Batch of Supercharger support braces:-

[carlos420uk]

Here's a batch of supercharger support braces I have made for some members of a car forum.

They are all made using a simple little jig I fabbed up to clamp the 2 plates in whilst I tack the diagonal in place.

All tacked up now and I have fully welded 2 trying different heat settings, weld sequence's etc to find out what give's the best weld with minimal distortion. I have come to the conclusion that hot and fast is the best way to go in this respect, so will use 125amps on the pedal flat out for the rest of these as that produced nice consistent welds.

The plates are 6mm flat stock, and the diagonal is 25x25x2mm box section.

If anyone has any input as to the the best sequence of welding to use on these (after tacking) I'd love to hear what you have to say. Or any other suggestions you may have. I'm always looking to learn something.

Carlos

 

[Wallace]

Is the supercharger bolted to anything other than this support?

Mike

 

[carlos420uk]

Yes of course, I'd be having a laugh otherwise

The charger unit (m62 / non intercooled) and it's cast manifold is a direct replacement for the standard intake manifold. The standard intake manifold weighs +\- 8kg and comes with a diagonal under brace like mine. Whereas the supercharger kit weighs close to 15kg including the manifold, but doesn't come with any additional support other than the 7 m8 bolts that it fastens to the head with.

For years people have suffered cracked manifolds and sheared bolt heads due to having no additional support. There is a supplier that fabricates a 2 bolt brace, but he won't sell them to anyone for love nor money (fits them with his own conversions only). So because of this I designed and made my own 4 bolt version to use on my own car.
I then got requests to make more for others running the same setup, so obliged with these.

If I remember I'll post a picture of one fitted to the engine so you can see the function.

Cheers.

 

[Pete.]

Looks like some of the baseplates have bowed slightly. Will this impact the way it works?

Are the baseplates stainless?

 

[carlos420uk]

Some of them are ever so slightly off flat, but to be honest were like that when i cut them from the flat stock even before welding. The picture makes them look worse than they are because of how I placed them.
If you put a straight edge along the flat it's no more than 0.25mm across the plate and I can live with that.

The whole lot is made from hot rolled steel, but I made sure to clean off the mill-scale before welding (still had some crap in the pits of the bottom plate come up though)

I oversized the holes also by an extra 1mm (9mm hole for the m8 bolts, 11mm for m10) to give a little extra wiggle room for fitting.

I have test fitted every one, and so far they all fit fine.

It took me a few goes to work out a good sequence for tacking and welding these up, and I did scrap a couple during this learning process.

 

[Wallace]

I'm thinking that a 90° bracket may add stress if not bolted to each face evenly and the weld central to each plate may also apply a bow that would have the same effect when the bolts are tightened.

 

[carlos420uk]

I understand your point, and agree. If the brace pushes up or pulls down on the charger it will create stress, and that would be counter productive - granted.

However when I bolt these on I nip up the smaller top plate to the bottom of the charger first and there is no gap or tension on the bottom plate. Same if I nip up the bottom plate first, no gap or pushing on the top one. If there was though the over-sized holes on both plates give enough movement in every direction to take the play out, or vice-verse tension / loading.

 

[PhillipM]

I normally use an adjustable rod with rose joints either end for stuff like this, easy to set the tension/compression as needed then.

 

[carlos420uk]

I normally use an adjustable rod with rose joints either end for stuff like this, easy to set the tension/compression as needed then.

Believe it or not I did consider that also but ruled it out due to the extra cost and time scale (I already had one of these made and in use) so decided not to go that way with them. Rose jointed and adjustable would be far superior though.

I think that a mark 2 version could be made like that using the same jig, as it wouldn't be hard to make 2 little mountings the rose joints could bolt into. What would you use to link the rose joints to make the length adjustment's, round stock threaded at each end with locking nuts?

Edit:- Balls to it, I'll order some rose joints and have a play next week

 

[Pete.]

Aah, you removed the mill scale - that's why they look like stainless plate - they have the same grainy texture to them.

Well, it's good that you've took the time to make them for your fellow forum members. One cheap bracket could save hundreds in broken manifolds.

 

[PhillipM]

Bit of tube with two nuts tigged in an some male rose joints

 

[carlos420uk]

Aah, you removed the mill scale - that's why they look like stainless plate - they have the same grainy texture to them.

