so i have my intake manifold apart and im sure i found the leak. now just waiting for my parts store to get the gaskets.... but i was looking at the 5-6th vac valves and the sleeve that going the engine. and i was wondering if i simply remove the sleeves or modified them would i see better hp? i know the 5-6th ports open up around 3800 rpms so below that she would run lean. but it just seams to me that its a non necessary set up on my vac sys. could any one ex-plane? or point me in the right direction for better hp for just cheap. i know hp is not cheap. but i mean like tune or something? just trying to learn more... thanks

 

I've argued with thousands of people over the port sleeves. Removing the sleeves on a s4-s5 has no negative effect. Replacing them with atkins or pineapple sleeves adds hp.

People will tell you you lose low end hp when the sleeves are removed and the can feel hp increasing as the sleeves open. Although this is a cool feeling what you are experiencing is the sleeves returning the hp they stole.

I pull the sleeves and lock open the DVI. I locked the DVI open with a beer cap, works/looks awesome. If you can afford atkins sleeves buy them they do help.

 

what is better hp? without the sleeves you will gain a couple/few hp way up top, but at the expense of low rpm power.

since these engines use an air flow meter, it directly measures airflow. these ports actually do two things, the first is to have more port, ie its just bigger, this is good.

the second thing is that it changes the port timing, like Vtek, since the port timing changes, the powerband changes. this is why you loose power down low, its also why, if anything you run rich with these things open

non necessary but it came with the car? the atkins sleeves are a good idea, they are shaped better, so they flow more air AND you keep the functioning system and your low end power.

 

I don't doubt that they give you some low end power or Mazda wouldn't of used them. It's probably to help at highway speeds when your engine is below 3000rpm. I also believe they steal a small amount of mid range power as they open or if they open too slowly.

The engine bay is much better looking once you eliminate the over complicated system.

 

ok that answered what i was asking thank you. now next when i pulled the sleeves out there was a slight bit of oil on them is that norm? i thought it was cuz its a moving componit, however will i now have extra oil going into the rotor housing? or will it not matter? and could i get a pic of what your talking about with the beer caps? slightly confused with that...

 

and if you dont mind could you post the atkins like for the sleeves? i cant find them on the sight. iv searched intake emission and almost every other sub link i could think of were they could of put it in? thanks again...

 

it depends on the exhaust, somewhat, but you can loose 15hp in the low/mid range without the ports, which is reason enough to keep em.