Today I took the 914 GT clone to her first autocross. I posted here rather than the paddock as I'm just getting my feet wet with the 914. Overall for the first time out I think I did good. I was 5 seconds off TTOD and this was on 5 year old Yoko ES100's. Here's a little rundown on the car before I ask some questions.
3.0 stock 911 engine with Weber 40 carbs.
911 Front struts with 3 inch ear calipers. Standard Boge inserts.
911 M calipers on all four corners. 20mm vented rotors all the way around.
Rear Koni shocks set to hard with 140 lb. springs.
Stock 901 transmission with stock 4 cylinder gearing.
Front 19mm sway bar no rear bar. Standard torsion bars.
Car corner balanced at 2100 lbs.
16x7 + 16x8 Fuchs with 205/55 + 245/45 tires.
19mm master cylinder.

Now the questions. The car seemed to be well balanced but I really struggled with rear traction. Coming out of turns it was very easy to spin the tires. And launching from the start was either spinning in 1st gear or a slight bog starting in second gear. And I quickly found out that stock street brake pads are not up to snuff for aggressive driving. I have some Porterfield R4S that I'm going to try. So you guys that have more power than me how are you putting it down ? I know better tires will make a big difference along with me learning how to drive the 914 vs. my 911SC but any tips to pass along ?
Overall I had a blast as I always do .

Well yes, tires.....and maybe an LSD.
I could light up my 10 inch slicks launching in 2nd gear with my little 2.7L so you can't get past that, but good tires will help. You will also find that R Spec (Kuhmos & Hoosiers) tires have much better recovery characteristics than street tires. This becomes important when finding the limits of that 3.0L's traction ...challenges.

On my first time out with the 2.7, I got about 200 yards on street tires before going backwards. I didn't take it out AXing again til I had some wider R specs in back.....the next month.

By "recovery" I mean what you see about 20 sec. into this vid.

http://www.youtube.com/watch?v=07wW-jT9Szw...layer_embedded#!

Heh, there are several "recoveries" in the vid. Some are more artful than others.

I can tell you one thing that will help a lot.......Toss the ES100's. I tried a set and even new they were terrible!!! Five years old would make them unbearable. The ES 100's were the worst tire I ever owned (but good mileage)

I replaced them long before they were worn out after swapping ends a few times during some spirited back road driving.......

Agreed about the tires, though all I could really find for the rears (size wise) is DOT-Rs on a quick search. You can figure on about a grand for R-Comps, and you still WILL have wheelspin. Lucky 914s come equipped with traction control. It's really easy to find. It's where your right foot rests. Just kiddin' ya. I had the same problem in JP's (now Britain's) car. I can work with you on tires if ya like.
The one thing that I notice on your setup is that the rear seems a bit unbalanced. 140 lb springs probably don't warrant full hard on the Konis. All I can tell you is what I'm running, which is medium hard setting with 200 lb springs. This is on a 4-banger 914, which is lighter in the rear, and it seems to work well. You may try going softer on the shocks to allow the rears to dig in a bit more. And if it were me, I'd consider going a bit harder on the springs as well. That being said, if you stuff a 3.0 too quickly in a 2100 lb car, you're lighting them up. My $.02
LSD would be great for making wheelspin more controllable, but it will not make it go away. I've heard nothing but great things about the R4S pads, but I've never had the privilege of using them. Other than that, have fun! The car sounds like it'd be a blast. BTW, how much AX experience do you have in the SC?
Mark D.

Mark thanks for the reply. Actually thanks to everyone that replied. I don't think I'm ready for R spec tires yet as I want to take it in stages. So I think I'll go with some Dunlop Direzza Star Spec tires as my next step in the right direction. I'm thinking 205/55 + 225/50 or possibly 225/50 all the way around any thoughts on that ? The Koni's came to me ( used ) with the hard setting already adjusted and with the 140 lb. springs. To adjust the shocks I have to take them off and compress/turn. I have another pair of Bilsteins that I think I'll add height adjustable coil overs to. I'm a fan of Bilsteins. And I'm thinking of going with 200 lb. springs what do you think ? At some point in time I'll probably have to go with sportier strut inserts up front and maybe a little stiffer torsion bars. I'm definately going to pop in the Porterfield pads. In regards to my AX experience I've only been doing it for 5 years now with the local PCA chapter. The past two years I've either been 1st or 2nd overall for the year in my class but I'm no expert, just a 52 year old guy having fun .

When I switched to Rspec I did Victorracers in the 205/225 sizes. My suspenders were the same as you're using ( but with Bilsteins) with the AR bar set on full soft.
The set up worked pretty damn good. Humm.... 10 years ago. Time goes fast when you're havin' fun....or gettin' old.

Rick, I just answered your eMail and then I reread this thread.

When you are ready to go better in the front, let me know, as I have a set of re-conditioned ( PMB - Eric) Koni front strut housings with the 3.5" spacing.

T.C.

Are you running the stock rear springs? I think 200 works well (with adjustable perch) with 19mm fronts. I use that setup but it's strictly for street. It does seem to be balanced well. Many encouraged heavier springs for the rear but I wanted a decent ride. Others can chime in but I know many use 225-250 rears but typically with larger tires.
Click to view attachment

Havin' fun is what it's all about. I don't care how competitive you are. If you're not having fun, why bother?
Are those Koni Reds? Adjustable perches are a good thing. I got a set because I needed to set the ass-end of the car down. It was rather stinkbug before, and it really helped the handling to make it sit like a Porsche. Heavier springs in the rear may help, but you don't want to upset the balance. If your front sway is adjustable, I'd say go for 200s or 225s in the rear. Paragon sells a coilover kit with 200s. Stock front T-Bars are fine, but good front shocks would be an improvement. If the front bar is not adjustable, I'd also start working in that direction.
As for tires, I'll tell you what I've been telling everybody else. The Dunlops are a great tire, but too cold blooded for the 914 IMHO. Your car may be a bit better at 2100 lbs than mine at 1925, but still, that's pretty light. Don't get me wrong. I'm running the Dunlops and they're a great feeling tire, but I won't be repurchasing them for that reason. I'm loathed to recommend a tire that I've never personally tested before, but the Yokohama Advan AD08s and the Toyo R1Rs both have a reputation of working better on lighter cars (softer compound). You may find someone running them and see if you can do a test drive. Both are a little more expensive. I think the Toyos a little more so, and they seem hard to get.
I think keeping the fronts the same size and going to 225/50 in the rears is what I would do in your situation. You probably want a bit of stagger on a six conversion, but going smaller in the rears may be a blessing in disguise, also for heat management. That being said, I don't really have any experience with six conversions. BTW, what did your front/rear weight balance come out at when you had it corner weighted? Just for my curiosity. Thanks. Hope that helps.
Mark D.
:EDIT: This thread is STILL worthless without pics!

Yes they are Koni reds with 140 lb. springs. And yes the ass of the car is a little higher than I like that's why I was wondering about the adjustable spring perches. I am familiar with Paragon and have looked at their kit. Seems like a good value. I have a 19mm H&H adjustable sway bar up front. It has 3 adjustment holes and I currently have it set to the middle hole. My mechanic did the corner balance and I forgot to get any data other than she was 2100 lbs. but I can always ask him. Thanks for the feedback .

Almost forgot here are some pics. I still have to install the rockers and valances but you get the idea. Her nickname is yellow jacket .

Bitchin! If I ever make it to Florida you'll have to take me for a ride. Good luck and keep us posted.
Mark D.