27 replies to this topic

[Classicmini63]

Thinking of purchasing a maniflow exhaust manifold for the MPI. It has a stage 4 head and SW5 Cam so I thought Id look at getting a better exhaust manifold/downpipe so its not restricting anywhere. Anyone have any experience with these?

Cheers.

[Sprocket]

Best you can buy...........

[Classicmini63]

Thanks for the reply mate. Think Ill be getting myself one then!

Cheers.

[Jarvey]

I've got the Maniflow Stage 2 manifold on my MPI and it provided a noticeable difference. More low down torque. Very happy with it!

 

I would ask Maniflow if you could get a Y piece with the sensor mount in place. Otherwise 1 & 4 will be black very quickly.

[Classicmini63]

Hi, sorry but not sure what you mean by that?

[Jarvey]

Sorry I was pretty vague.

 

The Maniflow manifold has the lambda sensor on the join from cylinders 1 & 4 so you don't get a true reading across all 4 cylinders so if you move the sensor down the system to where the 2 manifold branches meet at the Y piece then merge in to the link pipe you will have a much more accurate reading for the ECU to work with ... I think?

[Sprocket]

This is true, but be prepared as Lambda sensor heater works harder, is exposed to surface water and may cause failure sooner.

With the funky way the A series inlet ports are arranged it will always be an average reading at the tailpipe. Two cylinders a little rich and two cylinders a little lean makes an ideal average at the tailpipe. If you read only the rich cylinders, the already lean cylinders will be lean. Reading at the tailpipe should be lean average

[brivinci]

I have been running nothing but Maniflow from front to back and I love their stuff. Everything, that is, but there flex pipe. There was a thread about this a bit ago. They use a "knuckle" joint. (Not sure if that what its called exactly) Its like a one ball pressed over another, smaller ball and then held with tension by a spring. In theory, this allows for a good about of movement, and it does. Up, down, left, and right BUT, and this is critical, no back and forth movement. Our motors move back and forth a lot. I ended up replacing my Maniflow flex pipe with an RC40 one (I believe) from Mini Spares that resembles the original mesh flex joint. I was getting a lot of vibration and harmonic type noise with the Mani one and the RC40 joint seems to have fixed that. 

 

Again, I really am happy with everything else they sell and you might not experience the same issues I have. Just putting it out there.

[Jarvey]

Thanks Sprocket

 

So is it worth worrying about moving the sensor then? I have ordered a new ECU kit for my MPI ( No more running lean ) and I was going to get a new Y piece with the sensor mount in.

 

What do you think?

[Northernpower]

Hi, sorry but not sure what you mean by that?

This is what they are referring to. The lambda sensor in the Y piece as opposed to the centre downpipe.

[brivinci]

I hate to hijack this thread but wondering what LCB you are going with. My motor is currently 40 over with a Calver head, Calver special pistons, Piper BP255 cam timed to 107. Tappets are stock but might be going for a true 1.3 or 1.4 set. Currently running a standard Maniflow "injection" LCB. It was the only header they sold for the injection cars when I bought it. Now they have options. What are you thinking and wondering what others think I should be running?

[Classicmini63]

Im thinking about the stage 2 LCB as it looks to be the best one for my engine. So far its running an Avonvar Stage 4 head, ported and polished inlet manifold, 52mm throttle body, SW5 Cam, racing followers etc. It pulls really well and I could instantly feel the difference throughout the Revs. The only problem is that its a little sluggish at low revs, not necesserialy because of a lack of power but it feels more like its struggling to pick up at lower revs, whereas say from 2500 on, it pulls and pulls. So I think Jarvey mentioned he noticed a change in low down torque, which I also thought it would deliver, hence my interest. Because now Im getting more than enough fuel/air in, but the gasses out are likely to be getting restricted by the standard Manifold/downpipe.

By the way Brivinci, sounds like an awesome set up!! Ive thought about getting Keith to bore out my block, bigger pistons etc, if it starts smoking at any point.... Did you notice a big difference?

Also, Jarvey - what ECU are you getting? Ive thought about getting one but the prices are so high.

Cheers everyone

[brivinci]

As they say, there is no replacement for displacement. Going bigger is a good thing:-) As it is the only mini I drive right now (others are off the road) I have nothing to compare to but it really does pull nicely. I find that it seems to really come alive around 3500 though. Like it has a power band. I typically drive it hard all the time so it works for me but maybe the newer LCB design will help even more.

 

I just wrote Maniflow to see if they would offer a y-pipe with the Lambda ported added. Seems simple enough and more Injection cars will likely be running them down the road as its a better setup.

 

And Keith is a great guy. I can't say enough good things about him. He will never oversell you something just to make money. Talked me out of a bunch of things as they just aren't needed for what I use my car for. I trust him with all my Mini questions/concerns/performance needs for sure.

[jamesmpi]

Hi, sorry but not sure what you mean by that?

This is what they are referring to. The lambda sensor in the Y piece as opposed to the centre downpipe.

No CAT... Cheeky

Edited by jamesmpi, 09 March 2018 - 05:17 PM.

[jamesmpi]

It's also worth point out that moving the lambda sensor into the Y piece means having to extend the cable. You also need to find a good safe routing for it so that it doesn't chaff or touch the manifold and burn through