Air Filter And Exhaust Manifold.

[snave1345402286 0]

Hi all,

 

Next week I'm going to change the exhaust manifold, say removing the standard 405 mi16 manifold and put the 309GTi16 factory exhaust header.. (the one which turn like an octopus ) and eventually I will get some 3-5bhp with it . by the same go, I wonder if I have to replace my standard box airfilter which come with default k&n filter or replace it with the cone one .. like K&N or pipercross filter..will the aftermarket do give better response than the original one which was designed to give the amount of air the engine need "Vacuum at plenum entrance (new air filter) 0.039 bar @6500rpm " as frm the start the engineers knows that Mi16 was to response and behave like a Gti car. Anyone here to clear me out on this before I buy the aftermarket air filter ?

[ryan13961345402285 1]

Keep your standard airbox. It's good enough as it is.

I thought 405 Mi16 manifolds were the same as 309 GTi16 ones?

[JamesLeMans831345402285 0]

Cone seemed to make a fair bit of difference in mine, nice noise too. My std filter needed replacing tho so that could account for the difference. Mine is alos a phase 2 with the looong air intake route.

[cybernck 402 1 Cars]

I thought 405 Mi16 manifolds were the same as 309 GTi16 ones?

<{POST_SNAPBACK}>

nope, they're rightfully called spaghetti, banana or octopus

 

 

dutch guys say it gives 0 hp and 3 nm over the standard one though .

 

 

original 309 GTI16 air intake looks like a 205 GTI one btw .

[ryan13961345402285 1]

WTF? LOL. How the heck did they ever squeeze that behind a D6C? Nice bit of work though

[KRISKARRERA 2 1 Cars]

original 309 GTI16 inlet looks like a 205 GTI one btw

They really tried to do that before realising that the proper Mi16 inlet was better??

 

Although it might give better peak torque I wonder if the Mi16 exhaust manifold would have given better torque lower down the rev range.

[Jer309GTi 3]

WTF? LOL.  How the heck did they ever squeeze that behind a D6C?  Nice bit of work though

<{POST_SNAPBACK}>

 

The 309 GTi16 was only a LHD, so a bit more room where it matters

[cybernck 402 1 Cars]

WTF? LOL.  How the heck did they ever squeeze that behind a D6C?  Nice bit of work though

<{POST_SNAPBACK}>

this is how:

 

 

 

 

They really tried to do that before realising that the proper Mi16 inlet was better??

<{POST_SNAPBACK}>

oops, meant air intake as inlet, not inlet manifold.

 

it's just to do with engine bay space imho:

 

[KRISKARRERA 2 1 Cars]

Mi16 intake is better to look at I think. That thing and the expansion tank cover the lovely engine.

[snave1345402286 0]

the gti16 exhaust manifold give a fair 5-7 bhp was confirmed on highflohead.co.uk and other friends who has put it got a better torque, this manifold is also called "welders nightmare" lol I can understand why.. ! the gti 16 air intake though is a bit too long I think becoz of lack of space not as the 405, I'll keep my oem box intake for a while then and change it later to see any difference..I think some of you was gud to knw the gti 16 manifold.. so now go and get one you wont regret, but it's better to have insulating wrap on it so as not to heat the other hose by.

Edited December 12, 2007 by snave

[cybernck 402 1 Cars]

Welder's Nightmare is actually a name of one of DP-Engineering's turbo manifolds .

 

btw, is your avatar a "photoshop" or a real picture and do you have more pics of your car?

[snave1345402286 0]

It's a true picture I've taken, I make a focus on the wheel ( momo gtr replica ) and inside there is a brembo drilled disc with the standard 405 mi calipers, lowered with vogtland suspension kit, as you can see I have to re-do the paint and fix the bumper.. she is actually at the paint shop to repaint balck pearlescent gold and get the rims back to metalic grey , will post more pics when she will be back ..

[S@m 156]

I dont mean to bad mouth anyone, but in my experience, what hiflowheads say is often wholly inaccurate. I wouldnt deal with them (again) even though they have all the Mi parts you could ever dream of. Its a shame really.

Also, i thought that the GTI-16 had that manifold to get round the problem of the 405 one hitting the bulkhead (like it does in 205/309 conversions) as power figures seem to be the same for the GTi-16/Mi16/BX gti 16v everywhere ive seen. But as i type this im beginning to doubt myself as it is a work of art and closely resembles the 306 gti-6 manifold which peugeot put alot of effort into for power.

