ktomass

I had GBE MBC fitted to MY92 legacy (used it for over a year) and then tried it on MY96 EU-spec impreza. Both cars are totally standard except de-cat center section and backbox.

Impressions with MBC in place (fitted between turbo niple and waste gate):

Legacy - car got on boost quicker, max boost held was just below 1 bar and all seemed fine. But higher up the rev range from 5500rpm on the car seemed a bit strangled as the ECU would retard ignition (no knocking though). Now, standard car reaches full boost around 3500rpm but it seems faster in upper part of the rev range, and also a bit smoother from 2500-3000rpm.

Impreza MY96 - baically the same thing happened here. All in all they are quite similar technically.

Everyone is saying how transformed the car was after fitting the MBC but as said above i'm not so sure about this.

Appreciate your comments!

Thanks,

Kristijan

Falkirk.scoob

i have a MBC fitted and not had any probs(early days) but if funds allow in car is the way to go in my humble...

Peanuts

iTrader: (15)

fit a knocklink and boost gauge before anything else.
you can wind the boost up to 1.1 bar rather than just under a bar (which is almost standard anyway).
IMHO, they are a bit agricultural but effective none the less.
I run one and its boost held at 1.1 bar all day long, probably gives an extra 10-15 bhp over normal.
however, I have bought an electronic in car version because Im at the next stage in modding my car.
with the manual (unless you buy a dual stage hybrid from j-w-racing.co.uk - approx £100) you set it up and thats that, the only adjustment available is to stop the car, let it cool a bit and wind it in or out. In car you lean forward and push a button, also with the in car jobbie you can set up more than one map and flick between them very easily.

as a beginners mod, with supporting gauges and dials its excellent value for money.
(to show how effective they are, run your car at higher boost for a few weeks and then put it back to standard - you'll notice the difference alright!)

Andy

harvey

iTrader: (48)

Andy: What electronic boost controller did you opt for and what sort of money?

ktomass

Boost gauge and knocklink are already fitted. On Legacy I sometimes hitted a fuel cut with boost on boost gauge at 1 bar. On Impreza it was slightly more than 1 bar and also sometimes hitting a fuel cut. This happened in cold weather naturally. So this was max boost achievable without FCD.

EBC... probably better, but some guys on Scoobynet aren't rating it that high.

Thanks for your replies!

Kristijan

Edited to saythat I did put both cars back to standard and the only difference is that boost came in earlier (around 3000 Legacy and 3300 Impreza) then standard. See again my original post...

The_Judge

Kristijan,

I've had the GBE MkII fitted for exactly 1 year now. It's taken some fine tuning to get it right, but only because of mods made after fitting which affected the boost - Samco hoses, de-cat exhaust, to name but a few. I also had a period of trying out different fuels, with and without Millers octane booster, which required further messing with the GBE due to Knocklink activity. Then settled on Optimax without OB, and ran the boost at 18psi for ages during the winter. But as spring came and the weather started to get warmer, the Knocklink started up again, so the boost is ~16/17psi now. I think that's about the limit for a MY00 TD04 with the standard TMIC.

However, you're right in noticing the ignition advance being affected. I haven't got Delta Dash or anything like that, but I can feel that sometimes it's a bit stifled in the mid to upper rev range. And I occasionally get a amber/red flash at 3500rpm in a high gear at WOT, if I've been hammering it, and if I forget to do what I normally do to work around it (feather the throttle just below those revs, and then gradually open it up). Really annoying, as I know it's just an area of the map that could be ironed out if I had a programmable ECU, or a Tek remap. There's very little activity anywhere else in the rev range, whatever the gear.

Every car's different though, so trial and error play a big part in setting these up. As Andy says though, setting these up without boost/AFR/Knocklink gauges is a recipe for disaster.

ktomass

Couldn't agree more!

The same feeling as described here also lights on knocklink flink sometimes (very rare though) at WOT in 4th or 5th around 3500rpm. Anyone with Delta Dash tried to explain this?

Thanks!

Kristijan

The_Judge

I think the reason it does it is because the standard ECU maps simply can't cater for the modifications and increased boost. And ~3500rpm is roughly where maximum torque is (certainly on mine anyway).

And it only does it occasionally because it's in the rev range where the ECU is using the knock sensor, and so you're effectively seeing off the Knocklink and Bosch sensor what the ECU is seeing off the stock knock sensor. The ECU adds a few negatives to the knock correction for that rev/load, and so it doesn't happen again for ages. The negatives gradually become positives, and then wallop, the loop starts all over again... but I could be totally wrong there! That's how I see it anyway.