Maserati Ghibli II V6 2L - Simulator data

[stormrider123]

Hello there!
I'm making the physics for this car and I would like to ask for some information, perhaps someone who owns one and can make some measurements would be greatly appreciated?
Also, someone who owns one and have the simulator Assetto Corsa to provide some feedback would be invaluable.

Does anybody have and can share with me this car's Service Manual? I could find the biturbos' in http://www.maserati-alfieri.co.uk/, but would really like to refer to proper manual.
Lastly, does anybody have a torque dyno graph of a stock version of this car?

Cheers,
Felipe

 

[Nayf]

Hello there!
I'm making the physics for this car and I would like to ask for some information, perhaps someone who owns one and can make some measurements would be greatly appreciated?
Also, someone who owns one and have the simulator Assetto Corsa to provide some feedback would be invaluable.

Does anybody have and can share with me this car's Service Manual? I could find the biturbos' in http://www.maserati-alfieri.co.uk/, but would really like to refer to proper manual.
Lastly, does anybody have a torque dyno graph of a stock version of this car?

Cheers,
Felipe

Glad someone is doing this as I keep thinking of getting a setup.
There is a Ghibli Cup car model around, but last I checked it had the weight of 1700kg which not even me+car has that, and I’ve eaten many Mars bars.
I think it’s around 1300-1400kg.
Have you used Carfolio?
Modelling the torque - nothing below 2000 rpm
V6 wakes up 3000-3500
Turbos fire and bang, you’re in the future.

 

[stormrider123]

Glad someone is doing this as I keep thinking of getting a setup.
There is a Ghibli Cup car model around, but last I checked it had the weight of 1700kg which not even me+car has that, and I’ve eaten many Mars bars.
I think it’s around 1300-1400kg.
Have you used Carfolio?
Modelling the torque - nothing below 2000 rpm
V6 wakes up 3000-3500
Turbos fire and bang, you’re in the future.

Hello Nayf, thanks for your quick reply. I'm not a 3d modeller myself. In my mod team, I do partnerships with a friend that makes very nice 3Ds, we help in each others projects. But it's something that takes time so I do only physics of cars that I become interested and if he's also interested, then we have an in-house 3d. For this car, I found the 3d at actk garage. I don't know the origin of the 3d but I know that its physics were garbage so I started them from zero as usual.

You mentioned the turbos, so this (the attached picture) is what I currently have. I don't know how much boost (bar) these turbos produce, but I'm assuming a total of ~0.984 bar, parallel turbos, one for each bank of 3 cylinders.

For the suspension geometry I'm basing myself on the biturbo 430 service manual and I calculated it's springs from its static load ratings.
I'm also assuming a 54% front weight distribution because I couldn't find any data for it.
A total weight of 1435kg (1360kg + 75kg driver)

 

[Nayf]

Hello Nayf, thanks for your quick reply. I'm not a 3d modeller myself. In my mod team, I do partnerships with a friend that makes very nice 3Ds, we help in each others projects. But it's something that takes time so I do only physics of cars that I become interested and if he's also interested, then we have an in-house 3d. For this car, I found the 3d at actk garage. I don't know the origin of the 3d but I know that its physics were garbage so I started them from zero as usual.

You mentioned the turbos, so this (the attached picture) is what I currently have. I don't know how much boost (bar) these turbos produce, but I'm assuming a total of ~0.984 bar, parallel turbos, one for each bank of 3 cylinders.

For the suspension geometry I'm basing myself on the biturbo 430 service manual and I calculated it's springs from its static load ratings.
I'm also assuming a 54% front weight distribution because I couldn't find any data for it.
A total weight of 1435kg (1360kg + 75kg driver)

I think a more useful resource for you would be the Autocar test report, back when magazines bothered to measure such stuff.
I’d scan mine but it’s in storage pending a house move, but you can buy an old copy via eBay.

