 60-80mp for both the 944 Turbo and the later Turbo S in 4th gear acceleration tests:

944 Turbo:

60-80 in 5.0 secs
80-100 in 5.4 secs

Turbo S:

60-80 in 4.5 secs
80-100 in 5.3 secs


In case anyone's interested here the same 4th gear stats for the n/a cars:

944:

60-80 in 6.7 secs
80-100 in 8.3 secs

944S

60-80 in 7.5 secs
80-100 in 8.5 secs

[not a misprint]

944S2

60-80 in 5.3 secs
80-100 in 5.8 secs

924S

60-80 in 6.6 secs
80-100 in 8.0 secs

-MAS

Old 09-03-2001, 05:14 PM
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Check to see if those tests were done in top gear.

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Erick

86 951

http://www.pelicanparts.com/cgi-bin/pmpre/pm.cgi?action=display&login=aka_951
Old 09-03-2001, 05:17 PM
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I agree, try it in 3rd. Should be quicker, and lets get some info and prices on that 2.8 stroker kit

Old 09-03-2001, 05:24 PM
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