Branch Manifold - Make Much Difference?

[Guest rtsbasic]

Have a 2nd hand 4-2-1 manifold sitting in the garage waiting to be fitted, was wondering how its likely to affect the car? Will there be any real change to the power or noise? Am a bit concerned it might start getting too loud, it has a 3" peco on the back, and a straight through in the middle. Right now its about on the limit of how loud I'd like it to be, don't like having my eardrums popped when cruising down a motorway.

 

Will anything need re-tuning or adjusting to make best use of the new manifold? Its a 1360cc TU3 in a 106.

 

Thanks.

[welshpug 1,626]

Depending on the manufacturer and design of the manifold the TU series do respond quite well to manifold upgrades, you may find that the main cause of your loise issues is the backbox you have, 3" is simply far too big for a 1360 engine, let alone a firebreathing Mi16.

[Guest rtsbasic]

The noise doesn't bother me at the min, its nice and quiet when your cruising along, only gets particularly vocal when you start revving her hard. Would like to get a more discrete backbox in the future as it is a bit big for a 1.4 really, but it will do for the min.

 

Not sure TBH what manufacturer the manifold is, here's a pic:

 

 

Anyone recognise it? Its amazingly light.

[DaveW 6]

I found that when i had the 4 branch on with my janspeed it popped loads off throttle..

[Jrod 7]

I didn't notice any diff in noise.

[swordfish210 20]

a tubular manifold wont increase/drcrease noise, put a std middle section and rear box on it and you'll have a decent exhaust system then

[Guest rtsbasic]

I do have the standard middle section which is in good condition, you reckon it will be better overall to put that on? The standard back-box I have isn't usable, blows badly.

 

Bear in mind its on a 106 not a 205, to confuse things

[christopher 5 1 Cars]

I think it is the centre box which makes the difference to noise.

 

They do say that running without a backbox can affect torque due to the reduced back pressure.

 

I have a 4/2/1 a standard imtermediate and a supersprint backbox on a TU. It is very quiet all the noise comes from the carbs.

 

It is actually now quieter then the standard system I had.

 

You could put soem kind of inline box in the straight through system.

[Guest rtsbasic]

Thanks for the input. I'm going to fit the manifold today, and put a standard middle section on while I'm under there, seems to be the winning combo.

[JimLad 1]

Thanks for the input. I'm going to fit the manifold today, and put a standard middle section on while I'm under there, seems to be the winning combo.

 

 

When I bought my 205 GTI it had a standard system apart from a ridiculously massive back box which was absolutely deafening. It came off straight away to be replaced by a standard unit and the car was silent by comparison. Sure it went better as well.

[bren_1.3 1]

looks like a raceland item by the photo....

[Guest rtsbasic]

Why are these things never simple

 

Old exhaust came off no problem, popped some new gaskets on, bolted the new mani to the cylinder head no problem, went to clamp it up underneath, and the flange size is different, the metal gasket for my standard centre section won't fit into it. Its also missing the gearbox mount so I'm thinking its probably off an AX GT. Not quite the direct fit I was led to believe.

 

For the min what I've done is clamped the two halfs together, and used firegum to try and seal it. Seemed fine when I left the car to idle for a few mins, what are the odds it'll last? Bet I'll be under there trying different gaskets next week..

[macaroni 17 1 Cars]

I fitted a 4-2-1 CSC manifold to my xs and it made a great difference. It is also made for the xs and fits like a glove.

[Guest rtsbasic]

Will give the car a run tomorrow and see if it starts to leak or not..didn't when it was on the driveway, does sound different now though..not louder, just different. In a nice way.

 

While I was doing it I noticed the cambelt seems loose (able to move it maybe 20mm on the longest stretch), and worn. It looks recent but you can see the teeth outline on the back side of it. Ho hum, hope it hasn't stretched. Bit hesitant to drive it now.

[joe1joe 3]

with just the middle box the car sounds like it doesnt have an exhaust atall! i have a 2 inch front to back with 2 jetex straight through boxes (2 inch) and mines realy noisey near 100 db

[Guest rtsbasic]

Just taken it out for a drive with the new manifold.

 

Its rubbish.

