Hi guys,

Long story short i have fitted a GTi metal manifold to my 6N2, the car is feeling slightly underpowered compared to the plastic original 16v manifold, anyone have any ideas?

There is no vacuum leaks just feels slightly slower on acceleration..

Any help would be great

Thanks

Dimz

yes, bigger diameter manifold runners means less gas speed in the ports.

yes, bigger diameter manifold runners means less gas speed in the ports.

Oh really?

Bad for day to day power, perfect for nitrous ;p is the 6n 16v throttle body bigger than the 6n2 one?

Worth trying a bigger throttle body?

Thanks

Dimz

Were you not a motor sport degree student?

Were you not a motor sport degree student?

Mate to be honest when we looked at the two manifolds the port sizes matched up that's why i was confused, if i knew it was a bigger manifold then i wouldn't have asked the question..

sounds like an excuse for some head work :)

is the 6n 16v throttle body bigger than the 6n2 one?

no, both 60mm.. when choosing an intake manifold it comes down to what the intended use of the car is to be honest, smaller diameter ports will give you more torque lower down in the rev range but potentially could restrict top end power.. i know i prefer having more torque lower down, it makes it much more fun to drive around town..

also the length of the runners plays a huge part in power characteristics too, the length of the runners is inversely proportional to which rpm peak power is at, long runners for low rpm power, short runners for high rpm power

then there is the size of the plenum chamber to consider, on speed density injection systems like on these engines you need at least 80% of the cylinder displacement in the plenum chamber otherwise you get wierd signals at the map sensor, or strong reversion, or strange diveability issues caused by pressure waves in the intake

if you are indeed a motorsport student i am a bit dissapointed if i'm honest because this is basic theory

Edited 24 October, 201015 yr by SkodaBoy

is the 6n 16v throttle body bigger than the 6n2 one?

no, both 60mm.. when choosing an intake manifold it comes down to what the intended use of the car is to be honest, smaller diameter ports will give you more torque lower down in the rev range but potentially could restrict top end power.. i know i prefer having more torque lower down, it makes it much more fun to drive around town..

also the length of the runners plays a huge part in power characteristics too, the length of the runners is inversely proportional to which rpm peak power is at, long runners for low rpm power, short runners for high rpm power

then there is the size of the plenum chamber to consider, on speed density injection systems like on these engines you need at least 80% of the cylinder displacement in the plenum chamber otherwise you get wierd signals at the map sensor, or strong reversion, or strange diveability issues caused by pressure waves in the intake

if you are indeed a motorsport student i am a bit dissapointed if i'm honest because this is basic theory

Mate i know all this, i didnt know there was a difference in the manifolds or throttle bodys, guys i don't need to be taught what i already know, i seriously didnt know there was a different between the two..

Wow i give up..

Pleasure and thanks for the catch up lesson..

i tell you what you could try if you have access to vag-com... try advancing the ignition timing a couple of degrees, it might restore some of the lost performance in the lower rev range

Listen right, none of you know me so i sugguest you give it a rest, if i had known the manifolds were different sizes i wouldn't have posted up, the ports matched so i didn't think there was a difference..I asked for information on the manifolds..

I got a 1st class honors in my degree and ranked near enough top of the class, i have built various other engines and designed throttle bodies and concept turbo's and do not need some polo punks critising..

So do me a favour and unless you have something contructive to say, don't post anything..

Dimz

If you are indeed a motorsport student I am a bit disappointed if I'm honest because this is basic theory.

Not on the motorsport course I'm on.

I tell you what you could try if you have access to vag-com... try advancing the ignition timing a couple of degrees, it might restore some of the lost performance in the lower rev range.

Might not be such a great idea with the nitrous.

Edited 25 October, 201015 yr by varnish

Keep this on topic... !

iv just put a gti inlet manifold on my polo 6n2 and mine is the 75bhp model.

I had to make a bracket for the throttle cable to sit on being as though this didnt have one.

Mine seems alot more throttle responsive though and my only other mods on mine are air filter and exhaust system.

I'm not a mechanic, I'm a plumber so i dont know anything technical lol.

iv just put a gti inlet manifold on my polo 6n2 and mine is the 75bhp model.

I had to make a bracket for the throttle cable to sit on being as though this didnt have one.

you don't need to make your own throttle cable bracket you can use the bracket is from a german with AJV engine code, part number for the bracket is 036129785E but you will need to drill and tap the holes

Woah don chill man! Skodaboy was trying to help!

I cut the original bracket off my original plastic inlet manifold and bolted that to the manifold. I noticed today that my car sounded a little tappety. I think it's Blowing slightly from where I blanked off my egr valve off. I'm going to get some putty around it tomorow.

Do you know any Throttle body that will fit being as though iv got a throttle cable?

yes, the standard throttle body from a 6n polo with afh engine code will fit.. it's the same size (60mm) as the gti throttle body

Thanks alot mate, I'll get round to ordering one soon hopefully. Thanks again

they are about £350 to buy from vw. you will be far better off getting a second hand one from a breaker

don_stavrou - You might have a degree, but what does contructive mean?

don_stavrou - You might have a degree, but what does contructive mean?

seriously?? didn't realise this site had a spelling police?

don_stavrou - You might have a degree, but what does contructive mean?

And that was constructive..

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...#ht_1076wt_1139

is that the right throttle body?