AUTOCAR magazine 2 April 1997 featuring Maserati Ghibli Cup road test, BMW M3 | eBay

AutoCar Magazine. 2 April 1997, 114 pages and in good condition except for the front cover see picture. I can send a larger and clearer picture if requested.

www.ebay.co.uk

 

[Nayf]

Sorry pressed reply a bit too early.
Looking forward to seeing more of this, as I miss sim racing, multi class grids and realistic physics from the rfactor 1 days.

Also I’m too much of a wimp to take my Cup on track (the brakes really are… not great) so I’d rather wipe myself out on a virtual tree on the Eifel mountains than a real one

 

[stormrider123]

Thanks Nayf for the link. You are very lucky to be able to own one. The more I dig into it, the more I admire this hidden jewel.
I have a few easy questions before I throw the hard ones:

• Steering ratio
• Steering wheel turns lock-to-lock
• Does the front shocks sit on the bumpstops in static load? (attached pic bumpstop.JPG)

I have a basic v1 version in-game. I put a few laps in the nordschleife and my first impression is that the tail is quite a bit happy. And it is truly a beast of a car. That engine can easily overcome the rear tires' grip. I can only imagine how it should had been on vintage 90s tires trying to keep RPM about 4500RPM to avoid that short 2nd gear, while negotiating a mountain road. Is it how it really feels?

 

[Nayf]

Thanks Nayf for the link. You are very lucky to be able to own one. The more I dig into it, the more I admire this hidden jewel.
I have a few easy questions before I throw the hard ones:

• Steering ratio
• Steering wheel turns lock-to-lock
• Does the front shocks sit on the bumpstops in static load? (attached pic bumpstop.JPG)

I have a basic v1 version in-game. I put a few laps in the nordschleife and my first impression is that the tail is quite a bit happy. And it is truly a beast of a car. That engine can easily overcome the rear tires' grip. I can only imagine how it should had been on vintage 90s tires trying to keep RPM about 4500RPM to avoid that short 2nd gear, while negotiating a mountain road. Is it how it really feels?

Well, you tend to push harder a) on track and b) in game than you ever would on the road. I’ve yet to drive mine truly hard (waiting for another damper so another month or two) but, having driven others hard before…
In normal driving, even in the rain, I’ve found the Cup far more easier to drive than the 2.8 models, because there’s slightly less torque and it’s higher in the rev range. With the opposite in the 2.8s it’s conceivably easier to get caught out when it’s wet - the tyres are quite small compared to most cars with that amount of power and torque. It has no traction control, after all.
The difference is when you drive the Cup hard, you’re so much faster and up the rev range, keeping it on boost, it’s truly exhilarating. I can well imagine the margin between control and the local infirmary being very narrow when it’s wet, so I’ve tended not to drive Cups hard in the wet (and why would you?).

The big difference, and the key to the car, is the steering and steering feel. It’s so much more connected at the extremes than a ‘normal’ GT. The steering is low geared (like most 80s/90s) performance cars, but there’s a depth to the steering feedback that provides plenty of confidence. How you’d adequately transmit that into the game, I’m not sure. The rear diff does a magnificent job of keeping you planted in the dry. You can get them sideways, but you have to be committed. It is not inherently an uncontrollable monster, unless your right foot only operates in binary.

There are some drawbacks - the Getrag six speed can be a bit notchy, and the brakes are terrible. Not a lot of initial bite - a bit like 80s BMWs really.

The other that might be hard to get into the simulation is the adaptable suspension, of which there are 4 modes. 1 is comfort, 2 is default and 3 + 4 is where the Cup really shines. It it’s all working well then it really does transform the car, tightening things up. 4 is track mode.

I’ve heard people say it doesn’t make much difference but on a fully sorted car and on a proper drive you really can feel the difference through the steering wheel.

The Autocar test has everything you need, probably more than the manual that came with the car. IIRC I think it has the torque and power curve graphs, which will help.

Here’s mine taken today, the only Cup in Verde Foresta.

