Boost hesitation and intermittent lack of power

[LeeT5]

Lee - Why did you move away from the Mercedes one way valves to the Volvo ones?

...Because the Volvo ones were more manly.

[Gold 'N' Brown]

I recently bought the valves from Rufe and what I got looked the same as what you have pictured above (white valves). Now I'm no expert on such matters, and perhaps functionally they are every bit as good, but I just couldn't help but feel that the valves I've just fitted seemed of a lesser quality than the originals (which FYI were black on one half, grey on the other). They just don't feel as sturdy.

I agree with you on the quality, my OE ones were black and cream (I guess, originally white but go off white with age....but not grey).

Just for the record, I must point out that I was mistaken on the colour (piss poor memory). My original ones were all one colour, which was a creamy beige. The new ones from Rufe are black on one half and white on the other.

[htomi]

I got the same black & white yesterday.

[htomi]

Finally the car is back on the road. Checked after a 20-25 miles test drive. No errors/DTCs
Slight hesitation is now definitely gone.

List of failed parts:
1. One of the one-way valves was slightly leaking
2. Vaccum lines were aged and weak (on the one way boost circle)
3. Boost pressure sensor O ring aged
4. OTE pipe O ring damaged
5. V band clamp needed a replacement as it got loose.

Replaced parts:

• One way valve (2)
• Vacuum lines on the one way circle ( ended up using stronger & thicker hoses with the same inside diameter) + jubilee clips
• Boost Pressure sensor
• New O ring for the OTE pipe
• New V band clamp.

Part numbers as follows:

• Boost Pressure Sensor: 31355463
• Boost Pressure Sensor Bolt: 986049
• One-way valve (black & white) 9485451
• OTE Pipe O ring: 983891
• OTE Pipe Clamp (V band): 983322

I did 99% of the work myself, only the V clamp has been installed by my buddy mechanic. ( I lost my patient with this f** thing)

@LeeT5 & M-R-P
Thanks for all the help, much appreciated!

[LeeT5]

V band clamps are easy when you've had them on and off a few times. There's a certain knack to it.

[LeeT5]

Does the car drive nicer, feel stronger and more responsive?

[htomi]

Does the car drive nicer, feel stronger and more responsive?

Absolutely! Yesterday evening went for a longer drive (60 miles) and it felt more responsive, stronger. Overall the acceleration is smooth across the entire rev range and the car feels quicker.
The only concern remains, the 3rd gear 6100 rpm end limit in manual mode. I've asked this in another topic, however no definitive answers received yet.

Here is what I found on the us forum:
http://forums.swedespeed.com/showthr...s-and-SAEJ1349

The GT engine is tuned to deliver less power throughout the rev range. Volvo claims it will produce 300hp at 6000rpm except for the conflicting claim of max torque of 258lb-ft (it would take a tad over 6100rpm to get 300hp from 258lb-ft ). However, the entire area under the horsepower versus rpm curve is what I'm referring to. Here there is a substantial difference between the 6MT and the GT. And don't forget that torque is further limited to something around 240-245lb-ft in 1st and 2nd gears in the GT, so this is a hidden power limitation that is not disclosed to customers in their literature. Not only will peak HP be something around 275hp in 1st and 2nd, but the entire area under the power vs rpm curve is even that much lower. When you finally get to 3rd gear and up so you can experience the 258lb-ft, you of course find out that it is limited to about 5800rpm -- hence there is no case in which you can ever experience 300hp in the GT cars.

[LeeT5]

Absolutely! Yesterday evening went for a longer drive (60 miles) and it felt more responsive, stronger. Overall the acceleration is smooth across the entire rev range and the car feels quicker.
The only concern remains, the 3rd gear 6100 rpm end limit in manual mode. I've asked this in another topic, however no definitive answers received yet.

[/I]

With the greatest respect Htomi, why is it a concern? Seriously mate. Your thrashing the nuts off the car for what reason?

[htomi]

Just bugging me.... till I receive/find a definitive answer.

If this is the confirmed stock - factory limit on the 04 GT, then so be it and it will no longer bother me.
In case if I need to rev up that high, just needs to keep in mind to switch gear around 5600-57000 and that's it.

