New British sourced back boxes for Maserati 3200GT

[highlander]

Why go X pipe? Just cut the cat out and replace it with two straight pipes! £30 in materials and a few beers for a welding mate!

take it you give him the beer after not before he welds.......

 

[Neil Surrey Labs]

Interesting seems like a simple mod.

 

[CatmanV2]

So what's the noise difference and explanation between straight through, X-pipe and H-pipe? Anyone able to explain?

Cheers

C

 

[Almichie]

Enhanced noise!!

I take this back...

I've read up on turbocharger exhaust systems and ( I should have known this ) minimum pressure post turbo the better. As a centrifugal pump the higher the pressure difference across the turbine the more efficient, and so the larger and straight the exhaust pipe the better. Best of all... No pipe.

X pipe is good for NA but NOT turbo.

 

[Contigo]

Exactly x pipe matters for NA and firing order etc but on a 3200 just go straight.

 

[Almichie]

So what's the noise difference and explanation between straight through, X-pipe and H-pipe? Anyone able to explain?

Cheers

C

For NA application;

Straight pipe - optimise exhaust sizing; when you thing about a pipe you bed to think about the size for both flow rate and velocity. Flow rate is the amount of a substance that can pass through the pipe and velocity is the speed that it needs to flow for the given flow rate. And so you can see for a fixed size of pipe the more flow (volume) you try to get down the pipe the higher the velocity.

This goes hand in hand with pressure. The higher the velocity the higher the pressure drop across that pipe. So the more flow you try and get down the pipe the higher the velocity and the more back pressure you create.

This leads onto the type of flows within the pipe ; lamina and turbulent. The ideal is lamina where flow is moving constantly and directly. This helps scavenge the next pulse of gas from behind it, creating a small vacuum into which it is pulled.

The problem with engines is flow, and therefore velocity is not fixed. This means that you can tune an exhaust but it won't be optimised for every point across the RPM range.

An X pipe (I don't fully understand this) is supposed to create a transition of all eight cylinder pulses and smooths the pulses. Now I. An see that if the firing order of the eight cylinders is balanced across the two banks this would be usefully it would fill the gaps.

H pipe is the same but rather than the gases adjoining they expand into the link pipe.

X pipes are better at top end power release whilst h pipe is better at low end power release.

Turbo charged engines work entirely differently.... Tbc

 

[JonH]

Has anyone contacted BennyD. He can get custom made X or H pipes made from a dealer for £200. A number of SM members have taken this up, with very positive feedback.......I am next in que.

 

[Neil Surrey Labs]

just a couple of pipes fitted across where the big cat goes. Easy bit of work. Long Life exhausts anywhere will do this for you.

 

[CatmanV2]

just a couple of pipes fitted across where the big cat goes. Easy bit of work. Long Life exhausts anywhere will do this for you.

From what I read on tinterweb, an X, or H pipe works rather differently than simple straight pipes as you can get scavenging from bank a by the pulse of bank b, and vice versa. Also gives more space for the gases to expand by linking the two sides of the system.

Depending on my bill next week, I shall be talking to Benny or similar.

C

 

[Neil Surrey Labs]

Scavenging the other side of a turbo?

 

[CatmanV2]

Scavenging the other side of a turbo?

Heheh. No. I was talking about NA engines, rather

C

 

[SachaP]

I went the x pipe route without really knowing too much about the pros and cons. It has worked for me though, definitely a nicer sound and feels like it pulls more in each gear. Perhaps straight through would enhance further? Either way, this is a reasonably priced mod and I would happily make the change to straight through if it gives more performance/ better noise. The mod I really want to do though is installing race cats . Anyone changed to race cats on their 3200? Where and how much? I got a quote a while back which came in at around £750 all in if I remember correctly.

 

[LDM 3200]

No experience with modified Maserati exhausts (do have aftermarket back boxes which came on the car) but know that getting the best out of scavenger systems on other cars can be quite complicated and can loose driveability despite sounding better. I m not sure this would be so noticeable on a powerful V8 engine. - Probably another useless / pointless post by me - What sort of manifolds come on the cars, 4-2-1 or 4-1?

 

[CatmanV2]

4-1 as far as I can see from Eurospares

C

 

[Chrisbassett]

The euro-spec is 4-1
The US / later GS spec includes a catalyst box on the manifold, so not sure

 

[CatmanV2]

US are 4 into messy

C