Exhaust Manifold

[Henrik P 0]

Does any of you have any experience about replacing the exhaust manfold on a 205 1,9 GTI with kat to a "tuning" manifold? Will it make some horsepower and good sound ore is it just a waste of money?

[projectpug 0]

Hi

Just replaced my standard manifold with a 4-1 magnex makes a good sound , Not really sure about horsepower gains i suppose it depends on mods. However i don't know the effect on a "KAT" model.

 

Phil

[Henrik P 0]

Hi

Just replaced my standard manifold with a 4-1 magnex makes a good sound , Not really sure about horsepower gains i suppose it depends on mods. However i don't know the effect on a "KAT" model.

 

Phil

 

My plan over the winter is to port and polish my head, higher compression ratio another cam, maybe som carbs, remove the cat and the little muffler under the car and then get it rolled in on a dyno. My gold is 140-150 hp. But i don't know when the manifold is becomming to "small"?

[Henrik P 0]

Does anybody have good experiences about carbs on a 205 GTI?

[vickiw106 1]

i have just fitted twin carbs to my rally makes a big difference

 

as far a exhuast manifolds unless you are going for big mods such as big cam, carbs/tb etc the 4 branch manifold will wont gain you anymore power

[Henrik P 0]

i have just fitted twin carbs to my rally makes a big difference

 

as far a exhuast manifolds unless you are going for big mods such as big cam, carbs/tb etc the 4 branch manifold will wont gain you anymore power

 

Ok. But if i was going for what i wrote earlyer, port and polish head, mayby carbs etc, do you the think it's nessesary?

[wardy18 33 1 Cars]

id say so yes, i am running a 4:1 magnex into a stainless 2 1/4" system with 2 small silencers, is very loud but hey its a race car so its all good, im running a standard 1900 bottom end and head but the head has a max 60 thou skim giving 10.9 cr, 3 angle valve seats, rally catcam and am running twin 45 webers with a H&H dizzy, never been on a RR but ive been told by a few that im looking at approx 160bhp, the only trouble i have is when the car drops below say 3k rpm it will bog right down and splutter until it hits the power band of the cam again but this can also be due to not having access to a RR to get the ignition timing spot on and the carbs perfectly set!!

 

if your spending say 400 quid on carbs and all that money on porting and polishing i would save a little longer and harder and go for Throttle bodies, you wil see much much better results and more reliable long term!! carbs are good as a budget option to release power but you've got to know what your doing with them to keep them on top form!!

 

back to teh main issue thou, if you goin to teh trouble of a port and polish and then naturally a good cam (CATCAM) and carbs then definitely for the 4 branch exhaust manifold!!

[Henrik P 0]

id say so yes, i am running a 4:1 magnex into a stainless 2 1/4" system with 2 small silencers, is very loud but hey its a race car so its all good, im running a standard 1900 bottom end and head but the head has a max 60 thou skim giving 10.9 cr, 3 angle valve seats, rally catcam and am running twin 45 webers with a H&H dizzy, never been on a RR but ive been told by a few that im looking at approx 160bhp, the only trouble i have is when the car drops below say 3k rpm it will bog right down and splutter until it hits the power band of the cam again but this can also be due to not having access to a RR to get the ignition timing spot on and the carbs perfectly set!!

 

if your spending say 400 quid on carbs and all that money on porting and polishing i would save a little longer and harder and go for Throttle bodies, you wil see much much better results and more reliable long term!! carbs are good as a budget option to release power but you've got to know what your doing with them to keep them on top form!!

 

back to teh main issue thou, if you goin to teh trouble of a port and polish and then naturally a good cam (CATCAM) and carbs then definitely for the 4 branch exhaust manifold!!

Ok thanks for the answer. About throttel bodies. I am quite sure thats ilegal in Denmark, but on the other hand i dont know if the karbs are legal eather. The tuning i am about to do will be in the low range if we talk economy. The port and polish i will do my self. Not bigger walves ore anyting, just a little grinding here and there. But if i get throttelbodie i'l have to get another ECU right? like Megasquirt ore something?

[wardy18 33 1 Cars]

illegal.....thats shocking!!

 

yeh throttle bodies run on after market management which just adds to the cost of them unfortunately

 

still a good idea for the mani i reckon thou

[Henrik P 0]

illegal.....thats shocking!!

 

yeh throttle bodies run on after market management which just adds to the cost of them unfortunately

 

still a good idea for the mani i reckon thou

 

Year in Denmark a KN airfilter is considered illegal because it's more noisy But many "car inspectors" don't care about that. But Denmark is a s*ity country when we are talking about cars.

 

Throttle bodies is quite expensive then. But if i get a pro doing all the adjustments with fuel, cam and egnition it will drive pretty well don't you think?

 

still a good idea for the mani i reckon thou. What do you mean about that?

Edited October 19, 2008 by Henrik P

[wardy18 33 1 Cars]

yeh either way if you go for carbs or throttle bodies, a proper set up will see you good power increases

 

definitely in my view go for the 4:2:1 or 4:1 exhaust manifold

[projectpug 0]

If K+N is illegal then i don't know what they will say about carbs/bodies they make much more noise than stock unless coupled to a very well designed airbox. I would fit carbs/mani/portpolish all in one and then get it RR tuned for maximum benefit optimise the jetting on the carbs and also adjust the timing to the new cam. I would think 150 hp would be possible and still remain fairly good road manners. I would stick to a maximum of a 285 duration cam for a road car as they give excellent mid range power with only a little sacrifice low down. As Wardy mentions a rally catcam will not come on "cam" untill at least 3k more towards the high 4k plus revs.

 

Hope this help

Phil

[Henrik P 0]

Ok. Thanks for the answers