FS: Unichip and MBC
 

Anyone want a UniChip and Manual Boost Controller?

I'm selling mine as soon as I get my Vishnu Stage 1 remapped ECU (early Feb). It'll have the Stage 0 map on it, the plug-n-play harness (with the EMI Adapter wiring already done... but no EMI Adapter), and the MBC from my Stage 0 setup.

My Stage 0 is mapped for:
Vishnu 321 Up-Pipe
MBC @ 15.5 psi
Vishnu Underdrive Pulley
NKG colder plugs
Vishnu Intercooler Hoses

You can prolly run it as it is (Unichip and MBC) but I'd suggest getting it retuned by Vishnu (send it in with a list of your parts, and he'll send it back programmed for your stuff), or getting the parts the map was made for.

I'm asking $400... the unchip by itself is around $500 new, and this includes the MBC and harness.

Scott, Do you still have the UniChip for sale? What engine management are you using?

I would like to go with a utec but it's not STX legal.... It looks like the unichip is one of the only choices.

Theo

Nope, that was back when I was planning on running SM... but now I gotta keep the UniChip to stay in STX.

Maybe next season I'll make the move to SM, but that will mean at least coilovers, R-compounds, and an ECUTek... which may still leave me uncompetative in SM and cost too much. :lol:

Wanna sell your MBC Scott?

I am not sure what type of Mods I am gonna start doing but this is cool (Even Though I dont think will fit the 04's:
http://headrestembroidery.com/

Hey, not a bad idea...

How's about $15 shipped! (:lol: shipped)

Lol....you got it. I'll bring it to the meet on Thursday. Thanks.

Art it is not safe to turn up your boost till you get rid of the cat in your uppipe. You run the risk of over heating the cat then it will start to fall apart and shoot peices through your turbo. You remember that one night with jason it was about to happen thats the first time I had seen it I have read about the upipe cat going but that was nuts. :wink:

Boost won't be turned up, just more consecutive. Remember I peak at 14.5 but I don't stay at it. Should that be a problem.

Not to mention the Uppipe will be replaced soon...might as well have a MBC on hand.

As I've posted before, the issue with MBC's only comes into play in 2 situations:

1) if you have the boost turned way the hell up
2) if you are under a partial-throttle/full-boost (PTFB) condition

Think of it this way: you can run a ton of boost in a WRX motor as long as you can keep things cool enough to avoid detonation. The motor will not blow up simple because it's making a lot of power, it blows up when the a/f charge detonates early while the piston is still on the way up the cylinder. Preventing detonation is simply keeping things cool enough that they don't explode untill the spark plug goes off.

On a mostly stock motor, what keeps things cool is the fuel. If you have a rich enough mixture things won't detonate, especially at our high altitude. As the mixture leans out, things heat up. You can see this in the EGTs. On a WRX once you start getting to the 1550F EGTs, start thinking about not driving so hard, however I've heard the WRX motor should be good to 1600F.

When you throw a MBC in the mix, you have to remember the car's ECU is what controls fuel, which is the primary means to keeping things cool in a mostly stock car. If you have a MBC, you are putting more air into the motor than the ECU expects.

For example, you set the MBC at 18psi (not that the stock turbo can really put out that much boost, but for argument's sake). When you floor it, the car will open the fuel injectors all the way and try to dump enuf fuel for what it thinks is 14.5psi, since that's what the stock boost maxes at. Because you're forcing extra air in there, and because the stock fuel system can't handle all that boost, the mixture leans out. Do it enough and you blow up the car. Setting the MBC way high is obviously a bad thing.

Now let's look at setting the MBC at stock boost levels, say 15psi. At 15psi, you'd think it'd be impossible to over-boost. However, you need to remember that the ECU thinks it knows your boost curve. It thinks at 50% throttle at a certain MAF/MAP load, the car will have say 8psi of boost. But since there's a MBC on there, your car is actually producing 15psi! The ECU is dumping the proper amount of fuel for 8psi, not 15... so you can end up with a lean condition. This is where it's important to watch your EGT gauge... if for example, you're climing a long hill in 5th at 50% throttle, you will boost to max... the EGT's will rise. Once they start getting up there, you need to back off the boost, or floor it to trigger additional fuel. PTFB conditions don't occur too often, so it's usually okay to run a MBC set at stock levels, but you really need an EGT to watch things.

Now, regarding "overheating the cat" with a MBC. Let's remember what cats are for, and how they work. They're basically a metal mesh in the exhaust that heats up. The heated mesh is designed to burn off unburnt fuel in the exhaust so it doesn't blow out the back of the car.

What destroys cats is *not* hi temp exhaust, it's *rich* exhaust! If there's tons of unburnt fuel in the exhaust, the cat has to burn it... that's what overheats and destroys cats. Running lean due to a MBC will not destroy your up-pipe cat, since you're sending hardly any fuel out in the exhaust. Running lean due to a MBC break motors by causing detonation.

SSSSOooooooo......If I set the MBC to say 15 psi, and just watch my egt temps it should be okay? I have already seen them in 1,550 range (When doing 115mph :? ).

A big problem I see is that it only spikes at 14.5 psi. I would like to keep it consistant at WOT that it sticks at 14.5 or 15 so I can get full potential on the track.

Bingo... that's the point of the MBC set at stock boost levels... it doesn't back off... and as long as you watch the EGTs you should be fine.

One more thing to note, it's a little harder to avoid the PTFB conditions in an auto... just keep an eye on those EGTs.at 1500F think about backing off and letting the car cool... or hit the sprayer on the intercooler to try and eliminate some of the heat soak... oh wait... :lol:

Bastard :x :lol:

Thats gatta be done soon also.

I am spending to much money on keeping the damn car cool then on power mods....pfffttttt.