V6 tb boost pressure.

[Steve Webb]

I've always assumed that the V6 turbo ran with fairly low boost pressure, but seeing as its only a 2.0L lump yet still makes 200bhp or thereabouts it seems to me that it can't be that low pressure.

So what boost does this engine run, and it is controlled in a similar way to the Q4s or the 75 Turbo, Pierburg valve etc?

Cheers

[SpeakerDocktor]

GTV TB runs standard with ~0,8bar with a short overboost of +0.3bar (so max 1,1bar). The ECU's are the Bosch Motronic ML4.1 + Bosch EZK212 and turbo pressure is controlled by the waste-gate that's actuated by the pierburg valve that on its turn is ECU-controlled. I presume that's similar to other 'older' TB Alfa's.

My GTV has been chiptuned by Squadra Tuning (NL): boost is set to ~1.1bar with the same +0.3bar overboost when booting it, my TB is touching 1.5bar @ overboost at times :thumb: This chiptuning should yield +30HP (230HP max) and +60Nm (max 330Nm).

Cheers

[Steve Webb]

That sounds remarkably similar to the Q4, even down to the base boost and overboost levels.

I don't know where I got the idea the V6 was a low pressure turbo motor. :oops:

Does the GTV Map sensor read above 1.5bar? and how are your head bolts doing?

Be nice to see your car in the forum garage. :thumbsup:

Cheers.

[SpeakerDocktor]

AFAIK there is no boost pressure sensor anywhere, I assume it just follows a mapping of pierburg PWM actuation vs. trottle position/RPM -which might just be two settings of the pierburg; PWM normal boost and PWM overboost :tongue-007:
Up to now I'm not too impressed by the technical complexity of the Alfa turbo-control electrics :icon_wink: but if there a less parts, less can break down...right?

I do know the ECU looks at the air-flow meter (for GTV TB that flap connected to a potentiometer, no air-mass flowmeter); if that reads a too high flow, it thinks 'too high boost' and cuts the boost down via the pierburg.

And headbolts are doing fine...been running like this for 2 years now, although I do have a slipping clutch when overboost really kicks in @3000RPM -but only in winter with an outside temperature of <10?C. As there is no true 'measured boost' control, as air is colder my turbo has more boost...clutch doesn't slip in summer :lol-030:

Cheers, and I'll get some pics up soon -I just got here!

[Steve Webb]

No MAP sensor or control, Eeek! Seems to be a step back from the Q4.

[akiryz]

Consensus is that standard boost is 0.9 bar. Overboost 1,1. Confirmed with boost meters.

[Steve Webb]

Another assumption I have is that the engine uses a single turbo, doesn't this make the exhaust manifold a little complicated or is the exhaust mounted quite a distance away from the engine?

Either way is less than ideal I would have said, can't be much space under the bonnet of a V6 tb GTV. Any chance of some pics of the engine bay.

Cheers

[Brul(tm)]

Borrowed a couple....
http://www.alfabb.com/bb/forums/attachments/other-italian-cars/136947d1239820549-fiat-brava-v6-turbo-alfa-romeo-v6-2.0-tb-engine-8.jpg
http://www.alfabb.com/bb/forums/attachments/picture-room/67006d1179430863-my-gtv-tb-v6-italy-v6-turbo.gtv916iii-3.jpg

Let's take a look at the bottom to ;)
http://www.alfabb.com/bb/forums/attachments/picture-room/115107d1220720822-post-pic-your-alfa-gtv024-e.jpg

[Steve Webb]

http://www.alfabb.com/bb/forums/attachments/picture-room/115107d1220720822-post-pic-your-alfa-gtv024-e.jpg

Blimey, no wonder the sump is finned, its got exhaust pipe on 3 sides. I suppose it helps getting the oil temp up in the winter.

Do GTVs have an oil temp gauge? Wonder what standard oil temp is?

[wrinx]

:cool: I'd love to take one these for a spin.

wrinx

[Steve Webb]

So would I, just a shame I don't really fit inside the cockpit very well. Not much headroom as I remember.

[SpeakerDocktor]

Phase 2+3's have a slightly higher seat than the P1's, so this might help with little headroom. Don't have an original sunroof like mine, that does help 'lighten' things up, but cuts headroom by ~2cm :thinking-011:

There's no oil-temperature gauge as standard, I mounted an oil temperature sensor with adaptor plate in between oilfilter and engine. I actually took the normal coolant temperature guage, but through a switch I can toggle between the coolant and oil temperature on the original coolant gauge. Still have to really check if it is measuring right, but if it is correctly measuring now -oil temperatures of 110-120?C are 'normal' And oil reaches 100?C in about 6 miles...