 

[stormrider123]

Well, you tend to push harder a) on track and b) in game than you ever would on the road. I’ve yet to drive mine truly hard (waiting for another damper so another month or two) but, having driven others hard before…
In normal driving, even in the rain, I’ve found the Cup far more easier to drive than the 2.8 models, because there’s slightly less torque and it’s higher in the rev range. With the opposite in the 2.8s it’s conceivably easier to get caught out when it’s wet - the tyres are quite small compared to most cars with that amount of power and torque. It has no traction control, after all.
The difference is when you drive the Cup hard, you’re so much faster and up the rev range, keeping it on boost, it’s truly exhilarating. I can well imagine the margin between control and the local infirmary being very narrow when it’s wet, so I’ve tended not to drive Cups hard in the wet (and why would you?).

The big difference, and the key to the car, is the steering and steering feel. It’s so much more connected at the extremes than a ‘normal’ GT. The steering is low geared (like most 80s/90s) performance cars, but there’s a depth to the steering feedback that provides plenty of confidence. How you’d adequately transmit that into the game, I’m not sure. The rear diff does a magnificent job of keeping you planted in the dry. You can get them sideways, but you have to be committed. It is not inherently an uncontrollable monster, unless your right foot only operates in binary.

There are some drawbacks - the Getrag six speed can be a bit notchy, and the brakes are terrible. Not a lot of initial bite - a bit like 80s BMWs really.

The other that might be hard to get into the simulation is the adaptable suspension, of which there are 4 modes. 1 is comfort, 2 is default and 3 + 4 is where the Cup really shines. It it’s all working well then it really does transform the car, tightening things up. 4 is track mode.

I’ve heard people say it doesn’t make much difference but on a fully sorted car and on a proper drive you really can feel the difference through the steering wheel.

The Autocar test has everything you need, probably more than the manual that came with the car. IIRC I think it has the torque and power curve graphs, which will help.

Here’s mine taken today, the only Cup in Verde Foresta.

Thanks for the reply. What a beauty she is!

Regarding the steering feel, once you get the accurate data in the .ini files, the game engine does it's job to calculate what is transmitted to the Force Feedback in the steering wheel. Nowadays, simracing gear evolved quite dramatically and direct-drive wheels have become affordable and that really helps. The game engine takes a lot of parameters into it's calculation, including the suspension geometry, mechanical trail, scrub radius, caster, kpi, camber, toe, anti-geometries and so on. It also has individual modules for different types of suspension: DWB, Struts, Solid axles, De-Dion, and so on. As a physics developer, what I do is to try to get the numbers as accurate as possible in the .ini files. The suspension geometry I usually do it in a CAD software and sometimes in Lotus Shark.

For the magazine Autocar at ebay, I'm in France so it won't arrive before April.

Edit: Let me know once you're back into simracing and I will send you the car.

 

[stormrider123]

Hello Nayf,

By any chance, do you happen to know the corner weights of the Ghibli?
Thanks

 

[alpa]

There is a lot of wrong information about the weight of all biturbo cars (except 3200). And all engines before the ghibli abs and qp4 (so all 200/400 + ghibli non abs) had a very poorly mapped management, so they are quite inefficient in transients because the boost comes slowly. The 200/400 (even 5 bolt versions) and ghibli/qp4/shamal feel really different on the route, there are lots of subbtle differences in the suspension.

You can't use the 430 suspension to model ghibli. Ghibli/shamal/qp4 had a different suspension, even though they had a lot common parts.

Perhaps few pictures would help much more than explanations ?

Please specify which model do you model exactly ? Ghibli ? Ghibli what ? Non abs, abs, gt ? Cup and primatist were styled GTs. There were also 2 generations of Ghibli open cup (GOC) which were ghibli with the group A full ball joint suspension.

