Blow off valves on Enrico's pages

I got mentioned twice recently on Enrico's Maserati Pages! It certainly feels good to think that I'm giving something back having been helped so much by the Maserati community.

First of all... good to see that Yannick and I (and Jarle in Norway, who has something similar fitted to his 224) are in agreement with racing teams as to the proper location of the blow off valves! The picture below from Enrico's pages shows what appears to be a racing version of the Open Cup, with blow off valves located on the underside of the inlet piping leading to the throttle body.


But what drew my eye is that on this Open Cup, the boost control solenoid valve has also been replaced? It looks like it's that blue part to the right of the intake manifold? This suggests to me that, as I suspect, the OEM solenoid is not that reliable and perhaps is a bit lacking in performance. This replacement solenoid appears to have a screw adjustment on top of it... perhaps to control the boost setting, indicating that this solenoid is mechanically adjusted, which seems a bit odd for a racer?

Of course, I could well be talking rubbish, but it would be nice to find out!

On the Mov'it side, the new components are set to arrive next week. This is unfortunate since I'll be away on business next week, so the earliest possibility to fit the brakes will be the following week... I just hope the cold weather holds off until then, otherwise it's going to be early next year before I get to fit them!

Mov'it update

I received an email from Mov'it today confirming that new brackets have been manufactured and that these, along with a new set of calipers, should be dispatched next week, as soon as the brackets come back from being laquered.

So a pretty quick turn-around! I really hope that I can get them fitted before the icy weather hits!

Boost problems?

I've had a couple of emails over the past few weeks regarding problems with boost pressure on the Ghibli.

A lot of people don't actually notice when they're getting reduced boost, since even in fail safe boost mode, the Ghibli produces about 0.7 bar inlet pressure, which is good for around 270 hp on the 2.0 liter engine (which is still a pretty impressive amount of power from the small engine). However, the tell tale sign is that the boost gauge needle on the dashboard only makes it to the first half of the amber section, even during hard acceleration and high revs. The needle should go round to the top of the amber section, falling just short of the red section to give around 1.1 bar inlet pressure.

I've also heard reports that the reduced inlet pressure is accompanied by restricted engine speed, with the engine cutting out at around 4500 rpm.


So what's the culprit? Invariably, it's the boost control solenoid valve. This is a small, brown, plastic housed three way valve. On later ABS and GT Ghiblis, this valve is located on the front of the engine block, where the distributor used to be located on the older series 1a Ghibli. On these earlier cars, the valve is located behind the plenum chamber, beneath the fuel pressure regulator. The valve is labeled as item 3 in the drawing above. These valves are pretty standard in the automotive industry, so a Google search will yield some relevant background reading. Also, Enrico has an article on boosting a bi-turbo in his Maserati pages.

In summary, a signal is sent to the solenoid valve by the engine control unit. This signal is a series of pulses that control the amount of air reaching the wastegate valves on the turbos, (by controlling how "open" the solenoid valve is).

The solenoid is fed pressurised air from the outlet of the turbo via port C (there's little labels on the vacuum hoses that connect to the valve). If the solenoid is not working, this pressure is fed directly to the wastegate valve via port W. The wastegate requires about 0.7 bar to open, which is why when the solenoid fails you still get some boost. If the solenoid is working, then instead of letting air reach the wastegates straight away, it will direct the air instead through port R, which effectively vents the pressurised air to the atmosphere (so the end of this vacuum hose is not connected to anything!).

Once the desired boost pressure is reached (around 1.1 bar), the solenoid starts to direct the air to the wastegate via port W. This prevents the turbos from increasing the inlet pressure further by allowing the hot exhaust gases from the engine to bypass the turbochargers (it's these hot gases that make the turbochargers spin, so preventing them from passing through the turbos prevents the turbos from spinning).

The stock solenoid valves appear not to be too reliable. If it stops working then it needs replacing. Fortunately, this is a pretty simple job... disconnect the vacuum hose and the 2 wire connector and unscrew the fastening bolt to remove and the reverse to install a new one. The valves aren't too expensive and can be picked up second hand. However, given the reliability issues of the valve, I'd recommend getting a brand new one. Alternatively, consider getting a 3rd party replacement valve, as there are some far more reliable valves on the market. Since I fitted a new boost controller on my car (Turbosmart e-Boost 2), it came with its own replacement solenoid valve which appears to be very robust.

