Hi all,

A while ago I had a professional outfit (rally car builders) complete my downpipe and uppipe with exhaust wrap and then used thin wire to hold it in place - anyone know the best practice on how to do this (dont say visit the builders), although I can understand as its tricky to put into words...

Also, where do you get the thin wire from?

 

Mig welding wire is good, ideally stainless.... you can buy it on smallish rolls..... i wra[[ed mine, then started kind of at one end, and had a long length of wire, with the middle of the length against the header, then twisted it back and forth arond the pipe working my way along as i went, so that it was all held on nice abd tight..... sadly two years down the line though, it needs re wrapping.... i think the best solution for heat retention is the high temp coating... but the price...!!!!

 

look on ebay for stainless cable ties - proper way to do it

 

nothing wrong with using lockwire, which is how it sounds like they have done it

 

Stainless lockwire is what you want. Tricky to work with unless you have a proper locking tool though. Stainless ties do work but can be pricey and aren't always that easy to get really tight.

 

In work with us we use vary small guage wire for tying production tags to bits of steel.. just twist the ends together with a pair of pliers to get it realy tight!

 

Thanks for all the replies...stainless lockwire it is (must be same as rally guys used on my old downpipe).

 

I use 32 thou Goodridge Stainless Steel Lockwire and this or similar will be available from AS Performance, Rally Design or any other rally supply shop.
The locking pliers however cost between £25 and £85 per set and if this is a one off job it becomes expensive but lockwire is the way to go if you want a tie every two or three inches which is how I think it should be.

 

When i did mine I wraped it dry, then achored some stainless MIG wire to the turbo end with a stainless clip and wound round the wrap continuously like a helical turn around the pie about 30mm between each turn (pitch if you will).

After what seemed a kilometer of the wire I got to the end flange.

Tie off with a stainless clip or a large jubilee clip to be nasty.

API wrap with the tape soaking wet and very tight. They terminate with a clip.

When dry, the tightness is unbelievable. They use 50mm wide wrap.

Try wrapping a H&S sport cat downpipe to know the meaning of frustration....

Graham.

 

See 2 posts above......

Harvey Ported, wrapped and sprayed my headers, a real class job I took them off a couple of years later and all the wrap was still as tight as the day they were fitted

Just have to be carefull of all those sharp bits of wire sticking out LOL

Shaun

 

I have some stainless cable tie which come with a special tool to get them really tight, you get 2 different lengths in the bag, I'll post the lengths if anyone's interested ? But I know the longer one will go around a 3" pipe and the shorter ones I used for my HKS headers, whatever diameter they are.

£7 per bag

 

Cheers Harvey...think I'll go with Pliers rather than buy special tools as I hope this is a one time only deal and the last exhaust i'll fit (prob jinxed it now saying that)...

Interesting Graham, soak them...never heard of that before - I'll give it a go.

Thanks guys

 

one thing I would say - if going down the wire route

is to use lots and lots of short lengths, rather than 1 long length from end to end.

reason being, if one broke, then the rest will hold on fine!
but if you have one long length and one part brakes/snaps then the whole thing will un ravel in no time.

 

The DEI wrap I use should be applied damp, not soaking wet as the chemicals in the wrap which help it bind will be washed out.
Thanks for that Shaun. I have stopped spraying the wrap as I don't think there is a clear benefit in practice and it can make the wrap brittle and flake at an earlier stage.

 

 

Neat!

 

hi Harvey, don't you port the crosspipe as well? as it doesn't look to be opened up much/at all?

nice job on the wrap by the way

 

Top replies from all here, best "clean" topic I've read in a while on SN, cheers

 

ALL joints have to be ported for best results and that is what I do. Do not confuse simply increasing diameters and removing the soot witness marks with porting to achieve maximum velocity/flow.

 

Hi Harvey!
are the exhaust ports and the un-ported manifold ports the same size? I looked at the soot marks on mine (heads and manifold) and they seemed to be the same size.
So does opening up the manifold (and not the heads) cause a step/turbulence in the flow?

thanks for the info
Mark.

 

I suspect the soot marks you refer to are the gasket diameters and not the the port diameters.
As I am usually porting headers only and not cylinder heads then my porting is for O/E cylinder heads. It would be SLIGHTLY different if I were porting the head at the same time but head porting is a completely separate topic and requires regular access to flow bench equipment to obtain optimal results. It also requires the heads off the car.

 

Ah, I see!

so what is the diameter of the head port and the standard manifold port?

how much should the headers be opened up?

cheers

 

This much...



harveys work of course

 

anyone got a figure for the sizes?