Zero10

My O2 sensor is shot. I drove 6000 miles burning 25L of oil every 300 miles (what is tthat, 500L of oil?), then I fixed the motor, and ran a can of Seafoam through it. I plan to run another, then change the O2 sensor. At present I haven't even gotten close to 300 miles to the tank, I am getting 240-250 right now. O2 sensor is F'ed.

toddk911

"Your mech either suffer from very selective memory, compulsive lying or simply drives like a wuzz. There is no way to drive a car fast without being able to mash the throttle during acceleration. "

I asked the same question. You can mash the throttle, but I guess they shifted once it got to hp roll off, which on stock K26 is about 5-5,500 rpm.

sweanders

So what did he do at 4000 rpm's when the K26 spools like crazy? If you keep your foot down at those rpm's and don't have any boost control something has to give.

I am not saying that a 951 can't be driven without boost control, it will just be impossible for a person to react faster than the simplest boost controller. So to be safe and not blow something up you'd have to feather the throttle and keep looking at the boost gauge and there is no way you can do that all of the time when driving.

I know of people driving Saab turbos and Nissan turbos who simply block the WG signal and it seems to work (for a while) with those cars. But they have tiny turbos compared to the K26..

toddk911

Well, I know they were running about 2 BAR, i.e. 30psi. So for the stock system and turbo to build that much it would have been almost at the shifting point anyway. I.e. when the power was rolling off, and at that boost it would roll off fast, it would be time to shift anyway.

But yes, there was some feathering of the throttle as well.

I guess they went with what these cars are best at, the mid range. So instead of having a solid tq curve of 3K-6K then had a CRAZY tq curve of 2.5K-5K and had heavy, fast roll off up top. Remember, it was about 95% stock car, so they still had CV to help as well.

I will be stopping by the shop Friday, as they have a customer that is going turbo package on his 968 so I wanna see how that is going, have some beers etc. I will ask more details on how they had the car set up.

sweanders

Can the stock DME handle the data at 30 psi airflow?

danny951

To that, Todd, I'd have to say prove it.. prove it on your own car and show us the video of you driving hard for a few laps. If your turbo doesn't explode then we'll all be pretty amazed.

toddk911

Nope, not on my car

toddk911

Still trying to get to the bottom of Mustang vs. Dynojet. Got this from a local dyno shop that does high end cars, 996/7 TT, Turbo Vipers, Vettes, etc.

"The Mustang dyno is a load or Eddy current dyno whereas the Dynojet is an accelerometer or free wheeling weight. Our 224XLC is an accelerometer and an Eddy current all in one since we can turn the Eddy on or off when we choose. The Mustang doesn't have that luxury. "

He said you should expect MUCH lower readings on Mustang then Dynojet.

Zero10

The owner of this mustang dyno has provided me with some numbers from other people's cars, he is showing 14.2% lower on his than on a dynojet (owned by another dyno operator around here).
I can't quote the numbers since I don't have those people's permission, but he has the numbers to back it up. Some of these people ran the same day on both dynos, some different weeks, but they all showed almost exactly 14.2% difference (13.9% - 14.6%).
I guess that's good news for me

toddk911

mee too!!

As mine was on Mustang and I was like ...whoaaa, that is low for my mods.

toddk911

But, 15% seems a little high for me as that means I am making a lot more then I thought or more then the car feels.

I put down, still in rough tune, but only 287whp/270rtq with 19psi, LR Super 75, Hnt MAF, 3" cat back. I was expecting at least 300 at the wheels.

But at 15% difference that changes things a bit to 337whp/317wtq. And my doubts come to play there as that means I am almost 400hp wat the crank. Maybe I have jsut gotten used to the car but it doesn't really "feel" like a 400hp car. I have friends in it and they say "damn, it pulls like a jet taking off" So I don't know....

Zero10

19psi? Yeah, 300 at the wheels at least.

I rode in a 305rwhp 951 the other day, and it does feel like a jet taking off, except there is that extra noise of tires squealing every time he stomped on it, and I don't remember jets going that fast.

Mine feels like a 50hp car. My golf TDI feels faster (although I know it's not). Need to do some work with it, starting with this boost problem. But, I now have an oil line failure for the turbo feed line, so the car is parked again.... gah, problems everywhere.

toddk911

Yea, I think a lot of that is butt dyno.

I would go with maybe 10% difference from Mustang to Dynojet. For me that is about 318whp, which sounds about right. Plus not being fine tuned yet.

black944 turbo

You need to remember each dyno is different, so some may be 10% and others 15%. Remember that.

toddk911

Good point.