jproy

I know the P2R lower intake runner plenums have been out for a while now. Has anyone done a before and after dyno yet with them? I would like to see what the real world gains at the wheels were. Thanks

fuzzy02CLS

iTrader: (2)

The lower ones? I thought those were 1 offs?

jproy

I dont know. I thought they were making them from OEM stock on a machine for $350. I may have to just give them a call.

EL19

iTrader: (4)

^^^ cls6speednupe has it done. But he has so much other stuff done with it, its hard to see what kind of difference they made if any at all.

CleanCL

iTrader: (4)

http://www.powerrevracing.com/08accordrunners.html

Their listed for 2008 Accord, I'm unsure of fitment to a CL. But either way P2R can port/polish for you.

jproy

^^^ Thanks, I know where to get them and how much they are. The question is, has anyone seen what the real before and after gains at the wheel are?

CleanCL

iTrader: (4)

I'm guessing you mean lowers ported/polished to compliment the uppers which have been done already? If that's the case, my guess is 5whp to show up on a dyno in the top end. This is my guess on an N/A car judging by what I have seen on similar motors along with other v6 motors.

CLS6SpeedNupe

Call me Mr. Nupe

jproy

Yes, the lowers. I know there would be a gain. It probably is 5whp peak only at the top end. I just wanted to see if anyone had checked what the gain was on the N/A J23A2.

CLS6SpeedNupe

oooooo

Mike

nupe, if you have something to share then share it. if not then quit acting like you're too cool. this community was built on the premise of sharing and exchanging ideas for the benefit of everyone. if you can't share then why are you here? you expect help when you're looking for information but forget about getting you to divulge details of your build. are you going to play nice and share what you know? if not, don't let the door hit you on the butt on your way out.

RUF87

^^

It would be nice to know if it does, and what does $350 buy you.

BTW, I'm not a fan of all out PnP . . port matching and clean up yes, but not so much for polishing. Trying to remember . . . the old school rule that polishing was not a good thing unless you had a pretty exotic engine . . . boosted . . high compression . . . tunnel ram . . I don't recall too many years since I was that in to it.

Anyway, I did some port matching and cleaned up some of the bumps, but left it fairly rough while I was having the intake system bored out. I haven't done a dyno, but I can tell it loves the extra air . . and it's really crazy when the air temp is in the 40s or below . . that said, it doesn't feel that much better when gets in the 70s and up. I'm still trying to get to the track and see what it does, but weather closed the track last weekend, so now it's another 2 or 3 weeks.

Oh well . . let us know what you find out . . I'm wanting to break in to the 13s without NOS, turbo, SC or 3.5 build . . .

Ruf

TOPHER33884

iTrader: (6)

I believe that polishing helps as far as smoothing out the surface for smoother airflow.

TheWeez

If you have the time, why not port and polish them yourself? It's not that hard. Just pickup a set from your local junk yard to work with. Then when you put them on your car, port and polish the other set and sell them. I use to do it all the time with intakes for my previous car.

jproy

^^^ I intend to. I only asked if anyone had measured the gains from th P&P lower runners.

davepaul033

iTrader: (1)

Gasket matching and polishing the upper and lowers are a shitty bang for your buck if you are forcing air through it with a supercharger. If you are running n/a on the other now that makes all this work a little more worth it.

jproy

^^^ I agree. For the most part that is true. I am going to do it anyway.

davepaul033

iTrader: (1)

More power to ya, literally lol

TOPHER33884

iTrader: (6)

True....lol

RUF87

Yes, but there is a difference between porting & polishing and porting and cleaning up. Polishing is a mirror smooth finish and that is not always a good thing. I believe with NA and possibly other set ups that it's not best to polish. Just port match and clean up the rough stuff. It's still smooth, sort of like 100grit sandpaper, but not a mirror polished finish.

Ruf

davepaul033

iTrader: (1)

You say this because if its to smooth there will not be enough turbulence for the air and fuel to mix properly?

