Hey 914ers:

If you have been following my posts on 914 chassis settings, here is one that applies to ALL 914's.

To start, per my posts:

-I Squared the chassis with paralleled strings to measure and set the toe, front and rear. (Front = 0 to -1/16 toe, rear = 0 to -1/8" toe)
=Results: steering a bit "nervous", but all else stable.

-Camber: For Street cars, Standard front with -1 to -1.5 degrees rear.
=Results: nothing noticeable.

-I bumpsteered the front suspensions to within 0.008" from prefect at 2" compression.
=Results: nothing I could feel driving the car on the street. TBD on-track.

-CORNER WEIGHT BALANCED THE CHASSIS: With the car weighted for the driver weight, I adjusted the rear spring ht. and the front torsion bar ride height. For the rear, large diameter washers can be added to make adjustments, while the front is too easy with an 11 mm wrench.
=Results: WONDERFUL!! With all the previous chassis settings done, the car still wanted to pull to the right as though I were on a highly crowned road. After the balancing the corner weights, side-to-side, the car now runs STRAIGHT and TRUE right down the road. The sense through the steering is now light, equal and very linear as to where I want to aim the car.

Conclusion: Take the time to either build wt check lever, as per my photo or find a very strong STEEL ladder and wing it. Regardless, the benefit from the effort is completely WORTH IT!!!

If you have any questions, please let me know!

Terry
stewteral@verizon.net

Basically, you did it backward. Changing the ride height alters the alignment.
My corner balance has no discernible effect on performance....tho it hasn't been far off to begin with.....40-50 lbs tops.

Word on what the old guy said.
ride hieght to get in the ball park
rough alignment to get the wheels all rolling in generally the same direction
then corner balance
then align to a specification

STEWTERAL....Please explain the "Large diamenter washer" rear balance adjustments...( .I assume you do not have adjustable spring perches) and I suppose you have to remove the rear spring to insert the "large washers"..correct?...what size washer, inside/ outside dia.?...what thickness washer resulted in ...X.?.....weight transfer?...please explain because I would like to avoid the cost of coil-overs.,,,thanks.

ricky Racer:

You're overstating the situation: my adjustments were 30 - 40 Degrees of turn on the torsion bar height adjuster that allowed the front-end to balance within 10 lbs side to side WITH DRIVER WEIGHT on-board. Original corner weigths were off by 100 lbs: Keep in mind this is a V8 car.

The affects to chassis settings are extremely small and WILL improve on-track performance by making the car's handling more consistent side-to-side and more comfortable to drive. A comfortable car is a fast car over the long run.

Terry

Hey ME733:

Sorry if I confused you:
-I DO have adjustable rear spring perches, so the "Washer Idea" does not apply to me. If you have adjustable perches, you're SET.
-The "Washer Idea" was Blue Skying a way for those with STOCK non-adustable perches to be able to shim-up a spring and balance corner weight. The washers would need to have an ID to fit around the shock body and have an OD large enough to sit under the spring. I doubt washers this size can be easily found, possibly at McMaster-Carr. So I would look to making them myself out of aluminum sheet with 1 sheet-steel washer against the spring to take the wear.
I'll leave it to an interested forum member to give it a try.

Best,
Terry

Of course, sonny, you can't learn squat from a fat old guy.

Hey Ricky Racer,

Are you saying you have a lot of racing and race-car prep experience?
I'd be interested in learning what experience you have with which cars and tracks.

Have you always done your own chassis prep and tuning?
What kind of equipment do you use for chassis alignment?
Have you raced a number of different types of cars?
Do you have any special tricks you have picked up over the years?

Thanks,
Terry

I'm not Ricky Racer nor do i play him on TV ...

I happen to be the crew chief for a small Porsche racing team. We consistently place in the top 3 with many, many race wins and overall class wins under our belt.

To answer your questions:

- All the chassis prep and tuning is done by us.
- We use electronic scales and the Smart Racing strings, camber plates and camber gauges for alignment.
- I race and work mostly on Porsche's. 911, GT2, 914, Boxster, you get the idea.
- Yes.

My point? I agree with the old fart. You're doing it in reverse.

We always start by setting the ride height close to where we want it, then corner balance the car to fine tune, then align the car.
In that order.
Andy

Heh....you will be in 20-30 years.


Yes, Terry, I do all the work on my car....or did till I sold it, soup to nuts.
The exceptions were 2. I don't mount tires and I don't do the alignment by myself, but....A buddy up the street has an alignment shop. We stick it on his alignment rack and have at it. No strings here...not accurate enuff. IIRC, the thrust angle last time was .003 deg.....that's close enuff.

