18T And The 18 Psi Wall

[Chilled man]

If that was the case as Leroy said, why not get a custom 3" maf from a different car to run higher boost

or a P2 R ..... :excl:

[AverageVolvo]

Mbc no Bs Bcs or tcv, Water/Methaol injection 20 psi Rocks.

Without water injection 18 psi is about all your going to be able to run efficiently.

And yes TT has Maf adjustments as well as every thing else less a stand alone.

[lookforjoe]

If that was the case as Leroy said, why not get a custom 3" maf from a different car to run higher boost

Unless you are logging AFR's & timing, there is no practical way (other than dyno) to measure the differences between 18psi & up on stock Volvo turbo setups. 850's don't allow for timing data extraction via OBD, so don't know how you would accomplish that. I believe JCViggen (using TT) just works around it, using other data to extrapolate best timing, etc.

You can change the MAF Housing, however the MAF itself, I don't believe there are alternative applications that use that style Bosch MAF, but that allow for higher flow. I didn't have any luck sourcing one.

I hit the MAF ceiling very quickly with the hybrid 20g; the problem is more to do with the fact that you cannot tell what the ECU is doing with timing when the MAF is maxxed out. Using a 3" housing moves the operating window, so you don't hit max MAF until much higher up, therefore you can more readily see what the timing map needs.

example: 231 is max recordable

vs 3" housing - look at WOT (TPS 4.13-4.3v)

None of this will work with any off the shelf tune, so unless you have TT, it's a moot point. Standalones won't even use a MAF anyway, because of the inherent limitations, so it's a non-issue there.

[fischmama]

None of this will work with any off the shelf tune, so unless you have TT, it's a moot point. Standalones won't even use a MAF anyway, because of the inherent limitations, so it's a non-issue there.

Apexi SAFC will be an option here, No?

[flyfishing3]

i'm set up for 1.2 bar on a 18t.

IMO this is the max for a car my wife drives once in ahwile. i feel i could safely go a smidge up but its not worth it IMO. if i was going to try and grab an extra PSI i'd do it with a EBC. caveat, only 1 psi.

[lookforjoe]

Apexi SAFC will be an option here, No?

I don't know - if the systems it's designed for utilize a similar MAF to the Bosch system, then it would seem possible. I don't know enough about it, and glancing at the schematics, it lists Hot Wire, Flap & Pressure styles, ours is Film type, I believe...

[loseR99]

Unless you've done head work won't you reach a point where the engine gets choked if you're cramming more boost than it can handle? I'd rather run less boost, in a safe fuel and timing area, and pull harder on motor, then boost past the efficiency range and effectively go nowhere (ie. boosting more but revs hang or don't climb). I experienced this on the old S40, tuned for 20psi on a 14T twin scroll, but was only usable from about 70mph-130mph. It made less HP and more torque at 20psi, and more HP and slightly less torque on 17-18-psi (because it didn't drop off as hard on the top end and could stay more efficient).

Like someone stated above, if you're able to use a mbc or ebc effectively, get your car on dyno and tune for the sweet spot on your particular hardware/software configuration. I'd start at 15psi and work up, rather than 20psi and work down. There is a point of diminishing returns.

[lookforjoe]

Unless you've done head work won't you reach a point where the engine gets choked if you're cramming more boost than it can handle?

Well, any boost is a result of positive pressure buildup in the intake, which has to mean it's not flowing through the head.... as you said, it's all about finding the ideal spot for your specific setup.

Stock TD04's just can't run that much (20 +) boost efficiently. I know I tried

20psi on a 14T seems overoptimistic from the get-go! :lol:

[loseR99]

Different 14T. TD04L-14T...not TD04HL. Original from the euro T4 S40, which was the HPT model. :-)