The biturbo steering system is quite special, it's not a plain rack pinion system, it's a mix of the rack and the steering box systems. It's extremely efficient. Btw that's the reason why most of ghibli and even qp4 have cracked bodies around the engine frame: the body isn't solid enough to cope with the suspension forces. I own a ghibli gt whose front was completely destroyed by a hard driving probably on the track with slicks. I had to completely rebuild the front structure.

I don't agree about the adjustable suspension. To me it's useless. Of course some positions match better the springs, so they are more efficient. But try to replace them with AS Motorsport coil-overs sold here on this forum and you'll see what's a good suspension. However, again, the body and too weak to stand the efficiency of the front steering, so to me the body must be improved/repaired before switching to AS struts.

Btw I'm in France as well, near grenoble. Search for my pseudo on the web.

 

[stormrider123]

Thank you for your reply alpa.

I intend on creating the following versions:
-Ghibli II 2.0L GT (AM495?) and 2.8L (après 1995)
-Ghibli Cup 2.0L and 2.8L.
-Step 1 versions with aftermarket springs and dampers.

I started with the Ghibli 2.0L GT because this is the version that I will buy sooner than later, and then go from there.

For the active dampers, I'm using that famous Koni image. As I understand, it's basically an one-way adjustable damper (Rebound only) with 4 positions and a knee speed around ~0.13m/s. I won't bother with the 2 softest settings because it's a simulator after all. Nobody will be driving the kids to school.

The single most important piece of data that I'm in desperately need currently, is the weight distribution. I know that the Cup versions are ~50kg heavier at the back because of the tubular subframe, but the exact Front weight % still eludes me.

After that, I'm looking for someone to measure some of his car's suspension components, so I can improve my suspension geometry. Currently it was done by combining and analysis pictures and my general knowledge of suspension geometry and kinematics. In a simulator, the suspension geometry is basically the 3D positions in space (x,y,z) of the suspension attachement points.

The second most important piece of data, are the springs. From pictures alone I can make a general idea, but if I can get some measurements (free lenght, outer diameter, inner diameter and number of active coils) I can calculate fairly accurate rates. Paired with suspension measurements, I can calculate all the rest: the wheel rates, natural frequencies, damping ratios, weight transfers and so on.

Next, I can run a few CFDs simulations to build a fair idea of its aero-dynamics.

Last step is to improve based on people's feedbacks.

 

[alpa]

I have a huge stock of parts, including a ton of springs. And my '97 gt is currently in small parts.
The cup has nothing special except estetical details. The rear frame was introduced on gt ghibli (or may be abs ? Need to check. It came with the ZF diff). We'll have to have phone contacts if you want me to measure things, it's a tedious work, I won't do it if I'm not sure of its utility.
There can't be 50kg of difference because of the frame. The most heavy part is the tubular rear arms, they appeared on shamal (actually they came from the group A biturbo). The frame is not that heavy, may be 10kg.
The last control technique of my '97 2.0 ghibli GT data states 832/677 daN weight distribution. The previous CT numbers were 831/642 daN

 

[stormrider123]

I have a huge stock of parts, including a ton of springs. And my '97 gt is currently in small parts.
The cup has nothing special except estetical details. The rear frame was introduced on gt ghibli. We'll have to have phone contacts if you want me to measure things, it's a tedious work, I won't do it if I'm not sure of its utility.
There can't be 50kg of difference because of the frame. The most heavy part is the tubular rear arms, they appeared on shamal (actually they came from the group A biturbo). The frame is not that heavy, may be 10kg.

That's good to know, thanks.

You mentioned the Cup car, I though that its suspension setup was different, perhaps with stiffer springs at the front. Can you confirm that it has the same setup as the GT?

Regarding the measurements, it's not much really. I don't need all the measurements, moar is better, but I can get most out of pictures. Suspension is a system and everything is tied with a basic set of best practices. The problem with pictures alone is that 99% of the time, they lack references and are all angled in perspective.