Naaaa ...

First off, we don't do degrees.
Yepp, you heard that right!

We measure in 1/2mm increments over the diameter of the wheel.

I'll bet you a good cuban cigar that i can set up the 911 with the scales and strings just as good as your buddy with all his high-tech equipment.

Plus, using the scales and strings, i can make predictable changes at the track between run sessions if needed.

In fact, i don't think i've had a race weekend where we didn't play with the alignment settings.
Andy

And are you winning?

Yes!

Terry:

10-12 years back the car was Green....now it isn't.

Which part of the build are you interested in?
I have a boatload of "tricks" that most oldtimers here already know of.

Like having a youngster drive the car for you, lol.

A man's got to know his limitations.

JP Stein:

So your "racing experience" is 10 years with a slalom car? Did you do any of the driving, or just the wrenching?

Did the car ever get to a race track?

Why is the front-end so stiff on the slalom car that the inside front wheel is lifted of the ground? Is that to compensate for an open Diff in order to put the power down?

Best,
Terry

Hey Andy:

I have no argument with where to start the chassis adjustment process, but after finishing the first round of settings, one should go back around and verify/adjust the others.....wouldn't you agree? Since every adjustment effects the others, it is a continuing process of refining all the settings.

Now after setting toe, camber, ride height and corner weight, I will go back and verify toe and camber settings.

Have fun with your track cars, you have 2 truly great tracks up in NOCAL, while I have only WSIR and Buttonwillow here in SOCAL

Best,
Terry

Yes, autocross for 10 years & yes I drove it all that time...if not well.

It has a Guard TB diff & the rear is so soft that the inside front lifts off the ground under power. It has to be fairly soft as AX venues are not smooth for the most part.

Did a DE years back. Since I couldn't afford to do W2W went to Autocross where there is competition. I could see no sense driving around a race track pertending to be a race car driver. You should try AX...who knows, you may have the only V8 914 that handles worth spit. It's also a good place learn car control.

WORD on the learn how to drive via Autocross.
Most of my friends that now are fairly successful W2W racers were AXers first.
You learn car control and a 4 wheel slide at 100 MPH going into a corner does not seem like much of a big deal.

I do DE or lapping days everyonce in awhile. working on getting my W2W license. My skillz are good my wallet is still a bit light.

Terry has a reasonably impressive resume after racing for a lot of years. Not sure I've got it correct, but it goes something like this: 2nd in Calif slalom championship in an AC Cobra, SCCA FF, SCCA B-sedan, 944 (SCCA?), some sort of enduro racing, and now his 914 500HP 383 SBC/930 track car (with license plates). Though he's in his 60's (like me), he is still a Boy-Racer to the bone.

Andys

True, we always double and triple check the settings.

However, in my experience, the effects of corner balancing on the alignment are far greater than the effects of an alignment on the corner balance.

We do the corner balance first because if you do the alignment first the corner balance will tend to throw off your alignment settings enough that you have to go back and readjust your settings afterward.

In contrast, doing the alignment after the corner balance seems to have little to no effect on the corner balance.
Andy

... ...absolutely. ... murray

Hey Andy,

I think I can put the whole debate on "what to adjust first" to rest by letting you know that I didn't get around to building my corner-weight check lever until the last. I was kinda busy with a complete engine rebuild, replacing 1 of the dual master cylinders for the brakes and building & installing a new rear swaybar.

Shame on me: I was spoiled by the good old days with the formula Ford where I could load the car with my weight and just stick a bathroom scale under each wheel! Too easy!

So really there is NO arguement. Starting with the bump steer info I took on the rear suspension, I've calculated that the worst case "unintended-adjustment" change would be 0.025" change in toe-in. However, as we agree, going around all the setting again will rectify any such change.

Merry Christmas,
Terry

Terry,

Are you still using the coil over setup on your Koni shocks with the circlip and the four positions? I got these from Paragon Products in Texas 7 or 8 years ago. I would prefer it if the adjustment ring was a pinch clamp instead of a set screw so it didn't chew up the threads, but they seem to work fine. Just don't get carried away on the lock screw. I think TrueChoice has a similar setup. I figured it was the least I could do after your help on the wilwood brakes.

Kelly

Hey Kelly,

Thanks for the info! Yes, I've been running the funky circlip perch design for 6 years. I'll check out what Paragon Products is offering.

