22 replies to this topic

[dotmatrix]

hi.
I have been trying to find out. exactly what exhaust manifolds do people use in their real race engines with about 130hp, peak between 7000-8000 rpm? 1300cc naturaly aspirated

thanks in advance
Martin

Edited by dotmatrix, 05 April 2025 - 11:51 PM.

[Tupers]

Speak to Maniflow.

I’d imagine you’re in stage 3 LCB territory. https://www.maniflow...57&product=1120

[imack]

Maniflow large bore long 3 into 1 for me with an historic race RCM system.

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Edited by imack, Yesterday, 06:24 AM.

[nicklouse]

Usage is more important than power.

 

the Migla guys don’t use the 3 into one as the race LCB Maniflow do is slightly better on the torque.

 

Maniflow did a whole pile of development with a race team and what they offer is based on that. 
 

the other consideration is the 3 into one does sit lower and can cause regulation issues.

[dotmatrix]

Speak to Maniflow.

I’d imagine you’re in stage 3 LCB territory. https://www.maniflow...57&product=1120

Thats what i have. I does not seem to be optimal with my engine so i wanted to hear about alternatives

[dotmatrix]

Maniflow large bore long 3 into 1 for me with an historic race RCM system.

Thanks. Did you try lcb manifolds before the 3to1 so that you know what difference it made on your engine?

[dotmatrix]

Usage is more important than power.

the Migla guys don’t use the 3 into one as the race LCB Maniflow do is slightly better on the torque.

Maniflow did a whole pile of development with a race team and what they offer is based on that.

the other consideration is the 3 into one does sit lower and can cause regulation issues.

Ok. When you write race lcb its that stage 3 lcb you mean?

Which ever manifold i choose i will have height issues and will have to have it adapted as its my race metro engine and that has a shorter vertical bit of the exhaust manifold.

I should write and ask their opinion.

[imack]

Maniflow large bore long 3 into 1 for me with an historic race RCM system.

Thanks. Did you try lcb manifolds before the 3to1 so that you know what difference it made on your engine?

I previously had a standard bore Janspeed lcb but the engine was a very different spec.
I've run the 3 into 1 since the early 90's, primarily as Vizards book showed an increase in torque at low rpm, and my car is used on the road despite the engine spec. As Nick says, the centre branch sits below the outer branches at the collector and I frequently ground it on heavily cambered road surfaces in narrow country lanes. I've had to straightened it out and braze it up numerous times over the last 30+ years.

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Edited by imack, Yesterday, 09:01 AM.

[dotmatrix]

Maniflow large bore long 3 into 1 for me with an historic race RCM system.

Thanks. Did you try lcb manifolds before the 3to1 so that you know what difference it made on your engine?

I previously had a standard bore Janspeed lcb but the engine was a very different spec.
I've run the 3 into 1 since the early 90's, primarily as Vizards book showed an increase in torque at low rpm, and my car is used on the road despite the engine spec. As Nick says, the centre branch sits below the outer branches at the collector and I frequently ground it on heavily cambered road surfaces in narrow country lanes. I've had to straightened it out and braze it up numerous times over the last 30+ years.

Ok. Many thanks for the reply

[nicklouse]

 

Usage is more important than power.

the Migla guys don’t use the 3 into one as the race LCB Maniflow do is slightly better on the torque.

Maniflow did a whole pile of development with a race team and what they offer is based on that.

the other consideration is the 3 into one does sit lower and can cause regulation issues.

Ok. When you write race lcb its that stage 3 lcb you mean?

Which ever manifold i choose i will have height issues and will have to have it adapted as its my race metro engine and that has a shorter vertical bit of the exhaust manifold.

I should write and ask their opinion.

 

Ok you say Race Metro. 
 

we ran a 3 into 1 using the dimensions in Vizards book with a large repackable single box silencer exiting via the sill.

 

but this was custom made on the car. 1380 custom scatter pattern cam over 130 horses. This was back in the late 90s before Maniflow did their development.

[dotmatrix]

This is my car in its curent state. 1293, Vp8sp cam, 12.5:1 100octane fuel, Split 45's, longman intake, specialist components race head, stage 3 maniflow lcb and 2" one box system. And its currently at 123hp at 7250rpm and 133nm at 5800rpm. I know its a bit daft but i was hoping for 130hp with this setup.
The dyno guy thinks the extra achievable about 12nm and 12hp as per minis he have had on the dyno (swiftune bits)

I am looking for that a bit extra ofcourse :-D call me silly

Edited by dotmatrix, Yesterday, 10:19 AM.

[dotmatrix]

The engine

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[imack]

Love the split weber setup, would be my ultimate 5 port dream. Do you need to modify the bulkhead? That is something I wouldn't want to do.

[nicklouse]

Love the split weber setup, would be my ultimate 5 port dream. Do you need to modify the bulkhead? That is something I wouldn't want to do.

Not on the Metro. 
 

we got better results with the IDA but hillclimbing

[dotmatrix]

Love the split weber setup, would be my ultimate 5 port dream. Do you need to modify the bulkhead? That is something I wouldn't want to do.

Not on the Metro. 
 
we got better results with the IDA but hillclimbing

The headline for my races says hill climbing but there is not many hills in denmark so its more a 1 person short asfalt rally sprint through a forest