Lude Generation

the manifold will produce back pressure where the 4 go in to 2 then into one, the exhaust doesnt really produce back pressure as its normally a bigger diameter than the manifold so dont worry about it.

The better flowing the exhaust system the more air the engine can use means the more power the engine will produce think of the engine as a big air pump its designed to pump air as fast as possible.
People go on about back pressure like they know what it is and does and they dont. An engine doesnt need back pressure it needs sonic pulses to help scavenge the last of the spent charge from the cylinder, leaving maximum volume for the fresh incoming charge of fuel and air. Any left over spent charge will mean the explosion in the cylinder will be less efficient therefore producing less power.

A straight through will be better. My twin loop created so much back pressure, the exhaust gas temps reached glowing levels and melted my hangers off.
That's now if and a twin silenced 3" is on.

Cheers lads I've got it decatted but its got a silencer and backbox so gonna pop down to this local place which makes custom exhausts and see what they can do, cheers

Right! Happened a few times recently came to check my raditior coolant level and there wasn't much in. It was all In the overflow, I've tipped it back into the radiator and it happened again when I checked today, so as we speak I've poured it back in and left the radiator cap off with engine on to see if there are any bubbled etc trapped. What could the problem be ?

Are you checking this when the engine is stone cold?
The radiator should be full and the expansion bottle should be on at least minimum.
Only check when engine is cold.

I've checked it once when stone cold and it was in the expansion and today was luke warm and same again

How full was the expansion tank when you checked it and thought it was too full?
Then, how full was the expansion rank left after you had tipped it into the rad the first time?
Have you noticed any strange behaviour on the temp gauge?

It seems as the radiator has pushed the coolant into the expansion it was over the full mark when I checked but before was in between the min and max . the temp gauge hasn't budged. It rises to just below halfway and stays there. Went for a hour drive to Telford the other day and no movement on the temperature

mine doesnt move over halfway either

My temperature gauge never moves anymore than halfway either... might as well be painted on.

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