Manual boost controllers - anyone with experience ?

WRXtranceformed · 02-12-2005, 12:56 PM

Well, after riding in a friend of mine's 03 WRX wagon with the same performance mods as me with an uppipe added and a TXS manual boost controller, that car pulled so much harder than mine. Even without engine management. I can't imagine what it will do after he goes UTEC.

I've researched it quite a bit, but was wondering if anyone here has experience with MBCs. I know a lot of people say "well, that's the quickest way to a blown motor"... even when running stock boost levels. Apparently the newer 04 and 05 WRX ECUs have an open loop / closed loop delay that can compound the problem of detonation and extremely high EGTS.

Then there are some that say they're totally safe when used properly. Any thoughts ? Discuss.

.RJ · 02-12-2005, 01:08 PM

if you are sitll under warranty, the one surefire way to void it is to mess with any of the boost control lines or level

WRXtranceformed · 02-12-2005, 01:25 PM

Technically it's too late for that, since I have engine management (new peak boost ~15.7psi). I do have the option of reverting to stock and hopefully avoiding the dealership's eagle eyes :roll: at the push of a button. The biggest issue apparently with MBCs is PTFB (partial throttle full boost). That's what is tuned for in boost curves with engine management.

Damn though, this car pulled so much harder than mine in the lower gears =p I guess the tradeoff for cheap speed is the possibility of an expensive engine overhaul. I'll probably end up going Cobb stage 2.5 instead, but haven't ruled out a MBC yet.

Evan · 02-12-2005, 03:07 PM

slowly step away from the MBC and no-one gets hurt.

Maengelito · 02-12-2005, 03:21 PM

the only person i know in real life (and not just what i read on the intArnet) with an MBC on his wrx has had it in and out of the shop for several reasons. now i'm not sure about the 04 and 05 ecu's but i'm personally gonna stay away from more b00st for awhile...

Nis01 · 02-12-2005, 09:37 PM

He may be boosting hard now.. but his engine is taking the grunt of it.. Its not going to last long with a MBC set too high for safe levels. I say stick with what has been tested for safe parameters. Happy Boosting!

CaptainHenreh · 02-12-2005, 09:54 PM

MBC on a WRX = nono.

**G.Irish** · 02-12-2005, 10:17 PM

Ask Pete what happened to him when he had his manual boost controller...

white_2kgt · 02-12-2005, 10:22 PM

G.Irish Wrote:Ask Pete what happened to him when he had his manual boost controller...

damn, beat me to it!

--chad

PDenbigh · 02-13-2005, 12:58 AM

Ha, thanks for the intro.

Here's what a MBC will do to ya ;-)

[Image: IMG_3086.JPG]

That's Three, count them - THREE, pistons with the sides blown out of them.:roll:

The good news is that it's a great excute for a complete overhaul and buildup!

KPWSerpiente · 02-13-2005, 03:26 PM

Quote:Then there are some that say they're totally safe when used properly. Any thoughts ? Discuss.

A MBC won't blow up your engine....lack of fuel will. Anytime you increase airflow you have to increase fuel delivery.
Sometimes you need to raise octane level, sometimes you need to retard ignition timing. As long as you have the ability to monitor what is going on it shouldn't be a problem.

I have no clue what happened to PD's engine...but I have a feeling he wasn't logging knock counts when it happened.

-T

PDenbigh · 02-13-2005, 05:03 PM

It was the best 15 seconds ever. Ever.

-Van Wilder

KPWSerpiente · 02-13-2005, 06:36 PM

They do say your car will never run as well as it will right before it's going to go.

-T

**Mike** · 02-13-2005, 09:55 PM

KPWSerpiente Wrote:They do say your car will never run as well as it will right before it's going to go.

-T

who says? dsm guys? if so, i'd trust em, they're experts on the subject Tongue

:poke: :poke:

Dave · 02-13-2005, 09:58 PM

PDenbigh Wrote:It was the best 15 seconds ever. Ever.

-Van Wilder

I wish I coulda been there to see that :-D

Kaan · 02-14-2005, 07:35 AM

pete i dont see anything wrong with that block... JB weld that sucker back together and call it a day...

PDenbigh · 02-14-2005, 07:48 AM

Yeah, I figured a little JB Weld and some RTV Sealer should do the trick. That stuf's high temp baby. At least 300 Deg!

Kaan · 02-14-2005, 09:39 AM

Did you blow a hole in that thing? its a closed deck so i couldnt really tell.

PDenbigh · 02-14-2005, 10:13 AM

The block was fine. 2.3 Fords are iron baby. They have the same bore spacing as a 460 too, so they are tough as nails. The pistons were shot, the rods I'm not sure, but it all got machined and replaced.

So since I posted a before, here's an "after":

http://www.85xr.com/Block_Build.htm

Sorry to jack the thread.

Regarding MBC's, just don't turn it up as high as I did. What you are looking at is what a T3 will do to a stock bottom end at 25psi. I also didn't have an exhaust on it, just a downpipe dumping straight out. It was running fine at first, then I adjusted the timing of the cam, and all hell broke loose.

It was GLORIOUS. And fast too :-).

So, used correctly and with restraint, MBC's offer quicker spool and of cours higher boost. It's worth it to get a good one though so that you don't get a boost "spike" where the boost comes on strong, peaks at, say 18psi, then falls to 15psi.

Hope some of this helps![/url]

**Mike** · 02-14-2005, 10:41 AM

pete, new motor looks so pretty and clean... i want to touch it or something.

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