2 wks ago I ran into this limitation after a very long time. ( nearly forgot about that the limit exists). A 'Sunday driver ' made a long queue on the open road, driving around 50-60 km/h @ 100km speed limit. 5 cars were front of me inc the reason of the q, when saw a chance to do a take over. Pushed the S button, switched back to 3rd and floored the pedal. Passing the 4th car in one go, reached the 6100 limit and got surprised why the engine keeps screaming and no more acceleration. Half a second later realized what's happening and same time switched from 3rd to 4th.
So without this limit I would have been able to rev up to 7000-7100 (like on my old S60) and not loosing a 2-3 sec during the take over action.

[stricky1967]

Just bugging me.... till I receive/find a definitive answer.

If this is the confirmed stock - factory limit on the 04 GT, then so be it and it will no longer bother me.
In case if I need to rev up that high, just needs to keep in mind to switch gear around 5600-57000 and that's it.

You could go for the RICA TCM tune that removes the torque limits from the module, I did this when I first got the car 11 or 12 years ago, GT box has been fine, but have to say I never really thrash it.

[htomi]

You could go for the RICA TCM tune that removes the torque limits from the module, I did this when I first got the car 11 or 12 years ago, GT box has been fine, but have to say I never really thrash it.

Thanks!
I know there is a possibility with tuning such as MTE, RICA, Hilton to modify the TCM limitations, however it will put more stress on the drive-line.
That extra load can be compensated with frequent fluid change in all drive line parts.

Just one question, so you recon that you had the same/similar upper rev limit before the RICA tune. Correct?

[antonys60r]

I have a s60r geartronic but mine will rev until the rev limiter cuts in at 6700 rpm. I have only done this twice as I rarely rev it beyond 5000 anyway. In regards to the issue over torque limiting. 1st and 2nd are limited , the boost is limited to 11psi then 3rd and above 15psi boost is allowed. As far as I known torque is 260 ft lb in 1st and 2nd then 295 ft lb in 3rd and above.

[htomi]

Thanks Anthony!
Do you have a 04 S60R 5spd GT?

[stricky1967]

Just one question, so you recon that you had the same/similar upper rev limit before the RICA tune. Correct?

tbh I cant remember what the car used to be like before the tune, remember it being a fair bit slower off the line, I'll try a 3rd gear run when I dont have the mrs. sat beside me and let you know what mine does.

[antonys60r]

Thanks Anthony!
Do you have a 04 S60R 5spd GT?

No problem and yes I have

[htomi]

Gents,

I found several topic on the us forum where various members stating the same, that there is a soft limiter around 6100-6300 rpm 3rd gear on the '04 - 5spd GTs.
So my car is fine and this an expected behavior.

http://forums.swedespeed.com/showthr...with-2004-R-GT
http://forums.swedespeed.com/showthr...-Weird-redline

[antonys60r]

I'm always a little bit skeptical on some of the info on American sites. I know when in auto the tcm calls for a gear change at 6000rpm but I thought in manual you could rev to the limiter. What did yours feel like at 6300rpm. Mine hit the red line and I could feel it as the ignition was cut. Exactly the same happens on the Mrs car when that revs to the redline and the ignition is cut.

[htomi]

....I know when in auto the tcm calls for a gear change at 6000rpm but I thought in manual you could rev to the limiter....

Yes and no.

1st & 2nd I can hit the red line, no problem.
In 3rd I cannot go above the 6300 rpm. It feels exactly the same as you hit the red line limiter. As soon as the rpm drops below the limiter by few hundred, it pulls again hard till the limit.

Tbh, I cannot see exactly the needle (my eyes are not the best) but its somewhere between 6100-6400rpm.

I haven't tried to do the same in 4th as it will be a crazy speed.

[antonys60r]

Ok perhaps that is just the way it is then. A good car is hampered by an inadequate gearbox. ! Having said that the manuals have their own issues as well.

[htomi]

Ok perhaps that is just the way it is then. A good car is hampered by an inadequate gearbox. ! Having said that the manuals have their own issues as well.

As said above: it does not bother me anymore, and certainly can live with this limitation. Like the comfort of the GT.