Summer fun

After spending a couple of weeks in Syria at the start of the month, it was great to get back home and have the opportunity to drive to work everyday in the Ghibli. Without fail, I step out of the car with a big grin on my face and I'm simply loving driving it!

Following on from the discoveries in my last post, I've trimmed back the sensitivity setting on the E-Boost controller and voila... the stuttering during hard acceleration has stopped! I've now increased the gain setting slightly to compensate and to set the boost pressure right at the end of the amber section on the dash boost gauge (I need to check but this should be just over 1.20 bar).

I'm also now slowly increasing the gate pressure setting, which is the pressure at which the controller starts to open the wastegates. It's currently set at 1.05 bar, but in third gear at least there's scope to increase this. Since my 3200 GT turbos don't spool up very quickly, there's less risk of over boost so the gate pressure can be set reasonably close to the desired boost pressure.

I'm really happy with the way that the car is performing now. Acceleration is nice and steady, with a kick in the arse coming around 4000 rpm. Keep the revs below this and the car is very civilised, above this and its nice and aggressive with a quick throttle response.

The warm weather is testing the new oil cooler. Now that I'm driving it more I'm noticing how it performs. It's obvious that when being driven with decent speed, the oil temp is being kept pretty low as the water temp is maintained below 80 deg C and the oil pressure stays just below 5 bar.

Slowing down or stopping when driving through town, the water temp is elevated and stays between 80-90 deg C with the fan coming on alot. Also, the oil pressure drops to 2.5 bar. But as soon as you get some speed up and get air flowing across the radiator, the temp is straight back below 80 deg C and the oil pressure to just below 5 bar.

So my conclusion is that the oil cooler is working well. It has no problem keeping the oil temp low when driving at speed (with good flow across the radiator) and it manages to take the edge off the heat when the car is stationary, which is where the problems occurred on the track.

There's some noticeable additional load on the engine at idle though, particularly when the engine is cold. It's only small, but the engine is more prone to stalling now and a dab of revs is required to prevent stall when reversing with full steering lock. I will get this sorted though when the car is dropped off at the garge next week end... the idle needs setting a fraction higher I think.

The car is going for the annual APK (road test) next weekend and also to have a few things done:

1. Re-fit the original distributor; it was replaced with a new one to check whether this was the cause of the stuttering, but since it isn't then the original can be refitted.
2. The volt meter has stopped working completely, so the wiring needs to be checked.
3. The idle needs resetting.
4. Maybe fit the new springs. I'm in two minds about this though as the ground clearance around town is good at the moment.
5. See if it's possible to modify the left wheel arch to increase the clearance a little and prevent the tire from rubbing on fast or tight right hand corners.
6. Perform small service (oil change).

I'll try and capture some log data to show the changes in the boost pressure... I expect that the boost curve will be much flatter now at the top end instead of oscillating up and down. I think the top end is now performing much better as a result. Feels like the car is back at 330 hp, but I'd need to take it back onto the dyno to check this...

Maserati Ghibli V8

Today I had a holiday and so took the opportunity to visit Buddy at Wereld Auto.

I went there to find out more about the KMS, but spent most of the time discussing Ghiblis. He had two in the workshop. one was a MY93 series 1a (but had Mistral style wheels). It was having some problems with a seized turbo, but Buddy has been having trouble trying to source a replacement. So he's working on manifolding a small Garret turbo; designed to flow 180 hp and with a good bearing package, it should be spooled up by 2000 rpm and offer very good low rpm drive-ability (which is what the owner of the car is after).

Buddy says that if he can get the Garret turbo mounted satisfactorily onto the Ghibli's exhaust manifold then he plans to make a kit that will offer a bolt on replacement for Ghibli owners. He also says that by using the Garret turbo, there's lots of scope to play around with compressor sizes to open up tuning possibilities. He thinks he can come up with a kit for around €800 per unit, which is far cheaper than getting a Maserati original part! I'll keep you posted if he managed to pull it off!

OK... the other car was a a very special MY92 Ghibli, but with a Maserati Evoluzione engine and running gear from a Quatroporte, running on a KMS ECU and with larger intercoolers (actually from a Golf Mark IV TDi... they're twice as thick as standard Ghibli units, but the bottom (outlet) manifold needs removing and a new one welding on). Buddy took me for a drive in the car... I've not had that much of a buzz since being in the passenger seat with Top Gear's " The Stig" at the wheel. What a fantastic performing car! The brakes and handling could be improved, but the engine performance is very impressive indeed... the car felt like it had a huge normally aspirated engine, with bags of torque available at low revs... no having to wait for the turbos to spool up like on my Ghibli or having to drop the gears to get the engine revving in it's power band, just stick your foot down and away you go! Buddy's not had it on the dyno recentyl but thinks the performance is around 380 hp with a little under 600 N.m torque. He's set up the KMS pretty conservative so as not to stress the engine too far and make the car very driveable... for example the boost pressure is mapped against throttle position to avoid the big spikes in torque when accellerating out of corners that the car was previously delivering and catching the owner off-guard. It seems that Buddy has a fair bit of track driving experience and he said that the torque spikes were occuring too quick for him to reliably control.

Very, very impressive... kind of gets me tempted to try and source a Maserati V8 and have it fitted in my car! It's a bit tight in the engine bay, but it fits ok and there's actually more ground clearance underneath the car since the V8 has a shallower sump. Plus, since this Ghibli was registered in '92 it doesn't require cats which helps out too.

Regarding the KMS... Buddy still needs to find out if it can run an odd fire engine, so i promised to send on the info that I've acquired and he'll ask the manufacturer. So, lots to report back, but not much yet on the KMS!