[Autotechnica]

Hey guys, finally my car is running reliably and properly with the 19T setup. My AFRs are good and the car boots. I just have some questions about boost fade. I've seen that this is quite common with all the volvo/mitsu turbos. I got fade when I had my 15G, I get fade now with the 19T. Is it because of the internal wastegate or actuator? Does the stock one only hold around 15psi of boost? What happens is I get 20psi of boost when I first hit WOT in 3rd or 4th gear (I have a 5 speed), then after 4800-5000RPM it slowly drops to 15-16psi and stays there. I'm using the AVC-R and no amount of fiddling with higher rev duty cycles seem to fix the problem. Are there upgrades I can get to fix this? Everyone says to get the S60R mani, but from people I've talked to who have done this, this does jack for boost fade. It really seems more like the factory wastegate isn't holding the boost. Any help much apprecaited, I really love the 19T and it's making great results right now, just wish I could hold at least 18psi to redline. I've read something a while ago about someone modding a Garett actuator to fit?

BTW some basic mods as follows...

19T angle flanged, green injectors, RICA tune, walbro 255 pump, AEM AFPR, Apexi AVCR, M56L w/ bully modified R pressure plate and carbon kevlar clutch disc, 3" d/p, 2.5" exhaust, FMIC, EST RIP, TurboXS BOV, etc etc...

thanks guys,

Bry

[turbor850]

get rid of that BOV for one, or take it out and see if you can get higher boost in the higher gears, report back . . .

[B Mac]

An R manifold will definitely help smooth the flow out. Do you have n/a cams or anything too? I'm having the same problem with my 15g (n/a cams, 3" exhaust, R mani) so I think the only thing left I can do is get it tuned to add some timing in the top end. Have you talked to RICA about it at all??

[Autotechnica]

B Mac, on 27 June 2009 - 07:45 AM, said:

An R manifold will definitely help smooth the flow out. Do you have n/a cams or anything too? I'm having the same problem with my 15g (n/a cams, 3" exhaust, R mani) so I think the only thing left I can do is get it tuned to add some timing in the top end. Have you talked to RICA about it at all??

Getting a good tune from RICA is like playing the lottery. I'm just glad I finally have my tuning issues sorted out. The RICA tune was tunned too rich at low revs but too lean at high revs. I honestly don't know how cars are running around with 19T's that have tunes like that!

Anyways, I have N/A cams sitting in my basement, do they help at all?

turbor850, on 27 June 2009 - 07:43 AM, said:

get rid of that BOV for one, or take it out and see if you can get higher boost in the higher gears, report back . . .

Why would the BOV cause it to fade? I can tighten the spring so it barely vents, but it still does the same thing. BTW, I don't think the stock CBV likes seeing that much boost. I hate putting in the stock CBV, it's always death....

[dublin14]

As soon as i put on my R mani, my car felt smoother and better up top! I have a cracked intercooler, but could still feel the difference. I have to yet install my Precision FMIC. I think your crazy not to have an R-mani with your current set-up! More HP, smoother, and lower EGTs with the better flow... the last piece of the puzzle! I bought mine at "Cookstown auto wreckers" for $150, in perfect condition... try them!

[Autotechnica]

dublin14, on 27 June 2009 - 08:03 AM, said:

As soon as i put on my R mani, my car felt smoother and better up top! I have a cracked intercooler, but could still feel the difference. I have to yet install my Precision FMIC. I think your crazy not to have an R-mani with your current set-up! More HP, smoother, and lower EGTs with the better flow... the last piece of the puzzle! I bought mine at "Cookstown auto wreckers" for $150, in perfect condition... try them!

