16 replies to this topic

[beardylondon]

I want to replace the rusty exhaust on my 1990 Rover Cooper Mainstream.

 

I want to keep the car pretty standard, within reason, I am not looking to tune it, I have the Mk1 for that.

 

So I am thinking of using twin box RC40, no cat, it seems the best value for money. 

 

I just wondered what people's opinion on the RC40 vs Maniflow twin box, reason for twin box is I don't want it loud like my Mk1.

 

Also I will probably add an LCB at the same time too.

 

Many thanks.

Edited by beardylondon, 20 February 2020 - 10:58 PM.

[Cooperman]

I have a 1990 Rover Cooper 1275 road-rally car and I have a twin-box RC40 system with the original Rover Cooper exhaust manifold. It is quiet enough and the system is well made. It is a centre-exit final box with up-swept tail pipe.

[panky]

I fitted an 1 3/4" millennium stainless steel twin box centre exit RC40 over ten years ago and it's still like new, sounds nice and not too loud. The mild steel LCB I fitted at the time fell to bits last year so that's been replaced with a SS one too, very shiny.

If I was buying it today though I think I get a side exit one, tastes change I guess.

Edited by panky, 20 February 2020 - 11:43 PM.

[absx2]

I got 14 years out of a maniflow twin box system and the link pipe from the cast manifold is still like new.

Keeping the cast manifold and using the pipe does reduce cabin noise slightly.

The RC40 systems i`ve used are not as durable as the maniflow ones and the noise seems about the same.

If you want it quiet in the cabin keep the catalyst but they are power sappers on pre injection cars

[beardylondon]

Thanks all.

 

Minispares website says Maniflow is louder than RC40.

 

So if I get the stainless version of the 1" 3/4 twin box (below), do I need anything else to fit to the original cast manifold?

 

https://www.maniflow...58&product=1131

Edited by beardylondon, 21 February 2020 - 10:00 AM.

[absx2]

Stainless is slightly louder and tinny compared to mild steel and the sound deadening material will be long gone on the exhaust systems before the mild steel causes any issues.

https://www.maniflow...55&product=1113

 

That`s what you need when retaining the cast manifold.

Phone the chaps at Maniflow and they will give you good honest advice before purchase.

[beardylondon]

Thanks, very helpful!

That explains why my 21 year old playmini exhaust is loud!

[beardylondon]

For £40 more, I might as well buy an LCB, or is there another link pipe I need?

 

Stainless is slightly louder and tinny compared to mild steel and the sound deadening material will be long gone on the exhaust systems before the mild steel causes any issues.

https://www.maniflow...55&product=1113

 

That`s what you need when retaining the cast manifold.

Phone the chaps at Maniflow and they will give you good honest advice before purchase.

[absx2]

 

For £40 more, I might as well buy an LCB, or is there another link pipe I need?

 

Stainless is slightly louder and tinny compared to mild steel and the sound deadening material will be long gone on the exhaust systems before the mild steel causes any issues.

https://www.maniflow...55&product=1113

 

That`s what you need when retaining the cast manifold.

Phone the chaps at Maniflow and they will give you good honest advice before purchase.

 

Yes it`s expensive for what it is but every bit as good as an lcb for your purpose and a little quieter

Give them a call and you might get a deal.

[Cooperman]

A twin-box RC40 system is quieter than a Maniflow twin-box. With the need to keep rally cars within specified limits, on my rally 'S' I use a Maniflow 'cherry bomb' centre pipe and an RC40 rear box. The rear box I have welded on a skid plate front and rear and double-skinned the underside of the box. It is now very strong and quiet too.

The 1990 Cooper road rally car has tein RC40 boxes, both skidded and reinforced and is even quieter than the 'S'.

[beardylondon]

Thanks, I always thought a ‘cherry bomb’ was a boy racer loud exhaust, which part are you referring to please?

[andyapanel]

I recently fitted a totally stainless Manifold system to my RSP, getting tired of replacing Freeflow manifolds every few years.

It is not THAT noisy and it went together easily, unlike the Stainless RC40 I have on my Racing green, which was do-able, but tight.

There is a noticeable increase in torque, which is always a good thing.

From what I have read, the LCB is only useful if you have a REALLY powerful engine-for an ordinary 1275, you get more torque from a Cooper Freeflow. Another problem seems to be that joint sealing on LCBs can be a problem, though it is not a job I have ever undertaken.

Bottom line, buy Maniflow, IMO.

[Cooperman]

Thanks, I always thought a ‘cherry bomb’ was a boy racer loud exhaust, which part are you referring to please?

I fitted the cherry-bomb between the Y-piece and the rear box. On a rally car the centre box is vulnerable to being damaged whilst the bigger RC40 rear box can be set to sit partly inside the rear sub-frame and I welded skid plates and a secondary skin onto it.
It is quiet enough to pass the noise test for rallies which is quite strict.

Edited by Cooperman, 24 February 2020 - 04:02 PM.

[beardylondon]

thank you, so this one...

 

https://www.maniflow...ct&product=1085

 

I recently fitted a totally stainless Manifold system to my RSP, getting tired of replacing Freeflow manifolds every few years.

It is not THAT noisy and it went together easily, unlike the Stainless RC40 I have on my Racing green, which was do-able, but tight.

There is a noticeable increase in torque, which is always a good thing.

From what I have read, the LCB is only useful if you have a REALLY powerful engine-for an ordinary 1275, you get more torque from a Cooper Freeflow. Another problem seems to be that joint sealing on LCBs can be a problem, though it is not a job I have ever undertaken.

Bottom line, buy Maniflow, IMO.

[beardylondon]

Hi All,

I have my new RC40 to fit, due to take old one off, I just noticed this sensor plugged into the existing exhaust centre pipe. Its carb model with no cat, is it a O2 sensor?

Edited by beardylondon, 28 March 2020 - 07:52 AM.