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Posted by: corpselaurel Jul 4 2004, 10:12 AM

I have been reading and searching. So far I have eliminated the boxed trailing arms.
I want to stiffen the car up before I paint. What 'kit(s)' should I install?

I have read read that most of the pieces in the chassis stiffening kit are useless. Should I buy the kit and install the others?

I have also read that http://www.914world.com/bbs2/index.php?act=ST&f=4&t=12376 helps a lot. And I was also considering the http://www.pelicanparts.com/catalog/shopcart/9144/POR_9144_chasis_pg3.htm#item18.

I just don't know which combination I should install. Should I use all of them or do some cancel each other out (for lack of better wording). Post links to suppliers if you mention any.

I am open to the idea of putting a cage in but it has to be in kit form. Does anyone sell one and would I still need any of the stiffening mentioned above with a cage?

The car is not badly rusted except for the battery tray and underneath - completly gone. I will be repairing it. My plans for the car are daily driver with some autox. Next year I will swap in a more powerfull engine. Thanks for any help.

Posted by: trekkor Jul 4 2004, 10:25 AM

I recommend Engman's highly.
Nice thing is you can install it any time because it goes under the carpet kit and is concealed from view.

This kit really works. I tend to drive rather spirited on the back roads and this is a good boost.

Send your e-mail and I will send you a few pics of the easy install.

KT

Posted by: neo914-6 Jul 4 2004, 10:40 AM

Why not post them for all to see???

Posted by: corpselaurel Jul 4 2004, 10:54 AM

Here is a pic of the kit from pelican. Which pieces should I not use?
And should I install engman's and the Inner Rocker Panel Frame Stiffeners as well or just engman's? I just don't want to have to strip off por15 later on to weld more parts to the car.
Any cage kits as an alternative? After reading through some threads I am starting to worry about cracking due to high spring rates.

Which pieces should I not use?

Posted by: trekkor Jul 4 2004, 11:02 AM

Believe me I want to. I have over 50 shots of the entire install start to finish as a photo documentary ready to post.

It's not time yet...sorry.

I'll give one teaser.


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Posted by: trekkor Jul 4 2004, 11:11 AM

My understanding is this: if you box stiffen the trailing arms , something else has to give. Like the trailing to chassis bushing mount points. Very bad and costly. Rips and tears.

I landed a 3 wheel off the ground right turn in my Baja Bug of old that had a solid trans mount kit. Ripped the rear mount horn right in half. Some areas of the car need flexabilty.

I honestly dont know if the box kits help or not.

Posted by: corpselaurel Jul 4 2004, 11:33 AM

In my first post I stated that I have eliminated the trailing arm kit (for the exact reason you mentioned). I am trying to sort out everything else.

I know that some of the pieces in the picture I posted above don't really do anything; I just don't know which ones.

Posted by: trekkor Jul 4 2004, 11:55 AM

Come to the Napa 914 lunch July 19 and see/feel the install for yourself.

http://www.914world.com/bbs2/index.php?act=ST&f=2&t=13829

I should have the carpet in by then, but I'll bring the complete photo pack for all to see.

Posted by: corpselaurel Jul 4 2004, 12:14 PM

I would but it is way to far from me. It is in AZ right?

Posted by: i love porsche Jul 4 2004, 03:49 PM

so the trailing arm stiffeners are a bad idea?

Posted by: trekkor Jul 4 2004, 05:14 PM

My understanding is the load get's transfered to the chassis mount points and can cause cracking, splitting or failure over time.

So yes, bad.

Posted by: Eric_Shea Jul 4 2004, 07:27 PM

I have them (boxed control arms)... I don't think they're good or bad.

From what I understand they're fairly useless. The factory did it to chase after rear flex which was eventually found to be in the bushings. I really don't see how the extra stiffness could translate through the factory rubber bushings... they're quite substancial.

Now, if you had roller bearings then it might add to the issue but with stock bushings I can't see it.

Regarding the chassis kits... I have the basic factory style kit pictured above. I've heard good things about the inner longitudinal kits but no experience.

