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I found the lengths for the torque tubes. 55 inches for the 928, and 69 inches for the maserati. The QP5 TT will definitely have to be shortened to make it work in the 928. Not many companies have the stuff to do these specifically, vs. the corvette ones that come apart pretty simply in comparison. (from my internet based research)
I'm off tomorrow morning to inspect a drivetrain. I may end up combining the maserati and the 928 stuff, which could be the quickest way to get it all installed. I'll have more answers tomorrow night. I think I have a good idea how this can work with the minimum hassle and fabrication, I just need a few parts in front of me to get some better forward trajectory.
Last edited by throttlegrotto; 03-19-2024 at 01:38 AM.
One thing to keep in mind if you are planning on staying with the stock transmission is to manage the extra heat generated by the more powerful engine. I've got a S4 engine in my 82 track car (dyno'd about 335 rwhp 380 ft-lbs) and during my first couple of track events, the trans got so warm that I lost the ability to shift into the gears until it cooled. Nothing like heading down the front straight at full throttle, start the shift and feel like it hit a wall. No gears, coast to the side and wait till it cooled. Adding a cooler would have helped, but I got a deal on a 90GT trans and that pretty much cured my issue.
I found the lengths for the torque tubes. 55 inches for the 928, and 69 inches for the maserati. The QP5 TT will definitely have to be shortened to make it work in the 928. Not many companies have the stuff to do these specifically, vs. the corvette ones that come apart pretty simply in comparison. (from my internet based research)
I'm off tomorrow morning to inspect a drivetrain. I may end up combining the maserati and the 928 stuff, which could be the quickest way to get it all installed. I'll have more answers tomorrow night. I think I have a good idea how this can work with the minimum hassle and fabrication, I just need a few parts in front of me to get some better forward trajectory.
Originally Posted by Tom. M
One thing to keep in mind if you are planning on staying with the stock transmission is to manage the extra heat generated by the more powerful engine. I've got a S4 engine in my 82 track car (dyno'd about 335 rwhp 380 ft-lbs) and during my first couple of track events, the trans got so warm that I lost the ability to shift into the gears until it cooled. Nothing like heading down the front straight at full throttle, start the shift and feel like it hit a wall. No gears, coast to the side and wait till it cooled. Adding a cooler would have helped, but I got a deal on a 90GT trans and that pretty much cured my issue.
Just like Tom says - you will struggle with a stock non G28.13/55/57 box and the Maserati V8 upfront. Trust me, it would be much easier and cheaper to shorten the Maserati torque tube and mate it to the Graziano box, which is a lot better than even the GTS G28.57 box. I speak from experience - my race car puts out 435rwhp and about 500Nm at the wheels. Even with cooling and a freshly rebuilt GTS transmission (synchros, some gears and bearings) and the benefit of constant cooling, sometimes it struggles to go from 5th to 4th at the end of long straights... There is a chap on YouTube shoehorning a 4200GT engine into a Toyota/Subaru BRZ. That can give you a lot of useful ideas with regards to engine mounts, electronics etc... I think it's called Toyrati or something like that. Very entertaining!
for starters: shipping a 928 transmission (highlighted in case is comes up again in search to save someone else their back and other pains) DOES NOT weigh under 150 lbs in an igloo 120qt cooler. The igloo weighs 20 lbs. The kobalt 31 gallon wheeled container I brought with had similar interior dimensions, and weighed 9.5 lbs. The trans, bubble wrap, and a small piece of ¼ plywood to line the bottom was 170 lbs. A clutch assembly, torque tube, and trans on a pallet weighs 295 lbs.
This and a lot more was all part of my educational series on out of state car parts. I thought I’d have more answers, but now only questions until the parts are here. Which will be about a week.
here's about 4/5 of the whole story.
Found a (supposedly) great deal on a S4 driveline in CA. Getting the driveline home has been quite a bit more than I bargained (or budgeted for). Manual transaxles DON'T ship at 150lbs.
Well, I think I ended up with a pretty good deal for a significant headache and some inconvenience.
I am now waiting on a bell housing, and then the significant task of figuring out the adapter plate and clutch equipment needed to make this all work as intended.
Nice. Look at the underside of the trans (part of the structural ribs) just in front of the rear cover (and just behind where the rear cross member would be) and it should tell you what trans it is. The build date was 86 so could still be a G28/13. Pic below is my 79 with the g28/03 and LSD (12).
So the remainder options are: a maserati bellhousing and clutch setup, which are prohibitively expensive (and possibly as long as the S4/maserati parts - I'm waiting to hear on dimensions) or a C5 two piece bellhousing, which offers the same advantage as the 928, but at an even higher cost, if you thought that was possible. $400-$800 for the vette bellhousings. The C5 stuff gets me in the same rough dimensions as the S4 items, with the benefit of a push style clutch as opposed to the pull style porsche parts. Eliminating problems slowly and by hand is going to slow the progress here quite a bit.
Greg Brown offers a hydraulic clutch actuation setup I believe. Replaces the slave setup with something mounted directly inside the bellhousing. Not sure if it works with existing single disc setups or cost or availability, but something to check out.
So I've been down the rabbit hole of parts and stuff. I got an S4 bellhousing and figured out that the S4 front section isn't going to work. At all. bellhousing whomp whomp
So the remainder options are: a maserati bellhousing and clutch setup, which are prohibitively expensive (and possibly as long as the S4/maserati parts - I'm waiting to hear on dimensions) or a C5 two piece bellhousing, which offers the same advantage as the 928, but at an even higher cost, if you thought that was possible. $400-$800 for the vette bellhousings. The C5 stuff gets me in the same rough dimensions as the S4 items, with the benefit of a push style clutch as opposed to the pull style porsche parts. Eliminating problems slowly and by hand is going to slow the progress here quite a bit.
It's funny how you refuse to listen sometimes...
The belhousing and clutch are the same for both true manual and robotised manual Maseratis. As a matter of fact, they are the same between 4200GT, GranSports and Quattroportes. The throwout bearing is different, but in the grand scheme of expensese, it's chicken ****... The transaxle is the same - a lot of Maseratis are being broken for spares since the cost to fix them makes your endeavour with the 928 look cheap... Do a bit more research...
P.S. I just bought a complete Maserati 4200GT transaxle, with the actuator, solenid block, accumulator and electric pump - will use these as spares for my GranTurismo - to see if it can be used on a 928, for the princely sum of $500 on UK eBay... But go on, keep trying to fit 928 parts to an Italian V8. Will make for great YouTube viewing...
Are you two married? It's a process... Discovery, highs, lows, parts hunting, success, falure and folly. It's the journey.
Yeah, I sould like my wife... Just trying to help, especially knowing that the Maser parts cost the same, while are vastly superior... Progress, they call it...
03-19-2024, 01:36 AM