RUF87

Yes, that was the old school of thought. I know some guys have done the mirror port and end up with no improvement, and in a few cases felt the car ran worse. I have no personal experience on comparing the two, so that's why I posed it as a point with a request to see if anyone else would chime in and add their experiences. Since jproy is a real motorhead, I thought this was a good thread to throw that out.

Ruf

jproy

I agree that polishing is a waste of time when done to the mirror finish. It is only necessary to take it down to say 80 or 120 grit smoothness. Even if you don’t notice there is something to be gained from removing large casting marks from the passage ways inside a manifold so long as you do not change the intended geometry of the manifold enough to offset its intended design, especially when the car is normally aspirated. When you polish the surface of the manifold to a mirror shine you are at a point of diminishing returns insofar performance gain. I have never seen a high performance race engine for a track car that was not port matched and polished/smoothed casting marks in the intake manifold to at least 80 grit. The casting marks are there because of the molds, usually sand, from which the parts are poured with molten aluminum. In the case of mass produced cars it is not worth the hours necessary to smooth the bores of the intake manifold and runners over the minimal gains to be had. Its not cost effective to do it on a mass production scale so it is not done. The argument about leaving the casting marks for turbulence in the manifold is, IN MY OPINION, complete BS. I have never seen a race engine that had nasty casting marks all over the inside of the intake anywhere. When I was looking at the inards of an F-1 engine, among others, at the Barber Motor Sports Complex in Birmingham Alabama on a private tour with the head mechanic, not one had any kind of surface other than smooth to the tune of 80-120 grit sand paper. It is my understanding that the turbulence some people speak of is created by the directing of the shape of the manifold as the air is directed into the combustion chamber. I really don't know to much more than that. I can tell you that when done properly there will always be a gain from removing all rough casting marks from an intake manifold and runners.

Porting is always beneficial when done correctly. The volume of each runner must remain the same and their gemometry must remain identical. Removing enough material to match the ports where the upper and lower runner meet and where the lower runners meet the heads is always beneficial to flow especially when considering the margin of nastiness the J32A2 lower runners were cast with. They mate to the heads with a jagged circle on the lower runner side to a larger, perfect, squared oval on the head which is pretty smooth like it is, mine are. There is definitely something to be gained from matching the ports from the head to runner geometry so the air is not significantly disturbed as it flows from one part to another. If either of these processes is done incorrectly and one port is larger than another, flow to each cylinder can be changed and cause one cylinder to get more or less air charge than the.

When the air is forced into the combustion chamber the gains from a port and polish(smoothing) are seriously negated because the whole point of the smoothing and port matching is to make the air’s path less restrictive as the piston moves down vacuuming in air. When forced in with the blower or turbo I think it is still slightly helpful but not nearly as much. I have fun doing crap like this to the car so I am going to do it anyway mainly because I am still pissed I couldn’t figure out how to get the lower runners off last time I was in the motor and just want to do it now since I have seen how ugly the port matching is from the lower runners to the heads. Sorry for the rant but it seemed like some wanted some explanation. There are people here that know much more than I do so I am sure someone will chime in if I have said something wrong. Jim

davepaul033

iTrader: (1)

Damm jim I was just going to say that haha. Here are some pics of my gasket matching/port job.

http://s126.photobucket.com/albums/p...3/Head%20work/

RUF87

thanks . . . you pretty summed up most my understanding.

I basically cleaned up all the casting ridges and other odd bumps with a course stone, and then port match. But did nothing to open anything up, so I totally agree with changing the geometry.

Ruf

jproy

You do not want to apply the grinder or sanding wheel to any part of the mating surfaces of the parts like in these two pics. In the first pic, there is zero benifit from polishing the surfaces shown that are not mating surfaces. You only need to smooth the areas where there is high velocity air travel.




applying the grinder or sanding wheel to any of these surfaces will likely cause a vacuum leak and should not be done under any circumstances.

davepaul033

iTrader: (1)

So your saying I almost f'ed this up? I did not experience any vacuum leaks.

jproy

Yes