Took my "in progress" v8 conversion out for a spin the other day. 4.0 liter aluminum v8 from Range Rover. Ran strong but stock suspension was very spongy. Felt like driving mom's Buick. What have you done to retain the wonderful stiffness and handling of the original 914?

It's been a while, I don't trust my memory much any more, but I think the original springs were only rated at about 90 psi. I had a 2.0 and went with what were called autocross springs and I think they were 140 psi and it really handled great.

When I went to the V8, small block chevy which is quite a bit heavier, I used the 180 or 200 psi springs. Springs are part of the picture, but Sway bars make a HUGE difference.

someone here talked about this set up recently but yes - you need 200 lb springs or so i believe.

http://www.ground-control-store.com/produc...ption.php/II=76

jim

I used 180lb progressive springs on my last one and I have 200lb on this one. The prograssives are nice for the street.

Hey Streetover,

I've spend a LOT of time over the 8 years understanding the chassis & developing my 383 Chevy conversion car. With BIG help from AndyS, I now have a very good handling track car and would like to see if I can help with your setup.

First off, Using an all ALU engine is a great move , not only on a lot less weight than what I'm lugging around, but also less weight up high that creates body roll. The chassis was designed around a LOW CG engine and low roll. When there is a lot of roll, the suspension does bad things.

To start, we need review what your chassis is now: Frnt torsion & swaybar and the same for the rear. With that info, I can compare your settings to mine and offer suggestions what changes to make to achieve a good balance. I've made a wheel rate calculation spreadsheet that will allow you to plug in different torsion bar, swaybar and coil spring values to see the overall wheel rates at each end of the car.

I'm betting one of the first changes needed will be increaseng your rear spring rates significantly. When first running the track will "soft" rear springs, I had NOTHING but huge understeer! UGH!

Shocks are also quite important. I'm running Koni sport struts in front and special built Koni dual-adjustable in the rear. I'm guessing you're planning to use your car as a daily driver so Bilsteins or the Koni Sport shocks will serve you well. I believe the Bilsteins will give a softer ride.


BTW, I'm just up the 101 in Camarillo, so communicating should be pretty easy.

Best of luck,
Terry

200lb Eibach springs with Koni adjustable shocks on Ground Control perch's seem to work well on my car with an iron block 350 but your motor might be as much as 200lbs lighter. I would still think the same combination would work for yours as you can adjust it accordingly.

180 progressive rears. I need to add a rear bar but the 180's were a huge improvement. No chassis stiffenening. My engine is likely one of the heaviest ever installed in a 914. When I hit the throttle the front lifts until the unsprung weight becomes a factor. The car used to push real bad in the corners with the stock rear springs and the rear tire on the out board side would tuck up into the wheel well even when turning out of a parking spot. I drive long distances in the car so I'm willing to give up a little stiffeness in the suspension for the ability to sit in the car for 10-12 hours at a stretch.

I have a iron SBC and run 200lb spings on adjustable bilstein for the rear and Koni inserts up front. I also lowered the car about 1" all the way around as well.

No sway bars, no stiffening, and stock torsion bars. I am really happy with the ride and ride height.

Not to take away from streetover's thread...perhaps related to his ride as well.
My car is a street car but I would be interested if sway bars really would make a difference in how it handles and if so what would people recommend? Brand?
Mark

Sure seems like a lot of v8 conversions here is central Cali...we should all get together sometime for a bbq.

On the street 180s if you want a cushy/safe ride, 200+ if you want it a bit more neutral handling and stiffer.

I have 180s on currently and combined with everything else on the car it makes for a really great street setup. But in honestly i'll probably go to the 225 to 250 range based on my needs on the track.

this can not be answered well until you tell us how you intend to use the car. tell us your vision of this car in your life.
street
track
AX
street with some AX
street with some track
mostly track with some street...
what is your driving experience?
do you mind a stiff car?

Hey Streetrover,

I'll bet my direct answer to your question will make fur fly:

Assuming 22mm front torsions bars + swaybar, I would recommend 250 - 300 lb springs to balance the chassis. Neither of these rates will make your ride harsh.
I've been driving my car to the track with 400 lb springs and not been uncomfortable.

FYI: The actual WHEEL rate at the rear is 1.17 X the spring rate due to where the spring attaches to the swing-arm.

As I stated before, soft rear springs will give a bad understeer. Sure it's safe, but you won't be able to turn-in to a corner, so forget a spirited drive in the canyons.

