86 951 Driver

I have researched a few way of turning up the boost and what not. It looks like you can do it 3 different ways.

1. MBC-been around forever and is pretty reliable depending on what unit you use Also cheap in price (LBE falls into this catergory I guess)

2. Electronic Boost controller-Been around for a while offers many benefits such as different boost in different gears and what not. Faster spool up I think.

3. banjo bolt-This is an old school authority way. Don't know much about it, just know it is required by their chips.

To crank up the boost you need different chips as well to support the extra air correct?

Wastegate comes into play somewhere.

This is what I have found through my reading.

User 52121

LBE isn't really intended to be used as the sole boost controller. Typically it gets used in conjunction with the stock CV to help spoolup. The DME ultimately still determines max boost level via the CV. For a mostly stock car, these work great and provide good bang for the buck.

MBCs take the place of the stock CV and eliminates the DME's control over boost completely. Reliable, consistent. Requires a good stretch of road and a couple 4th gear WOT passes to get it dialed in. They seem to be affected by weather a little - cold days you'll get a bit more boost than warm days, so be aware of this if you dial in your car on a warm or hot day. Also, as it's basically a fixed valve, your boost levels will vary based on engine load. More load on the motor at WOT in 4th gear than 2nd means you'll get more boost in 4th than 2nd. (Hence why you set it in 4th gear... so you know what you're ultimate MAX boost is set to.) Downside is that you generally get 1-1.5psi less boost in 2nd than you do in 4th. You also have no control over the boost curve - just max boost.

EBC gives you a little more control over the boost curve - you can control both the max boost, and the rate at which it spools. Some also have warning and safety features built in, which is nice to have in the event you get an overboost condition and you don't realize it. Some also give you "gear based boost" to ensure you get the same max boost regardless of engine load.

The wastegate is the valve in the exhaust that opens/closes to control the boost level. Control is done via the vacuum/boost signal off the intake manifold. The stock WG's tend to have soft springs, which in turn tend to open early and vent boost pressure. This affects both spoolup and max possible boost. Either a refreshed stocker or an aftermarket like a TiAL tend to spool quicker and (while there is lots of debate over this) with their dual-port configuration supposedly offer better control and response.

You definitely want different chips over stock if you're going to increase boost beyond an LBE. I run Welt chips in my car, but only because that's what the PO put in, and they seem to work fine. If I were to start over I'd go with either Lindsey/951MAX or Vitesse chips. Since there is no MAP sensor stock, the computer has to guess at how much air passing through the AFM is actually boost (as you want a richer mixture and less spark timing with the more boost you add.) The aftermarket chips I mentioned already make the assumption that you'll be running more boost than stock and build their maps accordingly.

86 951 Driver

That helps a lot. Now I see why people would run what they do. EBC seems to give you a deal of control over the car. Basically you could get rid of the KLR. It sounds like it takes care of some of what it does at least.

LBE is something I would like to try out and see what its all about. Basically it sounded like you could crank that up a little bit and then it would only allow the wastgate to open when it hit the desired boost kinda sorta like a MBC. It was just limited with how high the boost could go.

So with the aftermarket chips would the LBE allow the stock CV to raise the boost to say 15 PSI. The KLR controls that sort of and then with aftermarket chips it raises the boost pressure.

Is a refreshened wastegate worth it or would the lindsey single port one be a better choice.

Willard Bridgham 3

If you get an EBC, don't get greddy, they're junk.

86 951 Driver

My point of this thread is to learn to do things the right way and learn more than I do right now about the 951 turbo system.

User 52121

You mean the CV. EBC will take the place of the CV. It will not completely replace the KLR.

Yes but since the LBE isn't vented, you can wind up with pretty big boost spikes. Though for the most part, you are right. The LBE is pretty much the same thing as a ball/spring MBC, except the MBC's are vented.

When you install the LBE, you generally have it set a few psi below your peak boost levels, so that there is enough time for the CV to take over before getting a big boost spike.


If you set the LBE to 15psi, you'll probably wind up spiking to 17-18psi before coming back down to whatever target boost level the DME/KLR are set to. It's usually recommended you have the LBE set to ~4psi below your peak boost level.

This debate happens a lot around here. Best bet is to continue searching and reading, and make the decision for yourself. I went with a TiAL over the Lindsey because a) I thought the TiAL was a bigger valve than stock and b) it was cheaper than the Lindsey once you factor in the core charge, etc. I now know the stock WG is also 38mm so not really gaining anything there with my TiAL 38, though it's still cheaper than the Lindsey and would probably still go that route.

86 951 Driver

How much did the TiAL wastegate run you?

User 52121

It was right around $400 including the adapter plates from Speed Force Racing.

running_cold924

$340 from Vic at Pauertuning.com. I am happy with mine

86 951 Driver

Just curious with this whole LBE since I am getting one now. If I get a set of chips will I use that to up the boost or will the chips actually turn the boost up for me? Meaning if I get some 944MAX chips set for 15-18 lbs of boost will I have to change any settings or get a MBC since the chips will limit the boost?

User 52121

Not 100% sure if the 944MAX chips utilize the stock CV. I know the Weltmeister chips do - though I think they only run around 13psi (based completely on seat-of-the-pants comparison as I did not have a boost gauge prior to installing my MBC.)

toddk911

Def check out the search and there is volumes of material you will learn from.

86 951 Driver

I have been doing searches. I would like to compile all that info into this thread. The safe way to do things and what not.

TurboTommy

There are no chips that have any hand in controlling boost.
It's up to the chip manufacturer to stipulate to the user how much boost should be run, and it's up to the user to control boost however they see fit.
There's always instructions (or suggestions) from the chip guy, but that's basically it, in a nutshell.

One exception is the autothority KLR chip which changes the duty cycle of the cycling valve to work more progressively from the TPS signal, but even that doesn't change max boost.

dirtyTurbo

Just thought id throw in my 2 cents. My turbo system is completely stock except for chips and the LBE. Maybe I have a defective unit, but where its set now the boost always jumps right up to 14psi and stays there before the wastegate opens(venting the wastegate to atmosphere with mostly stock exhaust makes this testing really easy )
So maybe I got lucky, but I say keep the stock CV and what not and just crank up the LBE to act as your boost controller. Works great for me!