Another RSR build - The begining

[wax105]

Thanks Flieger, a compliment since you have seen many tube frame and track cars...

I'm amazed at the amount of people actually looking at this thread but not saying a word!?! LOL I dont tend to write very much just let the pictures do the talking. If any of you have comments (good or bad) or suggestions, dont hesitate.

Well my work day got cut short by an empty propane heater tank in the shop so its a good time for an update! As all projects go, 25% more time and 25% more money then expected, the motor is not yet started but very, very close.

The 915 finally came back from PorscheHauss with the CMS side cover, all new seal and fasteners. I have good hopes this will work out fine to start, next we'll propably go for a 6s G50. In an effort to find tenths of a second here and there, I decided not to bend the 964 engine carrier and modify the tranny mount instead. This was an experiment that worked out pretty good, I was able to move the engine/trans. assembly 1.4'' forward. Doesnt seem like much but should be noticable on the scales! I strive for good balance and this is the kind of thing that makes a quick car of any make, details.













I boxed up the mount for strenght and will send it out for sandblast and powdercoating next month. I also took the time to fit the oil cooler, gave it a little angle forward following the soon to be duct slope. I will receive the steel fuel cell can and missing fittings on Monday, once its all fit I can get to work on the ducting. This should provide ample cooling!







I got myself a xmas present!




Fabcar shifter, its been modified at some point so like everything else in my life, it requiers some work... LOL But it look great!

So not a moment to soon, the motor is in and supported as it should! Good day





Thanks for watching everyone!

[450knotOffice]

Wow! I can't believe I missed this thread all year. I just went through the whole thing and am seriously impressed. Good job!

[Flieger]

What will your static driveshaft angle be? We have seen a couple CV joint/axle failures. The axle failure was a 935 replica (Reaper930) and the CV joint failure was on an RSR replica (Jack Olsen's car). They both had drivetrains moved forward and had lots of power.

Moving the engine forward is good for handling, but make sure you use CV joints that are strong enough and with enough range of motion not to bind.

[wax105]

I was also concerned about the axels until I test fitted, the amount of change is marginal. I have however inquired with the local racing cv axel shop and they could easily supply me with a bulletproof set if the need presented itself...

Do you know how much Reaper and Jack advanced the drivetrain?

Thanks 450knotoffice

[Flieger]

I think Jack did two inches or less forward of the stock 72 location. I cannot remember if Reaper moved it forward, but his car was lower. With him, power was also an issue, though it seemed the failure was a combination of fatigue and bending load being applied to the torsion bar of the axle shaft, possibly caused by suspension binding due to bottoming out. Cup cars break axles quite frequently, apparently, due to the high power and stiff suspension. If they go over bumps without lifting, the wheels loose traction and the axles load/unload too quickly.

[wax105]

The difference should be about 1.8deg on each end of the axel, not enought to change much. Power on the other hand will put more torque stress on the axel (not my problem right now)lol, if I expect any problems with the cv's, it will be caused by the diff...

[mjshira]

drop a note to Tyson, I am sure he can walk you thru what they did on BB2

[911st]

Wow!

If you can drive even half as well as you build, no one is going to be able to catch you!

[911st]

Sorry, duplicate post.

[Flieger]

Originally Posted by wax105

The difference should be about 1.8deg on each end of the axel, not enought to change much. Power on the other hand will put more torque stress on the axel (not my problem right now)lol, if I expect any problems with the cv's, it will be caused by the diff...

Found the threads, in case it helps

930 Snapped Axle CARNAGE!!!!!!!!!!! RWHP problems...

CV Joint -- Cage disintegrates at the track

[jmitro]

Wow wax105, this is an awesome build. very impressive fab skills. did you seam weld the chassis at all? what target weight do you anticipate?

congrats on the new wife and new baby. my time in the garage decreases as my 5 year old gets older, but luckily I enjoy time with her even more than working on my project cars.

[SP2]

Wow! Whoa! Super nice job!

[Schumi]

Originally Posted by wax105

Starting to get very anxious now!! But allready daydreaming of the version 2.0 for the future... It just never stops this madness!!! Maybe something like this:

Who's is this and where can I find more info on it?

[wax105]

Flieger - mjshira
Thanks, thats gold!

Originally Posted by 911st

Wow!

If you can drive even half as well as you build, no one is going to be able to catch you!

It's the thing I do best!!

jmitro
No the tub is not welded, at this point its only along for the ride... Weight should be hopefully around 2000lbs, my ultimate dream target is 4-5lbs/hp. I'll build the most powerfull race turbo motor I can afford and remove the amount of tub needed to reach my goal... lol

"This we dont need, cut! This we dont need, cut! This we dont need, cut!"

[wax105]

Mike
Sorry I dont have any info, was found during a search for 993 suspension conversions on rennlist I think. Didnt find any real build stats but its pretty straight forward, the important part is a proper jig to align everything up. Me like!!

[wot]

more on the car with the 993 rear suspension

http://instant-g.com/Cars/GT3R/Cage/index.html

[wax105]

Erik, good show man... More dreaming now! Thanks

You're way up there in North Norway, I lived in Stavanger for a while but never made it up past Bergen, nice country!

[KTL]

Carl,

Thanks to you for continuing to post updates. Everybody learns alot by watching what you're doing!

Care to share some basic details of how you plan to set up the pedals? I've thought about switching to a dual master cylinder for making brake bias adjustments, and I like the idea of Tilton pedal system since it puts the weight low in the tub. Plus I don't want to spend the money for the Fabcar MC setup.....

[wax105]

Thanks KTL!
"Hope the family is doing good and that all went well with the new Baby! Actually I think I hear your wife calling you for a diaper change... "

Well for pedals, as you know I went with the Tilton floor mount setup. They are the best bang for the buck and really nice quality. I made a raised aluminium floor pan for the cockpit that gave me a very nice surface to mount. I have two of the mounting bolts going thru the plate and floor and two others just thru the plate. It's plenty strong but I think I'll drill out the two optional mounting holes and get 6 total.

I wanted the complete assembly, masters and all, to fit inside the car without going thru the firewall, you'll need the compact M/Cs. If setting up a purpose track car, driver positionning for me is paramount. I wanted to have the pedals centered with the steering column, I had to massage the tub with an 8lbs hammer to make a little room for the clutch m/c... That erea is double skinned and no visible signs of the mod in the wheel well!

For my specific application the system called for .700'' front and rear masters. With this setup the front and rear lines are independent of each other, as opposed to a proportionning valve that changes the amount of flow forward and rearwards. I much prefer this! The pedals come with the balance bar that allows for front and rear m/c travel adjustments. This will change proportioning between the both and will be adjusted via the bias nob you see on the bottom of my switch panel. As for the clutch m/c, the general rule is it should be the same size as the slave cylinder you will use. I think I'll go with the CNC 7/8 slave, adaptation to the 915 is not bolt on but should be relatively easy. Setting the clutch release and adjusting the travel is the most important. I'll let you guys know how it goes once I've tried it out...

[KTL]

THanks for sharing the details Carl. I suspected you modified the floor to get the Tilton assembly up and out of the divot on the floor for the factory pedals. I agree the balance bar setup is the way to go to ensure that a proportioning valve doesn't become a link that joins the circuits

I'll be interested to see your setup for the clutch actuation. I saw a similar setup on a 930 trans that I thought was a cool trick. Incidentally someone on the forums (BoxsterGT) recently asked about a hydraulic conversion on the 915, so you could help point us in the right direction.