no more boost drop and added turbo pressure

[Yarddogperformance]

ok guys so ive had a few posts about boost pressure and a few other things, well the drive shaft repair is still in the works as i found a good unit in the junk yard.

no boost and volvo, ive learned a few things and thought id share. now if you do not change your own oil, with your own hands please leave this post at this time before you severely damage your vehicle.

so i had a high rpm boost drop and a lack of power, upon witch i have found that i have a high pressure short block and a low pressure head and tune. so when i retardedly turned the boost up to what i though was 10 psi, ( 10 psi in the engine) was really cruising about 30 psi in the charge tube, thus opening the gate and dumping the exhaust. i also found that the tcs is controlling traction with the performance of the engine and not dragging a brake like american cars do.

so, any one want real power?

well i had given up on turning my boost up so i thought well ill just make it chatter and when the turbine goes out ill go for higher flow at the same pressures.

so i disconnected my bov, and my waste gate feed off of the charge housing, with a chuckle i thought well ill move the waste-gate feed to read post throttle boost, and ill use boost pressure to hold the bypass closed and it may be slow but at-least it'll have chatter.

well she chattered all right, not only does she chatter but im getting full boost at 1500 rpm, with no high rpm drop, im talking 10-13 psi, from the ecm all the way through the engines range, mileage went from 24 to 28 without the rear shaft.now with the rear shaft im getting 25 on windy days up hill.

however if your car is front drive be carefull, because when shes above 1500 rpm boost is instant, and traction breaks immediately, but man is she fast.

they say we need darton sleeves and 30 psi to kill the m3, but i do not agree, i think for a stock m3 a volvo plumbed right can kill it like a wasp in 2 gears, and hold it at bay above 120mph

thats all guys, if anyone has questions id be happy to answer, ive put 5k miles on since this mod, no issues or noises

[abscate]

Do you think you really have a hybrid block head or just a low pressure boost turbo?

The LPT is designed for boost at low rpm, the HPT in the T5 and R models give boost at high rpm

Be careful playing with boost with ME7, if you look in the TUNING forum you will find people who bent rods making small changes

The 1998 and earlier P80s are more forgiving

[Sommerfeldt]

Okay, so it may be that I'm just a dumb Scandinavian, but I'm having great difficulty deciphering what it is you're talking about.

- Putting 30 psi into your engine (somehow with a stock turbo?) will blow an unsleeved and unprepared engine. How you get one pressure in the "charge tubes" and another in the engine is also a mystery.

- Your stock turbo will do nothing good at 30 psi in any case - all heat and no play makes Volvo a dull boy.

- What on earth do you mean by "post throttle boost"? Are you plumbing the wastegate from the intake manifold?

- How would the TCV control traction?

My T5 with the HPT has "factory" plumbing, and while what abscate mentioned plays in here, it's certainly boosting from ~2k, building and holding just fine. If there's one thing that's dangerous to rods and engines, it's high pressure at low rpms - even 13 psi at 1500 seems like a risky move.

- S

[Yarddogperformance]

Ok guys here's the creyola version.
Boost in the charge tube is higher than boost in the engine
Volvo reads charge tube boost

So you set turbo to 13 psi in the engine, and viola the pc says no it's 30 psi because the pressure drop after the throttle.

So, if you move the Watergate sensing line after the throttlebody the pcm still controls boost, only now the engine sees 8 psi,, when the computor sees 8 psi. No tune, just a cleaner version of the factory tune, no extra boost, just a corrected boost.

[hausmeister]

So, what's your 0-60 time with these very special mods?

[Sommerfeldt]

Look... I'm not trying to rag on you, but you're being a little wooly about this.

You're saying that the 15G on my car will spin up 30 psi and then dump it? I'm picking up vacuum & boost for both my gauges from the vacuum tree, and that means it should either be just twirling its needle like a ballet dancer on crack, or hardly show anything at all. It's certainly not showing 30 psi at any point, and these are mechanical gauges, mind you.

The wastegate is getting its line directly from the TCV, not from any kind of "charge tube" - so back to my question: Where are you plumbing your wastegate from, if not from where its supposed to be from?

And are you using a BOV with a recycling system? Because that's not exactly ideal either...
I'm just trying to understand what you're saying here - I appreciate the crayola version.

- S

[abscate]

ME7 monitors the charge tube pressure just before the ETM, and of course the ECU map knows that this is not the boost pressure after the ETM.

Manual boost control will give you more kick, but it will also bend rods. Two turns the wrong way on an ME7 wastegAte, you will bend a rod.

[Sommerfeldt]

So... in essence, Yarddog is simply tricking the ECU into thinking pressure is lower than the actual pressure where it’s expecting to measure from?

Correct me if I’m wrong, abscate, but the trouble is moving the boost curve too much, right? Ie. too much boost at too low rpms? So if Yarddog’s plant sees 13 psi, the actual pressure where it should be measured at any given rpm is probably far higher than it should be, already?

Seems riskier and riskier.

- S

[abscate]

Boosting and tuning is out of my expertise, but the guys in the tuning forum like ARD know their stuff.

I’ll push this discussion here when done.

[villagepc]

Do you have any videos of your car pulling 13psi at 1500 rpm? I've love to see it.