Posted by: corpselaurel Jul 4 2004, 07:59 PM

After doing some more reading I haver decided to install the clam shells, the inner longs, and the 10 piece kit pictured. (I really wish someone would call out the pieces that I hear are useless in the 10 piece kit, I don't want dead weight. I even numbered them!)

My main concern is with the rear shock towers. I have read that with high spring rates (~300# I believe) they start to separate over time. There doesn't seem to be any kit to fix this that I am aware of. (Please let me know if there is, or if someone does it) So I will wait to tackle that problem until next year when I hope to have a cage put in that ties to the rear shock tower. http://www.914world.com/bbs2/index.php?act=ST&f=2&t=13274&hl=stiffening has been very informative.

I will go ahead and do the welding, and por15 everything. And when I am ready to install the cage I will remove the por15 where I need to weld I guess. I will not be doing the boxed trailing arm kit. I read in a few posts on hear that for various reasons convinced me.

Which ones are useless?!

Posted by: Eric_Shea Jul 4 2004, 09:09 PM

I believe it's 6 and 7 but not certain.

It doesn't matter because you can't put them on your car anyway. They only go on six cylinder models. They go where your engine mounts currently reside. So... unless you want to cut off your mounts and go with a six you have no worries.

Posted by: 9146986 Jul 5 2004, 08:07 AM

There's a areospace engineer in the Texas/MUSR group, Al Swanson, who did some analysis on the 914 rear trailing arms, and found that welding the kit to them may actually WEAKEN them, due to anealing the metal, which takes the strength out of it.

From what I've been able to discearn, the trailing arm box kits are pretty much about marketing, and bragging rights.

PK

Posted by: Jeroen Jul 5 2004, 08:26 AM

If you're planning to put a cage in your car, I wouldn't mess with any of these kits

Waste of time/money IMO (if you're doing a cage) plus you're adding a lot of weight to the car (which will become mostly useless once you put the cage in, and will be pretty much impossible to remove then)

If you feel you have to do something now, I'd go for Engman's kit.
I wouldn't do the out side clamshells (unless you have rust issues on the outer longitudinal)

About the GT-style chassis kit. I think you need the pieces that reinforce the the outside suspension pick-up points and ties them to the frame rails. The ones that go higher up (outside of the shock towers and further back).
That's what I seem to remember anyways. There was a thread here that showed which pieces to use and not to use.

We've had some pretty good threads about cages and the GT chassis kit when this board was just a few months old. I'll see if I can find them for you.

cheers,

Jeroen

Posted by: Brett W Jul 5 2004, 08:53 AM

In my opinion 3 and 8 are fairly useless, but I think a lot of cars already have them in there. My car had them, the other car that I am doing work on have them and several chassis I have seen have them. MAybe the factory started putting them on the later cars. I have the factory kit and don't know if it made much difference.. I may try Engmans kit when I get the chassis pulled back into shape.

As far as the trailing arm kits go, the trailing arms don't flex they twist. Look at how the load paths are applied. If you want them stronger, make new ones and make them round.

Posted by: Eric_Shea Jul 5 2004, 10:28 AM

with Ya-Roon

If you're going cage the rest is "probably" useless. I would do the cage and pieces of the factory kit which tie the suspension in further to the chassis.

Posted by: RAR Jul 5 2004, 12:39 PM

I've heard of this, but haven't heard the details. If mild steel is used for their construction (likely) they wouldn't harden sufficiently in the first place to allow for any annealing. If they were a high carbon steel (unlikely) they should have been hardened to a point that allows flex, but only after considerable stress (hard driving), flexing being preferable to breaking.
Application of heat can make things more brittle. Perhaps that is one of the objections to welding on the boxed arm kit. I wouldn't think that careful welding would do that much harm, and thicker metal would be better in general. I'm not supporting one point of view over another, but would like to see more data.
The transfer of stress (reinforcing one point transfers the load elsewhere) does sound viable. Making the components round to stop twisting also sounds good.

