Ported Throttle Bodies - Really! Madness

carlings2

Hi Guys, just thought I'd have a little moan and ask are some of you totally mad! I just tried to sell a brand new throttle body with no success on here or ebay and regularly see old TBs ported and polished selling way in excess of what I was asking. :crazy: So I thought id give a little perspective on this. The standard throttle body inlet is shaped with a cone spiral that directs the flow first to both sides of the opening butterfly, then after the butterfly the spiral continues on into the inlet. Why is it spiraled - to get the air spinning into the chambers, for maximum mixing with petrol gases, the spiral is polished anyway. Polishing the lip may help but wouldnt give any extra BHP. The ported and polished tb grinds out this spiral and is followed by polishing the whole lot, Does this give any extra BHP - No is the simple answer, could it make running lumpy - Yes because your fuel air mixture is not rotating quick enough, and is just effectively dumped into the chambers. Just check out the problems on this site people have reported with ported and polished TB's, usually done by amatuers with a drill and a dremel, its easy stuff but not that technical. If you want to port something go for the head and open up exhaust outlets to match manifold and highly polish, the inlets needs smoothing only you do not highly polish these just smooth and light polish as you want those gasses mixing and moving. Getting more air at the TB in the first place may give you 1 or 2 BHP but thats it im afraid so please dont believe all you read about ported and polished TB's. Uprated sports Cams etc bigger valves, mapping all increase BHP Ported TB's do not. Anyway thats my rant and you guys buying these need to save your money for better things. 🙂

boothy2_2

do you feel any better now thats off your chest notsure.gif 😃

carlings2

Yes Thanks, just looking for my Dremel now!

boothy2_2

LOL!

vocky

actually the throttle body only has air passing through it, the air enters the inlet manifold then exits the inlet manifold and finally the fuel is added.

so a ported and polished throttle body is a good idea and does work very well - if done correctly

carlings2

Yes only air passes through, but the whole idea is this air is spinning when gets through to fuel being added, To port a throttle body for this engine you would need to bear this in mind due to the design of the inlet. Additionally, unless you increase the size of the butterfly this further negates the porter, does it not, and not a single one of these sold either on this site or ebay has had this done, in other words i have yet to see one thats done correctly as you put it. Come on stop misleading the guys on here!

How much BHP do you reckon a ported and polished TB done at home with a drill and a bit of emery will add then?

vocky

as the air enters the inlet chamber it stalls before entering the air intakes, so I cannot see how the tb can make the air spin.

the idea of a ported and polished throttle body is better throttle response, certainly the highly tuned z22se engines benefit from a ported throttle body with regards to a power increase, but sadly no one has done a before and after rolling road session.

The ebay polished throttle body's claim a massive bhp gain, I have no idea if they have the proof of that or not.

I do know you get a better throttle response, if there is a little more bhp (and it would be little) then great.

So I cannot see where I mislead the members of this site as I've never claimed it will add 20 bhp.

Daniel

i was always on the understanding it just made ya throttle response better but it can only help 🙂

MikeS

if the 2.2 manifold is already restrictive then porting the TB wont do a lot imo

it might help your acceleration feel a bit more crisp and responsive but thats it

it is like putting a sport cat on a standard cat back system, it might free it up a bit more but you still got the restriction further on

i aint saying a ported and polished TB is a bad thing as i had em on c20xe and x20xev engines, put a ported tb inplace of one that has done 80k that is filthy and oily will always help