Implementing overboost protection with eboost2?

[Jonas_R]

I got this idea that I could implement overboost protection into my eboost2 gauge.

But I'm a bit unsure how the overboost protection works?

Is it affected by the amount of boost set in the boost map or is it "simply" a question about meassure air flow through MAF and then meassured pressure at MAP sensor?

Also does it send any other signal then to the N75?

My idea was to use the AUX input on the eboost2 via a relay, so when the ECU pulls the N75 the eboost2 would change to a different Boost Group. In this boost group I would simply set the boost pressure to mechanical boost.

Of course this is only possible if the overboost protection is working without taking the boost map into account. If it takes the boost map into account, then I guess you would need a boost map that is similar to the one you make with the eboost2.

Ofcourse I also need some kinda signal that can trigger the relay. I pressume I can't the N75 signal, since it will be pulsing between on/off, and when overboost protection kicks in it will simply be off.

Perhaps this is overkill, but it would be funny to implement just to add another safety meassure. The eboost2 has a boost spike function that returns boost to mechanical pressure.

[GazzaG60]

cant say i have done this with mine. sounds logical though. what the feature does is reduce boost by half if you overboost by over 2.2psi. so set the obs number to around 2.5psi above target boost.

i tend to use just the alarm feature so i know where its at can understand the usefulness though. Also i dont use a boost map. im using mine in basic mode and just ramping it in

how did you pipe the solenoid in the end. did you use the standard method or the method for helping to clamp the gate harder.

[Jonas_R]

I mounted it in dual port setup, and seems to have rather nice spool up on the RS2 turbo.

Thanks for clearing up the boost spike safety feature.

About the boost map, then I was refering to the one in motronic, just to clearify that.

My plan was to run 1.7 bar peak and then going down to 1.5 bar boost around 5800 rpm or a bit before, so I guess i need to use the RPM feature in the eboost2.

[GazzaG60]

have a look at COR. its the offset correction function. allows you to spike a turbo that cant hold it at the top ideal for rs2.

you set your peak, set the max rpm and set the point at which it drops off. the rest is magic. ive not tried this but it looks good for it. maybe add a little on the sensitivity too.

[Jonas_R]

Cool I will look into that

But think I will start out with getting it to run 1.5bar flat out, think that should be possible on the RS2 turbo

[GazzaG60]

this is where the cor helps. it can control the drop off of the turbo that occurs when you set the boost controller so it will compensate to get a nice flat boost curve.

[S2central.net]

Cool I will look into that

But think I will start out with getting it to run 1.5bar flat out, think that should be possible on the RS2 turbo

I personally think 1.5bar at the redline on RS2 is pushing it a little but you might be OK... Keep an eye on EGT and AFR. With big intercooler it maybe OK with regards air temp. Suggest you monitor IAT on your ZT2 as well.

Don't forget that 1.3bar at ~6000rpm is in 360bhp territory so the RS2 injectors don't have much more headroom. Well you have some with a 4bar FPR of course. Use the tools you have there to monitor things nicely along the way... To save you running back and forward to your tuner, it might be nice idea to use variable FPR so you can adjust for good mixture at WOT to keep AFR & EGT good and avoid any knock of course. If the ECU cannot adapt part load maps to that higher FPR then you can get remapped again. Just a thought...

[Jonas_R]

Thanks Paul will do that.

When you say 1.5 bar at redline is pushing it, are you thinking of the turbo then?

What would you call not pushing it - 1.4 bar redline and 1.6-1.7bar peak? When should the boost drop of the peak around 5500 RPM or a bit later?

The car was mapped for around 24-25PSI peak and 22psi redline, so I should be oki on fuel.

[S2central.net]

For safe runs at first I would start with max of 1.6bar up to about 5000 then slope off to about 1.3bar on 6000rpm. Then watch the AFR data carefully as you increase boost levels beyond that. If your Motronic was setup for 22psi (1.5bar) at redline (by which I mean 6000) then you might be fine.

[GazzaG60]

agree with paul.

boost controllers are great. provide, i feel, a much better and diverse control set over boost. however you need to ensure the tuning of the ebc is within the confines of the map. looks like you may be ok though. running that bit lower may have no loss in hp also due to the turbo being well out of efficiency at those boost levels. im no expert on the rs2 turbo. its way to small for my liking.

remember extra boost may require a cut in timing.
also gonig 100 DC on the injectors can cause a few isues and amplify det possabilities.

keep an eye on EGT and WB02.

[Jonas_R]

Yeah will start with the 1.3 bar flat and then add the 1.6 bar peak later on. And when I get that sorted I think I will take a trip to Sweden and get the rest sorted

I remember my tuner saying that I should see around lambda 0.82 around full WOT.