Posted by: Qarl Jul 5 2004, 12:43 PM

Has anyone bought and installed an off-the-the shelf roll cage?

Autopower
Stable Energies?

Just wondering if anyone has BTDT?

Posted by: RAR Jul 5 2004, 12:51 PM

Speaking of rollbars, is the biggest benefit of same for a 914, tying the front and back of the car together at the top? Has anyone tried using high strength metal tubes in place of the heat tubes in the rockers (don't know what OEM are made of)?

Posted by: Jeroen Jul 5 2004, 02:53 PM

Here's some good reading...

http://www.914world.com/bbs2/index.php?act=ST&f=2&t=4702

cheers,

Jeroen

Posted by: Jeroen Jul 5 2004, 02:57 PM

More...

http://www.914world.com/bbs2/index.php?act=ST&f=2&t=42

Posted by: corpselaurel Jul 7 2004, 03:30 PM

I read a thread the other day which had a few diagrams on reinforcing the shock tower - I'll see if I can find it.

Here is what I am leaning towards (may change of course):
engmans
clams
10 piece

next summer I will see (after I save up and the car runs) if I can have a shop reinforce the shock/strut towers with out a full cage. The more I think about it the more I realize that I would probably hate driving the car on the street with a cage in it. That being said I would still like to autox. So I would like a cage that meets the minimum requirments to bolt in. So I could take it out when I am on the street.

I would still get the benifits of the reinforments since they won't be part of the full cage.

I don't know much about rules and classes etc. I want to build my car the way I want. I don't really care if I get put into a class with faster cars. I just want to drive.

Opinions?

Posted by: corpselaurel Jul 7 2004, 03:40 PM

Does anyone have instructions or a diagram for the 10 piece kit? I want to start por15ing my car but I don't want to paint where I need to weld and I don't know where they go.

Posted by: Jeroen Jul 7 2004, 03:47 PM

If this is a street / AX car, don't get a full cage, don't even get a bolt-in.
Have a rollbar if it makes you feel safer, and leave it at that.

Next, I'd get Engman's kit and use the required pieces from the GT kit

Like I said earlier, unless you have rust issues on the outer longs, ditch the clamshells

The rear shock tower reinforcements are only needed if you go to 225# or bigger rear springs (and that's very unlikely for a street driven car)

cheers,

Jeroen

Posted by: corpselaurel Jul 7 2004, 03:57 PM

Safety isn't my concern, I just thought you had to have a cage to autox in some places. I might visit the drag strip to (since this car is so light and I plan to install a different engine down the road). But I guess I could wait untill I actually need one esp. since I am poor.

I have some rust on the rockers but it isn't that bad. I thought the clams were to stiffen not to repair though (since on pelican's site they say to use the repair kit first.) Engmans does more than enough then so that the clams won't help? I don't want extra weight or cost if it doesn't help.

I am still new to the 914 world but I have read about a few guys running over 400 front and 300 back spring rates. My brother had a mk3 and mk2 gti with 600# and 400# pound springs daily driven. (I love to drive them handles like they are on rails and IMO fine on the street.) So I wanted to have the car ready to accept these in case I wanted to go that route.

Posted by: Rob Ways Jul 7 2004, 07:49 PM

Would the interior weld-in kit work well with a welded in roll bar with a forward bar?

Posted by: Jeroen Jul 7 2004, 08:04 PM

Hey Rob,

You have a "petty" bar on your rollbar, right?
(from the top of the rollbar to the pass.footwell)

My guess is that with a set up like that, Engman's kit wouldn't add much (if any) stiffness
Not quite sure though. Depends a lot on where the pettybar attaches in the front

Call Brad, he knows your car... I only saw it at the WCC and didn't pay that much attention to the details of your rollbar

cheers,

Jeroen

Posted by: Jeroen Jul 7 2004, 08:14 PM

Those are no compromise race cars that run on smooth surface tracks.
On rougher surfaces (like street and AX venues), such high spring rates will make the car bounce and skitter and you'll loose traction/grip instead of gaining it

cheers,

Jeroen

Posted by: TimT Jul 7 2004, 08:35 PM

I run 450/front-350/ rear

down from 600

600# springs were undriveable...

with the current 450/350 combo... it works at most tracks..

Pocono long makes my car bottom when entering the infield..

spring rates are probably fine... just have to play with the damping....

Posted by: corpselaurel Jul 9 2004, 07:34 PM

I think I will pass on all of the kits and do something like this next summer:

Posted by: Rob Ways Jul 9 2004, 07:55 PM

I have a weld in bar (tied into the rear longs and upper door jam) with the front pass long tied in instead of the floor. It does stiffen the car..... mainly on turns but not to the extent a cage would.

I was thinking if the inner long kit works.... it might add the cage stiffness without the cage. - A real plus since a cage is about $2K these days.

With tying in all the points in the 914 diagram, you should consider the class it puts you in. BTDT - you may be putting yourself in a class you don't want to be in.

Posted by: Aaron Cox Jul 9 2004, 08:03 PM

rob, can you post a pic of your roll bar please

Posted by: Rob Ways Jul 9 2004, 08:25 PM

OK- This first pict is the pass long tie. Note the weld in vs bolt in. I figure bolt in is worthless cause it gives.


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Posted by: Rob Ways Jul 9 2004, 08:27 PM

Here's a pict of all the upper points. The front bar is bolt in but not at the hinge points. When I turn hard I can feel this bar tighten.


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Posted by: Rob Ways Jul 9 2004, 08:29 PM

This pict is the front pickup point welded into the long. Again its bolted on but not at a hinge point. Going into the long was Brad's idea and it makes sense. The only bad thing is that when I jack up the car from the front donut, the windshield gives (cracks). This may be my car's flexy nature by itself.


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Posted by: Rob Ways Jul 9 2004, 08:31 PM

Here's the driver's side. Note the position of the front bar changes going into the side long. Looking over to the pass side blind is a chore with 5 pts on.


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Posted by: Rob Ways Jul 9 2004, 08:33 PM

Here's a closer look at the drivers side point. Notice how well the bar fits into the corner. The welds are strong. I could probably lift the car with a crane by the roll bar (but why?)...


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Posted by: Rob Ways Jul 9 2004, 08:34 PM

I just had to post this one again.


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Posted by: Aaron Cox Jul 9 2004, 08:49 PM

can you still fit a passenger?

Posted by: trekkor Jul 9 2004, 09:52 PM

I'll say this about chasis stiffening coupled with a stout suspension package; when I hit it hard out in the woods coming down a VERY sharp turn under hard braking, it sounds like a 747 landing as the tires lock and land several times due to massive wheel lift.

yeah buddy

Posted by: Rob Ways Jul 9 2004, 11:37 PM

Passengers fit OK, but its at least 3 inches forward. I've toyed with the idea of fitting the crossbar better, but I don't want to give up its function.

Trekkor. Wheel lift and lock is fun but if you're after fast keep all four on the ground. What's your setup?

Posted by: trekkor Jul 9 2004, 11:56 PM

Koni yellows- full soft front, full firm rear
31mm Smart Racing front bar set 75% soft
150# Eibach rear springs
Falken Azenis 39psi front, 41psi rear

I have a stock rear bar to install this week.
Also carrying 200# springs to Alameda...just in case

I expect to look like a different driver next Saturday.

KT

remember this?


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Posted by: Rob Ways Jul 10 2004, 12:01 AM

Why soften the front? What torsion bars? Who told you to put on a rear sway? (most people dont- but I agree with it BTW)

Posted by: Rob Ways Jul 10 2004, 12:07 AM

This is what it should look like.....


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Posted by: trekkor Jul 10 2004, 12:18 AM

I am the experimental child.

I believe the soft help eliminate understeer along with the stiff rear end.
Stock torsion bars.

Brad is the designer- I just pay and play!

FYI- Bill, Randal and the Jagermiester six car all lift.