While you're replacing the solenoid valve, you might want to consider removing the little restrictor that is located in the exhaust port R. Removing this restrictor allows more air to escape to the atmosphere, which means there's less air reaching the wastegate via port W. Since there's less air reaching the wastegates, they stay closed a bit more, hence increasing the inlet pressure a little. Removing this restriction will increase the inlet pressure by about 0.1 bar... see if you notice any difference in power?

So, keep an eye on that pressure gauge! The gauges are there for a reason, so get familiar with where they normally operate so that you can see when something changes. Don't rely on the engine warning light popping on (in my experience, it doesn't come on that much, even when there are problems). Also, don't rely on your mechanic to pick up these problems, since unless they takes your car for a decent drive they won't notice such things.

Maserati Ghibli V8

I was talking with Jorrit last week while he was trying to fit the new brakes on the car. We got 'round to the subject of fitting the Maserati 3200 V8 engine in the Ghibli.

I know that Modena Performance in Germany can make this modification and Jorrit knows of another person in Germany that can make the change. Enrico also has the upgrade documented in his pages (which is where I got the picture from) and he's lucky enough to have drivent the car!

I've always been put off the idea primarily by the thought of the engine sump on the longer engine resulting in further reduced ground clearance on the front of the car. However, after talking with Jorrit, it appears that the V8 engine actually has a thinner engine sump. Therefore, ground clearance at the front of the car with this engine shouldn't be any worse than on the standard Ghibli.

The other thing that puts me off this modification is the weight. The Ghibli is a pretty balanced car, but I imagine that with the extra weight at the front of the car then it would start to understeer a fair bit? Jorrit commented that the extra weight would be more than balanced out by the extra performance of the car and I suppose that if the car was set up well, the understeer could be balanced around fast corners with oversteer controlled with the right foot.

The 3200 V8 is a lovely sounding engine... if you've heard a 3200 GT fitted with a nice exhaust, you'll know what I mean. However, I've heard stories that it's not the easiest or cheapest engine to maintain, even compared to the V6 engine in the Ghibli, which has to be well maintained else it's not very forgiving.

It's got me thinking again though. I came across a low mileage 3200 GT engine a couple of years ago going for a very good price. It was from an insurance writen off car, but the engine was in perfect condition; it was the rear of the car that had been smashed up. I was only after 3200 GT turbos at the time, but they wouldn't break the engine for me, instead prefering to sell the entire engine as one piece. I've always had a tinge of regret that I didn't buy that engine. For double the price I paid for the 3200 GT turbos that I acquired, I could have purchased the entire engine! Admittedly, it would probably take a couple of weeks to fit the engine into the Ghibli.

Maybe if this opportunity presented itself to me again I'd be less quick to dimsiss it.

Mov'it developments

Seems that Mov'it are keen to rectify my misfitting brakes. They've asked for measurements from which they can design new adapter brackets. They're also talking about supplying me with new caliper billets; seems that they make two designs of calipers, one that's a single piece like the ones I've been supplied, the other a split two-piece caliper.

The one piece caliper mounts to the adapter bracket on the underside of the caliper. In this specification, I don't think the kit will fit to the Ghibli series 1a. However, I suspect that the two piece caliper mounts on the inside face, which means that there should be sufficient clearance to fit to my Ghibli.

I'm very interested to see what they come up with!

In the meantime, I thought I'd mention fuel. I've been running my car exclusively on 98 octane super unleaded fuel for the past few weeks (as opposed to Shell V-Power, which is 97 octane). The car appears to drive much better with the 98 octane fuel, particularly BP Ultima. I've just put a tank of Texaco 98 in, which doesn't appear to perform as well. I'm yet to try Total's offering, but will keep you posted, but my preference is for BP.

