New HP after Port and Polish

[spriggan0072]

My '94 SL went to the shop and i'm getting my upper and lower intake manifolds, heads, throttle body ported and polished. with this alone, what kind of HP are we talking about? i don't think i'll break 250, oh and i might throw some headers on, but i'm not sure what kind yet. but with just the port work alone, what HP am i looking at?

[Thourun]

I bet you feel it pull a bit harder farther into the RPMs. Who knows about power, it depends on how the job is done and your other mods.

[Kev3000GT]

I'm gonna do the same thing. I don't know about HP, but it can't hurt to port, especially with high miles.

[spriggan0072]

well, i saw the port work yesterday, oh my god, this guy should have charged me another 300 for it. my throttle body is like paper thin now. couple of friends told me that the motor should be putting out something like 280HP so i'm gonna be getting like 250HP to the wheels i think. i'm gonna try and get some pics, the before and after shots look like concrete vs glass.

[Linebckr49]

i'm gonna be the first to call BS on this one. you're hoping to put down 250 Whp from just a port job? i'd like to see some before and after shots. also, there's much talk about the flow characteristics of our cars already being quite optimal. Do you have a VR4 or NA? What other, if any, mods do you have? If you even THINK you might be pushing 250 whp <cough, cough> then watch out you don't run it lean with all that extra air in there!

[youngvr4]

a lot of cars have put out 60 extra ponies from a port job, of course some less and maybe some more.

though i've never seen the dyno sheet my buddy said he gained 30 something to the wheels from a port and polish

i've heard many people say it does wonders. but i dont know first hand, only what i've heard so.......

[stfuad]

Why would he run lean? Between the MAF and o2 sensors the ECU should adjust.

[Linebckr49]

Originally Posted by stfuad

Why would he run lean? Between the MAF and o2 sensors the ECU should adjust.

for one thing, the MAS is before the intake plenum (where the porting job was done) and should really not have much, if any, effect on the porting job, unfortunately. he could use to upgrade to a larger MAF like that from a Camaro or something.

secondly, the O2 sensors won't do crap, unless he has a wideband O2

[Musashi3000GT]

Is timming really that sesitive? I figured all those people out there who p&p would get discouraged if it where so complicated.

[Igovert500]

spriggan, would it be possible for you to do a dyno run? I think it would be quite beneficial for our knowledge and for others contemplating doing this to their NAs if we had some solid numbers to look over.

[k3smostwanted]

Originally Posted by Linebckr49

for one thing, the MAS is before the intake plenum (where the porting job was done) and should really not have much, if any, effect on the porting job, unfortunately. he could use to upgrade to a larger MAF like that from a Camaro or something.

secondly, the O2 sensors won't do crap, unless he has a wideband O2

also, just to add. i dont know what the stock fuel injectors are rated on the SL's but with 250whp, you might be getting into your fuel injectors maximum flow rate, which would make your car run lean. 250whp is somewhere in the range of 295-325bhp....so thats like gaining 100bhp from a port job...not gonna happen....but im with these guys. i wish you the best and try and get it on a dyno to see what kind of gains you got!!!

[sLADe781]

How does polishing something increase hp?

[k3smostwanted]

porting and polishing the inside of an object enables air to move at a greater velocity and volume....polishing something good ables things to move across it easier. take a bowling lane for example....if it wasnt waxed the ball wouldnt slide across it at such a fast rate, more friction = less speed...same applies with air in your engine, the less friction the faster the air will move, which will allow more air to flow through the engine. i think that should help...

[sLADe781]

Yeah, that makes sense. Hehe Thanks.