So I got another mini and plan on doing a decent build with it.
i spent alot of hours porting out these things and then I topped it off with a 400grit sanding so they're pretty smooth.
I wanna see what the best power i can pull out of it with ONLY aftermarket parts being the cam , sc pulley , intake , exhaust and injectors and tune.. so basically just bolt ons. I'm very curious to see how it will compare to my tpr2 , 21psi sprintex on meth pretty much full built mini , though it was a semi budget route. This other mini is going to be a bottom dollar , super budget build. So I plan on using a Newman cam and it will probably be a ns2. So it will be a more aggressive cam than my other mini as that's running a ns1 but it does have bigger upgraded valves n springs and stuff in its head.
I do plan on using a facelift sc and I've been porting the intercooler horns and i ported the header flange too and I will also port the intake Manifold.

 

I touched up the intercooler horns better AND ported the supercharger too now also..

 

after all that work bet you're glad it's not a six or an eight...

 

lol...

 

You sould invest is some finishing tools... bumps and lines are not that good for airflow, you want a smooth finish.

 

it's actually pretty smooth, smoother than it looks, that's just how the castings look when ground into. I've went over the inside with 400grit and it's pretty smooth. They're already far smoother than they were oem when removed. Not too smooth because i DONT want the intake side glass smooth, matter fact someone did testing and dimpled the entire inside of an intake manifold and changed nothing else and the car DID gain airflow and more evenly distributed fuel. I've read making intake too smooth will actually hinder fuel atomization. I know that had alot more effect on cars that were carburetor injection but you'd think the same would apply to a fuel injection... though the fuel injectors sit much further down the intake tract on fi vs carb.
So the main thing I do in our intake is correct the airflow path so it's not taking such hard,sharp turns as well as enlarging all the insides to allow more cfm airflow. Also when porting and enlarging the insides it removes all the slag and uneven castings.
I'm not expecting some massive power gains with all my porting , it's just mainly to increase the allowed cfm through them to accommodate the extra max psi along with making more boost at lower rpm's because of the 19% pulley..
if I really wanted to get crazy about the porting I'd port the intake Manifold so the furthest port away from the inlet would be the largest and get smaller as they get towards the inlet to even out the airflow better.
I've seen people showing how the #1 runner and on down gets less fuel and air because it's the furthest away port.. lol but that's going much much too in depth imo. It's not like they run lean on any cylinder because of that but it's something just to thinking about..
it's actually amazing how terrible these intakes are stock. Some even have slag from the casting inside and there literally just CHUNKS of casting and random rough spots and the inlets have humps on the tops and bottoms inside. Just like on the sc inlet , the right side literally has a flat wall the air hits and has to go around befor it goes in. You shoulda seem how much material came off the inlet of the sc alone.. are intakes arnt made for performance in mind. They're made to be mass produced, cheap and as easily as possible. They also must meet strict noise regulations too and they will purposely restrict the intake system inorder to make it less noisy.. plus a small intake is going to give better mileage too..
the port jobs arnt done yet either guys... I do plan on better polishing the exhaust ports in the head and I will make sure all ports ect are even. I just go at them when I don't have anything else to do.
though yes your are rite , I should smooth out the intake side better and i will.
I have to get an intake manifold too and start on that so I don't need to rush to get mine off my car done inorder to put the car back together.
so if anybody has an intake manifold fir cheap I'd be interested OR I have some parts I can trade..jlmk
once I get all my oem stuff off , ille take pics of everything side by side so you can see how much ive actually really opened this stuff up.. like the sc hat , wow I made much more room in that and made the turn down much less drastic and the mouth much larger.

 

I ported the boost tube , not much BUT I did remove the wall in it as well as the supercharger to help direct the air path better. I also ported my intake Manifold since I removed it durring my clutch install.
I ALSO then sanded the insides to smooth them out until they were smoother than stock. I opened up the ports a decent amount and opened up the inlet ALOT , as well as reshaped the inside
then I took the wire wheel and sandpaper and made the intake Manifold SHINE , not perfect but the spots you can see while installed have been polished up very well.
so the ic horns , boosttube , Manifold and the sc have all been ported and polished and then externally shined up..
I can't wait to install this stuff and feel the change.. I know just switch to a 19% pulley over stock will be a big help but then add ontop of it all the ported intake components and the supercharger having coated rotors and porting.. this should make for a nice bump in power..

