Tuesday, March 21, 2006

APK action items for Jonny's Ghibli

Here's a list of things that need to be checked/fixed when my Ghibli next gets serviced:

  1. Windscreen washer nozzles; the driver's side nozzle needs adjusting to point in the right direction, since it currently leaves a big patch of unwashed glass which impedes the driver's view of the road.
  2. The fuel pump is making a whizzing noise; it probably needs cleaning or replacing.
  3. The courtesy light in the boot isn't working; probably a faulty connection somewhere in the boot.
  4. It's almost time for the big 60,000km service, so the timing chains will need replacing.
  5. I'm going to order a new front exhaust section from Larini; I'm positive that the catalysts currently installed have become restrictive after the car ran for a while too rich (due to a dodgy connection on the Lambda probe I think the car was running in open loop for a couple of months, although it's strange that a warning lamp never came on in the dashboard?).
  6. I may ask Jorrit at Auto Forza if he can set up the buttons on the center console to illuminate when the driving lights are switched on.
  7. The radio isn't working; I suspect that either the antenna has stopped working or that there's a bad connection/broken wire between the radio and the antenna.
  8. Since the car will now be garaged and off the street, I may get the damaged bumpers changed out. There's also a dent in the underbody after a mishap with an hydraulic jack that I'd like straightening out.
  9. The belt driving the alternator is slipping slightly and needs tensioning.
  10. Sounds like there's something loose in the airco ducting, maybe a leaf? It stops when the fan is switched off.
  11. The volt meter still only works periodically. I can live with this, but I'd so much like it fixing!
  12. The tracking is slightly off; seems to get knocked off centre pretty easily.
  13. The clutch pedal is squeaking; I think it's the spring that needs oiling a bit.
  14. The handbrake needs tightening. Again. The Ghibli's handbrake seems to be a bit problematic.

Once the exhaust is changed out, I'll take the car back to Rica Engineering to get the fuel remapped; it's currently running a bit rich, which is loosing a few hoursepower I suspect.

Other than that, the car seems to be running pretty well, although I've not been out in it for a few months... waiting for the salt to get washed off the roads!

Friday, March 03, 2006

Wheels for Maserati Ghibli MY92

I've been looking for new wheels for my Ghibli for ages now. Don't get me wrong, it's not that I dislike the OEM wheels (I've got the OZ racing 7 spoke 16" wheels, see previous postings for pictures), it's just that there's so little ground clearance on ym Ghibli.

Having said that, I do think the Ghibli looks good with larger diameter wheels and the decrease in the effective offset from the wider later wheels fills up the wheel arches much nicer. But my biggest problem with the Ghibli is getting over speed bumps and living in the Netherlands this is a common problem. It really breaks my heart everytime I hear the catalysts scraping on the ground; this car was obviously not designed with catalysts in mind and they must have been fitted as an after thought, driven by regulation.

It's not just the catalysts though. Not only are there lots of speed bumps in the Netherlands, but lots of brick roads. Couple this with subsidence and there's lots of potential for catching the anti-roll bar and engine sump on the uneven brick road services. So my driver for fitting larger wheels (other than for aesthetics) is to increase ground clearance (although there is another way, by inserting some spacers in the strut towers... ask Enrico for details).

But here's where the problems start. Maserati use really weird wheel fitting specifications, particularly on the early Ghiblis. Mine has a PCD of 5x106mm. I've not seen any other car with this PCD. I'm informed that the center bore is 58.5mm and the offset is ET35. I've looked long and hard for off the shelf wheels with these specifications, but to no avail. The only real option for a perfect fitting wheel is to get them made.

Here's a schematic I've put together of what I think the OEM wheel specifications are versus what I think I'd like. I'm not 100% confident with the proposed offset, but I've not got around to measuring it up properly yet.


One place that does sell customised wheels off the shelf (they appear to make blanks, which they drill out the the PCD and center bore to order and fit hub spacers to attain the correct offset) is Compomotive wheels in the UK. This company supplies wheels to the motorsport industry, noteably for rallycross.

Their MO wheel comes in 18" diameter and both 8" and 9" widths, which would be perfect for the front and rear wheels repectively on the Ghibli. It's probably not a wheel I would choose normally, but given that there's not much alternative (other than having a custom wheel manufactured and paying the price!) I could live with the design; it looks a bit retro and fits the 80s styling of the Ghibli. If you're interested in these wheels, try contacting Mark at Compomotive wheels.

Another alternative is to acquire a wheel with a PCD of 5x108mm and use some wobbly bolts to attach the wheel to the Ghibli's hub. This PCD is more common, particularly with wheels for Volvos. However, the offset of these wheels tends to be a little bit too much and a wheel spacer will be required to get the wheel nice and flush with the Ghibli's body. However, when using wobbly bolts, it's not recommended to have a wheel spacer thicker than 5mm, unless it's hub-centric. Try getting a hub-centric wheel spacer with these specifications. If you go this route, then try talking to William at Performance Alloys in the UK.

I'm still in two minds as to whether or not to purchase these wheels, since I'm also toying around with getting a new exhaust, which should help remedy the ground clearance problem with the catalysts and give me some more power to boot.

I'll keep you posted.

Wednesday, March 01, 2006

Blow off valves (BOV) for Ghibli

 
About a year ago I installed a pair of blow off valves on the Ghibli. I have an MY92 Ghibli with a 2.0l bi-turbo engine that did not come with recirculating type blow off valves that were fitted to the later MY94 cars. Therefore, every time I changed gear, the turbos would stall as the pressure on the inlet side of the engine backed down to the compressors.

This effectively increased the spool up time when accellerating after each gear change, making the car feel momentarily sluggish. But worse than this, it was putting unnecessary wear and tear on the turbos as they were constantly being accellerated and decellerated, which effectively decreased the longevity of the turbos.

To remedy this problem, I got help from the guys at Forge motorsport in the UK. After measuring the dimensions of the aluminium intake pipes prior to the throttle body, I asked the guys at Forge if they could weld the blow off valves directly onto some new pipe sections. These were then direct replacements for the existing pipes.

The location of these valves is pretty good, since they're located close to the throttle body, which means that they bleed off pressure pretty quickly without the entire inlet system pressuring up. The control line for the two blow off valves is teed together before connecting to the back of the plenum chamber; Jorrit at Auto Forza drilled a hole, tapped it and installed a push fit connector on the back of the plenum chamber for me. The control lines are blue in the picture above, but I've since replaced them with black hoses and fed them beneath the plenum chamber so that they now look like they were fitted by Maserati.

In action, the valves work very well. The car feels more lively when driving hard and feels like it's more poised and ready to go when accelerating hard through the gears. And of course, it makes a great sound as the valves vent off into the engine bay with each gear change. It's not too loud though; since I have two valves fitted, the air is not rushing out with as much vigour as it would with just a single valve. It's still loud enough to scare a few people walking in the street though.

I'd definitely recommend anyone with a pre MY94 Ghibli with no factory fitted blow out valves fitting these valves. Posted by Picasa