Thats my 2 cents anyway.

Sam

[KRISKARRERA 2 1 Cars]

Well I wasn't sure whether to approve that post or not, but I have and I shall see if I get the slipper from Cybernck.

I'm a bit dubious about the GTI16 exhaust manifold adding 5-7bhp, had it been that much surely Pug would have said so. Also the exhaust system from valves to tailpipe isn't that restictive on a standard Mi16 so perhaps it would be more useful on a highly modded engine such as Kristian's 2.3 litre Mi16. Actually I think he has got that manifold on there, doh.

[S@m 156]

Also, looking at the picture the GTI-16 manifold doesnt seem to have the siamese design of the 405 or BX manifold, which cant be too helpful, but then maybe thats because it doesnt have a branch for each exhaust valve, just one for each pair.

Sam

[cybernck 402 1 Cars]

^ it is tuned lengths though, whereas Mi16 one isn't.

[S@m 156]

Good point, but does it actually flow any better? it should but all power figures ive seen seem to be the same with either manifold. (although power figures are always questionable).

[JeffR 51]

Snave,

 

They certainly are a work of art (& stainless too), but bear in mind that the GTi16 pipe outlet diameter is only 54mm, compared to the 8 branch one at 63mm, which will require a different (smaller) engine downpipe.

 

I've got a set which I've had modified bringing the dia, back to 63mm.

 

The outlet angle is also different to the 8 branch, & you'll need a new engine pipe without the centre divider- like the GTi6 system.

 

Cheers,

 

Jeff

[cybernck 402 1 Cars]

like i said a few times, dutch boys found out it gives 0 bhp and 3 nm over standard (mi16) manifold.

 

that should explain why the quoted power is always the same .

[snave1345402286 0]

Ok , for the manifold it still remain smething to talk about . but know that I 've change the oem airfilter.. mean the big airbox. and have made a tailored adapter then put an air filter, OMG it really roars big !!! when the second throttle open up over 3500 rpm.. it's sound like a lion roaring. hihi all my jap's car fanatic friend remain astonished how can an engine roar like that just with an air filter and stock exhaust. ! I have drive the car over 2 - 3 hours for the ecu to adapt with the huge air intake of the filter.

 

By february I will see for the Manifold.. by now .. see another pic of my baby with rims repainted lamborghini grey. enjoy !

[Jer309GTi 3]

Yes they do sound very nice with an aftermarket filter. My mates dad asked me what carbs I had on my car when he first heard it

 

Cars looking lovely btw

[MiCRO 0]

Looking nice, are these 17"?

[B1ack_Mi16 67]

About the gti16 exhaust manifold, as Kris mentions I have this manifold on my 2.3 litre XU engine with Mi16 head and race camshafts on it.

 

The engine is dynoed to about 260-270bhp with this manifold.

 

I did modify mine a little though, as it was short on space in the 205 engine bay when using the taller XU10 block compared to the XU9.

 

Had to chop off the outlet and welded on a 2.5" V-band flange, opening up the outlet to true 2.5" in the same operation.

 

Pic:

 

I believe Peter Taylor did some flow tests and the standard 405 Mi16 exhaust manifold is the better flowing one, at least compared to the XU10J4RS/306gti one which also is of the same spaghetti design as the 309 gti16 one (and probably flows in the same league as the gti16, gti16 might flow a little bit better as it's 38mm inner diameter tubes instead of 36mm on gti6 though).

 

So when used on engines with more or less standard spec. camshafts I don't think they contribute much at all as mentioned earlier in this thread. However when you start tuning the engine the pulse effects in the manifold starts getting more influence on power as the overlap is increasing.

 

At least my engine pushed out 250bhp+ with this exhaust manifold, which I find to be a very good result

Edited January 12, 2008 by B1ack_Mi16

[JeffR 51]

BlackMi16,

 

What's the extra plate I can see welded to the flange? Is it something to do with strengthening as these pipes are prone to fractures around there apparently.

 

Jeff

Edited January 12, 2008 by JeffR

[B1ack_Mi16 67]

Yes this strengthening plate was not there on the first manifolds, but they used to crack so they added it later on.