I called Ground Control the other day, to see if I could buy just the threaded perch and was told I had to buy the WHOLE kit WITH springs for $200. The story was that they could only warranty the whole kit.....I'm not buying the story nor the kit.

I'm glad if I were of help on the Wilwood brakes. A detail I didn't mention: when setting up the in-out spacing of the caliper an easy trick is having a friend (wife, small child?) stand on the brake pedal with the caliper in the correction position and then just measure between your adapter plate and the caliper mounting tabs.
Find a washer of that thickness and weld or braze it in place! Ta-Dah!

Best,
Terry

Click to view attachment


Hey Joe,

I agree that there are benefits to slaloming that I learned from high school throught early 20's. My dad had a REAL 289 Cobra and it would consistently take TTD. We both had a slew of trophies. However, my dream was road racing.

When I first went for my SCCA driver's license (after Russell School) I noticed right away that the NON-autocrossers would approach a corner, ease on the brakes, down-shift through every gear and then enter the turn.

By contrast, with my slaloming education in compressing activity to the shortest time possible, I would go deep into a corner, brake as late as possible, down-shift the FF once (from 4th to 1st) while braking, load the chassis in the turn and get back on the power preparing to accelerate out. Autocrossers worry about milliseconds!

So we are on the same page: Autocrossing is a great training step to road racing.

Best,
Terry

Terry,

Care to put a date on that photo

Actually you ought to consider posting that photo or any others from the period onto the Tam's Old Race Cars site. That's a historic photo!

Andys

Thanks a LOT Andy, you want tell how old I am!!

The photo is From the October 1970 Week-end Dad & I ran the California State Run-offs in Santa Maria (NCCSCC vs. SCCSCC). I was beaten that week-end and had to settle for 2nd: Elliot Forbes-Robinson showed with Richie Ginther's PERSONAL 914-6 and it was poetry watching him drive...How's that for irony?

Elliot was/is a great guy to talk to and since he had raced HIS silver 289 Cobra, he was interested in Dad's car. Elliot was just beginning his professional career and was not only a great guy, but a VERY GOOD driver. He shared his experience of driving at LeMans in a 911, doing 150 MPH at White House with the 917 Porsches just BLOWING by him at 180+ on the outside line. I don't believe his talent was ever fully reconized. A couple years ago, at 63, Elliot was still VERY FAST in a Rolex Prototype he drove that season.

That week-end was the finish of my autocross days: I bought the Formula Ford later that fall.

BTW: SPEED TRIAL USA track week-end will have nothing but rain. With my Hoosier DOT slicks, I have to stay home....but then, I don't think it would be much fun running those tires, with that much HP in a low-polar-moment chassis on a wet track!
Your HISTORICAL bud,
Terry

I have set the ride height on the car and in the process of corner balancing. My car is right hand drive so the numbers will look a bit strange. LF=382#, RF=507#, LR=532#, RR=527# with the driver in the car and sway bar disconnected. Are you guys able to balance the front end with the driver in the car? BTW the driver in this case is 250#.

Thanks,
neilca

Hi NeilCA,

YES, you CAN do better on the corner weights. Even with the V8 engine my numbers were LF=645, RF=635; LR= 795, RR=755. That's 10 lbs diff front & 40 lbs rear.

To get these result took a LOT or going around the car a corner at a time and a lot of patience.

To get it close you will need rear ride height adjustability. So your choices are:
-Stock 914 FAT shocks: Ground Control threaded alu perches + springs = $200.
-If you are going for serious track driving, the Koni 8611 dual adjustables are the way to go and since they are the standard 2" diameter and cheaper adjustable perches are available.

I hope this helps,
Good Luck....Terry

I had 2 formula, and 1 IT7 guy come over to my shop with chamber gauges, scales, and Dunlop gauge. Basically we spent three hours adjusting everything. I make this point because earlier posts indicated a particular sequence for chassis setup. I believe the sequence is you adjust everything at the same time because everything changes everything else. That being said, you start by making large adjustments to get you in the ball park, as you refine the setup the changes become smaller and smaller. The end results for me were

Chamber

LF and LR -1.6 dg
RF and RR -1.5 dg

Corner weight*

LF-440 RF-450
LR-500, RR-560

Ride Height**

LF-2.75" RF 2.5"
LR-3.5" RR-3.6"


We have 1/16" toe in on the rear and 1/8" toe out in the front

The next step is to take it to the track (Road Atlanta) and get tire temps to see what the car wants.


