25 replies to this topic

[Archived4]

Hi all, just wondering what exhaust you have on your road rally car?

Was considering an rc40 twin box but saw it hung low so it would be destroyed on whites.

What you running? I am tempted to make a diy one, unless there are buy out the box options

Cheers, Nathan

[jaydee]

Get the centre exit and mount it with cotton reels at the back, it wont be low really.
You're gonna scrape the sump guard waaaaay before the exhaust once fitted correctly.
The only problem is to make it well solid, and fitting some extra mountings will help.

Another option is the somerford's rally exhaust which is really good but it costs double the rc40

[dean]

A decent rc40 side exit will produce more power than centre exhaust. I can't see a centre having more clearance as it still has to clear the subframe but I could be wrong

But a exhaust sold by somerfords like said above maybe worth looking into. also maniflow will have something.

Edited by dean, 09 February 2013 - 09:46 PM.

[BritishRacingGreen]

A decent rc40 side exit will produce more power than centre exhaust.

Why does a side exit produce more power than a centre exit? Have you any proof?

[rally515]

Back pressure ? not heard of any tests/dyno runs for this + its engine specific.

[jaydee]

Nah all fuffing due to the fact that on a low-tuned engine a 1.75" exhuast is too big so a side exit with slightly more back pressure will give better results.
On a properly tuned engine theres no actual difference, apart from the fact that you can easily RAISE a centre exhaust, not so easy with a side exit.

[dean]

Tested by Keith Calver

Bit of reading but worth it.

http://www.minispare...4a-71fe260530b6

[jaydee]

This meant the RC40 was obviously not causing any power loss at all despite those differently formed bends. I suspect they may cause a slight restriction on engines producing over 115-120bhp though.
thats not very clear..
I dont want to join the bandwagon of the anti-KC but this also smells of some sort of publiclity for the classic RC40, a difference of 0.8 bhp is not a couple of bhp. Noise level? i'd be curious to see the db readings.
What happened to the readings at 4400 rpm?
Oh..and by the way you're gonna loose more bhp by wheather/altitude variations.

[dean]

Well it's the only test I know of and have read. I have Not got the money or the equipment, knowledge to test myself

Sorry cant comment, or heard of the KC bandwagon , to me he has done a lot for the mini to keep it going.

If it was me for a road rally exhaust I go for a twin box. Side exit. With a decent freeflow manifold.

But like I said check out maniflow. They more than likely have done exhausts for rally minis with ground clearance in mind.

[Archived4]

Cool, cheers for the replies. I will try a side exit twin box system wih my lcb And will put a flexi pipe bit after the manifold as apparently they break otherwise with the vibrations and all that.

[minisi35]

For the last 6 years I've used a 1 7/8 maniflow twin centre exit system, it's been bomb proof. It's done 20-30 events over some very rough whites and its a beautifully made system with great welds and comes fully skidded. It's solid rubber mounted in the centre mounts. I use rubber tie bar bushes and m10 bolts on the rear mounts.
As for noise when first fitted it was 89db and has only increased to 94 Db at the last event I did last year. I've bought the same system for my new rally car so I know it will pass the new "welsh road rally" regs at 2 meters but as for how it fairs with the new side DB test then I have no idea!! I'm not that bothered at bhp as if your cars too noisy you won't get to start the events.....
But in the end as long as you have a long sump guard (covering the y piece) and the boxes as skid plated the you could use any system you want. I know cooperman uses a rc40/maniflow mix

[minisi35]

Hope this helps, this is my preferred system
http://www.maniflow....58&product=1141

[Archived4]

That looks good value! Will order one when I have the funds

Cheers!

[minisi35]

Well it's never let me down, what events have you got planned?

[rally1380]

Agree with minisi35....Maniflow is a superbly made bit of kit. I too have the twin box centre exit and it is very solid!!! and quite enough to keep the noise guy happy. The paint has burnt off mind you but i don't care. I used 2 x Minispares competition exhaust mounts on the back and the uprated centre one and its mega secure.