Inlet manifold porting question

SuperTom86 · Post by **SuperTom86** » Tue May 30, 2017 12:49 am

Hey guys,

I'm currently doing some work on my h22a8, some of which consists of fitting an ATR inlet manifold along with a 68mm throttle body.

Now, it's obviously going to be a good idea to port match the inlet manifold to the new TB, but I've saw two different versions of what people class as 'porting'. First version seems to just be port matching the inlet to 68mm where the TB bolts on. The second option is cutting the top surface off the inlet and porting out the internals.

Can I ask what any of you guys have carried out in the past? Is it sufficient to just port match the inlet? Or is it actually benifical to have the whole inlet manifold opened up and fully ported?

I've been quoted £275 by a local tuners to carry out the full internal port job but I'd like to know if it's actually worth it before I take the leap!

Thanks!

Post by **vanzep** » Tue May 30, 2017 6:33 am

Im no expert but two areas need port matching - the throttle body to inlet manifold if your enlarging the tb (up to 68mm)and the injector ports where the inlet manifold meets the block - there is also a little bit of clearancing work done there as well

here is a link to info from rosko racing - they call the atr the Euro R

http://roskoracing.com/TechBlog/?p=87

Post by **NafemanNathan** » Tue May 30, 2017 7:37 am

Yeah the Rosko Racing guide is a good guide. You certainly don't need to be looking at cutting the plenum open your port the insides unless you're aiming for massive power gains (like around the +290bhp) in which case other options would be to consider ITBs.

It is a more common practice to port out the internals of a standard h22 inlet manifold (the dual port, IABs version) which joins the two runners of each cylinder together.

Note that all these options will require a retune to actually benefit tour car's performance.

SuperTom86 · Post by **SuperTom86** » Tue May 30, 2017 8:12 am

Thanks for the feedback guys! My build is only an h22a8 with full bolt on's and a Hondata S300 so doesn't sound like it will be worth while forking out the extra cash to have the plenum opened up.

I'll get back in touch with the machine shop and explain to them that I only want the inlet & outlet ports done. Will be interesting to see what the difference is in price for the work! Thanks!

Post by **NafemanNathan** » Tue May 30, 2017 8:29 am

Plus the work around the injectors and chamfering the top edge where the IM meets the head. It'd probably be work while giving them that link to the Rosko Racing site

SuperTom86 · Post by **SuperTom86** » Tue May 30, 2017 10:57 am

I'll actually have to have a nosey at my IM later and have a chat with the tuning shop who has worked on the car. After looking at the Rosko 'how to' and what is necessary to ensure fitment, I suspect some of this work may have already been carried out to mine, as the intake is already fitted along with EGR delete plates. I wasn't aware until now that there were some small mods needed to make it fit.

mercutio · Post by **mercutio** » Tue May 30, 2017 5:10 pm

As already said all you need to do is port match the manifold doing that is fairly easy just match the gasket to the head and the manifold will show you how much metal to remove the same with the throttle body use the gasket as your guide

mercutio · Post by **mercutio** » Tue May 30, 2017 5:11 pm

the roughness in the body of the manifold helps atomise the fuel air mixture smooth isnt always good with engines especially on the inlet side of the head

SuperTom86 · Post by **SuperTom86** » Tue May 30, 2017 5:39 pm

mercutio wrote:As already said all you need to do is port match the manifold doing that is fairly easy just match the gasket to the head and the manifold will show you how much metal to remove the same with the throttle body use the gasket as your guide

Thanks for the input mate! I've been in touch with the machine shop earlier today and explained what I need done. They've said it's a fairly small job and shouldn't cost too much.

Post by **NafemanNathan** » Tue May 30, 2017 9:21 pm

Woo!