I'm not here to complain about the check valve, just had an interesting experience on the way to work that I'd like to share.

It's abnormally cold here today, and it was this weekend. Temps in the 20s at night, 40s during the day. I drove the S this weekend, even during the 20 degree weather, with no problems. I drove the S to work this morning and after driving most of the way there in traffic the lanes opened up. I didn't downshift, but floored the car in 6th gear, at about 80 MPH, and noticed that the car hesitated (check valve). I haven't had this problem in almost a year, but it felt familiar. I let off the gas a bit and the car took off, back at WOT and it hesitated...I played around with it up to 100 MPH.

Out of curiosity, I decided to do another 80-100 run in 6th gear WOT and watch my gauges to see what they showed. I was surprised and disturbed. When I mashed the gas the car sputtered. The Air/Fuel ratio was not rich enough, I'd have to consult my manual for a true reading, but it was leaner than normal. My EGT's soared and hit ~1,575 C before 100 MPH. I let off the gas as the temps were flying towards 1,600 C, the highest number on my gauge. The highest numbers I had ever seen before, cruising steady at 120+ MPH, was 1,500 C.

I'm not sure what this means, but I'm sure someone will make sense of it. I'm not real concerned, because I'm going to AEM EMS soon and the check valve will be gone.

 

My unscientific reply:

The weather has been close to identical in Seattle the last few days. I have the check valve as well. The behavior you are describing has occured consistently for me. I do not have the benefit of gauges (until Friday), so I cannot confirm the exhuast temps/lean condition. On the other hand, my cat-back burbles and makes nifty noises when the exhaust is hot. It normally takes 10 minutes of driving for this characterist to display. This morning after a stumble, the exhuast almost instantly started burbling. The car had been running for only five minutes.

I order the Comptech ESM three hours ago. After reading thread upon thread of issues with the prior solution, and with a recommendation from RT: it seems like the way to go. Hopefully RT will chime in here, since he's has more experience with Cold Weather/SC/Checkvalve than I have.

 

[QUOTE]Originally posted by jerrypeterson
[B]I order the Comptech ESM three hours ago.

 

AEM has promised a delivery date? You have my attention, tell me more.

 

Already released, click here.

 

Wesmaster,

what exactly is "Check Valve"

 

The check valve "bleeds" the boost away from the MAP sensor, so that it does not get sent to the ECU. If it does get sent to the ECU, the ECU will retard timing (or something?), and the car hesitates quite a bit. There are a million threads discussing this, most of them back in the early days of the SC kit. Comptech has created an ESM which is an electric device to help to replace the check valve, the ESM sends a constant range of voltage to the ECU so that it cannot physcally send the voltage that shows over X amount of boost. The ESM is essentially a version of the GhostBooster that was created by a SC owner back in the day. Comptech blamed some of the SC bracket cracks on the GhostBooster when the cracks first surfaced, then turned around and released their own version. Just a little history lesson.

 

[QUOTE]Originally posted by Wesmaster
[B]
The ESM is essentially a version of the GhostBooster that was created by a SC owner back in the day.

 

Wes,

RT was telling me about a new check valve that he claims is alot better than the Comptech setup. PM him for more info.

Nick

 

[QUOTE]Originally posted by Pappy
[B]Wes,

RT was telling me about a new check valve that he claims is alot better than