S70 T5 Overboost

[acshortt5]

Originally Posted by 960kg

It is a shame really that all what i believe in and basically what i have trying to prove to myself and other mere mortals still comes through when people start to put it down in black and white!

Yes, i do appreciate responsible jobs that people have but not when they take it out of the work place and do preach it in public and treat people as if they are better than`.......

It is nice to be a Director of a company and also a book keeper of whatever and also yourself to be a Surveyor but where you measure things up with a tape i was the one that had to read what you had written as up to 5yrs ago i was a builder and a responsible one and not "cowboy".......

The thing is you didn`t know that until now as i keep my private world private and don`t like to make myself superior only when dealing with the Public in my working environment.

You will see in my statistics that i have put down Joiner which is correct but i am more than that but that is sufficient for me. I don`t have the need to elaborate and bore those that haven`t even got a job. I am simply 960kg and that is all i want to be known as.

So all your explanation to me, how to be, i already know and used to practise at work, but you still cannot resist talking to me like a child.

OK, so i have apologised to the OP......but that is where it ends, yes, i may be childish in my ways and to a lot of others on here but there are those that may belive what i have written and i have always supported the underdog and i am not afraid of saying so in public.

I can "undo" and "do" my ignore list at choice, so i will not miss anything.

I don`t wish to talk anymore about the subject as i think it has run it`s course and at least the OP wasn`t scared off which would of been a shame ,at least it seems he is being sorted, one way or another!

Keith

I'm not bothered what you do for a living, I haven't felt the need to check out your profile or your statistics as neither matter to me. What matters to me is helping people out on this forum with good advice.

If you don't want to be treated like a child then I suggest you stop acting like one.

Let's cut the drama queen crap for a moment:

Say the OP followed your advice, went to Volvo and got them to do the work (i.e. change the vac hoses connected to the BCS). They would have done the work and taken £100 off him. On his drive home the OP tests the car out and finds that it is no different - it still reaches peak boost and then spikes on gear changes. Would you refund him his £100? Would you even apologise and admit you got it wrong? Somehow I doubt it.

A big part of this forum is about saving people money. To do that you need to give good advice. If you are going to give advice that you have learned 2nd hand then that's fair enough but you should make sure that the circumstances in both cases match.

This thread should have been done and finished at post 2 when the query was answered correctly. If you wanted a discussion about your opinion then that's fine, even beneficial for the forum, but you should have posted an OPINION not a FACT. If you don't know the difference between fact and opinion then you should look it up in the dictionary.

It's nothing personal, if anyone posts a fact that's incorrect then I or someone else WILL post to correct it, it's how forums work.

By all means put me on your ignore list but remember this: if you post incorrect information then either myself or someone else is going to correct it, there's no getting away from that. So grow up, learn from your mistake and move on.

[outnumbered]

it is a sad day when members have to point out the correct information over and over again and still the Trolls come out to play thank you Andrew for your help in trying to put it into perspective for the OP. the T5 that i had did exactly that.spiked on gear change
mike

[ColoradoSoul03]

Ok, I know I’m bringing up an old topic again, but my 1995 850 T5 is doing the same thing. I don’t have actual boost numbers because I’m going by the factory gauge that does not have numerical values. When under full or near full throttle, there is a momentary spike in boost when the car shifts. It is an Automatic Transmission car. There is a slight but very noticeable pop in the exhaust when it happens as well. Now, my understanding as the difference between a manual and an automatic car when it comes to shifting with a turbo is that when you shift a manual, you let off the gas obviously. This causes a cut in air, fuel, and also opens the CBV, BOV, DV, whichever you like to call it which releases the boost to prevent a lean condition when the throttle is reopened after the shift and also prevents damage to the throttle body and intercooler piping due to the sharp increase in boost when the throttle is suddenly shut and the turbo is still spooled. Now, with an automatic transmission, obviously you do not lift the throttle when the car shifts. As the engine’s RPM increases, so does the turbo’s RPM because the faster the engine is turning, the quicker it uses the air so the turbo has to spin faster to maintain the boost level at whatever setting it is. Now, when the transmission shifts and the engine’s RPM suddenly decreases, the turbo is still spinning fast enough to maintain say 11 psi at 5,500 RPM but now the engine is only turning 4,000 RPM. There is a spike in boost before the turbo slows back down to the necessary RPM to maintain 11psi at 4,000 RPM. This is a normal thing to happen but, if I was the manufacturer and I was programming the ECU (The Bosch Motronic ECU is a VERY GOOD ECU), I would program it to open the TCV right at the shift to fling the wastegate wide open to drop the turbo’s RPM at the same time the transmission shifts. The ECU and TCU communicate constantly so the ECU HAS to know when the transmission is going to shift so it can react properly. It’s either I would program for the TCV to fully open (basically run straight mechanical wastegate instead of holding the boost out of the wastegate’s reference hose and bleeding the excess into the inlet pipe before the turbo) or I would do what VW does on their DSG cars and I would cut the ignition and fuel right at the shift. Now, on my car, all of the hoses to do with the wastegate and TCV are brand new and I’ve recently replaced the turbo as well. This condition has stayed throughout the hose and turbo changes. To me, this is either a normal operation which has been compensated for in the ECU to add more fuel and drop timing right after the shift, poor programming of the ECU if there is not a compensation, or a lagging TCV. The latter seems the most likely. So, does anyone have any experience with the Heavy Duty TCV from IPD? I am getting ready to have the ECU flashed with IPD’s software and I would like to know if this is something that needs to be corrected before I have to flash done. Obviously the flash is going to raise the requested boost in the ECU so this spike is going to be exaggerated after the flash and I really don’t want to cause damage or blow the engine because of it. Or, does IPD’s software compensate for this issue? If they have addressed this issue and the problem doesn’t happen on their software, there may not be anything to worry about. Another note: this really seems to be most significant when the car is in “Sport” mode, probably because the shift logic is different and the ECU and TCU are running a more aggressive map for everything. Sorry for the novel you all had to read and I hope I wasn’t ambiguous with anything.

