Would like to hear opinions on six conversion chassis stiffening kits. Is this just a good idea for any six, street or track 2.0-3.6? Did factory sixes have their chassis reinforced or were all 914's built the same in this regard? Are all kits created pretty much equal? Where would you buy yours from today?

I put the Engman kit on my 3.2 conversion. I'm beginning to reassemble the car now so unless winter holds off another couple of months I won't be able to give you an opinion until sometime in March. This kit seems to be universally praised on here.

The factory style GT rear housing kit seems to get a lot of "well, if you're doing a GT clone and want it to look authentic . . . " kind of responses. Same overall mixed opinions on the boxed control arms. In fact instead of the old factory styled one, check out Tangerine's (Racer Chris) updated take on it where you can add Heim rod braces.

There are a bunch of threads on here about various seem welding techniques, tower braces etc., etc.

The Engman kit has receiced so many positive reviews, it seems like a no brainer. Just make sure it gets welded correctly.

You need to be very careful when welding in an inner long kit. I got mine right but I know some people that seem to know what they are doing and still tweek the tub. Mine is from engman and this car is very stiff. I think I posted it hear, I'll do a saerch and see if I can find it.

Depends if you want a bar. If so, line up and get the V-Bar from Mark and don't add any additional weight.

I have a V-Bar and the factory stiffening pieces.

Carerror's build thread is over on NARP in the garage. I did not mention what I did to support the chassis while I did the welding. I shimmed the tub up to where the longs were level and checked them regularly during welding. click on the NARP logo below and go the garage. I just bumped it to the top.

We are welding one in as I write. We buy from Rich Johnson and his is a repro of the original GT but flat and needs to be bent into position and spot and seam welded. We always follow what the factory did and come out fine. Since we are installing a 3.2 this kit is perfect for street spirited driving.

I cut out the cross brace on the floor on the driver side. Mind you that this car is A/X only and we should never have a side impact. That allowed me to lower the seats. There is a pic in the link here that shows how much lower the seats sit.

http://www.914world.com/bbs2/index.php?sho...=112183&hl= Look for the black car. Thomas head is lower than the targa bar.
My thoughts were that I dropped the CG of the driver 2 inches and the instructor 4 inches. The passenger seat is a fiberglass unit from a sand-rail bolted directly to the floor.
As Brant has suggested you could cut it out and move it forward of the seat to mount a race seat. That cross bar is of very thin metal. The only stuff I have found thinner than it is the pivot point for the rear trunk. I don't believe it is 25 gage.

Opinions....oh we have those here.
The stiffening on a new tub would be for fatter tires (thus flares)
That is what puts the stress on the tub, the wider tires that dont let go of the contact patch as fast that the 165 tires that are original.

The rear chassis stiffening GT kit is to make up for a very poor weld at the shock tower. This is a bandaid and does not really solve the problem, it just masks it.
It also reduces your tire width on the inside so you may need to add spacers as a result of using this kit.

The right way to fix it would be to remove the rear firewall at the shock tower joint and seam weld the shock tower.
You can also, with alot of measuring, do this weld from within the shock tower, you need really good penetration and it will weld through...less fuss.

The inner suspension ears...the place the rear trailing arm bolts to, is also a weak spot. There are a few kits out there to do it...Chris Foley sells on I think...
First, add metal to the inner ear (foley has that all cut) to add strength to the ear itself.
Second, you can choose to add a brace that attaches the inner ear to the rear lower firewall to keep it from twisting off.
I would suggest you do both.

The Engman inner long kit, or the outer long overlay kit (AA) both do similar things, and you should consider it.
These cars are almost 40 years old and the tin worm has reduced the structural intergity of the longs over the years.
These kits add weight, but they all a new layer of steel.

The caution is that these cars move ALOT when you weld these kits in, so bracing the door openings and taking your time (two or three days of slow welding) will ensure you do not twist the tub with all the heating and cooling that happens to the longs while welding.

Look up Jaroon here and look at his tub restoration to find the inner shock tower pictures.

There are many threads with inner long replacements.

There is one more place to look.
Drop a penny from the top of the windshield down onto the floor of the car...almost right there is a crack in the lower part of the inner long.

