Turbo Check Valve Question.

[BosnianLanos]

Don't worry guys, I have NO desire to build a turbo system, but I just have a question to ask that might help a couple of people out. Some people hit stumbling blocks when they try to turbo 'Woos because of our MAP sensor. It is meant to detect fluctuations in the engine vacuum, but as soon as it sees boost (pressure over atmospheric), it freaks out and doesn't let the car rev more than 3000 RPM. Many people have used check valves to get around this because it is a one way valve that doesn't allow the MAP sensor to ever read boost and the car works normally. However, I think there may be another way to solve this problem... The aftermarket has PLENTY of GM-Style MAP sensors specifically designed to work in high-performance applications. They seem to be a direct bolt on-plug in replacement for ours, and I was wondering IF these would work on our cars, and WOULD they solve the issue of the MAP sensor panicking and effectively eliminate the need for check valves? This is what I am talking about:

http://www.jegs.com/i/MSD/121/23131/10002/-1

http://www.jegs.com/i/Holley/510/538-13/10002/-1

http://www.jegs.com/i/MSD/121/2312/10002/-1

They have all sorts of varieties. From N/A to 30 PSI. It seems like a MUCH simpler fix than fiddling with check valves. The cost also isn't too bad.

If my idea is totally off, or I've completely misunderstood the ideas of MAPs and check vavles, feel free to bash me! I'm no turbo expert and have never claimed to be, but I found these things while searching on JEGS and was wondering if these would solve some of the issues of our turbocharged brethren.

/discuss

[jidasas]

The problem with simply plugging in another map sensor is that they show pressure with a voltage...i.e. our stock map sensor has a range from -.5 - +.5 volts (example not accurate) And our computer knows which voltage corresponds to atmospheric and which to a vaccuum...the other map sensors also use the same -.5 - +.5 volts but they correspond to different pressures. i.e. the computer it is designed for recognizes .5 volts as 10 psi and -.5 as atmospheric (again an example and not accurate) So when you have 10 psi that sensor sends a signal of .5 volts...so if hooked to our engine and we run 10 psi then it sends .5 volts to the ecu and the ecu thinks we are still using the old sensor and our a/f ratio gets messed up cause it thinks we are running no more than atmospheric pressure. I hope you can understand my jumble.

Jimmy

[MMamdouh]

ok if the problem is with POS check valves... why can't you use a check valve just like the one on the vacuum line of the brake booster?

it already handles a great deal of vacuum (some -20PSI or so) so if you put it on a line inbetween the intake and the MAP i recon it will b a very reliable tool.

what do you think guys??

MMamdouh