Robin W.

Hello everyone,

My electric conversion is done enough to be my daily driver again.
300v LiFePO4 battery pack split 2/3 rear 1/3 front, 11" Series DC motor with 1000A controller. 300ft-lbs, 200-220hp, 100km range, it's a blast to drive!

The problem.
I had to switch batteries part way through the build which put more weight then planned on the rear end. Ir weighed the car on an industrial scale on the weekend.
1298lbs Front
2992lbs Total
1694lbs Rear
43.5% Front / 56.5% Rear

The front lost just over 100lbs from stock, and the rear gained 300lbs over stock. The car is up 204lbs vs pre-conversion weight with a full tank of gas.
I'm not worried about the total weight, the car has enough torque to make it a blast to drive.

The question.
What is a cost effective method to bring the rear ride height up and properly support the extra weight. Similarly cost effective method of bringing the front down. (The shocks/struts likely need to be replaced anyway).

admiralkhole

You could adjust the eccentric bolts on the rear trailing blades and raise the car up almost an inch, more than that and you could reindex the torsion bars. All free.
In the front you can get coilover sleeves and springs from paragon, ground control, etc and they don't cost too much.
New shocks and struts would compliment your adjustments. Depending on your strut type, you might be able to just put inserts in instead of getting whole new struts.

I have some lightly used kyb rear shocks I can let go for cheap if you're interested.

Do you have any videos of the car in action? I would love to see what it's all about!

thirdgenbird

I want this, for fun if anything.

Can you give a rough cost of conversion?

I would really look at putting larger torsion bars in to compensate for the weight gain. The front coilover kit is the way to go up front. This will let you fine tune the height.

Van

If you're going to re-index the torsion bars, you could also put in larger torsion bars (like from a turbo).

Robin W.

I don't have any video yet but I'll get some, I was wondering about just re-indexing, but was a bit worried about carrying the extra weight. Might be interested in the kyb's let me put together a plan.

Stupid question.. the coilover sleeves work with a factory strut with replaceable cartridge? Any criteria on matching the spring/shock?
(I still have lots to learn)

I'm in around 20k (CAD) including the car, could have done some stuff cheaper, could have saved a bit doing some stuff right the first time.

I've been reading and learning about suspension, some things are hard to relate to because almost everything is about racing or high performance, I'm just looking for a street set up. I'll look into larger torsion bars, I did see a formula somewhere I'll have to dig it up again.

Good info, I'll have to get aquanted with torsion bar specs and what my car has, what's available on the used market etc.

Thanks everyone.

V2Rocket

howabout just some of the 1" lowering springs?

thirdgenbird

He would be stuck with the front ride height they provided, but based off the picture it may be about perfect. You could adjust the rear to match.

Arominus

With that much extra weight you should go bigger torsion bars period. I'd say 26mm or maybe 27mm vs the stock 23.5mm and upgrade the rear sway to 18mm. The turbo t-bars are no bigger than the NA ones unless the turbo was M030 or a turbo S (25.5mm). A new set of T-bars will be about $300, and totally worth it. Once you get the rear end to proper height see what the front does, it should drop a little bit since the rear won't be in "squat" mode anymore. You may not need to drop it once that happens and the weight loss up front will make the stock spring rate more effective for what's up there, so basically a free upgrade for the front.

You need more spring rate, reindexing wont do that for you as torsion bars have the same spring rate throughout their entire travel. Cranking them up to make up for the weight will just preload them more and mean your more likely to snap one. Your car is now weighted more like a 911 than a 944 and you should be looking at what they do for suspension setup with all of that mass in the ***.

BikePilot

Def need more spring rate. Probably cheapest way is to do coilovers all the way around. For the rear you can do really stiff coils and ditch the tbars or less stiff coils and keep the tbars. I'd be inclined to do the latter with the extra weight in the rear. Alternatively you can go with just stiffer tbars. You will want to match damping to spring rate.

Adjustable coilovers up front will let you set it up as needed.

You may also want to increase the size of the rear sway bar relative to the front, particularly if the weight is sorta heigh up I'd think.

Butters944

Yes. Paragon's $265 front coilover kit utilizes the stock strut. All it is is a threaded cylinder that sits on the factory lower spring perch, with a new lower perch on the threads supporting a smaller 2.5" spring. Looks like you have an 86, so replaceable strut cartridges, that's good. The spring goes around the strut so any stock fitting shock works. For a street setup I'd recommend 200# springs 10" length. It's what I have, a little stiffer than stock but comfortable enough on the street.

http://www.paragon-products.com/Coil...arhk-r-xdo.htm

(will post pics to help you understand how they work if you want)

Arominus

I forgot to add, do not just lower the front to match here, you absolutely must increase the spring rate out back, otherwise you will be blowing through all of the rear wheel travel instantly. You must have it if you want the car to handle right. Otherwise you will be bottoming out very easily, hell I have that problem now with a stock car on koni yellows at high speeds.

Robin W.

Ok, I'm learning!
More research came up with this:
http://forums.pelicanparts.com/porsc...rsion-bar.html
and
http://www.cip1.ca/ProductDetails.as...de=C12-6569-26

The bonus on that set is the price AND the fact they are in Canada.

What do you guys think?

For the front I think Butters944's link to Paragon is the best solution giving me adjustability.
200lb front springs and 26mm rear torsion bar seem ok given the abnormal weighting of my car??

Thanks for all the help guys, all of your comments are helping me grasp the bigger picture on what I'm trying to do here.

MAGK944

Assuming l&r weights are equal this will give you a stock ride height-

Stock Front:
1398lb/2=700lb
165lb*0.92=151.8lb effective
700lb/151.8lb=4.6in

New Front:
1298lb/2=650lb
650lb/4.6in=141.3lb
141.3lb/0.92=153.5lb

Old Rear:
1394lb/2=700lb
23.5mm=126lb
700lb/126=5.5in

New Rear:
1694lb/2=850lb
850lb/5.5in=155lb
155lb=25mmTB or 275lb coilover (275lbx0.56=155lb effective)

Summarize:
New Front Springs about 155lb
New Rear TB about 25mm
New Rear Coilover 275lb (tb's removed)

If you want to up the spring rate from stock and keep the same f&r balance you could probably go with
200F/370R. But you will have to change the ride height to bring it back down to stock with coilovers or shorter springs. A higher spring rate will raise the car. Hope this helps.

-calcs done on the fly, welcome corrections if I'm wrong

MN

Electric conversion.
I wonder whether electric conversion of older Porsches will be a new trend?
MN

Butters944

It's already becoming a huge trend, especially with the 924's