I am SOOOOO Tempted

[azapa]

Only Maserati could turn a piece of poor engineering into an alleged sales plus-point!

Excuse me, but that's just good and fortunate engineering. Surely starting should offer the least resistance to ensure faster catch my kids (and I) love it too. Win win.

 

[voicey]

You don't need to mess around with a pump - you need a vacuum tank with two connections, one to the intake manifold and the other to a Pierburg valve. You control the Pierburg by applying 12v to it, this then applies the vacuum to the exhuast.

 

[CatmanV2]

You don't need to mess around with a pump - you need a vacuum tank with two connections, one to the intake manifold and the other to a Pierburg valve. You control the Pierburg by applying 12v to it, this then applies the vacuum to the exhuast.

Cheers Voicey. Not sure adding a drilling into the manifold, piping it to a vacuum bottle and adding a pierburg valve is less messing around than adding a pump? And we'd still have the loud start 'problem'

Another option would be to tap into the existing system, a la GTS:

http://www.eurospares.co.uk/parts/maserati/granturismo-2008-4-2/engine/additional-air-system-43153

There's clearly a tap under the inlet manifold to create vacuum in the bottle, and an outlet from the bottle to the solenoid valve that controls the secondary air system. So I guess it would be possible to tap into that line between the bottle and the valve, run a pipe do the back of the car and connect up (which is exactly what the GTS and Strad have. It's just a t-juntion in the hose) Still won't solve the loud start and seems like still more work than dropping a pump in the boot. Just more plumbing, really.

If the pipework was already there, though, it'd be a winner

C

 

[conaero]

Manifold vacuum can be picked up from several points around the engine. 12 inches of mercury at idle is what the engine vacuum should be...and no jokes about Freddie please

I have been playing with vaccume gauges to tune the Opel, it's all very interesting stuff.

[video=youtube_share;utUSI-JYhVU]http://youtu.be/utUSI-JYhVU[/video]

 

[CatmanV2]

Manifold vacuum can be picked up from several points around the engine. 12 inches of mercury at idle is what the engine vacuum should be...and no jokes about Freddie please

I have been playing with vaccume gauges to tune the Opel, it's all very interesting stuff.

[video=youtube_share;utUSI-JYhVU]http://youtu.be/utUSI-JYhVU[/video]

Cool! Used to do the same on the old 116 Giulietta

Problem is there is *less* vacuum at WOT. Max vacuum is (probably) at idle. Certainly at high throttle there is less vacuum than at idle. This is why they use vacuum bottles as a reservoir.

Another consideration is that removing the manifold (if you want to tap it for a new feed) means (in theory) 8 new gaskets. At a mere £20 *each*.....

Any other pickup points would be interesting though.

C

 

[voicey]

If you have a vac tank already then T into one of the lines from it and use that to control your pierberg.

 

[CatmanV2]

If you have a vac tank already then T into one of the lines from it and use that to control your pierberg.

Oh yes, all the GT's have one. Not clear *why* but what they hey.

Yes, indeed 'someone' can probably insert a t-joint and run a hose all the way to the back of the car. The other solution I can do myself....

C

 

[CatmanV2]

*Mine*

C

 

[safrane]

Well done pal...close to moving onto a GT myself but don't want to make the same error as I did moving on from the 4200.

 

[Contigo]

Well done pal...close to moving onto a GT myself but don't want to make the same error as I did moving on from the 4200.

No chance of that, GT is light years ahead IMO.

 

[CatmanV2]

No chance of that, GT is light years ahead IMO.

Got to agree. Even mine.....

C

 

[CatmanV2]

Waiting for me when I got home. Not had a chance to unpack them yet.

<happy dance>

C

 

[zagatoes30]

Nice

 

[Contigo]

Waiting for me when I got home. Not had a chance to unpack them yet.

<happy dance>

C

So after much more reading about the 4.2 GT vs 4.7 GT lump apparently with the same boxes on (MC boxes Valved which you now have) there is very little difference in the exhaust note. This is from back to back tests with H pipe and X pipe so they should really transform your car. I look forward to hearing it!

 

[CatmanV2]

Not half as much as I do!

Current ETA for return is next weekend. Then I'm in the US for 10 days, so first weekend in October is looking like a Josh visit

C

 

[CatmanV2]

So

Just how stiff are these valves supposed to be? I'm *assuming* they should move with finger pressure? If not, what's the first steps to trying to free them off?

The actuators move if disconnected, but I can't get the valve arm to move at all. I assume it's meant to move in the direction of the actuator?

C