Updates & changes: I can't tell a "short" story! LOL! |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Updates & changes: I can't tell a "short" story! LOL! |
Cracker |
Oct 13 2016, 08:04 PM
Post
#1
|
Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States |
Silver lining - starting from scratch is ALWAYS better!
A month ago, I ran into my first real problem, at Barber - I blew an outer CV less than 2 laps into the weekend. The root cause was I had a lowered the drivetrain to avoid a section of existing rear structure (lazy is never a good excuse!) - this caused tthe angles of the CV to be too extreme. In addition, I had also lowered the chassis beyond what was practical with my stock suspension set up. One caveat: The car liked it and felt great on the track but the angles were not sustainable! In speaking with Chris Foley (thanks a million for answering my calls!!!) - he likes the hub center to pivot shaft centerlines to be within .250" of an inch to each other. My pivot shaft was 1.5" lower and coupled with the lowered drivetrain (which lowers the drive flange on the transaxle) - my CV went kaBOOM. My pivot shaft to hub delta is now only .5" - more inline with what Chris would like to see. I share all of this (my stupidity) to hopefully help someone else avoid the same pitfalls. I weighed the options and there really wasn't any choice - to make the car safe at high speeds and to KNOW the changes would allow the CV's to last, I had to cut out the rear structure out, raise the trans to the proper level, fabricate the new exhaust, and rebuild everything around what was left. I also had an issue with my wing strut at high speed, staying stable - deflecting rearward. The wing was a variable pitch...but it wasn't supposed to be! All of this re-work provided a great opportunity to fix this along with everything else. Another bonus, in picking Mr. Foley's brain was integrating his suggestion to implement structure that helps keep the longs from twisting - in relation to each other. It is still not exactly complete nor what I'd like in total structure but if I add too much more - people might call it a race car - not a hot-rod! (IMG:style_emoticons/default/poke.gif) My exhaust was a little loud - not too bothersome to me but it didn't meet the 103 dB requirement at many tracks - even ours out East. I "invested" in the Burns Stainless 2-stage system for LS engines. They have a removable baffle which creates an more open system. It is supposed to knock the sound down to about 97/98 (I was at 106!). The cans were too big locate below the floor - so topside they are! I like it anyway (even if it raises my CG)! Here are a few pictures of the completed project - just in time for tomorrow's departure for Road Atlanta. If any of you local/regional folks want to come on out - I'd enjoy meeting you - come on by. No cost to get in - you'd be my guest. Now if more than 3 people looked at the "paddock" - someone might actually show up. (IMG:style_emoticons/default/blink.gif) If you have suggestions and ideas - please share them. Tony |
Cracker |
Dec 1 2016, 08:54 PM
Post
#2
|
Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States |
TC - I believe that definitely qualifies as a "race car" diffuser... (IMG:style_emoticons/default/sunglasses.gif)
T |
stownsen914 |
Dec 5 2016, 11:41 AM
Post
#3
|
Senior Member Group: Members Posts: 913 Joined: 3-October 06 From: Ossining, NY Member No.: 6,985 Region Association: None |
A diffuser can be done on a 914 - it just ain't easy! Pic below of the one I did on my car a few years ago (pic isn't the best due to the shadows - I outlined the rear of the diffuser in red on the picture to highlight it). The biggest challenge, aside from making the diffuser itself, was getting the exhaust and shift linkage out of the way. I also raised the engine and trans slightly so they don't sit lower than the floor pan of the car, so I could make a true flat bottom front to back.
In case you're wondering, the thing sitting on top of the car is the engine lid, which was off for this pic. Attached thumbnail(s) |
Lo-Fi Version | Time is now: 25th May 2024 - 12:41 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |