Chassis Stiffening.., How far to go? Options

[OllieG]

Hi,

I'm at the stage in a very slooow build where I need to think about chassis stiffening.. I'll do the regular GT kit but I don't know whether to do either or both the Inner Long Kit and Roll Cage.

The long term plan is to fit a Suby 3.0 N/A and use it for mainly street but also hill-climbs/sprints/autoX here in the UK...

Any thoughts or advice?

Thanks, Ollie.

[Andyrew]

If its mainly for street, General advice is against a roll cage. as if your not wearing a helmet you could do more damage to your head if you get in an accident without a helmet.

You need to check with the sanctioning bodies that you plan to run with to see what is required if you DO need a roll cage or a hoop or something.

The regular GT kit does not really do much for stiffening. There are some good pieces but the real kicker is the inner long kit. That will do the most for stiffening. Then stiffen up the rear suspension ear with a reinforcing plate and a tube from the firewall. That is really all you need for a good street car that can take some abuse. Especially if you are just running sticky street tires.

[OllieG]

Thanks for the input Andrew, helps alot. Think I'll hold off on the roll cage at this stage and just go for the inner long kit..

Ollie.

[JmuRiz]

I'm in the process of getting the inner long stiffening kit put on my car. It'll be a while before I can speak with any authority on how much it helps though.

I'll have to look into the rear suspension ear mod too.

[76-914]

Ollie, I'm doing that exact conversion. There were so many opinions on this subject that my head was spinning. I don't plan on AX; just some spirited driving occasionally. I contacted Chris at Tangerine Racing and asked which of his products I needed to complete the stiffening process. (I had already installed Engman's kit inside.) Chris said he believed that I did not need further upgrades given the info I had given him. This from the man that manufactures and sells re-inforcements for our suspensions. Not to mention his racing experience. (IMG:style_emoticons/default/beerchug.gif)

[OllieG]

Cheers guys, yep I can see the sense in strengthening the suspension ear, and it's not a big job.

Does a connecting tube from the ear to the firewall make a big difference? I would want to make sure it didn't get in the way of the engine before I welded it in..

[Mark Henry]

I'm watching this thread as well, I haven't done anything yet and I'm also wondering if I'll need anything.

3.0 /6, bit of a hot engine say 250hp, on a real solid car as rust free as a 914 can get.
Stock narrow body, 205's mostly street, maybe one day a DE but I doubt it. Sure I open it up... but I'm not stupid like as I don't want to break poop.

[bulitt]

Cheers guys, yep I can see the sense in strengthening the suspension ear, and it's not a big job.

Does a connecting tube from the ear to the firewall make a big difference? I would want to make sure it didn't get in the way of the engine before I welded it in..

Go onto the tangerine racing website. Chris offers a removable link set-up to brace the ear to the firewall, and a reinforcement kit for the ear!

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.tangerineracing.com-13632-1371143412.1.jpg)

[Andyrew]

That bar makes the biggest difference with big or sticky tires.

If your car has any rust its something you should consider and they are fail points.


I have an engman long kit and seam welded rear points. The engman kit gives the car the stiffness it needs and the seam welding is just for piece of mind.

I run 285's in the rear and do quite a lot of drifting, so there isnt typically much force put on the rear suspension ears, but I have seen to many crack and to much flex to know that it needs the reinforcement at some point.

[BritCarJim]

hmmm. i should be following this too....

[Rand]

"piece of mind"

Love it. Reminds me of an Iron Maiden tune. Or I could give you a peace of my mind.

Pay attention to what has been said here.... The GT kit is crap. Especially the junk behind the firewall. Your head may spin because of all the talk, but these days there is no need to wonder. The head spinning is obsolete. Easy answers today.

[Elliot Cannon]

When you install your kit, drill the holes bigger. It make for a stronger weld.

[carr914]

The original GT Stiffening Kit was Quess Work at best

The Inner Long kit is great - too bad Engman is no longer with us (IMG:style_emoticons/default/sad.gif)

I don't have any experience with the Firewall to Ear Bar, but I have seen one and it looked good

[scotty b]

IMHO any car over 120 h.p. should have a long kit. ANY car that sees regular track use should have a long kit regardless of h.p. I'll second what Elliot said. Open the holes up a bit. Weld the corners together ( where the sides and rear piece meet ) I'm doing a Subaru 6 and will be doing a long kit and Chris's heim rods, one of Marks GT roll bars (more for looks ) and probably nothing more, and I drive pretty hard.

[914forme]

There are several ways to stiffen a 914 chassis how radical do you want to go?

My current chassis has a Brad Mayer 914 Limited outer log kit, runs all the way back from the front of the log to the rear outer suspension console. Has an Egmann inner kit, and full seam welding. I built the inner suspension console stiffening bars much like Tangerine racing sells, Chris was not making them at that time. Don't forget the suspension console while your there. I also have an outer one that ties the rear outer suspension arm to the logs. It is adjustable and makes setting the suspension toe much easier. If it stiffens I am not sure. Since it is auto-x mainly I have a Roll bar, added a lower bar that ties the lower points together. It pickups the lower Seatbelt points also and is mounted to 1/4" plate that wraps down the logs to the floors, ties in at 4 planes super strong mount for a bolt in roll bar. And a Petty bar down to the passenger footwell, which was re-enforced and ties into the logs. Not bolted to the floor like most I have seen, The petty bar is removable, at the track a passenger can ride with it in, though I normally remove it. For the road, I will remove it all the time.

Oh it has a GT kit, but that was done before I got a brain. In reality it was done after it became legal in PCA racing, thank you Jon Lowe, it was not hte best thing, but with no other choices legal choices it helped.

I had a bolt down top which I laced with a set of metal gussets it added about 10 pounds up top. It has since been removed as the Windshield pillars proved to be to flexible for its installation. I cracked two windshields with it in place. This was before I stiffened everything else up, so I might add it back in. Considering I never take the top off, I have also thought about bonding a carbon fiber skin up there over a metal frame. Or doing a metal skin like the 916.

For a street driven subby I would just add the 914Ltd outer logs and be done.

And the Engmann Kit was good, it would be even better if it extended through the firewall section and went up the inner logs to the inner suspension console.

Then that will lead you to rear suspension arms stiffening, don't wrap more metal around the box, make the box into smaller boxes. And the front is pretty stiff from the factory, a long as you don't cut out the trunk wall or floor. If you do you will need to add metal back in to stiffen it back up.

You can also add lower door bars and tie them through the logs with DOM and build a dash bar that runs up under the dash. put it as high as you can get it. You can add a Box section to the inner tunnel to make a raised console, don correctly it would stiffen the car the key is getting the loads moved to the outside of the chassis.

I have also seen two different home grown systems. One 914 I parted was supper solid even though the logs where rusted apart. At some time someone welded 3/16" plate steel to the bottom of the bottom of the car. That would stop small caliber rounds. And my favorite part out ever agin semi rusted logs, door gap true as ever, some one took the time to get pressure treated 4x4 pounded into the log section. Still to this day figure it took a lot of (IMG:style_emoticons/default/smash.gif) by one (IMG:style_emoticons/default/screwy.gif) group of guys to solve that issue in the most original way I ever found. Or maybe it was a group of Morgan enthusiasts.

[Mark Henry]

IMHO any car over 120 h.p. should have a long kit. ANY car that sees regular track use should have a long kit regardless of h.p. I'll second what Elliot said. Open the holes up a bit. Weld the corners together ( where the sides and rear piece meet ) I'm doing a Subaru 6 and will be doing a long kit and Chris's heim rods, one of Marks GT roll bars (more for looks ) and probably nothing more, and I drive pretty hard.

(IMG:style_emoticons/default/huh.gif)
Your damn opinion makes me more work (IMG:style_emoticons/default/mad.gif) (IMG:style_emoticons/default/slap.gif)

(IMG:style_emoticons/default/poke.gif) (IMG:style_emoticons/default/shades.gif)

[J P Stein]

The following link will show one how to stiffen a 914's chassis.....that part comes after the painting.(the thread covers a couple years. see pg 4)

Stiffening by tying in the shock towers was THE BEST mod I ever made to enhance handling. You want easy?..... buy sommore band aids and you won't even come close to stiff. No roll hoop is needed, just a roll bar & some imagination. Ayup, it was a race car but didn't have to be if the planing was better.

All this cage got replaced by something better designed & lighter.




http://forums.pelicanparts.com/porsche-aut...-we-got-em.html

[JmuRiz]

... will be doing a long kit and Chris's heim rods, one of Marks GT roll bars (more for looks ) and probably nothing more, and I drive pretty hard.

Does that mean I need to call up Chris and get the heim rod kit for my car too? Just wondering...
I need to order some type of stainless fuel lines anyway.

[sean_v8_914]

inner long kit with bigger weld holes, weld corners
inner suspension ear scab plates AND seam weld. the spot welds errode and pull apart. i dont think 914 needs teh heim links untill you go big or sticky on teh tires

the targa top will squeek less

[OllieG]

You guys rock...thanks for all the tips!

Goin' to get on it...