new(ish) to the 997tt
03-09-2015, 09:49 PM
#1
Racer
Thread Starter
new(ish) to the 997tt
I picked up a manual 09 turbo cab (some milage on it, but CPO) nearly a year ago to replace a '00 m roadster that I drove for the last 10 years.
There are two things I'm still having a hard time figuring out:
I've driven other turbocharged cars before, but this is my first real experience with a variable vane setup. Is there any way to keep the boost up when you're not actually fully on it? With the older tech, I could just keep the engine speed up and would mostly maintain boost trough a short corner. I can't figure out a way to do that with this car. Admittedly, this is academic, as even off-boost the thing is hardly slow. That said, does the GT2 behave the same way? Or is this just a desirable trade-off for the street car?
When braking to a full stop, while going slowly, say a stop sign in a parking lot, 10mph to 0, on dry, but not epic traction, the front end will lock up and the ABS will chatter. This happens particularly when driving in a more civilized manner. When I'm on it, I've not experienced anything quite like it, though I have encountered what I think is PSM kicking in to curb understeer as I learned to adopt my driving. This may or may not be the same thing. It's been doing this since I got it, with at the time new tires. Is this normal or is there something up with my particular car?
There are two things I'm still having a hard time figuring out:
I've driven other turbocharged cars before, but this is my first real experience with a variable vane setup. Is there any way to keep the boost up when you're not actually fully on it? With the older tech, I could just keep the engine speed up and would mostly maintain boost trough a short corner. I can't figure out a way to do that with this car. Admittedly, this is academic, as even off-boost the thing is hardly slow. That said, does the GT2 behave the same way? Or is this just a desirable trade-off for the street car?
When braking to a full stop, while going slowly, say a stop sign in a parking lot, 10mph to 0, on dry, but not epic traction, the front end will lock up and the ABS will chatter. This happens particularly when driving in a more civilized manner. When I'm on it, I've not experienced anything quite like it, though I have encountered what I think is PSM kicking in to curb understeer as I learned to adopt my driving. This may or may not be the same thing. It's been doing this since I got it, with at the time new tires. Is this normal or is there something up with my particular car?
03-09-2015, 10:04 PM
#2
Racer
The brakes should not be doing what you describe? In cars with all these systems it sounds like sensor, or a stuck caliper maybe a proportional valve ? Abs should not activate unless a wheel stops turning?
03-10-2015, 01:51 AM
#3
Rennlist Member
Assuming you have the sport chrono option, sport mode should give you more immediate throttle response and lessen that lag sensation - unless of course you're already talking about sport mode.
I would get the brakes checked/fixed ASAP. That does not sound normal at all, and CPO should cover it.
Congrats and enjoy!
I would get the brakes checked/fixed ASAP. That does not sound normal at all, and CPO should cover it.
Congrats and enjoy!
03-10-2015, 02:10 AM
#4
Rennlist Member
Are you running an after market wheel setup? Can't that mess with ABS?
03-10-2015, 02:49 AM
#5
Racer
Thread Starter
Thanks for the thoughts!
I sure hope it's not a stuck caliper. I can't imagine that would be good for the pccb disks.
Sensors or proportion valves seem like good thoughts. Since I know a spot that reproduces it, I'll see if I can get a video to hand over with the car.
Wheels are stock.
I sure hope it's not a stuck caliper. I can't imagine that would be good for the pccb disks.
Sensors or proportion valves seem like good thoughts. Since I know a spot that reproduces it, I'll see if I can get a video to hand over with the car.
Wheels are stock.
07-10-2015, 02:47 AM
#6
Racer
Thread Starter
While the dealer said they could not reproduce the issue, and everything WRT ABS passed their tests, I finally figured out what was going on. The car, despite being CPO, had huge (15mm front 17mm rear) wheel spacers on it. Pulling these makes the ABS behave like I would expect it to. It also makes the whole car feel about 10x more nimble, and makes me understand why someone would pay for PCCBs in order to reduce the unsprung weight.
It also explains why I felt like the thing was an impossible mess (literally) in the rain, and why the steering was heavy and numb compared to the S.
Unhappy that it took me 6k miles and 18 months to figure this out, and that a CPO car came with poorly thought out mods, but at least I have it sorted now.
It also explains why I felt like the thing was an impossible mess (literally) in the rain, and why the steering was heavy and numb compared to the S.
Unhappy that it took me 6k miles and 18 months to figure this out, and that a CPO car came with poorly thought out mods, but at least I have it sorted now.
07-10-2015, 11:06 AM
#7
Drifting
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Makes sense! Spacers are more for looks than performance. Glad it worked out.
Btw I use to have an M Roadster too, miss it!!! M Coupe will eventually replace that hole in my life haha
Btw I use to have an M Roadster too, miss it!!! M Coupe will eventually replace that hole in my life haha
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07-18-2015, 03:15 AM
#8
Racer
Thread Starter
OMG, I still remember test driving the m-coupe. The only car I've that I didn't own that I confidently got sideways within minutes behind the wheel. That thing with some sort of forced induction is automotive nirvana. Yes, if I could have it all, there would be one in my garage.
The turbo, and there's more than a little fault with those effing spacers, just does not inspire the same amount of certainty. My hope was that it, being rear engine and all, would be a new challenge. So far I'm loving the thing for both it's engine and performance while running smoothly through corners. But when it comes to going sideways, I really miss what I would do with the roadster (never mind the coupe, that thing is simply brilliant).
Honestly if I was to go to a track day at this point, I'd steal my significant others f31 diesel wagon. I just don't have the confidence to toss the turbo into a corner somehow, knowing I can work it out when I get there, that I do with the BMWs. -- Sad actually, because from a service and upkeep perspective, they are a disaster that I'd like to not waste any more cycles of my life on.
The turbo, and there's more than a little fault with those effing spacers, just does not inspire the same amount of certainty. My hope was that it, being rear engine and all, would be a new challenge. So far I'm loving the thing for both it's engine and performance while running smoothly through corners. But when it comes to going sideways, I really miss what I would do with the roadster (never mind the coupe, that thing is simply brilliant).
Honestly if I was to go to a track day at this point, I'd steal my significant others f31 diesel wagon. I just don't have the confidence to toss the turbo into a corner somehow, knowing I can work it out when I get there, that I do with the BMWs. -- Sad actually, because from a service and upkeep perspective, they are a disaster that I'd like to not waste any more cycles of my life on.