TB993tt

don't melt those puppies...

AC/911's

That's A Lot of Boost, Leak?

tacker

Hey Guys,

I'm finally getting settled in after a long weekend. A great weekend for family and friends. Disappointing performance numbers. My best run was 200.9
The car was faster the last time out with 680 hp k24 18g setup vs the GT30 880 hp setup.

I had a list of issues that surfaced at this event.
The Cause of the most issues. This past winter I was preparing the engine for a dual Throttle body setup. The first part of the project was to add the additional sensor so i can tune bank 1 Cyl1-3 and bank 2 Cyl 4-6 This was done to help see the effects of the Dual TB. This involved adding pressure sensors for reading exhaust back pressure,map and temp sensors. ALL good stuff. Well not really, when I added the sensor they automatically were used in the tune and were making trims that were unexpected. My tuner dialed in and did a quick setup of the sensors. But this was still was causing some weird trims because one off the sensors was reading off at atmosphere. So I lost some time there.

CHT Temps, Friday I was seeing CHT1 400 degrees F at the end of the run CHT2 was 340 d which is normal. After double checking the scaling. I decided to re scale in the morning when the ambient temp and CHT temp would be the same. The EGTs and AFRs were matching up so I decided I had a voltage issue with CHT 1.

So i added more boost, then I started having misfire issues.

At 180mph I stated hearing a loud whoosh of air coming thru the sunroof. I taped it up but the tape was getting ripped off. This happened twice. I let of the throttle when this happened. I was afraid my sun roof was going to fly off.


So now back to the Dyno with a hotter set of coils and fresh plugs and fix the sensor voltage issues.

I'm currently using individual Thermocouple amplifiers for each sensor. I may need to buy a multi channel amplifier that has 1 input voltage. The voltage difference between 350degrees f and 400 f is only .05 volts IIRC

here's a couple pic

AC/911's

Maybe Loose the sunroof, (I did, bad pick outside after soda blast), Lighter wheels, & loose Tail.
I'm guessing that's not much $$ with what's been spent?

tacker

I'll tape the roof down for now. I'm afraid if I fill the roof with a fixed panel I wouldn't be able to stop myself from removing the drip rail. If I remove the drip rails I'm afraid I would be able to stop myself from building a integrated roll cage. You get what I'm saying

OverBoosted28

I'd say you have enough power to overcome any weight penalty, the integrated cage would impose. And losing the rails/sunroof is shaving weight. :-)
Nice stuff. Wish I coulda bought the K24/18s

Basal Skull

sounds like fun!
Seems Porsche did not engineer the sunroof for higher speeds. If I recall, MOD500 lost his sunroof, never to be found again also at 180 ish mph.
I'm sure you'll get it sorted. Will you have a chance to do more runs in the current configuration (after sorting) or are you going ahead with the dual throttle bodies?

TB993tt

A few pics from my stash to discourage this particular path








The main thing is you enjoyed your weekend and were safe. Issues with the pretty extreme and bespoke set up you have are par and I'm sure you will get it dialled in for next time

tacker

I've looking over the log and still can't determine what's causing the power loss. The only thing I got at this point is the turbine exit temperature on side 1 is a 100 degrees F less than side 2. Which would indicate I may have a problem with side 1 turbo. I'm not certain at this point. I did inspect the turbos days before the event and didn't see anything abnormal. The turbos are the ALPHA 30s. I'm using oil as the coolant and maybe the temperature fluctuations caused an issue with the plastic bearing cage. Don't know. Boost /rpm is close to the dyno plot but not a great comparison. Waste gate duty cycle is normal
The car should trap a 145 to 150 but I'm at 130 ish this would indicate about 600 hp. The engine leak down is good the AFRs are perfect so It's gotta be the turbos Or my maps are reading a false high number.

I'm on the fence with making any changes to the intake. I know I can expect around 60 hp with the same boost. The Hp will keep climbing instead of the typical drop at 6400. Just don't know if I have the time this winter to take this on. Either way I will resolve the current issue before making changes.

Thanks for the pics. Defiantly discourages me from taking on that massive project.
Mike

993Godspeed

Mike, just catching up with posts. Sorry to hear you had so many issues man. Your car once sorted will not disappoint.

Basal Skull

Mike do you think there may be a flow difference between one side to the other of your custom cf air intake? that could perhaps cause different in temps, maybe take a look with a scope to make sure there's nothing loose?

Felix

I'm curious to know what sensors you're using to measure the air temps?

tacker

http://thesensorconnection.com/therm...e-thermocouple

Requires an amplifier.

I'm in the process hooking up CHTs on all 6 cylinders thru one multi channel amplifier. This should tell me what's going on with the cylinder head temps.

I don't think it's a intake flow issue. Mostly because the same setup was used on the dyno and the CHT was very good. It's only when I added the additional CHT and ran one thru the X-10 I/O expander and one thru the S8 with individual AMPs I started having issues.

While I'm waiting on parts, I installed a Guard diff and billet stubs. Sticky tires are on there way.

Gonna sell my diff and stubs if anyone is interested.

Bradford

Are you able to make any test runs anywhere prior to the Texas Mile or just the dyno? Also, other than the sunroof issues, how stable is your car at 200mph?

tacker

I took the car to the strip and my best trap was a 134. I didn't get my runs and I spun tire a lot. The car is surprisingly stable at 200 but the surface at the mile is not great. The runway has expansion gaps and changes from concrete to asphalt to a really coarse stone / asphalt.
I have some vids I'll post soon