86 carrera weight?

[doofdog]

I am trying to input the weight of my carrera into the gtech pro I have just recieved. the sticker in the door says 3417 is this correct. The car is completely stock with ac and a sunroof. any estimates on what my car weighs? Thanks

[stlrj]

With a full tank and me in it, I got 2960lbs on the scale.

Joe Garcia
86 Carrera w/sunroof

[doofdog]

Thanks alot. with me I figured around 2980lbs I have nothing else in the car. I weigh 210 lbs still I only get a reading of 132 hp out of this gtech pro. Does anyone else have a clue why so low. I figure it reads rear wheel hp so I figure around 180 at least. does anyone else have some readings?

[Eric Coffey]

I think that any "dyno" you can plug into your cigarette lighter receptacle is bound to have a fairly large margin for error. Just my $.02

-Eric

[Blackdimonds]

What altitude do you live at? And, how warm is it? These things will have a large effect on the "Real" horsepower. Just ask NHRA drag racers that race at different altitudes and temps.

Paul
81 911SC/RS

[Kurt B]

There's no way an 86 weighs that much. My 84 Cab weighs in at an even 2756!

I've never used the gtech for HP measures, so I'm not sure, but definitely, you're either not punching down fast enough, or you're not going to high enough RPMS to get the HP you are looking for or something...
Or, it's broken, but I don't think so.

Punch it. You must accelerate as quickly as possible to get the right measure. It is going to compute your max acceleration on a certain time interval (it'll take the fastest one), and it'll use that to find your max HP.

[doofdog]

well so far I managed to score 153 in second gear. I am going to red line. cant quite figure out what im doing wrong. im getting low measurements in my viggen also. did get a 0-60 time of 6.3 though but I think that might be optomistic. (in the viggen)

[Superman]

I suspect the 6.3 for the Viggen is about right - they are quick cars, aren't they?

The weight figure in the door jamb is the maximum permissible weight of the car, fully loaded I believe. GVWR=Gross Vehicle Weight Restriction or something like that.

------------------
'83 SC

[bfranklin]

What measurements are you getting in your Viggen? 153 rear wheel hp is nothing to sneeze at, prob around 190-200 hp at the crank. Given that that is not what your 3.2 is rated at, several factors can affect this value. If it is a hot day, your engine will produce less power. If you enter your weight below what your car actually weighs, then your numbers will be low (i.e. if you enter the spec weight but have a bunch of tools and junk in your trunk like i do ) Obviously if your engine is a bit out of tune, that can affect things - ever hear of those guys who say 'my car is fine' and then somebody tunes it and they say 'oh my god it screams!' Some units can be innacurate, but judging from your 0-60 numbers for the Viggen, it seems okay (usually if something is wrong with the unit everything is skewed). Personally I find that the 0-60 measurements are a little more accurate (although usually a bit optomistic) than the hp readings. Haven't tested mine on my 73 S yet, but my 97 M3 would give consistent 190-195hp numbers, and dyno readings usually ran between 200 and 210 hp for those cars. Although it shouldn't be *that* much of a factor in 2nd, I guess wind resistance can make a few hp difference as well. I'd bet if you ran your car on a dynojet you'd probably get around 165-170hp peak. See if your viggen reads in the 190's, seeing that it puts out roughly the same hp as my M3 did.

Either way, ain't it fun?

Brad

[doofdog]

It is way fun. I thought the figure was low for the viggen but it right on. I forgot HP was limited in first and second. 180hp in first and 200 in second so a reading of 180 in second is about right in second gear being that it would measure rear wheel HP. So why do I get 130 in the porsche and 115 in second gear. I am going to try a tune up and valve adjustment to see how it helps. Ill share the results.

[RarlyL8]

How are you launching your car?
I posted some time ago about the trouble I was having with the g-tech due to launching difficulties. The tires fry or the motor bogs, no happy medium.

Also, how often does the instrument read out HP figures? I was under the impression that you had to make a full run. That might explain the low figures I got. Quarter mile time seems to be in the ballpark that I expected.

[doofdog]

In the saab I start in second and nice and stedily go to redline then slow below 30mph and it reads accurately the porsche I have tried a quick start to red line and that read 100 or so a slow start in first wich read 133 and a second gear accel that cme in around 150 or so. Its always the same for the saab but the same or less for the porsche. If its right and 133 -150 is still low and I would think something was wrong but the car does not feel honda fast.

[bfranklin]

RarlyL8: The HP measurement mode on the G-tech reads and remembers the peak calculated rear wheel hp - i.e. if you start off slow in 1st gear, shift into second at 2500 rpm, floor it, it will still read your peak hp as you pass whatever your peak hp rpm is. Hard 1st gear launches sometimes mess up the peak hp rating because you jolt the car and it squats a bit. This doesn't affect things so much on the 0-60 and 1/4 mile times because those are figures attained over a relatively long period of time, but the hp reading is instantaneous.

doofdog: Sounds like you're doing everything right, and seems like the unit is okay. Hmmm I still wonder if your car is heavier than the number that you're entering. I assume you're adding in driver weight etc because you're getting good numbers for the Viggen. If you're really worried about it, organize a 'dyno day' with your local porschefiles and put your car on a dynojet. Heck I might even drive up from NY to join in