Glad i'm not there anymore

 

When u finish all the cars at the unit son!

 

Appreciate the hard work!

 

Next job?

Take the shell off the spit on 2 post lift, then offer up dummy engine with 997 GT3RS gearbox so we can work out the fabrication required to fit the control cables and gearbox mountings.....

 

Well, although it's a tight fit around the front of the tunnel, the gT3 box will definitely fit. Front mounting & gearcable routing are probably going to be the most difficult aspects of the installation to resolve.

 

Taken a few days to work out the best way to mount the GT3 gearbox, in the end we decided to fabricate a new front mounting for the original GT3 bushes.

Here's the progress that Marc has made so far:

 

As soon as the mounting is finished we will sort out the cable routing & do the necessary changes in the tunnel for the GT3 gearlever, then finally the shell can go for stripping and coating.

 

Colin

This is a very interesting project, I can not even imagine what time and money it would take to get to the finished product. One of my race buddies here in Houston is building a 1974 Carrera 3.0 RS according to FIA homologation specs (down to every little detail of the factory IROC cars, including the Kugelfisher injection). He says that there is no way you will get your RS project homologated to FIA rules, and do historic racing and rallies, due to suspension, gearbox, motor, roll cage anchoring points/locations, etc, etc. Is your project a car that will be used just for regular track days, or is it supposed to be backdated and classified as a historic (i.e. FIA homologated) race car? Just curious, because when (or if) I get the time and money (???), I would like to do the same thing myself.
In any case, thank you for a very interesting thread!

 

At the end of the day, the 9mRS build programme is firmly focussed on the requirements of the individual who orders the car, in this case the customer wanted a trackday 3.0RSR but with 400+hp 3.82litre 9m engine + 6 speed gearbox with the chassis to match. Since the early 911 body is a pain to update to this level (ask Singer...) he readily accepted our suggestion to start with a 964 tub. Of course, from the very start FIA homologation was not even a consideration.

 

Due to the relatively late decision to fit a new GT3RS gearbox instead of trying to replicate or find a suitable 993RS box we now found ourselves with a whole load of fabrication work to do on the tunnel area of the 9m11RS in order to get the GT3 box to fit (properly). Unfortunately with all the other work we've got going on in Panelcraft Marc quickly found himself at saturation point, so in order to pull the programme back on track we're now recruited a new 9m staff member & race car fabricator, Owen.

This week myself & Marc brainstormed the changes required to the shell for the GT3 box installation. After translating the ideas to Owen, we left him to his own devices for the week and the photos below show the results of his efforts.

The GT3 box is a lot larger around the nose, so the first thing to go were the handbrake tubes so that we could reprofile the central tunnel reinforcement under the seat.

Next up was the gearlever installation. The brainstorming pointed us towards relocating the lever inside the tunnel so that we did not have to run the cables up inside the car. One immediate advantage of this is that the stock 964 handbrake lever can be retained, so that's one less thing we now have to worry about. However, even after trimming the standard GT3 gearlever housing it was still too wide to fit inside the tunnel, so after cutting out the stock 964C2 gearlever box the next job was to selectively widen the tunnel to suit the housing.

With the tunnel sorted Owen made a mounting plate for the lever which was plug welded into place, the slot at the back is the exit point for the cables.

The next job will be to relocate the handbrake cable tubes & then we can turn our attention to changing the angle of the cable mount on the gearbox itself. The final job I will then be left with will be to measure up, draw & have motorsport specification control cables made to the exact length required.

With jobs like this you just have to eat the elephant in small chunks......

 

Lordy, lordy! You guys make santa & the Easter bunny look like amateurs! Great thread as per usual!!

 

The decision to go with the GT3 gearbox set us back considerably on the production plan, simply because this was the first time we'd done this upgrade and nobody envisaged the amount of fabrication work required to get it to fit properly. Making the decision to recruit a specialist fabricator to add to the team has paid dividends though, as not only has it taken the pressure off Marc's workload it has also allowed us to progress on the bodyshell for the new 9m96GT3RS-R project and next week we will be preparing another 9m93RS shell before embarking on another 9m93 Speedster project. Busy times!!

Hence it was a relief that we delivered the finished 9m11RS bodyshell to be paint stripped and coated this week, thus achieving the first major milestone of the project. We've been quoted three weeks to collection, so with a bit of luck we might be laying on the paint before Christmas.

The engine parts have now started arriving as well & we've been promised the CNC machined crankcases back next week, so I'll be following up the bodyshell progress with the engine build as this happens. More later foks.

 

quality of work looks exceptional. Genuine Matter cage rep through to the engine bay.

Why the GT3 box?.... genuinely interested. Having owned a 996 GT2 and a 996 turbo in the past I am all too familiar with the 996 gearbox issues.

 

We chose the GT3RS gearbox because of the 9m 3.8HL engine we've got planned for this car. It's the same engine package that is now in the black 9m93RS Widebody, to see why the GT3 box is an obvious choice take a look at the dyno sheet below which compares it to the same customer's 997GT3RS. At some point you have to assume that Porsche know what they are doing when they choose gear ratios, so since there is very little difference in the performance, torque & rev range between the two engines going for a brand new 997GT3RS gearbox actually works out cheaper than replicating it with a re-geared 993 6 speed. The bonus is the accuracy of the cable change system, it is simply streets better than the 964/993 rod change.

We've ran GT3's on track for years and other than syncro & diff wear we've not uncovered any issues, so I suspect that the problems you are facing with the GT2 & turbo boxes are more as a result of the torque output of modified turbo engines than an inherrant fault in the design?

 

Any update?

Cant wait to see more