Kevin Michael

You had to go and bring up the weight and gearing

mark kibort

Yep, he did. the 2.72 didnt buy a GTS much in the way of 1/4mile times, for obvious reasons, but that 3600lbs isnt going to break 13, unless it drops some weight. Just look at the car and driver reports of cars that can break 13 seconds. Low 13s might be expected, but the 12s will require near 450hp flywheel or a much lighter weight. But, the drag guys already know all this.

potsiewebber

I will let you know when i break into the 12's boys and girls.

cobalt

I have to agree those numbers seem to good to be true for just an X-pipe. If they are it might be time to look into one.

Mine is stock and I dynoed at 295 RWHP and 320 torque car weighs a total of 3505 with a little more than half tank of fuel, 5 speed car. With a Gtech meter the best I can do for a 1/4 is 13.5 sec at around 104mph, although I can see these numbers fairly constantly and that is on a stretch of road that has a slight up hill grade.

IIRC autos are generally slower and heavier even with the added Hp and torque I think braking into the 12's will be tough. You might get close. According to the calculations if your car weighs roughly 3750 pounds with fuel and driver you should theoretically see 12.9 second and 106 mph trap speed or some close variation depending on how quickly the tranny shifts.

Mike Frye

Anthony, I think he said his car was converted from an auto to 5 speed. He's got dual disk clutch 5 speed, no cats AND a K & N filter .

You should have been there, the dyno setup and shop were VERY nice. I didn't have anything to compare it to, so I don't know if the machine was calibrated wrong or what. I HOPE it was right because my numbers were pretty good too, but I think the other cars that were there looked pretty reasonable.

Tony (Toofast): How about your numbers from that day, were they more or less what you were expecting?

cobalt

I missed another dyno session? Didn't see the thread. Glad to hear your car is doing better after the last one. Would have liked to done another pull aftermy tuneup which was greatly needed last go around.

I still don't think even with a 5 speed and no cats he should see much better than the numbers I posted that is depending on gearing used. Still fast enough where needed. How does he pass emissions without cats and boy it must be loud. Would be curious to how it feels with less back pressure.

Mike Frye

AH! Sorry you missed this one. It was just this weekend down here in Lakewood. We had a few guys not show up so we actually got beat on the group rate a bit. I remember yours was done just before a tune-up last time.

James is from PA, and I think they have different inspection laws over there, maybe something to do with the MY?

The shop was really nice and we're planning to go back again in September, I'll let you know.

As far as the dyno, if it's got the right CF (SAE) and the temp, humidity and barometric pressure were right what else could be wrong?

123quattro

For reference I just ran my 84S in Bristol, TN this past weekend. With all my gear in the car and me it weighed 3450 lbs and makes 270whp through a 5 speed. I ran a 14.7 @ 97 mph. Ambient was around 80F. 60' was a 2.3 and I had to pedal it all the way through first. I'd guess on a well prepped track the best I could hope for would be a low 14.

cobalt

I am not doubting the numbers. They are more than likely close enough. You just need more HP without a diet to get these things moving much faster than they do. I can see high 11's in my turbo with 385 RWHP and 390 torque but the car only weighs 3100 pounds and is geared differently. It also launches must faster with close to a 4 second 0-60 time and shifts much faster than the 928's.

Let me know if you guys do another. If not just for the company, I would like to see if the tune up helped at all.

cobalt

Assuming you have no wheel spin and you add roughly 200 pounds for driver you should see 14 seconds with a 100 mph trap speed.

RicerSchnitzzle

If it looks too good to be true... it either isn't or more is done to your car than you know about.

The thing with dyno parties... They attract lots of new business for the Dyno operator. If the numbers come out too low, the new patrons don't return. The crowd gets restless etc.. Any good dyno operator knows how to "Adjust" to grade on a curve. Dyno's are just for bragging rights. You can tune on any dyno as long as you use the same one each time. Total number is not as important as the delta. Between calibration, weather, operator error (Even self induced) etc.. it's about impossible to get the same results from the same type of dyno just driving across town. Most folks go where they get the highest result so the can inter-brag. Owners know that and some, not all, will play around to build business.

Personally I think G-tech is one of the best tuning tools as it measure only real world conditions. It allows you unlimited runs for consistancy, and factors in real world cooling and airflow. Plus weight and wind resistance.
Don't care how HP you show on your merit badge...how fast can you really get there? If you pick the same stretch of road to tune with on the G-tech, other than weather, all factors should remain fairly constant and allow a decent delta for comparrison runs. The newest G-techs will datalog A/F as well.

potsiewebber

Just for reference, i ran a 4.4 0-60 recently with the g tech pro. I havent been able to do a quarter mile run yet. If i keep this car around long enough, my plans are to lighten up the car a bit by replacing the seats and lightweight wheels and tires to start.

cobalt

Are you sure of that? that seems too good to be true. Is the 5 speed box geared differently than the normal GTS box? I can barely see 5.2 seconds 0-60 and it should take a lot more power to drop you down to the 4.4 second range or at least 500 pounds off the car. Every 1/10 below 5 seconds takes a lot of extra power and although you are seeing 44 hp at the wheels and 30 more ft lbs of torque I would expect you to see a 5 second 0-60 with the numbers you are talking. the power to weight ratio is just too high for anything below that.

potsiewebber

Well, i will have to run it again and see for sure! i DROPPED SOME WEIGHT BY GOING TO THE 5 SPEED TRANNY, and lost some weight by going with the dual disk clutch along with lessening the rotating mass but only the track runs will tell for sure. Because of this discussion i may have to move my track trip up and go in June if i can find the time.

potsiewebber

I dont know what the gearing is in the tranny.