 

Any idea on HP gains with all the porting? I should take my Mini to the dyno and get a baseline...

 

will you be doing the HVAC vent ducts next? Gotta be 8hp hiding away in those easy...

 

Why didn't you port the SC outlet, not enough material? That's where most porting gains are on the intake side. Also smooth flow isn't always the best. Air turbulence creates a little back pressure that SC crave.
That's why ppl lose power/boost when going no cat/res on the exhaust side...

 

I did port the supercharger... with the 19% pulley and ported intake stuff , granted because of new clutch I have been taking it easy buuuut my car built 11psi baaaaaarely so let's call it 10psi max at 6000+rpm at full throttle... lololol I can see 19lb at part throttle at just over 5000rpm now..
didn't you see that giant right side edge I'd removed from the sc and boost tube ? That entire inlet was opened up massively.. go look at thevsc inlet and see how much material i removed and airpath corrected...
trust me , the car has really really woken up from the porting..my iat's too are good too surprisingly though like I said I haven't been able to push it really hard so I'm sure the stock ic will be getting overwhelmed..
once the clutch breakin is done , I will toss in the step colser plugs , 440cc and tune it..
and I've NEVER seen a car loose power removing the cat , changing headers and exhaust maybe yea but NO ENGINE LIKE BACK PRESSURE . BIGGEST misconception around. The word your looking for is scavenging and headers , down pipe and collector and exhaust sizing determines how much they scavenge between each exhaust pulse.. you don't want back pressure. I know you guys are looking for the chance to flame me any given chance but to argue that this porting isnt effective and a huge improvement is just silly. Our engines dont come factory performing at their best. They come to meet strict environmental standards and todo so and to save money also in production they will cut corners anywhere they can and alot of times engines need to be choked down to meet noise standards and stupid stuff like that
.I suggest reading this

https://low-offset.com/guides/exhaust-back-pressure/

 

actually yea , I will be installing vents on those and I modified the plastic behind the intake too and opened that up for true cold air. Not some nice heated up header air..
mock me all you want idc...

 

Have any of you commentating ever seen what befor and after numbers look like on porting ??? There's amazing videos and articles all over.. it's been a goto performance gain for along as we've been hot rodding.
once you get over and accept that the cars we buy are not setup for maximum performance ( though they sure like to convince you otherwise) youll get what im trying to say..
to meet certain mileage, noise and lack of pollution requirements as well as strict budgeting for manufacturing.. you'll see how much an engine gets choked down to meet those standards.. lol i take it most of you never looked inside your intercooler horns and intake Manifold.. I'm sure all that slag material and casting humps REALLY HELP air flow. Or maybe the intake silencer too helps along with the catalytic converter.. haha cmon guys.. you HAVE to get over this misconception that the engineers built them the best they can get..yea I know they put alot of research and stuff into it but they end goal was far different than what my goal is..
I can make this car get 40mpg again and you wouldnt hear it idling next to you. It would be a slug but hey , it would drive great and get AMAZING mileage BUT THATS NOT MY GOAL...
go watch videos of befor n after dyno results OF JUST INTAKE MANIFOLD porting. And alot of times they only gasket match it and itle make that much of an improvement.
mock me all you want.. I really don't care honestly. I just think its silly you think porting the things I have was a waste of or hurt the cars performance.
tryst me , the car feels 2x as powerful as befor..and ontop of it all IT IDLES SMOOTHER, started up easier and took a few less cranks and also to turn over and it's also making almost 2x the boost now... o yea , no cel light on or anything either might I add. AND I'm running catless headers even.. so I must know a little bit what I'm doing.
in summer once this car is done I will dyno both of my mini because I want a comparison my self.. I'm very curious what power I can make with very minimal aftermarket parts. I'm kinda trying to see what the cars capabilities are with pretty much stock parts. Only aftermarket parts will be for support like fueling and tuning but that'll come very last and as it is needed. Though I'm sure if I go wot it would lean out running the stock injectors already..