Best,

Terry

Hey Sean,

WELL SAID.....this is the info I was hoping to learn.

Terry

Im not sure I would recommend 22 front tbars on a street car.. I have them and with the v8 in the back the front gets pretty light over bumps and bounces around quite a bit.

The fact that he currently is on STOCK suspension I think that he should simply go with a aftermarket front sway bar and 180lb springs, combined with koni yellows front and back and adjustable spring perches on the rear (for ride height adjustability and corner balancing).

The setup that you mentioned Terry would be much more appropriate for a car that hits regular track days. Which doesnt sound like the case here.



However this is all just hearsay, Like Sean said we wont know what he really needs until the OP posts what his goals are..

Hi Andyrew,

From my experience with my 914V8:
-With the extra added weight of a V8, I would recommend stiffening BOTH ends of the car. Keep in mind that extra weight on "stock" setting ends up with a very soft suspension.

-Your comment about the car getting light and bouncing around speaks to SHOCK Absorbers, not springs. The Koni Sport Shocks dampen in REBOUND which stabilized the car in just the mode you offered. Stiffer springs will reduce suspension travel, roll and camber change, all of which are good goals when working with a 914 chassis.

-With the extra power & torque, all a 914 will do is understeer! I would like ALL 914V8 guys to NOT be afraid of stiffening the Rear Spring Rate! As I mentioned before, 300 Lb/in springs do NOT make the ride harsh and the ONLY way to move from "Terminal Understeer" is stiffening the rear. Also, a rear swaybar is very helpful in changing the balance from BIG understeer to MILD understeer. With my car, once I added the rear swaybar, I was able to soften the spring rate down to
400 lb springs (470 lb/in wheel rate + swaybar rate) from the previous 450# units.

-One should keep in mind that SPRING RATES are what determine chassis handling. The thought of using Shocks to change handling does not understand that shocks only dampen the action of springs. At best, a shock can input a short invertal of input to the chassis, such as at corner turn-in.

-While you might be right about my set-up being better used for a track car, I feel
180 - 220 lb/in springs are just TOO WIMPY to get a 914 V8 to handle well. Of course, we are still waiting to hear what the owner wants to do with his 914.

Terry

All that discussion on spring rate is interesting, but some of it depends too on how much tire he's going to be running.
300-400 lb springs would feel a lot softer with big meats under wide flares but probably feel like riding on bricks in a narrow body with 205/60s.

The other thing mentioned is all the extra weight. 250 lbs is not that much extra weight.

My SBC is just over 300 hp and i'm running 2oo lb springs, stock sway bar in the rear and a 911 bar up front, 22mm I think. The tires are 215/60s all the way around on 15x6 front and 15x7s rear.

I used to drive 34 miles of canyon road to Estes Park, Colo every week and it was just a HOOT. It was a perfect balance and I could steer it with throttle on the increasing and decreasing radius turns.

It all just has to balance to get a nice combination you like.

all you guys are quoting spring rates for a iron sbc not for a rover/buick alloy v8!

this engine is smaller over all and uses aluminum heads and block!

much lighter than a sbc. prolly about 100-150lbs lighter.

180lb should be plenty with good shocks [bils/koni]

160lb's might be hard to find unless you go after market adjustable coils over kit.

Great feedback so far! Generally this car is to be used as a daily driver. I drive 80 miles round-trip to and from work through the Cajon Pass in sunny So Cal. I've modified the trans with high (H) freeway gears, Occasionally would like to spend a Saturday or two each month enjoying a run around the local mountain roads at elevated speeds.

I'm not intending to spend any time on the track ... ever.

So...does anyone have a deal on a pair of these stiffer springs? Say 200 lbs to start. Sway Bars?

I'm also a bit confused...am I to understand the front suspension employs torsion bars? I know the rear is supported by coil springs and NOT torsion bars (like torsion bars on the VW's). I thought the fronts used struts that provided suspension and suspension dampening simultaneously.

BTW...stock fenders and wheels.

Ohh and here's a little added info from wikipedia about the weight of the engine.

"Known variously as the Fireball and Skylark by Buick (and as Rockette, Cutlass, and Turbo-Rocket by Oldsmobile),[3] the 215 had a 4.24 in (108 mm) bore spacing, a bore of 3.5 in (89 mm), and a stroke of 2.8 in (71 mm), for an actual displacement of 215.5 cu in (3,531 cc). The engine was the lightest mass-production V8 in the world, with a dry weight of only 318 lb (144 kg). Measuring 28 in (71 cm) long, 26 in (66 cm) wide, and 27 in (69 cm) high (same as the small-block Chevy)[4] it was standard equipment in the 1961 Buick Special."