There was a pretty extensive test done on this chassis at a lab back in the 70's when the original and optimal cage was designed for SCCA racing. This is documented in the series of articles from the PCA in a set of books called "Up Der Fixin"
They strapped a chassis to a table and vibrated the chassis...
It ends up that the sweet spot, or the weak spot is that area directly below the windshield frame.
Its about 6-8 inches back from the a-pillar on the long itself...just about where it attaches to the floor...it starts cracking from the bottom up.

The rollbar setup that McMark is about to reproduce bolts a bar right at that spot and triangulates it to the top of the targa bar.
Ideally you would want to have that bar go directly to the top of the rear shock tower, and another one going to the top of the front strut tower....but that is not a simple path.

Do some looking around at the cages that are being built to see where people are tying things in....

Rich

I used the Engman Kits (inner suspension tabs, brace for inner suspension tab, seam welding, Engman kit for inside cockpit, sheet metal kit for rear framing on suspension points, outside longs kit from Brad Mayeur, seam weld shock towers and inside the cross member in the rear trunk. I probably did some more things but this should take care of the major items.

Care on welding by watching the heat build up along with the car being supported with 4x4 members (both cross ways and length ways). Car appears not to have warped and I am in the process of cross balancing and weighting.

The car is not the flexi-flyer that a 914 is noted to be; it is stiff and you feel the road; just the way I like it. Running 21mm sway bar, 22 torsion bars, 200# rear springs, stock 16mm rear sway bar, Koni Adjustables on four corners, adjustable spring perches in the rear, 911 Carrera front suspension and brakes, 911 rear brakes with e-brake mod, Sway-A-Way axles with 911 CV and splined stub shafts.

Engine is a stock 1987 Carrera with fuel injection, and using 901 gear box with the appropriate Kennedy Clutch package and 1983 to 1984 flywheel and ring gear.

It does make a difference and I still like what I have done. The entire purpose for my car is strictly "project basis" and will only be used in further related projects; and it will only be driven on the highway.

Steve Hurt

Forgot to mention, I really like the looks of McMark's roll bar. I will be watching it develop and will probably get it. I would like the detachable side bars; maybe I will start to Auto-X in my retirement years.

Even with McMark's roll bar, I think you would have to use some of Engman' inner kit, and Chris Foly's rear suspension braces.

I think I made an error and possibly gave the credit to Engman for the rear suspension bracing kits. I got those from Chris Foley. The quality of all the different kits offered for the 914 are exceptional and meet/exceed any requirements you might have. Just plan your needs and make sure they cover the way you are thinking about the project. They are worth the effort and price paid. You do not have to go to the lengths I have but again my car is strictly "a project car" where I can try different things I may want to do.

Good luck and I hope you enjoy your 914 like the rest of us "sickos'".

Thanks for all the responses so far. One of my questions has not been answered yet.

"Did factory sixes have their chassis reinforced or were all 914's built the same in this regard?"

My conversion is getting a 2.2 and will most likely only be driven on the street with occasional autocross and possibly some PCA DE's. I really want to get my car running and rolling...just trying to see if I should take the extra time to put in the reinforcements now or wait until a later time when car is freshly painted or flared. BTW..The paint isn't bad now...just not show quality by any stretch...

All but the GT's were the same. The GT's is where the stiffening came from.

No.
The basic /6 chassis is the same as the basic /4 chassis with only a few minor differences none of which are related to structural support.

The real problem is that people (like myself) put in engines that have more than twice the HP and three times the torque of a original 2.0L /6.

Combine that with wider, much stickier tires and you get a lot of stress on the chassis that the Porsche engineers did not have to deal with in 1970.

Which is also the reason why the factory GT stiffening kit is, IMHO, useless for anything other than a period correct GT replica build.

The kit was never meant to handle 300+ HP and 300+ torque ...

Thanks everyone! Let the discussion continue

Paul...All the welding fumes and fiberglass resin you've inhaled over the years have caused you to not think clearly...

Light in the head, light in the car.....

I did the Brad Meyeur Outer Long kit. Its 11 more lbs than the engman kit, but it is very strong (1/8" steel). It runs from the rear trailing arm mounts to under the front fender. The other way people go is just to put a cage in the car...

Oh and I got the Brad Meyeur kit from Rich Johnson, his info is in the member vendors section.

I can only agree with you. And so can my wife and daughter.

i studied the engman kit, and designed/installed my own version.i call it the viagra kit.stiffened it right up

Yeah, something like that.....

Did you call your doctor after it was stiff for four hours?

DR Bombay