If you can give me those in the picture, I will be very grateful:
Rear:
A) Spring free lenght
C) Spring wire diameter
E) Bumpstop lenght
+Shock full extension lenght
G) Lower control arm lenght

Front:
B) Spring free lenght
D) Spring wire diameter
F) Bumpstop lenght
+Shock full extension lenght
H) Lower control arm reference dimension.

Thanks

 

[alpa]

Yes Cup have shorted springs but I have a set. This is the only difference. I'd need to remove one from a rear shock. The shocks are supposed to have appropriate dumping rate but I doubt its the case, all this stuff seems to be very approximative. Like the engines. All ghibli and qp4 I've tried had a quite approximative and loose behavior compared to their supposed performance. They stay well on the route, but they pump and are slow to react.

Not sure I have a bumpstop in a good condition. I think you asked somewhere if the car seats on stops. Of course not !
Arm length is not enough, you also the caster. Or I dont see why you'd need all other details. Useless if you dont use caster and camber. And again the steering has a special lever system, if you dont modelize it you dont get the reall sharp behavior. 4 bolt biturbo had a regular steering system and had a typical understeering boring behavior.

 

[stormrider123]

Yes Cup have shorted springs but I have a set. This is the only difference. I'd need to remove one from a rear shock. The shocks are supposed to have appropriate dumping rate but I doubt its the case, all this stuff seems to be very approximative. Like the engines. All ghibli and qp4 I've tried had a quite approximative and loose behavior compared to their supposed performance. They stay well on the route, but they pump and are slow to react.

Not sure I have a bumpstop in a good condition. I think you asked somewhere if the car seats on stops. Of course not !
Arm length is not enough, you also the caster. Or I dont see why you'd need all other details. Useless if you dont use caster and camber. And again the steering has a special lever system, if you dont modelize it you dont get the reall sharp behavior. 4 bolt biturbo had a regular steering system and had a typical understeering boring behavior.

Salut alpa, je vous appelle à tout.

Before, I'll post a reply here.

For the suspension alignment, I have the data from this sheet below: caster and kpi were the 2 pieces of data that I needed from it. What I ask in the forums, is the data that I don't have or rather have a confirmation. I have been researching this car for over a week now and so I collected a lot of scattered data from forums and websites.

Here's my current suspension geometry and it is based on the chassis schematic of the biturbos but adjusted with the Ghibli alignment sheet:

 

[Nayf]

Having driven a GT and a Cup back to back, they do feel very different @alpa - then again, like a lot of hand built cars whether from the UK or Italy, by my this point there’s no real uniformity to how they all drive.

80s and 90s Astons (less so DB7s) and Bentleys vary from car to car, depending how close it was to pub opening time.

 

[Nayf]

Also @gemini i think has comparative torque curves for the 60 ‘normal’ 2.0 Cups and the Japanese 2.8 Cups, of which a handful were made.

 

[stormrider123]

Also @gemini i think has comparative torque curves for the 60 ‘normal’ 2.0 Cups and the Japanese 2.8 Cups, of which a handful were made.

These?

 

[alpa]

Salut alpa, je vous appelle à tout.

Before, I'll post a reply here.

For the suspension alignment, I have the data from this sheet below: caster and kpi were the 2 pieces of data that I needed from it. What I ask in the forums, is the data that I don't have or rather have a confirmation. I have been researching this car for over a week now and so I collected a lot of scattered data from forums and websites.

Here's my current suspension geometry and it is based on the chassis schematic of the biturbos but adjusted with the Ghibli alignment sheet:

View attachment 124279
View attachment 124280

I don't have ghibli data. All I can tell is that suspension is wider at front and rear, the front wheel hubs are consequently different. So suspension angles are certainly different from 430.
But the arm mounting points are the same as on 222 5 bolts. Same for the steering: mounting and rotation points were the same. The GT body metal sheets still had the biturbo holes that were no longer used. Few chassis parts were modified, usually by cutting/welding on top of.

 

[alpa]

These?

Seem consistent.
But the cup engines have nothing special compared to GT