Weird DYNO results.........thoughts?

Hey everyone, had my "standard" 01 tt dynoed today at Prosport, in Stockport, Cheshire. Here are the results: I have never had a car rolling roaded and what has caught my attention is the top bit or curve near the "500" torque side. Should this be here? Is that a change from 5th gear to 6th gear? Also what is puzzling me is, my car has standard exhaust, filter et etc. Only had it 2 weeks and no mention of a re-map by previos owner, thats not to say it wasnt remapped before then, BUT 1. How is is making 469bhp at the fly? but only 320 at the wheels? 2. Ss there really a loss of 140bhp from fly to wheels? 3. Also does this 469bhp figure mean it has a map, albeit a crappy one as you would expect more than a 49bhp increase from a map alone or am I expecting too much of a standard engine? (standard 420bhp, 2001, never more than 0.7 bar sometimes spiking 0.8-0.9) thanks

don't know much about 996TT but generaly you lose 15% on fwd and Rwd car and about 25%on 4Wd it due to the gearing in the transmistion and diff 10%-15% on a stage one map is about right ,stage one would just smooth the power and torque curves and take the lean points out of the fueling map ( car makers lean off a little at the tested mpg speeds 56 and 75 mph etc )it gives them better figures so with other cars this sounds about right Rob

4wd's really loose 25%?! WOW!

I have just been informed that these 'spikes' indicate a possible coil failure, is this deffinite or could it be something else contributing to the spiking? thanks

the spikes would show loss of power OR lifting off throttle for gear changes if your talking about the second pic i would say the deep spikes are gear changes the smaller ones missfires was the power run done in third if so first change came at 1500 rpm second at 2K then left in third for full power a 4K Rob

Firstly, do 4wd's really loose 25% as they only give 5-40% power to the front (I think). This is the curve for my 996TT in standard form. You can see a few little lumps at the bottom upto about 25mph when it reaches 6th gear and then full throttle to the top. Your powercurve has different scales on it. BHP x RPM x Torque I have BHP x Velocity with wheel HP and Engine HP. (my car was 2wd for the run so the wheel HP would be lower in real life). I then had a custom map done, 0.9 bar peak dropping to 0.8 bar. Still standard car 487.7 Bhp at flywheel 545ft/lb torque. Do you feel the car runs ok or did you take it because you have a problem. [/img]

Had mine Dyno'd on Wednesday and the PSM played silly buggers, even when turned off (looks like it has with yours). It looks like switching the PSM via the switch doesn't turn it off completely (maybe have to pull a relay from somewhere?). JohnB: 185mph on the dyno? Yikes! Did they really have the fan power to move that much air or did they not care?

I don't think that will be coil failure as that would not be different in different gears: The coil doesn't get more load when you are accelerating or cruising - it is merely a fixed electrical current whose frequency depends on engine revs alone. I think it may be Traction Control cutting in: When you switch PSM off it doesn't switch off TC. 911s rely heavily on aerodynamic downforce at the rear at very high speeds: Without that (i.e. on a rolling road, without a 180 mph 'wind' on the rear spoiler) the rear tyres will most likely not have enough downforce on the rollers to stop them slipping against the resistance of the rollers themselves. Unlike tarmac, a roller's resistance is proportional to speed, due to having to spin a much greater weight, than a pair of light alloy wheels, very rapidly on somewhat less efficient bearings than a 200 mph supercar!

Hi Bob, not sure you'll ever find a dyno that can shift 185mph of air. The important thing is that the engine stays cool. There were two big ducts at the front of the car and two extraction ducts sat close to the vents in the bottom of the rear bumper to draw the air through the intercoolers. Also it was bloody freezing in there! If you check my prevoius posts, you can see the vid on the dyno. I would also like to think that all tuners "care" about our cars, as Wayne does at Chip Wizards. Surely these guys should know how to fully turn off the PSM? They obviously don't know what they are doing.