Hi Guys,
Okay, I got the car back today. On the options sticker under the hood I cannot find anything that references X-50. The only thing close is "X-70", and I'm sure that isn't related.
However, I did take it out on the highway this morning and tried a few 3rd and 4th gear pulls. It was very cold and dry this morning, -32F, and it now pulled 1.0 Bar consistently.
I think that the cold temperatures are allowing an increase in boost pressure. When it was a little warmer, -20ish, it would only pull 0.9. I still can't help but wonder if I will be back down to 0.6 or 0.7 if an when it finally warms up.

 

The other way to tell if you have an x50 car is to check the rear intercoolers for the deeper grooves that came on the GT2 as those are the ones that were used on teh x50 cars instead of the smooth intercoolers on the k16 cars.

My car is an X-50 car, even though it was not listed on the spec sticker under the hood. I had to check the intercoolers, and then I got the original build sheet from Porsche USA that had them added as a special option.

Also, the temps won't make that much difference (for boost levels). My flashed k24 car is consistant at .9 at almost any temperature. I've driven it temps from -10 to 110. the turbos will still make the same boost as thats computer controlled despite the temperature. There may be a small variance (+/- .1 or so), but not much. The power difference in the car from hot air to cold air comes from the density of the air, not the boost pressure. So, 0.9 bar of 25 degree air would make more power than 0.9 bar of 95 degree air.

Even if the ECU chooses to limit boost to .7 bar, the air in the intakes will be cooler on a cold day -- hence more dense. This means at that pressure and temperature, your engine will be burning more fuel air mix at a given rpm -- that means more power even at the same boost level.

The reason any car drives better with cooler air is due to the amount of oxygen in the air. When the air is cool, the oxygen molecules are more tightly packed together, allowing more thourough combustion. When the air is warm, the oxygen molecules are less dense (far apart) and not as much will reach the combustion chambers.

Cool air will not "give" you more boost, it will only provide more oxygen to the car. The turbos and engine run more efficiently in cooler weather.

Someone mentioned their stock x50 hitting 0.9 in colder temps. If this is true, it was likely just a spike and not something that would have been considered a sustained boost level repeatable over and over in 3rd and 4th gear. Seeing .9 on a non-flashed (k16 or k24) car is rare and is likely just a spike. If you're seeing this numbert consistantly and repeatedly along a wide ambient tempp range, you have a flashed car.

 

I agree on most of your info given but I THINK,My Opinion>>>>>Is that the boost does increase in cooler weather>>>>>>There are many forums on here,you can check them out,that others and myself have experieneced boost creep as most tuners call it when it gets cold.With waste gate mods it is even worse.The guys with EBC's have many forums on cold weather making them turn down there boost and also leaner AFR's. You are lucky to have a hold on yours in all temps...We are all supplying info to help each other out,its all good........

 

get it tested, you could be doing damage thats about, 20k or so... really i live in so cal, so i have never experience that problem.. anyone that deals with johnspeed would be considered lucky. he's a stand up guy!!!

 

Thanks Mike......I do not know every thing,,BUT what I know and experienced I will pass on AND others can make there own mind up.....Its all about how much input you get and what you get out of it to make your own mind up............Isn't the whole idea of NOS to condense the mixture,as it is colder the more denser,to get more of it in which in turn elevates the" pressures" that translates into power.....something like that......just as in colder weather you have a higher pressure barometer which acts like a booster also.......Just my thoughts....Have a great night

 

You can also take a look under the car at the turbos and look for the yellow or blue id label on the turbos. There is a 996 part number and a Borg Warner part nubmer which will identify the type you have. I can't recall the part numbers

 

Sounds like a fun car!

Make sure to datalog it asap so it's not a hack tune. With some luck the job was done by someone who really knows what they are doing, but if not... it could be designated for racegas only, and be too aggressive on ignition which mainly is the risky part.

If the tune is good (safe) upon testing, drive with good gas and be happy!

 

Ehi are you serious -32F?????!!!!! Now THAT's cold...

 

Yeah, and that was in the Sunshine. I saw -40.5 on the instrument cluster temperature gauge last night.

 

on a few occasions my car hit a peak of 0.9 bar in 2nd and 3rd, but drops to .6-.7 almost immediately thereafter. My only mod that I'm aware of is a Tubi exhaust. my honda mechanic thinks that due to the freer flowing exhaust, it allows the turbos to spool quickly and surpass the limit for a brief second.

Any thoughts from the peanut gallery?

 

Hmmm......SO,do you think with those cold air temps and with those high barometer type days......thats why he is getting that much boost??????.......I think so.....

 

Yeah, you're probably right, the quick spool in the cold probably allows the boost to run up pretty quick before the ECU has time to correct. That might be a little dangerous though, but if it's only for a secone, it should be ok.


Damn, thats cold. Thats in fahrenheit? My record on the readout is -17 F.

 

Hey,
-40 F is the same as -40 C. Its up to -22 right now and it feels warm.
My car hasn't been peaking at 1.0. It has been steady at 1.0. I am guessing it has been flashed, so I think I am going to get a cable from EPL and just have them flash it. I wan't their launch control anyhow.
Once it gets a little warmer I am going to climb underneath and confirm what the turbos are.
Can anyone explain how to tell if the diverter valves are stock or not?
Thanks
g

 

I have an 01 996tt and after about a week of ownership the exact same thing happened to me it would boost as high as 1.0 bar (no flash) I took the car to my independant porsche tech IMA motorsport (they are also board sponsors) They determined a loose hose either boost or wastegate can't remember and when it was tightend the car's boost never went over 0.8 bar. This is my two cents but it seems identical to the issue i was having. Hope this helps and makes sense.

 

Interesting... did it give you a check engine light or throw it into limp mode?
g