over boosting on my 87 951 help!!...very long

[ripic951]

hi everyone, i was wondering if anyone cna help me, i just bought a lindsey boost enhancer last week and the first day i put it on i took it out on the highway.
so it was awesome, truly an amazing difference, much faster, but i was in 5th gear, going maybe 100mph and i gunned it and as the boost came up, it jsut shut the car down, like when it overrevs how it jsut shuts the engine down, so i didnt think anything of it, i dont drive that fast anyways too often, but now its doing it in 3rd and 4th gear too, so its gettign progressivly worse, i called lindsey, they said it sounds like the computer is shuttign the engine down due to overboosting, they also said it maybe the wastegate is shot, or maybe vacuum lines may have leaks, i have a k-27 turbo from windward, anyways any one have any suggestions why its doing this?, also the guy from lindsey said to pressurize the line to the wastegate with 10psi from an air compressor, i have an air compressor but how do i get the air compressor to do only 10psi? any other thoughts?...the boost enhancer makes it so much faster, i dont want to remove it...help jeff

[Blackfoot]

i had the overboosting thing in my previous 951. it only did it under extreme conditions, like full throttle at 90 in 5th with a passenger about (extra weight).

i'd listen to lindsey; do you have a mechanic who can check the items lindsey mentioned? i think an aftermarket chipset like weltmeister may cure the shut-down, but the car may have other issues.

[Lawrence Coppari]

Get a pressure regulator. It is something just like the pressure regulator that drops your water pressure to your house pressure or drops your natural gas line pressure to your house pressure. It is a spring loaded valve contraption. It is a common item. You need one for an air compressor however. Don't get the one that drops it based on flow rate. You need one that drops static pressure (no flow pressure).

I may have not made myself clear: The pressure regulator is for your compressor, not your car! It is how you get 10 psi from a 110 psi source at flow or no flow.

[This message has been edited by Lawrence Coppari (edited 05-19-2001).]

[Mrmerlin]

[QUOTE]Originally posted by ripic951:

Hi RIP, it sounds like your over boosting the system and that parameter is controlled by the DME, and KLR, to change it you need to have different chips in the respective boxes, otherwise maybe a boost regulator to cut out out the DME function, this is in there to prevent the engine from blowing itself up from a overboost condition, also to note that if the boost is inctreased much more than you have now your getting into the range where a different fuel system might neeed to be used IE bigger injectors and Higher pressure fuel pump, and of course then it might be time to have the head O ringed, so the head gasket stays in place,

I know that there are other members on this page that will be able to tell you exactly what to do, but this is what i have learned from a owning a 951 for a few months...now for the handling department.........Stan

[1.2gees]

I agree with Blackfoot and Stan, you may wanna look into other upgrades, before you decide to keep everything on the engine.

However, to solve the problem at hand, you can simply turn the boost down to 9psi, on your adjustible 'boost enhancer'.
Ahmet

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It's all the driver...

[ripic951]

hi guys thanks for all the input, i do already have a bosche rising rate fuel pressure regulator, and to 1.2gs i am goign to turn it down to 9psi, the guy from lindsey suggested that also. I also do have upgraded chips init for the k-27, someone i believe mentioned that as well...another question, im going to have to put another boost gauge in, does anyone have a link to a site that tells how to do this?...i saw one somewhere on some guys 951 webpage but i have no idea where it is...are vdo the one's to go with..thanks...jeff

[ripic951]

hi everyone, i fixed it, i think, i had a hose come loose so it msut have been leaking somewhere...thanks for the input....jeff