Bob

front t/bars run thru the arms front to back.

struts hold the shocks.

stock rear spring rate was under 100lbs so going to 200lb would be a big jump. i'd start on 180s.

Hey Bruce,

Just for reference: my car runs 315/35-17 Hoosier DOT Slicks with a very stiff racing carcass. For a SOFTER ride, I'd go with your 215/60 tires with a tall, soft sidewall. Even on the Hoosiers, the ride would not upset the wife with 300 lb springs.

Secondly: the issue of weight is not just about lbs for a 914, it's about TALL weight that makes the car want to roll in corners. The 914 was designed with a low CG of a V8 engine and a low-roll chassis. After bump-steering all 4 corners, I learned that the rear suspension TOES-IN .100" for each inch of compression (the loaded tire in a corner) while the other wheel TOES-OUT the same .100" as the unloaded wheel. This means BOTH rear wheels turn toward the center of the corner in roll.
Thus, understeer is guaranteed unless mods are made. My guess is that Porsche
wanted to be SURE of no oversteer in the era of Ralph Nader.

I'm glad you like the balance of your car, but have a question about balance: With narrow tires, are you changing the handling with the trottle (power induced oversteer)? If you were to take a corner on the limit at 50-60 on a steady , slightly-positive throttle, what would the car do? Would it be neutral, understeering or oversteering?
-- I'm thinking understeer, but since U/S is stable, it's not a bad thing and especially if you like it. My case is very different: I'm trying to micro-tune the chassis balance for the max cornering speed on track and I HATE understeer.

Happy motoring on those Colorado roads!

Terry

Bob, Im going to reiterate my statement earlier.

Start off with new shocks, Koni yellows would be the best option.

Then an adjustable front sway bar and 180's in the rear (Progressive if you can).

Adjust the ride height to your liking and get an alignment.

If your serious, you should start corner balancing the car as that will let you get the most out of your setup... But you most likely wont ever need to go that far.

Hey Streetrover,

Thanks for the info on your "Application" with the 914. Since you are LA based, I was thinking dry-weather driving 98% of the time. However, the Cajon Pass can be very treacherous in winter and there is no car I know of WORSE to drive in rain and snow than a 914!

The other side of seeking "perfect balance" is that the car will be tuned to a certain
road condition (dry) while be way too stiff and prone to break loose in slippery conditions. If you watch racing, you hear them talk about "softening the chassis" for racing in the rain.

So I want to back off my early recommendation and suggest 200 - 250 lbs as appropriate for your safety. I would suggest starting with the 200 lb springs and see if you like the car. Also, I'd recommend going with the smoother Bilstein shocks.

BTW: Stock tire sizes (i.e. narrow) are much BETTER in slippery conditions that wide performance tires. When it starts to get nasty, I suggest pump them up high (34 lbs) to get max tread drainage.

Enjoy your ride!

Terry

hey Terry,
I miss the colorado roads, we left there many years ago. I can't really answer your question about the understeer or over, It was just a delight on the mountain roads. I can remember putting down the power in the turns and lifting it would trun in slightly and adding power the back end would squat just a little and straighten out some.

I know 205/60s on the front 15x6 wheels is a little large and I may have had a better foot print if I'd used 205s. Over all though is was a blast.

I know what you mean by the low CG... I did some auto cross while I was in CO and a nice set up 2 litre would clean my clock. I know my car was way more fun on those mountain roads, because I'd also done it in a '73 2.0LE that I'd had hotrodded by Sims in Dallas before I built the V8 car.

Lowering the car some helps and I imagine the little alum. buick will be a nice set up.

Bruce,

Trailing throttle oversteer, now that is a fun setup. It seems you have worked your way around the dreaded "terminal understeer."

Hey I look down at your personal info and was surprised to see that you got your first Porsche in '64! Dang, you must be as old as I: my first car was a '54 Porsche Cabriolet which I bought in '64!

Best,
Terry

Bruce,

Trailing throttle oversteer, now that is a fun setup. It seems you have worked your way around the dreaded "terminal understeer."

Hey I look down at your personal info and was surprised to see that you got your first Porsche in '64! Dang, you must be as old as I: my first car was a '54 Porsche Cabriolet which I bought in '64!

Best,
Terry
[/quote]
AGE? check the birthday fairy report tomorrow!