Ow and that GTV underside is actually my GTV's underside :icon_wink: afaik all V6's have finned sumps, actually all Alfa's we've had in the family have had finned sumps -don't know better that all Alfa's have fins?

On the bottom view, I now have a sport-cat fitted and 'small' Alfisti middle damper. On this pic it's still original cat + open pipe on the spot where the middle-exhaust damper should be (previous owner placed that). Once I fitted the sport-cat, idle gave too much noise + things ratteling in the interiour, hence the 'small' middle damper now:blush: I'm now thinking of getting the Alfaholics middle-damper, just to tune it slighly down more.

Cheers
Martijn

[Steve Webb]

Thanks for that info, I tend to steer away from cars with sunroofs due to the headroom issue. Mind you it not a problem in the Disco. There is enough headroom in there to wear a tophat!!

Sounds like the V6 tb runs with pretty hot oil as standard. Even out on track in the middle of summer my Q4s oil temp didn't get above 100c. How big is the oil cooler on the GTV?

Have you got any video of the car with the new exhaust. Be interested to hear what a V6 turbo sounds like under load.

[SpeakerDocktor]

Don't have a video of my own GTV, but this one http://youtu.be/_kTRFf79Eqk sounds awfully close to mine.:driving-014:

Cheers

[Steve Webb]

Not usually a fan of white cars but that one looks great (apart from the steering wheel).

Are the grill vents (just under the bonnet line) standard on all GTVs? Can't say I've noticed them before.

[SpeakerDocktor]

Yes, those grill vents are standard for the phase 1&2s. With the facelift of the p3 styling (>2003) the whole nose changed and those specific grill vents were gone.

Cheers

[MikeC164]

Have you got any video of the car with the new exhaust. Be interested to hear what a V6 turbo sounds like under load.

Hi, just joined this forum. I have an alfa 164 v6 turbo. These videos are of the car with a new rvs exhaust system from downpipe tot the end :-)

Alfa 164 V6 Turbo Spettacolo Sportivo 2011 Part 1 - YouTube inside -- nice from 9.20 to 10.05
Alfa 164 V6 Turbo duplex exhaust EPS - YouTube exhaust

[Steve Webb]

Now I like that sound, less harsh than the normally aspirated V6, sounds almost like a vintage race car.
I bet the 164 has a little more space under the bonnet too.

Oh and welcome to the Forum.

[MikeC164]

Now I like that sound, less harsh than the normally aspirated V6, sounds almost like a vintage race car.
I bet the 164 has a little more space under the bonnet too.

Oh and welcome to the Forum.

Thanks :-)

Yep, got some space left.. Few weeks replacing the intercooler for a stronger waterintercooler :) Should provide some extra horses!

http://img444.imageshack.us/img444/2105/alfa164bella.jpg
http://img850.imageshack.us/img850/9062/20110608006.jpg
http://img508.imageshack.us/img508/4392/20110608010.jpg
http://img694.imageshack.us/img694/9859/20110426005.jpg

[Steve Webb]

Few weeks replacing the intercooler for a stronger waterintercooler :)

Do you mean you've got a chargecooler? Air to water cooler?

Be interested to see how you install it.

[MikeC164]

Yes indeed :) all the parts arrived. The IC, some adjustment parts, waterpump ford focus RS, waterreservoir,oilradiator saab 9-5 used as radiator for the IC and some small parts. Starting to build it in week or so. Ill post some photos :)

gr Mike

[MikeC164]

To keep the oil from heating up, 2x larger oilcooler placed in the wind:

http://img33.imageshack.us/img33/2386/20111016013.jpg

[Steve Webb]

To keep the oil from heating up, 2x larger oilcooler placed in the wind:

Does it make much difference to the oil temp? And does the 164 have a similar exhaust setup to the GTV?

[Xti]

Welcome, Mike!
My first impression listening that sound was something like "ouuuuch, this car realy hurts". And the Milanos...

Great 164 and I see a lot of care, congrats.

Cheers,
Cristian.

[MikeC164]

Does it make much difference to the oil temp? And does the 164 have a similar exhaust setup to the GTV?

Yeah, makes a huge difference, especially on track. Cools down 30degreesC compared to the previous oilcooler.. It's a good and safe base to start increasing power/turboboost now. :-) Looking at the pic of the gtv above, I'd say the exhaust setup is exactly the same :). Not 100% sure though..

Thanks Cristian! :D

An old vid 0-100 (before new exhaust system):

Alfa 164 V6 Turbo 0-100 - YouTube

[Steve Webb]

-30c is a big drop in temp, I'm guessing the larger oilcooler increases the total amount of oil in the system as well which is going to help as well.