[acshortt5]

It shouldn't be popping in the exhaust on gear changes. I'd have a look and see if you have an exhaust leak first of all - my mx5 (miata) popped and sounded like a rally car with antilag, especially on overrun, when I had a small leak at a joint in the exhaust. I've never had any popping in the exhaust on the volvo.

Personally I don't think it's poor mapping at all on the factory ecu, I find the shifts and power delivery to be extremely smooth, certainly on a par with other younger autos I've driven.
Time has moved on of course and there may well be better ways of mapping the gear changes now but this is only because other aspects of engine management have advanced such as coil on plug with individual cylinder monitoring and VVT as opposed to what we have which is cylinder firing driven directly off the end of the camshaft (via the rotor arm/dizzy cap) with a single coil providing power to the plugs - they did the best with what they had at the time.

I run the IPD TCV, it has not made a difference to me but I have not had a remap.

I've not noticed any difference in boost levels in sport mode. It just makes the gearbox hold a lower gear for longer (and burns more in fuel) so when you put your foot down it does "feel" more aggressive.

If you have queries on the IPD map you really ought to direct those to IPD to get the best answers and have a look on the american volvo forums as there should be some reviews out there.

[ColoradoSoul03]

Originally Posted by acshortt5

It shouldn't be popping in the exhaust on gear changes. I'd have a look and see if you have an exhaust leak first of all - my mx5 (miata) popped and sounded like a rally car with antilag, especially on overrun, when I had a small leak at a joint in the exhaust. I've never had any popping in the exhaust on the volvo.

Personally I don't think it's poor mapping at all on the factory ecu, I find the shifts and power delivery to be extremely smooth, certainly on a par with other younger autos I've driven.
Time has moved on of course and there may well be better ways of mapping the gear changes now but this is only because other aspects of engine management have advanced such as coil on plug with individual cylinder monitoring and VVT as opposed to what we have which is cylinder firing driven directly off the end of the camshaft (via the rotor arm/dizzy cap) with a single coil providing power to the plugs - they did the best with what they had at the time.

I run the IPD TCV, it has not made a difference to me but I have not had a remap.

I've not noticed any difference in boost levels in sport mode. It just makes the gearbox hold a lower gear for longer (and burns more in fuel) so when you put your foot down it does "feel" more aggressive.

If you have queries on the IPD map you really ought to direct those to IPD to get the best answers and have a look on the american volvo forums as there should be some reviews out there.

There are no exhaust leaks. The exhaust is brand new from IPD and it was properly installed. The popping to me sounds like either a lean condition due to the overboost on the shift or possibly an ignition or fuel cut due to the overboost. And yes, there is no difference in boost between normal and sport, just a more aggressive shift logic and holding more RPM. It may shift faster though by tightening up the delay between the clutch packs in the transmission which will also give the turbo less time to react to the shift. I completely understand the physics of what is going on with the overboost, I’m just wondering if the ECU is already compensating for the issue with increased fuel or if the compensation is not working due to a lagging TCV. Other than this slight issue, this car runs simply amazing even with 265k miles! For you folks on that side of the pond, that’s about 427,000 km!

[SteveSarre]

Hi ColoradoSoul03

I haven't read the whole of this old thread (it's such a long one), and I don't know anything about 850s.

But on a 1999 V70 AWD Manual using a VIDA Dice diagnostic device I noticed some spiking on gear change. No popping or any other noticeable problems.

The diagnostic device let me watch boost pressure and also the turbo control valve duty cycle.

I replaced the TCV (replaced with known good), which I don't think made any difference but what greatly reduced the spikes was replacing the vacuum line check valves. That car had two. You can test them by blowing. They should let air through one way, but not the other. Cheap to buy (I bought non volvo). While you are at it, might as well replace various vacuum lines if they need it.


Make sure you install them or their replacements the same/right way round, and keep the same connections to the TCV.

I went on to check some other similar Volvos, and found quite a few failed check valves.

HTH
Steve

[foggyjames]

In other news...you're still alive, Andrew! Long time no see...!

cheers

James

[acshortt5]

Originally Posted by foggyjames

In other news...you're still alive, Andrew! Long time no see...!

cheers

James

Hi James

Yes still alive although life keeps finding increasingly inventive ways of being difficult for me.

I might try to get to castle Combe this year (if it's on). I suppose if we have a gathering at the current time one led by a doctor is probably the way to go....

[foggyjames]

I think that's true for most of us!

No word on CC this year. The Doc has been having a rough time of it with family health problems, so it might have having a year's hiatus.

Will be good to see you as and when!

cheers

James