STEAL!!!! Do they have anymore? Maybe they have some tranny's too

BTW, do you ever get out to meets or even the track? I'd love to see your car. We can discuss all the things wrong with the RICA tune and the 19T.. lol

[dublin14]

Autotechnica, on 27 June 2009 - 12:05 PM, said:

STEAL!!!! Do they have anymore? Maybe they have some tranny's too

I bought mine early this year! But call them if they have "any" Volvo 2.5T 04+ manifolds, with the last two numbers ending in "2 1" thats what you want. Mine came of an XC90, there all the same for the 2.5T engine!

[dublin14]

I have only been out on the track in my Volvo a few times. Most of the time i spend on the track is in the US racing in the NASA with a great friend of mine who trusts me in his 600HP C6 Z06 track built! He actually just had a World challenge Katech C6R built for him, 660hp and 2600lbs and no expense spared... she well be finest car i have driven yet. Next spring if my i beat this last ticket i will be picking up my own C6 Z06 for the street and track, if not i wait one more year I have more plans for the Volvo, in the next while put on my UR pulley, NA TB,and the FMIC. Then Porsche brakes, and Konis/IPD sway bars and then i will spend more time at the track. Shes in for paint as we speak!

[turbor850]

Autotechnica, on 27 June 2009 - 10:58 AM, said:

Why would the BOV cause it to fade? I can tighten the spring so it barely vents, but it still does the same thing. BTW, I don't think the stock CBV likes seeing that much boost. I hate putting in the stock CBV, it's always death....

turboxs bov have washers to tighten them if iirc ? what spring ?

[Autotechnica]

turbor850, on 27 June 2009 - 08:39 AM, said:

turboxs bov have washers to tighten them if iirc ? what spring ?

The whole point of adding washers is to tighten the tension of the spring. I assumed you already knew how a BOV worked and I didn't need to explain adding washers. Theoretically you're just tightening the spring. Add enough washers and the BOV won't vent and you just get compressor surge. I've already ruled out the possiblity of a leaking BOV. Anyways, I've seen on every single 19T video or even in person that there is boost fade past mid ranged RPM's. I just wanted to know if there were actuator upgrades available. I still see fade on my friends 19T w/ S60R manifold and CBV, so I assume it has to do with the actuator. As per my understanding, people normally get BOV's to run higher boost when the stock diaphrams max out and tear.

[Autotechnica]

dublin14, on 27 June 2009 - 08:39 AM, said:

I have only been out on the track in my Volvo a few times. Most of the time i spend on the track is in the US racing in the NASA with a great friend of mine who trusts me in his 600HP C6 Z06 track built! He actually just had a World challenge Katech C6R built for him, 660hp and 2600lbs and no expense spared... she well be finest car i have driven yet. Next spring if my i beat this last ticket i will be picking up my own C6 Z06 for the street and track, if not i wait one more year I have more plans for the Volvo, in the next while put on my UR pulley, NA TB,and the FMIC. Then Porsche brakes, and Konis/IPD sway bars and then i will spend more time at the track. Shes in for paint as we speak!

Sweet, is the N/A TB larger? Just out of curiousity do you know where I can score a pulley to replace the A/C compressor?

[dublin14]

Autotechnica, on 27 June 2009 - 02:52 PM, said:

Sweet, is the N/A TB larger? Just out of curiousity do you know where I can score a pulley to replace the A/C compressor?

Its a NA TB modified with a 960 plate! Bigger and better flow! Not sure about the pulley?

[RZT5]

Your boost fade is happening because of the combination of a small turbine housing relative to the amount of air you are trying to flow, the wastegate flapper's diameter, and the actuators ability to hold the wastegate closed. Out of this list the only one you can modify without changing turbos is the actuator.

I would try modding a stronger actuator to fit, or get a custom built one from forge for example. The 19T actuators are meant to control boost effectively at around 12 psi on a volvo whiteblock. the pressures inside the turbine housing required to make 18psi at redline on our motors multiplied by the area of the wastegate flapper and the length of the flapper arm is simply more than the amount a force the actuator can produce which is why its opening.

