Exhaust system change

[Drakman]

Hi Guys and Girls,

 

I have a 2014 Duratec Roadsport 175 that came with a single exhaust outlet through the side of the car.

I now have the 4 individual primary pipes, collector and the side exit silencer.  I need to cut/enlarge the hole through which the 4 individual primary pipes pass.  Does anyone have a template and or measurements for this enlarged hole.   What would be the best way to cut said hole, what tooling do i need to get the best result.  I have  asked a couple of mechanical shops here and none want to touch it when they see the car.

Cheers

Dave

[Jonathan Kay]

I think that the measurements are in the archives. Please let me know if you can't find anything and I'll have a look.

Recommended tools have included abrasive flap wheels and Dremels with cutting discs.

Jonathan

[ECR]

Use any template as a guide only! Start small and enlarge, trying pipes in position frequently. Leave enough clearance on pipes to accommodate engine rock. Patience is the key.

it's actually not that difficult once you start...

[Wrightpayne]

I've done a couple now. As ECR says, slowly and a bit at a time.

Tools I used were a junior hack saw blade with the pin knocked out and gaffa taped to hold it, orientated to cut on the pull stroke. Some small tin snips (I have a set of jeweller curved snips). Half round file and various grades of wet and dry to finish the edge. Sharpie and plastic ruler.

If painted be wary of using masking tape up to the very edge of the cut as you dont want to peel the paint off with the tape (I've known someone peel the chrome off a headlight they were altering!!). Reseal the ally edges with paint once you're happy its the right size.

My technique was not pretty mid task but looked good once complete. Use the saw blade to rough out to the desired size - this often meant cutting little triangles of ally, as the blade doesnt cut curves very well, then blend in the cuts with the file. The filing needs to be done gently with light pressure. The ally is quite soft and can distort easily. On straight sections I used the flat of the file at an angled to get a reasonable length of file along the cut edge and file it straight.

 

I've read about others using an emery flap wheel to enlarge the hole, which I did when increasing the height of the steering rack holes by a few MM. I think there is too much material to take out when doing the exhaust aperture.

Ian

 

[Tony P]

I made much use of large Q-Max punches, which give nice, clean, distortion free curved (well, circular obviously) cuts -- but I can't remember how I determined the shape of the cut-out to begin with! I'm thinking I must have taken a template from another car and repositioned it to suit my engine installation.

[Drakman]

Hi Guys,

 

Thank you all, I will have a look through the archives and see if i can find the measurements, thanks Jonathan.

 

Cutting the side out isn't something i look forward to!

 

Cheers

Dave

[Nigel Riches]

Not sure of the chassis tubes layout around the exhaust exit area but when I fitted a Raceline 4-1 system I needed to slightly "squeeze" the No.3 pipe, I think it was, to clear a side tube. Admittedly this is on a 1982 car, and there may be some differences in how the chassis frame is made on later cars. Be brave get stuck in, go for it.

[Drakman]

Hi Nigel,

 

My chassis is the SV version, from what i can see i have plenty of room around the tubes.  The current primary pipes measure 37 mm OD and the replacement primary pipes measure 45 mm OD so i am hoping i might get a little more urge out of the engine.  I will get the car tuned for the new exhaust as soon as it's on and running.

[Drakman]

Hello Jonathan,

 

I have had a look for exhaust cutout measurements but so far i am unable to locate anything.  Can you point me in the right direction please.

 

Cheers

Dave

[Jonathan Kay]

Sorry for the delay.

I think that tools are now covered.

I had a quick look in the archives for templates. That showed that most of the discussions aren't about Duratecs, and I assume that the correct cut-out is different for different engines.

I recommend a search along the lines of:

https://duckduckgo.com/?q=site:caterhamlotus7.club+exhaust+template

https://duckduckgo.com/?q=site:caterhamlotus7.club+exhaust+template+duratec

Jonathan

[Drakman]

Thanks Jonathan,

 

I will have a look and see what turns up.

Cheers

[D Jones]

I found the process relatively simple, remove the old exhaust and offer up the new primaries, one of them will pass through the existing hole. then set out the location of the other primaries relative to this and cut to a tight hole, offering up the next primary as the hole increases.

once all fit through the tight hole, remove them all, draw the shape of the finished hole you like (allowing some clearance for engine movement) and "tidy up" the hole with a flapper wheel fitted to an electric drill.

I  used jar lids as a template for marking  the radius sections of the holes, and have a look at images of other cars to understand the shape required.

It only took a few hours.

[Drakman]

Thank you D Jones, sounds logical.  I'm just waiting on my silencer to arrive and I will get to it.

Cheers