It's nice driving the car in this colder weather... it certainly seems to perform better with nice cold air entering the engine and flowing over the intercoolers, so I'm making the most of it before the snow and ice comes!

Mov'it developments

I've been corresponding with Mov'it this morning by email and it appears that they're going to make some new adapter brackets and send me some different caliper billets for my car. So sounds promising...

So far they've been very good following up. I just hope it continues... but for now it looks like their very good looking product is backed up with excellent service!

Mov'it anticlimax

Yesterday I took the new Mov'it brakes 'round to Jorrit at Auto Forza to fit to my car. The disc fitted perfectly, but unfortunately the calipers sit in the wrong position, approximately 18mm too high above the disc, as you can see in the attached picture.

It seems that the kit has been supplied with adapter brackets designed for the later ABS and GT versions of the Ghibli and not for my Series 1a version. The mounting bracket on my car is different to the ones used on the later cars (which Jorrit confirmed by removing the front wheel off a Ghibli GT that he had in his workshop and having a look).

It's a real shame, since the kit is of excellent quality; even Jorrit was impressed! I have no doubt that the kit will fit on the later versions of the Ghibli and would look absolutely fantastic, but unfortunately it doesn't fit on my car.

I'm currently talking with Mov'it to determine what to do next... I'll keep you posted as to the outcome. I hope that they can come up with a solution for fitting them, since I really want them to work!

Mov'it brakes have arrived

The brakes were delivered on Monday afternoon to my office. Damn they're heavy! I generally cycle to work since it's only 5 minutes away from my house, so there was no chance of taking them home with me on Monday night. So I picked them up in the car last night (Tuesday) instead.

I've not unpacked them, although I did have a quick peak. Everything looks good, but will have to see if they'll fit OK, which will be tomorrow when I pop 'round to Jorrit at Auto Forza at lunch time to get them fitted. I'm hoping that it will be a direct fit with no modifications required... I'll take my camera with me, record the event and post some pictures.

I drove to Amsterdam in the Ghibli yesterday. It's running pretty good at the moment, with plenty of torque since I reset the E-Boost controller; there's certainly far more torque than there ever has been, requiring less gear changing when driving on the motorway, although I typically still drop down to 4th to overtake or to make some space between me and whoever is tail gating me (which seems to be increasingly common).

I've noticed a couple of things different on the car since I fitted the BMC air boxes. First of all, the noise. The induction noise is very noticeable. I don't mind this, but some people might. It's generally on throttle lift off that you hear it... a growly sucking noise. The spin up noise from the turbos is also more noticeable. The roller bearing 3200 GT turbos that I have seem to make more of a whistling noise than the stock Ghibli turbos?

The really interesting thing though with the change in air boxes is related to temperature. To install the the replacement air boxes, I decided to vent the carter hoses to the atmosphere instead of re-cycling this hot, oily air back into the induction system. As a result of this, the engine takes longer to warm up. It also appears to run considerably cooler according to the temperature guage on the dashboard. Where before I typically ran around 90 degrees, it now seems to hover below this mark. I'm very suprised that there's such a large effect and can only imagine that if recycling this air has such an impact on engine temperature then it must be having an impact on performance too? With such warm air no longer entering the cyclinders, there should be an increase in power?

The climate control inside the car has also been effected. Since the engine takes longer to warm up, so does the warm air entering the cockpit. In fact, there's no warm air entering the cockpit for about 10 minutes after starting up the car, so it's probably a good job that I don't drive the car in the winter, otherwise it would be damn cold driving to work in the mornings! Even when the car has been running for some time, unless the engine is working reasonably hard, the warm air entering the cockpit is generally much cooler than it was before the modification.

The other noticeable effect is the smell. When the car is stationary, particulary when coming to a standstill after the engine has been working hard, there's a very distinct smell of oil/fuel that briefly enters the car through the cockpit ventilation system. Again, I don't mind this since for me it makes the car feel more like a sports car and less like a modern convenience product, but I can imagine that some people would not be too happy about this.

I'm not sure where the heat exchanger is located to warm the air into the cockpit, so I'll have to check to figure out why there's such a big change. I'll try looking into it at the weekend and post my findings.