[EricF]

RZT5, on 27 June 2009 - 03:54 PM, said:

Your boost fade is happening because of the combination of a small turbine housing relative to the amount of air you are trying to flow, the wastegate flapper's diameter, and the actuators ability to hold the wastegate closed. Out of this list the only one you can modify without changing turbos is the actuator.

I would try modding a stronger actuator to fit, or get a custom built one from forge for example. The 19T actuators are meant to control boost effectively at around 12 psi on a volvo whiteblock. the pressures inside the turbine housing required to make 18psi at redline on our motors multiplied by the area of the wastegate flapper and the length of the flapper arm is simply more than the amount a force the actuator can produce which is why its opening.

Good post. That said, the 300/70 19T actuator should be more than sufficient if it's in good shape. Given how much travel these actuator springs need to do, I wonder if they ever start to get tired?

My 19T/manual setup was absolutely dead rock solid with just a bleed type manual boost controller, even to 23-24 psi it would hold the target boost level until redline.

I would try messing with actuator arm preload, less preload should be less spiking. Aside from that, maybe try a new or different actuator. The 300/70 worked perfectly fine for me, but maybe not for others.

As an aside, on my blue car currently (B21FT with nice-flowing head and decent cam), I spike 24-25 psi and fade to 19-21. This is with the angle outlet housing and the wastegate flapper essentially wired shut. With a ported conical housing and the same setup otherwise, the fade was to 16-17 psi by redline. I think now it may be the exhaust limiting it, or it could just be the turbine wheel itself though based on my past experiences with the 19T I'm inclined to try other things before accepting that possibility.

[TorqueSteer]

Im leading towards the small turbine housing. On my Td05 housing, I have zero fade on stock manifold, stock heads etc.. The wastegate is also very strong. Maybe you can order one from Hahn and retrofit it on there.

[turbor850]

EricF, on 27 June 2009 - 05:28 PM, said:

Good post. That said, the 300/70 19T actuator should be more than sufficient if it's in good shape. Given how much travel these actuator springs need to do, I wonder if they ever start to get tired?

My 19T/manual setup was absolutely dead rock solid with just a bleed type manual boost controller, even to 23-24 psi it would hold the target boost level until redline.

my auto when I had a 19T would fade a bit in 1st and second and stay rock solid 20 psi in third . . . maybe you need a new boost controller

TorqueSteer, on 27 June 2009 - 06:29 PM, said:

Im leading towards the small turbine housing. On my Td05 housing, I have zero fade on stock manifold, stock heads etc.. The wastegate is also very strong. Maybe you can order one from Hahn and retrofit it on there.

wastegate from Hahn is 10X stronger then any td04 wastegate, Fiore has one on his td04-super60-turbzilla and his is just hold any boost anytime, no fade

[lookforjoe]

Autotechnica, on 27 June 2009 - 10:58 AM, said:

Getting a good tune from RICA is like playing the lottery. I'm just glad I finally have my tuning issues sorted out. The RICA tune was tunned too rich at low revs but too lean at high revs. I honestly don't know how cars are running around with 19T's that have tunes like that!

Anyways, I have N/A cams sitting in my basement, do they help at all?



Why would the BOV cause it to fade? I can tighten the spring so it barely vents, but it still does the same thing. BTW, I don't think the stock CBV likes seeing that much boost. I hate putting in the stock CBV, it's always death....

I only had about 2psi fade on my 19T using the stock CBV (shimmed for 20psi) - and a LSP MBC.

[JCviggen]

lookforjoe, on 28 June 2009 - 02:43 AM, said:

I only had about 2psi fade on my 19T using the stock CBV (shimmed for 20psi) - and a LSP MBC.

Why does it only go to 5500rpm? It's at 6-6.5 that the 19T really drops off, no surprise at 5.5K

[TBM]

I get the same exact behavior from my 16T. I thought it was related to a small boost leak somewhere (even though I've done Stage 0), but after reading your post, I'm almost convinced it's something else.