 

There's no blowing or gases leaking, but it feels a lot softer to drive, throttle response in the low revs doesn't exist. Never did I expect a branch manifold to cause this, and I can't figure out why, it was a direct fit onto the engine, and the joint onto the center pipe flows freely and isn't blowing.

 

I hope its the manifold anyway, will put the old one back on tomorrow and hope for the best.

[macaroni 17 1 Cars]

Just adding a tubular 4 branch manifold won't necessarily increase power/torque, it has to be a good manifold.

 

My xs with a 4-2-1 manifold felt much stronger in the mid-range and I compared it directly to the standard manifold when it felt flat and lacking in urge.

 

You might be better off trying a bespoke manifold, for the 205, rather than bodging this one.

[bren_1.3 1]

a friend has a 106 rallye with a raceland tubular manifold and it doesnt even get going to 6000rpm..... similair sort of performance your describing. totally gutless.

 

the works cars used the standard manifold and ive never felt the need to fit anything else. maybe i should try one of those CSC jobs though...

[Guest rtsbasic]

I wasn't expecting a tubular manifold to make a dramatic difference - little bit in the mid-range maybe from what I've read. Didn't expect it to decrease performance. Anyone fancy an AX GT manifold?

 

Once it gets going 5000rpm+ its pretty rapid, but I wouldn't say faster than it was without it. And as my indicated redline is 6000rpm, its a bit pointless really. Yesterday when I had the carb sorted and normal manifold, I finally understood what people have said about getting pushed into the seat when you put your foot down. I'm praying that fitting the old manifold back on will give me that back.

 

Strangely the car idles better now though, does the back-pressure through the exhaust affect the idle in any noticable way?

Edited February 16, 2008 by rtsbasic

[DaveW 6]

What car is this on then?

[Guest rtsbasic]

As I said in my first post, its a 106. More specifically a 1.4 106 XT, 1992.

 

I took the branch mani back off today, now the car feels normal to drive again. Odd thing is, I measured the port sizes, and they're a couple of mm bigger on the branch one as opposed to standard. No blockages either. Might just port-match the standard one now, or get a Raceland 106 one.

[christopher 5 1 Cars]

a friend has a 106 rallye with a raceland tubular manifold and it doesnt even get going to 6000rpm..... similair sort of performance your describing. totally gutless.

 

the works cars used the standard manifold and ive never felt the need to fit anything else. maybe i should try one of those CSC jobs though...

 

 

Standard manifold but what about the downpipe Bren? I recall seeing a twin tubular downpipe. Was this used on the works cars perhaps??

 

I'm running a CSC one on my Rallye Bren for your info. I have no issues.

[bren_1.3 1]

whoops! yeh i forgot about the twin downpipe! ill see if anything is going on the group buy..

 

I'm running a CSC one on my Rallye Bren for your info. I have no issues.

 

im not dissing them or anything, its just he's not the first person to lose all mid-range from fitting a tubular manifold on a 106...

 

I took the branch mani back off today, now the car feels normal to drive again. Odd thing is, I measured the port sizes, and they're a couple of mm bigger on the branch one as opposed to standard. No blockages either. Might just port-match the standard one now, or get a Raceland 106 one.

 

i read something about needing the step, or mis-match on the exhaust port to stop gas reversion? maybe Sandy would know something about that?

 

those raceland jobbies look cheap aswell. theres a thread on the 106 forum about them and their QC.

[Rippthrough 98]

Yup, the step around an exhaust port is deliberate to help prevent exhaust reversion

[Guest rtsbasic]

whoops! yeh i forgot about the twin downpipe! ill see if anything is going on the group buy..

im not dissing them or anything, its just he's not the first person to lose all mid-range from fitting a tubular manifold on a 106...

i read something about needing the step, or mis-match on the exhaust port to stop gas reversion? maybe Sandy would know something about that?

 

those raceland jobbies look cheap aswell. theres a thread on the 106 forum about them and their QC.

 

Thanks for the info..manifold wise I'm thinking leave it for now. Just going to get it running top notch how it is now and then re-evaluate what parts might be worth changing.

 

The odd thing is, since all this messing about with the manifold, the car idles spot on now, doesn't feel like its going to choke itself on tickover and hasn't died on me coming up to a junction in days. Will never understand these cars..

 

So anyone interested in an AX GT branch manifold?