 

Losing boost is not the same as losing power...

 

I know, others don't see it that way. Also depends if the port job is bad... Everyone seems to believe there is a big issue when the boost drops. In reality there is less restriction

 

I was doing no such thing. No shade in all honesty. Just wondering why you didn't port the the outlet side of the SC. Yes I have sewn before and after numbers. Usually slight drop in boost, IAT, bump in HP...I'm used to working on SC V8

Im not surprised you have better IAT. If nothing else, you increased the efficiency of the blower. Now you dont have to feel so bad spinning it harder

 

that was my goal. Because I'm running a 19% pulley I wanted the sc to be as efficient as possible. I DO plan on running an electric waterpump too once i get a stock flange modified to do so. Imo , this setup is darn close to my Sprintex. Though that's making 21psi on a bvh and cam it does run hotter. So all that extra boost , there is a trade off.

 

I wish I had thought of porting my entire intake system while I had it all apart last year during my long block replacement ordeal.

I have a set of 4 aluminum grinding bits but they are only about 3" long - and 1" of that is in the grinding tool. What do you use to reach deep into the supercharger horn?

 

I believe it's a 6in thicker shank porting bit , I change bits to get at the angles better. I have a bunch of different sized bits and style heads.. a good trick to start smoothing it all out well is use copper wire wheels because you can get small enough ones to fit all through out and it really does a good job actually. Then just hit it with like a 400-700grit sandpaper by hand..it's time consuming but the results are rewarding.

 

Really digging all that good work. Looks super time consuming. I'm "almost" inspired to tear mine down and fool with it.

 

what I did was grab parts from a salvage yard or ebay to get them dirt cheap and when ever i had the extra time or was inspired id go do somemore porting..
I've also found you get what you pay for with porting bbits.. my buddy bought me a 200$ set for porting his stuff for him and those bits vs Amazon, ebay or harbor freight. The expensive ones cut so much cleaner and faster..
I also found spraying a thick weight oil or jack hydrolic fluid inside the thing I was porting to help keep the bit cool and from clogging up with aluminum. I'd also stop every 5min and cool down the bit by dipping it oil and then wire brushing it clean and porting again.
I still have an extra set of ic horns and a non facelift sc I could port out and sell if anybody is interested..

 

Check out how much room for improvement there was in my Sprintex intake horns.. because of how the casing is designed its good as is and honestly would be a pita to make sure it was fully cleaned so I left the casing alone.

 

Miniman -

Overall nice work...
BUT. one poster mentioned the surface and the dips and pockets in the airhorns, as seen in the part below.
After spending a LOT of time porting cylinder heads, intake manifolds, and verifying my work on a flow bench, for yeah, since about the early 70's, and on many different platforms, and making pretty good money at it..! I can say that the pockets seen in the part below, could...very well hurt flow at different air speeds, and...during airspeed changes (quick throttle open).
As you mention, the surface finish isn't too bad, but with the fuel injectors, in the cylinder head, all surfaces upwind of the fuel injectors can well benefit from a smooth, almost polished finish for an overall smooth, high speed airflow.

Cylinder head work. For your next cylinder head port work... In MOST cases, it can (usually is) actually be detrimental to flow, by lowering the floors, both the intake AND the exhaust. Smooth and blend the floors to any new wall surface, but don't "lower" the floor.

Your car, your decisions.
Just another's, somewhat experienced take on things.



Mike

 

yes it definitely can be improved. A fellow member showed me a great way to get the insides polished with sandblasting so I'm going to be doing that.. the grooves arnt neeeeearly as deep as they look. Its not glass smooth but it's definitely not groovey or rough. It is still smoother than oem casing with all that slag and sharp turns inside.
Hopefully i get the sandblasting tool and learn how to use it.. then things will be removed and further polished by sandblasting. It should open it up abit more too.

 

What does 'lowering the floors' mean?