Exhaust Swap

[Graham King]

I am shortly getting a Powerspeed Exhaust, and am just considering what to do for MoT. I need to be able to fit the current cat for MoT so have 2 options, get Dave to modify existing silencer to fit or keep the whole exhaust and swap back for MoT only.

 

I prefer the idea of keeping the exhaust complete so that if I need to at any time I can refit. How easy is it to swap exhausts back over, have read about problems caused by current stud lengths, can these be cut down, or removed and replaced by cap head bolts. If they can is this a straightforward job to do with the engine in the car or does the engine need to be removed and taken to an engineering shop.

 

Any advice gratefull received.

 

Thanks.

 

Graham.

 

R7 GPK

Superlight #85

[Shaun_E]

Studs can be cut down by quite a bit - makes a real difference. Mr Andrews kindly removed mine for me using a very funky stud removal tool and I then took the hacksaw to them before refitting with same funky tool. If you dont have access to the funky tool then you need to use two nuts locked together to remove them. I guess you could chop them off in situ though?

If the 4-1 has separate primaries then removal and refitting is fairly easy. I have no experience with the standard exhaust so can't help there.

 

Yellow SL #32

[Graham King]

Shaun, thanks for the info, I am having one made with separate primaries but it was refitting the old I was more concerned about, did Dave remove yours with the engine in the car? I guess I may be able to ask Powerspeed to remove them for me when they fit the exhaust and use some caphead bolts to replace them. Was it fairly easy to remove the studs with his "Funky Tool" 😳

 

Does anyone know the size of bolts required and where I may be able to get them from.

 

Thanks.

 

Graham.

 

R7 GPK

Superlight #85

[Kevsta]

I used some bolts that have an allen key eye at the end so that they can be removed if I need to. Also used copious amounts of copper slip on it. Obviously if you shorten them then cut the end without the allen key eye! I would avoid bolts....studs are used for a reason!

[Shaun_E]

Engine was being rebuilt so was out of car but the tool is basically a socket with some clever internals that grip the stud so could easily be used with the engine in the car.

Once cut down, a chamfer was added by holding the stud against a grinding belt at 45 degrees - this is probably the only reason why you couldn't easily chop them off while still on the engine.

The potential for cross threading if using bolts instead would, I think, be quite high while trying to hold the primary with one hand and insert the bolt with the other. Primary number 4 is normally held on one stud and uses a turned down allen bolt for the other hole (right next to the water rail connection) and the bolt is a right bu99er to get in sometimes.

 

Yellow SL #32

[shn7]

Graham,

 

Go with keeping the complete exhaust and shorter studs. Then it's all easy to swap. It will just looked a bit on with the std exhaust in place and a rather oversized hole in the sideskin. Not a problem for one day/week a year I'm sure 😬

 

Steve.

[Graham King]

Thanks guys, looks like shortening the studs is the answer, Shaun what was the chamfer for?

 

Graham

 

R7 GPK

Superlight #85

[Shaun_E]

Makes it easier to get the nuts onto the studs - take a look at the end of any bolt/stud and you will see a slight chamfer. For clarity - I did mean a chamfer all the way around the exposed end of the stud.

 

Yellow SL #32