Well, it's good that you've took the time to make them for your fellow forum members. One cheap bracket could save hundreds in broken manifolds.

Yup, and what a pain in the a$$ it was cleaning that scale off! Might have to try the Citric Acid method next time, and see how that works out for me.

"Could save hundreds on broken manifolds" are the operative words here I think As I say there is already a brace made with a very similar design to serve the same purpose as mine but fabricated by someone else. They have been used for a good few years now on the Supercharged Lotus scene without any problems that I know of.

Will mine do exactly what it say's on the tin? Who knows to be totally honest; it's not like I have any long term testing data to back up the theory, but everyone who is having one of these will know this, and I'm sure it won't be the first un-tested performance based product to ever be used by people (Take the brake master cylinder braces some companys make for instance)

I am certainly no professional fabricator or weldor, but I have a little workshop setup at home and like to have a go at things to see what I can come up with. I've learnt a lot from making these braces / brackets and the subsequent Jig that was needed to do so and that's worth more than anything to me

Cheers.

 

[carlos420uk]

Bit of tube with two nuts tigged in an some male rose joints

That sounds easy enough. I have some round tube about the right size for some M10 nuts to weld in already so happy days. I assume you can get rose joints in left and right hand threads to allow adjust-ability in situ?

You don't happen to have a link for a good company to buy the rose joints from? I wander if I could use some U section (Square edges though) with a hole drilled each side to accept a bolt and possibly spacers for the eyelet on the rose joint? Or maybe just cut some small thick walled box section up, even 2 piece's of flat would work.....

Thanks for the kick up the bum on this though. I should have done it adjustable from the get go really to make my life easy in the long run fitting wise.

 

[Pete.]

Rose joints aren't cheap - £5 an end for M10. They can also vibrate loose especially with opposing threads, so be sure to set them then loctite the locknuts.

Your fitting could be made easier to fit and give some adjustment by making slotted holes rather than round ones.

 

[carlos420uk]

Looking to purchase a milling machine in the next few weeks, but other than a file what else could be used to make nice clean slots?

£5 per end isn't so bad tbh, I could live with that to make something that bit better.

I had some rose jointed track rod end's once, never again though. They must have died within 3 months due to dirt ingress (What did I expect with no rubber boots lol) I think for this they would be fine though. I'll be sure to use Loctite.

 

[carlos420uk]

Will post some pics of how straight I'm managing to keep them after welding later if I get time. I must spend an hour welding one up, letting it cool between welds

These things get clamped up good and proper too, it seems to help...

P.s Quick one, does 70s2 offer any less distortion / shrinkage than using 308 or 309 ss rod in this situation? I have heard 309 is better for possible contamination / impurity's when welding MS?

 

[PhillipM]

They only need to be cheap and nasty joints for a static application like this tbh, but yes, about 4-5 quid a joint for m8/m10 size.

I had some rose jointed track rod end's once, never again though. They must have died within 3 months due to dirt ingress (What did I expect with no rubber boots lol) I think for this they would be fine though. I'll be sure to use Loctite.

I run rose jointed wishbones on my daily driver and they're still on the same joints 4 years later...

 

[carlos420uk]

4 years road use, on rose joint's I'd say that's good going. Do you have anything to protect them, or are they just bare?

The ones I got must have been cheap junk then, as they just went all sloppy on me after a few track days and some road miles.

I'll order some m8 or m10 sized joints Monday morning and should have a few mark 2 versions made up by the end of the week. Can you get an M10 male threaded rod end, but with an 8mm eyelet to accept an M8 bolt on the mounting "ears"? If so that would be ideal. Not sure if an M8 thread would be strong enough?

 

[Wallace]

If you want something cheaper to fabricate, how about a pair of T brackets that have one bolt connecting them horizontally?

 

[Epicyclic]

I reckon I'd leave them as a solid assy but, if you can dowel the large bottom plate to place using two dowels on the opposite diagonal to the fixing bolts. This would be done in place on the engine, and if there was any gap under the supercharger some shim would do the trick. Dowels could be 5mm dia. silver steel or similar.

I think I'd look to profile the plates, or at least radius the corners, and also make sure I got each plate as flat and square as possible after welding. Job for your milling m/c when you get it? Lightening holes could look good too!

Not keen on the complexity of the rose joints, they just might come loose even with thread lock, and there must be some "play" in them to have rotational movement, obviously only a very small amount when new.

Just my 2p worth...