Bass GT3

Guy's

Hope you can help me here. I currently have an '81 vintage 924 shell, which i race here in the UK. I am currently rebuilding the car, and am looking to fit a 968 box into the car.
Can anyone tell me what is involved in changing out the gearbox carrier? As i understand it, the bar running across the rear needs to be cut out and a late '44 or 968 type installed. What's involved??
Alternatively, is there a modification piece/kit available to effect this change.
just for your info, i am looking to change boxes as the 944 box is too high between 4th & 5th. So although i may never use 6th, i will have a usable 5th. However, there is a fair chance 6th will be used on some of the faster circuits here, as i run 21" diameter slicks. Car is making circa 370bhp, so yes it will pull it!!



Many thanks,

Steve

Airflite40

is the drivetrain still 931??? If so then you might have better luck over on 924board.org

have you considered an S2 trans??

nice car!!! post some pics of that beast!!!!

Spidey944

That TRS wing looks to be a much better piece then most I have seen, even from the distance in the picture! What is the manufacturer of it? If it's an AIR piece, it musta taken a lot of work to make it look that nice.

MPD47

Steve you will need to fit either the 944 or the 968 crossmember and torque tube. All late 944/951 torque tubes are the same, the 968 units are different. The 968 box will bolt upto the 944/951 torque tube however I cannot garuntee that the crossmembers are interchangable (I know they bolt up to each other however driveline angles will change depending on what combination of parts you use.) You will need to either cut out or modify the 924 crossmember as this is a bolt in affair in a 944 Turbo. I've got a 968 box in my 951 and it does bolt in with zero drama but as you know the 924 is fairly different. I also have no idea if the axles will bolt into a 924. *shrug* Not sure if that's any help.

-M

Bass GT3

Hi,

No, the torque tube is 944, as is the rear end. (Kokeln beam soon!!)
I am currently running a 944 box, but 5th gear is killing me. There seems to be a huge gap between 4th and 5th. So i have aquired a 968 box, as it has more usable ratios for my racing, even if i barely use 6th. I also have the yoke type beam that the box hangs from, but i don't think this will bolt into a '24 chassis. So what needs doing??
Re the wing, a friend of mine made it!! he makes most of my FG panels, doors included.
Re 924.org, i am very active there, but it's focused on the 24, rather than the 44 or 68.
If you want more pics of the old girl, go to 924.org and search for posts by Bass GT.
just a little info. 2 litre tubo, circa 370bhp!! Fun?? Oh yeah!! Very light, and fast. last seasons build (250BHP) was only 0.5 second slower than a 440bhp 911 RSR!! Should be sweet with the full fat engine in

Steve

Bass GT3

M

Thanks for that. see my previous post re the current running gear. So you have a '68 box in?? Would you have any pictures, especially up under the rear showing the box/hanger arangement.

Many thanks,

Steve

MPD47

There is the 968 crossmember it's aluminum rather than stamped steel and has a much higher hump (but has a much longer hanger).


968 Box in (keep in mind it uses a standard 944 axle on one side and a unique one other the other). Unequal length. I can take more photos for you as you need them from above or below (as my floor is removable).

-M

Bass GT3

You are a star sir!! many thanks for that. Just what i was looking for.
Yes, that s the hanger i have. Does it bolt into captive nuts in the chassis rail? Looking at thos pics, i can cut out my current crossmember, and bolt in the new hanger. Might just be worth drilling through the chassis rail and using long studs ect. I plan to possible triangulate the cage down to those positions as well.
If you do have any more photos, i would love to get them. any chance of mailing them over??
Finally, whats the length of the unique drive shaft? Did you modify an original, or have one custom made?

Many thanks

Steve

MPD47

I can put some high res ones online for you. I'll try and take a bunch more for you tonight (depending on when I get home from work as I'm still here). I use the factory 968 axle on the one side and just spares I have laying around on the other. It does bolt into captive nuts in the rail so you'll have to decide what you want to do there.

Bass GT3

Thanks a million!
No rush, whenever you have a moment would be fine.
Regarding the mounting nuts, i will probably drill through the chassis rail, and bolt it right through.
Interesting with the floor cut away as well. Whats the reason for this? Do you have pics of it closed over? What are the advantages of this?

Steve

333pg333

As an aside Steve, may I assume this is your car pictured here? I like the front ducting very much. Is this primarily for the i/c or the radiator? Were you able to measure a temp drop with this ducting in?
Also as a stop gap measure for your gearbox, you could try putting an S2 cw&p in the 951 box. It shortens everything up measurably and would suit many tracks. You just lose top end speed so it does depend on what track your running on of course.
Great looking beast though.
Patrick

Bass GT3

Hi
Yes, thats her. The duct is for the IC. Regarding temp drops, i was measuring close to ambient!! However, heat soak started to set in, so it was slowly rising. I plan to fit a water spray onto the new build. The car is primarily used for Hillclims/sprints here in the UK, so the runs are vet short. I did some testing at the track with a camcorder and strips of wool. I placed the wool around the duct, and found that the deflector needs to come around the sides, as i was seeing air spilling back into the duct. The IC is fully shrouded in the front, so the air is pulled right through. Also, the duct is placed right at the point of lowest air pressure on the bonnet, which aids the through flow. In my opinion, size of the intercooler is secondary to it working well. This really seems to work very well.
However, on the new build, i shall be fitting a K probe to the IC outlet/inlet, so i can graph the IC temps a lot quicker and more accurately.
Concerning the gearbox, i currently run a 944 box, not 951. Everything is OK, except 5th gear. There sems to be a huge gap between 4th and 5th. So my options were to have a new 5th gear cut, or fit a '68 box, as this has very evenly spaced ratios. Aalso, as i run 21" tyres, the gearing is very short, so on some tracks, such as Goodwood i might actually need the 6th gear. Last year i was pulling out of the last corner in 3rd, and maxing out at about 120 as it would not pull the tall 5th gear.
FWIW, here is a little video of her in action lastyear. Only running 250BHP here, but still pretty nippy!! As you can see from the 2 pics, she'll happily light the rears up in 2nd. And these are super sticky Avon slicks





Steve

PorscheDude1

Great car, cool pics!

PorscheDude1

That hill climb looks like lots o' fun!

sweanders

Only negative about the 968 box is that it is 14 kg. heavier IIRC.