I saw a car in Reno carry the front wheel 200 ft around a sweeper. They placed high up.

KT


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Posted by: trekkor Jul 10 2004, 12:29 AM

Here's the car with the long lift.
Don't have it lifting on "film" though.

All these fast cars that lift, why? To stiff front bar?
Is it understeer forcing the inboard wheel up?

I'm scared


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Posted by: trekkor Jul 10 2004, 12:40 AM

point of reference:

here's what it looks like with worn out stock suspension.
Same venue, similar turn, speed.


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Posted by: Rob Ways Jul 10 2004, 12:43 AM

I shouldn't drive and tell... but the rear bar keeps the front down. The front suspension keeps the rear down. I personally like the stiffer torsion bars.

Bill and Randal drive fast for multiple reasons. Bill's car plain and simple is a friggen rocket. Randal is sorting out his suspension now and is making big strides this year with times with virtually less effort.

For us street / AX drivers, the key is to get as much as you can out of what you can put into it. Keeping all 4 wheels on the ground isn't sexy or exciting, but from what I've seen its faster.

Brad is the prophet on these matters.

Posted by: Rob Ways Jul 10 2004, 12:43 AM

Oh, the Jagermeister car is N/A IMO

Posted by: Rob Ways Jul 10 2004, 12:45 AM

I dig the last picture and how you are leaning your body inside to try and help!!!!!!!

Posted by: Rob Ways Jul 10 2004, 12:49 AM

I know this sounds crazy too, but I think the roll bar tied into the foward long helps too.

THis is why I am intrigued by the interior stiffening kit. I'm just not willing to be a "tester". If it can further reduce flex and aggressively stiffen the car further, it could be a "must have" item. I hope so... we'll see I guess.

Posted by: trekkor Jul 10 2004, 01:08 AM

Come to Alameda, Rob.
I have not run the stiff kit yet in a/x.
I like being the " tester ".

You should sit down into my car and feel the obvious difference. Even stand in the door opening and jump up and down if you want!!

Run it up and down the paddock if you like.

KT

Posted by: Rob Ways Jul 10 2004, 01:15 AM

Thanks for the offer.

I've got kid duty but I'll be springed for the LPR AX on July 25, and for the Zone events in August at Alameda.

With the stiff kit. I understand the theory and its effectiveness with a higher HP car. For an AX application, I want to feel the flex or lack of, and relative stiffness you like to have in concert with your suspension. 914s flex in multiple areas. A welded in cage takes a great deal of flex out of the car. I'm hoping this kit does the same thing, and ideally complements the roll bar as well.

Posted by: trekkor Jul 10 2004, 01:22 AM

Rob, I was putting new wheels on today and when I lifted the rear of the car from the motor mount bolt the front of the car came way off the jack stand.

I believe this kit with the cage will put you in happy land.

The weight ( 18# ) is worth the test. Do do still have sound deadening behind the back pad?

KT

Posted by: Rob Ways Jul 10 2004, 01:38 AM

The latteral stiffness is there with my forward bar. When I jack the front wheel, its about 2-3 inches above the rear (but suspension travel is a part of this too).

Happy land with the roll bar is where I want to be. Hopefully you can take me for a ride at the next AX event we both attend.

I've stripped the car of the engine sound proofing, but the floor tar is still on. I'm also thinking about taking the center console and radio out.... I also need to scrape the black coating off the wheel wells.

Posted by: trekkor Jul 10 2004, 01:48 AM

The first thing Brad noticed about my car when it was on the rack was the fact that it has no undercoating ( 40#'s ).

It you want the tar out, I found an air chisel is magic.

KT

Posted by: 914momo Jul 10 2004, 01:53 AM

I've been using a propane torch and a wood chisel it works great

Posted by: Racer Chris Jul 10 2004, 05:56 AM

IMO the Engman kit is ony good because of the easy install.
The clam shells are a better stiffener if you are prepared to do the work. I don't think both are necessary.
I also think the 10 pc kit is a waste for the most part.