Lindsey Racing Boost Enhancer

[74goldtarga]

Lindsey Racing Boost enhancer - What is this and how does it work? Thanks

[AaronM]

Call it a pre-wastegate. It restricts flow to the wastegate until an adjustable threshold manifold pressure is reached, which means that your car will build more boost.

[Streckfu's951]

Originally posted by 74goldtarga
Lindsey Racing Boost enhancer - What is this and how does it work? Thanks

It acts like a MBC while working in line with the CV. It prevents the boost signal from being transmitted through the CV to the wastegate until the desired boost is reached.

The stock wastegate, when controlled by the CV, begins to bleed boost as low as 9psi before peaking at ~12psi.

The LBE prevents the bleed signal from opening the WG so early which allows quicker spool response.

It's NOT a good idea to use the LBE to raise the boost without compensating the fuel.

[sellingporsche]

It's NOT a good idea to use the LBE to raise the boost without compensating the fuel. [/B]

This is a VERY valid point. I elected to go with a HKS EVC (Electronic Valve Controller) aka boost controller which I imagine is the same as the Lindsey unit. If you dont raise the fuel pressure the boost will cut when you boost for long periods of time.

[Streckfu's951]

Originally posted by sellingporsche
This is a VERY valid point. I elected to go with a HKS EVC (Electronic Valve Controller) aka boost controller which I imagine is the same as the Lindsey unit. If you dont raise the fuel pressure the boost will cut when you boost for long periods of time.

I'm not familiar with the EVC but the LBE is purely mechanical. It uses a ball and spring as a pressure valve. The spring preload (set by screwing the two body peices of the LBE together) determines the boost pressure in which the signal is sent to the CV.

I made that point because some people are tempted to adjust the LBE beyond the stock boost setting without adjusting their fuel. This will result in an overly lean condition which leads to either overboost (what you described) or detontation which will cause the headgasket to fail.

[74goldtarga]

Helpful comments, I just bought the car - today in fact. Boost enhancer is in place, boost seems to rise to 1bar then fall back, sounds like I need to adjust the enhancer to a lower setting, I don't want a blown headgasket. How much boost is the stock 951 engine supposed to handle? (Stock is 0.7bar but what can it safely take)

[Streckfu's951]

With the stock turbo and wastegate, the boost will always bleed off at higher rpms. The turbo runs out of steam and the WG can't hold the boost.

You may want to consider an aftermarket boost gauge as it is difficult to determine your exact boost pressure with the stock gauge.

If you are on stock chips, just keep the peak boost on south side of 1 bar. If I remember correctly, the stock peak boost in 4th should be 12.8 psi or .8 bar.

[AaronM]

Originally posted by 74goldtarga
Helpful comments, I just bought the car - today in fact. Boost enhancer is in place, boost seems to rise to 1bar then fall back, sounds like I need to adjust the enhancer to a lower setting, I don't want a blown headgasket. How much boost is the stock 951 engine supposed to handle? (Stock is 0.7bar but what can it safely take)

Remember that the guage is absolute pressure, not boost pressure, so if the guage in the dash is at the "1" marking, then there's zero boost, that's atmospheric pressure.

Typically a chipped car will run around 15 PSI, which would be right about at the "2" bar mark on the guage (atmospheric pressure, which is 1 bar, plus one bar of boost equals 2 bar of absolute pressure).

[nynor]

Originally posted by AaronM
Remember that the guage is absolute pressure, not boost pressure, so if the guage in the dash is at the "1" marking, then there's zero boost, that's atmospheric pressure.

Typically a chipped car will run around 15 PSI, which would be right about at the "2" bar mark on the guage (atmospheric pressure, which is 1 bar, plus one bar of boost equals 2 bar of absolute pressure).

not exactly. at my altitude, the atmospheric pressure is about .8 bar. therefore, at 1 BAR, i have some boost, over atmospheric. PLUS, NA engines will be running at vacuum, in terms of intake manifold pressure. therefore, any positive pressure in the intake is boost.

[nize]

actually, i believe 1bar on the stock gauge is atmospheric pressure, regardless of where you happen to be.

[myskyon]

also i have noticed that my stock gauge is not corect with my aftermarket one. at 0psi it is correct but at 15psi the stock shows the stock boost no diffrence than when i first got the car. so i wouldnt trust the bar gauge at all.

[nynor]

Originally posted by nize
actually, i believe 1bar on the stock gauge is atmospheric pressure, regardless of where you happen to be.

1 BAR is atmospheric pressure at sea level. at the altitude where i live, the atmospheric pressure is about .85 BAR.

[nize]

yes, but the stock gauge doesn't measure atmospheric pressure at sea level, it merely shows the difference between pressure inside the intake and outside air.

so even if the atmospheric pressure were 10psi or 50psi outside, it would match the pressure inside the intake when the motor is shut off, giving you a 1bar reading. make sense ?

[nynor]

nope. turn the key, without starting the car. the gauge does read what the atmospheric pressure is at altitude, because this is the pressure inside the manifold. therefore, at my altitude, my gauge reflects this. 1 BAR is NOT what the outside air pressure is... 1 BAR is 14.7PSI. this is a static concept. therefore, if for some reason the outside air pressure were 50 PSI, it would be ~4 BAR.

thus, no matter what the altitude, full boost on a given turbocharged car is, most likely, is the same.

[nize]

when you turn the key without starting the motor, what does your gauge read ?

[jakemu24]

Whats better then, LBE or a manual boost controller? Either way what would a safe boost level be for a 951?

[nize]

neither is good actually, as they both bypass the built-in knock protection failsafe.

between the two, the lindsey is a little bit safer though.

if you want to bump boost and still be safe, the only two ways i am aware of are;
1) the wolfe3d engine management system from lindsey
2) the megasquirt engine management system (build it yourself)

both retain the stock knock sensor and utilize it to protect the motor properly.

[nynor]

Originally posted by nize
when you turn the key without starting the motor, what does your gauge read ?

my gauge reads about .85 BAR, which is the atmospheric pressure at my altitude. remember: 1BAR is 14.7 PSI, always and forever, which is atmospheric pressure at sea level. at my altitude there is simply less atmospheric pressure, which is why my gauge reads less than 1 BAR, and which is why cars at this altitude have less horsepower, and therefore the numbers are corrected on the dyno, unless they have forced induction of some kind, turbo or supercharger.

[nize]

what altitude are you at? i will have to test this on the next mountain run.

[nynor]

my house sits at approximately 4900 feet. i regularly take runs up mirror lake highway which, at one point, is around 9K or 10K feet, at bald mountain pass.