VR Senator with LSx454

Agree, really great info and exactly what these forums are for.

I think there is maybe a third option though which is what I am doing which is what DiPhillipo do. So option 1 is an X pipe or merge where the flow from one pipe crosses to the other to scavenge the other side. I can see why you would want to do this further down the back. Then of course there is the old school H pipe going between the two main pipes to balance the pulses. But then there is the "kiss merge" like I am doing. Which is taking two bends, and drilling a quite small hole, only 20mm in each where they touch. Then the two bends are welded together in an X shape, but really I imagine (could be wrong though) its behaving more like an very short H pipe rather than an X merge?

 

Really good info and posts guys much appreciated. I like the look of the pic above, will def try and minimise the bend, and see what you mean naaf, I guess you call it lazy, I call it neat but i get what you mean. I need to bring the pipes into the centre to go into the mufflers so it's got to come in anyway but will definitely look to minimise the bends whee possible.

 

Think I am going to do an H pipe, it's naaf's fault , I think he's right and it will look and work neater, less bends, straighter flow. For a tig beginner like me making it a true touch kiss means its a pretty tough weld down along the valley created by the two 45 degree bends whereas with an H pipe it means I just keep the two pipes parallel to each other from the centre mufflers forward then 45 bends out to the cats. I do reserve the right to change my mind in the next couple of days though ha ha.

 

Come on, have you read my build thread, I don't do anything simply because its easier, ever. But I do try and weigh up all the pros and cons and try (not always successfully) to choose the best option based on all the factors (for me). I had a good look at it last night. It will perform better, less bends, you are not asking the gas to do a double bend on itself, the entry to the two mid mufflers is actually reasonably wide apart (maybe 300mm), to me I don't think it makes sense to force the two pipes to meet each other in the center of the car then back out again when a short H pipe will do exactly the same thing but better allowing the main pipes to stay dead straight into the mufflers. There is no benefit in using the kiss merge in my application. As naaf has said above, and its backed up by what I have read recently, there in no actual flow across the H pipe, its just a pressure balance, so it doesn't need to be large. Mechanically it doesn't want to be too light and flimsy though, 2" seems the go.

 

Well have to say I am bloody happy with the exhaust so far. Took a while to work out how I wanted it to run, really wanted it tucked up as much as I could. Have got the pipes done from the collectors through to the mid mufflers. Only tacked at this stage and haven't done the H pipe yet but getting there. May have to get a bit more straight pipe for the rear section but will hopefully start on that maybe during the week. I reckon pretty blood good so far for an amateur

 

ha ha, master of none....

 

I don't think so, there's the factory heat shields there, if its a prob I could line them with more sheet. I will keep an eye on it though.