* The corner weights are rounded due to fluctuactions in the readings caused by friction (sticksion) in the suspension. Weights are with the 250# driver in place. Sway bar is disconnected. 8 gallons of fuel are in the fuel cell and the oil tank is full.

** Ride height is measured from the bottom of the stock jack nubs located at the four corners of the tub.

Hey Neilca,

That's great to have a bunch of racers help you set up your car! It sure made all the work go more quickly.

When will you go to the track? I'm very interested in what think about how the car feels.

Enjoy,
Terry

I am looking at a test day March 19. I will repost after that with results. Hopefully with tire temp data. Also hopefully everything will work, it will be the first time I get this new car up to speed!

NEILCA,

Have a great time, I wish I could get back out that soon!

What track will you be running? I'll be very interested in what you experience.

Tire temp data would be great to build a 914 database...
BTW: what tires and sizes are you running?

Best,
Terry

I will be running at Road Atlanta on Goodyear cantilever slicks, 9.5X23X15 all the way around. I plan on starting with 18 PSI in the front and 21 PSI rear.

Your slicks won't like that much camber. About half as much is typical.
I wouldn't use that much toe out up front. The car might turn in real nice but I think there will be a lot of drag on the straights, the car will have a tendency to wander.
Your front ride height seems way too low to me.
And why run the rear starting psi so high. The rears heat up faster so I typically have them set 1/2psi lower than the fronts.

Test day results,

The weather was absolutely perfect 69 degrees no wind and sunshine. I was in a goup with a bunch of Spec Miata's. Did two sessions and the car performed flawlessly. This thing just stuck like glue, I couldn't get to slide even when I goofed up. First lap was a 2:04 the best lap was 1:54 lots of 1:56's in between. One comment about the SM guys, they are some really good drivers and despite their reputation very courtious. They don't give you a lot of room but enough room.

Now for numbers,

First the ride height was not a problem. The car didn't scrape or bottom anywhere. I did have tie wraps on the shock shafts to measure shock travel but I have not measured it yet.

The toe out in the front was very noticable, ie scary as hell, on the first lap. The car was wandering all over the place. Then a Miata passed me and like in the movie "Up" I said "squirrel" and the wandering was completely forgotten and the chase was on. I didn't notice the wandering again.

I had on Goodyear 430's all the way around the tire temps were

First session
LF 118,137,143 PSI 18-25
LR 132,143,146 PSI 20-24
RF 138, 136 130 PSI 18-18 this tire has a bit of a leak
RR 140, 140, 135 PSI 20-24

Second session
LF 128, 140, 149 PSI 18-23
LR 129, 143, 147 PSI 20-23
RF 141, 136, 131 PSI 18-23 Leak appears to have stopped
RR 148, 143, 140 PSI 20-23

Based on these numbers I believe the LF could stand about 1/2 degree less camber. But that is the only change I would make at this time.

Hey Neilca,

Glad you had a great time! Your tire temp numbers look pretty even, but as you noted the LF could use less camber.....and what do you think about the LR?

I don't know the Goodyear 430 compound, what temp does Goodyear recommend as optimal for the tire? I ask because I had a chat with Hoosier and found that even though my temps across the tires looks good, ALL my temps were BELOW where the tires generate max GRIP!

So I have a couple choices: 1) with the balance finally coming right, I have to GET UP ON THE WHEEL and driver FASTER & HARDER.....or 2) buy a whole new set of SMALLER width tires that will run hotter by themselves.

.....Can you guess my choice?

Enjoy those track days!!

Terry

Terry,

Yeah the left rear could use a bit less camber. The Goodyear 430's are a medium compound. The temperatures are below what Goodyear would like to see, but it was only 69 degrees that day. My events in May and July will be about 25 derees higher in air and track temperature. To generate more heat I could go with the 240's, which is a softer compound and more grip too.

This was my first time at speed in 14 years so I expect I will be generating more heat with more seat time. It was a gas, next event is Time Trials at RA in May.

Just a point of reference - I think the current FProd lap record is a 1:38 or 1:39, set a couple years ago in late March. My best during the National in 2005 (my first time at RA) was about 1:46 with 140hp, a poorly adjusted Rennshift and no practice/qualifying.
I was slow through the esses, not knowing just how much speed could be carried down into the valley.

The softer tires aren't going to generate any more heat, they will just grip better at lower temps. The way to get the tires hotter is to carry more speed throught the turns. If you didn't feel the tires slipping against the pavement you don't need a softer compound to go faster.