Good morning - for a 3.2 914/6 build do I ideally want to run the inner stiffening kit and the outer?

I have the inner kit in hand, wondering about this one from Maddog.

I do understand they reinforce different parts of the car. Talking about this kit, stock picture of the back, similar plate is provided for the front.

Thanks!

Click to view attachment

There’s a brad mauer (sp) outer long kit
A maddog inner long kit
A classic GT stiff kit
And tangerine racing rear stiff kit.

My setup will be the tangerine kit that supports the rear suspension console and the maddog kit that stiffens up the longs from the inside of the car. It’s the setup I feel comfortable with but like everything, there are multiple ways to get there.

Good morning- hope you had a good week.

So, since they address different parts of the car, not overkill?

Not in my mind.
I want to strengthen up the consoles since they can become a week point with wide grippy tires. The inner long kit should help with chassis twist. Maybe not as much as the outer long kit but I’m building a driver, not a track car.

I haven't really pushed the 3.2, but I find the chassis OK as is. Compared to a lot of cars of the era it seems pretty solid. A lot depends on how you plan to drive the car and what other modifications you are making.

I did both on mine .. I just felt it was necessary because I had to do so much rust repair it just tied everything together nicely..

These cars have sometimes been referred to as "flexi flyers". I have the inner long stiffener and the Tangerine suspension ear stiffener. I consider these stiffeners a must if you increase the horse power above stock. If you drill the holes out a little larger, you can make a stronger weld.

But remember that (too much) heat isn’t your friend when welding the longs.

I need to do this. The car has the GT stiffening kit and works fine, but I want to add the longs stiffening kit for long term integrity. Over time, as the chassis is worked back and forth with grippy tires on the autocross course, I'm sure that its going to start cracking somewhere.

On a solid car, BUT inner longs are on my to do list.

My car has both. John Williamson from Otto’s always recommended the rear kit for Racing as well as the boxed trailing arms. The inner Long kit does help the ride and makes the car feel more solid. My car inner frame still separated behind the battery. The battery acid weakened the spot welds, which caused them to break loose. Your asking for trouble running Racing tires on a car that does not have all the suspension pickup points attached via a full roll cage.

I'm working on a 6 that had some significant chassis rust. The customer had supplied Brad's kit for this GT build.

After lots of discussion with the customer (who is open minded), and other 914 guys; I'm doing the inner kit, the Restoration Design outer clamshells, an augmented GT kit, and some pieces from Tangerine.

I've done 3 Mayeur kits, which I think are the strongest, but I didn't think it "elegant" enough for a real 6. No offense to my good friend Brad, they are just more crude. Here's the R-D piece: Click to view attachment

This is the first inner kit I've installed and it's an original Engman kit (R.I.P. Mark Bland). This kit isn't scored correctly for the early brake handle indentation (which is different than later cars). I don't know if Maddog makes an early and late version.

I added a little 90* piece to the bottom of the inner kit to tie it into the floor pan.

I'll post a video link in a day or so, and pics, if I can figure out how to grab still frames from my youtube videos.

Great discussion gentlemen, thank you.

I have only the Engman inner long kit installed on my car. I’m not making any value judgements about the others when I say that. I think the factory style kit is necessary when you use racing tires. I recall sitting in an autocross planning meeting with Steve Nieslony when he mentioned his inner fender ripping or cracking from the forces generated by the race rubber. DOT-R tires are essentially race rubber so...

Inner and outer longitudinal stiffening
https://www.youtube.com/watch?v=WqGV--1bVAU

I totally agree. That's why it took me so long to install these things. Weld, let cool. Weld, let cool. Rinse repeat. It's also a good idea to install door struts to keep from tweeking the frame. I would hate to do all that welding and then realize the doors won't close.

My conversion car has Brad’s stiffeners, and it is amazingly solid. I’d agree that I’s not use it on a factory -6, but it does it’s job very well (as should the RD clamshell). Definitely brace the door opening while doing any welding whatever you choose.

Good morning.

How do you brace the door opening properly?

Maybe do the rear section of the cockpit first and then the inner longs?

I too have done the rear panels.....but if your going to race, DE, auto-cross hard. Having a cage to the suspension points is the answer. Best, markClick to view attachment Click to view attachment

And we have reached the slippery slope...

Nice build.

Yup my car was originally an Ottos build and it has the GT-type kit as well as the boxed trailing arms. John called this "armor plating". It also has a 10-point welded cage and some other repairs and reinforcements. Still, compared to a modern car (or an early 911 coupe), there is more flex. No issues with this setup running relatively high HP and g-loads (race suspension with no rubber bushings and 10" slicks).