I replaced my clutch recently and while everything was apart I decided to gasket match and polish the interior of the parts I could.
-I opened up the TB circumferance a bit and polished the interior of it both the in and the out
-Next was that black plastic piece connecting the TB to the SC intake . I opened up the exit of the black piece with a dremel to more closely match the SC input opening
-After the SC I gasket matched the large "horn" to the SC output opening and I polished inside the connecting horn as far as I could both at the in and the out which leads to the IC
-After the IC I polished inside the smaller "horn" input and output and also gasket matched it to the intake opening
-I gasket matched the exhaust to the exhaust manifold and had the precat gutted
I have 15% and a 2% ,WMW exhaust ,cust cold air and I'm only seeing 14 to 15 lbs of boost and idle vac is 15in cold and drops to 11 warmed up
Did i make a mistake by doing all the work ?

 

If it's done properly, it won't harm anything. 15 psi sounds about right for a 15% pulley.

 

I also have the ATI 2% damper if that makes a difference. Car runs very smooth and seems to pull nicely .I'm just wondering why I'm seeing only 11 in of vac when warmed up

 

if it's of any help I just had the same issues , low boost low vacuum and it was caused by belt slippage and my crank pulley slipping . The car ran perfect and fast ect but only made 11psi of boost and 11vacuum and I thought it was normal from the day I had it, even though I knew the numbers were off I had no cel or drivability. Then finally my crank pulley broke fully and I found my belt or that pulley had been slipping from day 1.
lol I fixed it and the car is a world of a difference , it makes 16psi max boost and 17 vacuum in idle .
Maybe check the tension on your belt but yet thelower vacuum numbers may be caused by the porting you did . If you ported the tbody and it doesn't fully seal around the blade I could see the low numbers. I'm not sure if opening up things as you did would effect the numbers so much but I could be wrong.
I would check the bpv too since it's easy enough.
by chance , did you port around where the throttle blade closes? If so that's your issue . You can rite in front and rite behind but it's kind of pointless to port a throttlebody as it's only as big as the blade is. But that blade needs to be able to fully seat.

 

I stayed away from the lip where the plate closes I just opened it up a bit and polished it well ...both input and output . New tensioner and new belt where installed at the same time as the clutch and all the matching/porting .
I think I'm going to test for leaks . I forgot how I did it on my STI since it was a long time ago but I'm sure its easily researched.
Also going to put a mark on the SC pulley and belt ,drive a bit ,and then see if the mark is off .
The car runs great ,really smooth . I just want to be sure I'm not loosing boost/vac leak somewhere

 

theres an online video how to smoke test them. The port you use is rite down to the left of the intake filter . Just get a cigarette and vacuum hose to fit in the port and blow smoke on in and look for leaks .
Are you sure you have the correct length belt ? This is why I actually do love an alta product as with its tensioner arm you can adjust it to run multiple belt lengths
is your tensioner oem ? I've read alot of non oem ones donot provide enough resistance on the belt and will slip once aftermarket pullies are used in conjunction with them.

 

The belt seems to be ok however I used an after market tensioner that supposedly was oem with the label ground off . I forgot where I got it . I'll look into the tensioner you mentioned. Thanks
Probably a stupid question but how does a vacuum pump push smoke into the engine. I'll look for the video . I remember on my STI I pressurized the intake somehow .

 

I just used a cheap fluid transfer pump with a cigar in one end and the other line into the cars vacuum system and as you pump it pulls smoke off the cigar and into the intake system , if theres a leak the smoke should leak past it.

 

Awesome suggestion .I happen have one in my garage and I smoke cigars ! Where did you tap into the system

 

 

A drop in measured manifold pressure (airflow resistance) at the same or higher power level would actually indicate that your porting worked exactly as intended.

 

Frank -

All good stuff.
Next time you have your header off, it's a good idea to make the flange opening a little larger than the cylinder head opening.
This helps a thing called "reversion" (or backflow) from happening. This will help keep the intake air/fuel charge clean. As with most cams, there is a time when "both" the intake and exhaust valves are open. While a proper "blower" cam tries to keep this to a minimum, it still happens.
Any time that there is low/no boost, some amount of reversion takes place. Having a ridge around the exhaust helps to keep the amount of backflow / reversion to a minimum.

Mike

 

Thanks guys . Mike . When I had the exhaust off I marked the gasket outline on the flange and opened it to match . I also wrapped it .

 

I'm still wondering if my belts slipping at high rpms. I tried marking the belt and a pulley but that's difficult to match back up after driving
So .. with a 15%and 2% crank I'm using continental 6k1388 and I'm showing 50%of 1 hole on the tensioner . Should I go to 1385 ? Which brand ? Gates?
Gatesk060539 (6pk1370) 1385mm was too small

 

I dont know on the belt length but I would consider the alta tensioner. I was able to pick up slack enough on my stock belt length and 17% pulley with it , it's easy to adjust and get set too and you dont have to worry about it breaking and destroying your crack pulley then .you should look into that route exp with the smaller pullies . I've read ALOT on these forums and I have seen ALOT of issues with aftermarket tensioners not keeping propper tension on correct length belts and even oem ones having slippage issues.
the alta almost makes it in a fixed position . I read that these serpentine systems really dont need an adjustable tensioner exp with a harmonic dampener... I'm sur theres going to be some for and against it but with your problems your having , knowing for sure the belt isn't slipping would be a good start.
but atleast smoke check it and make sure your bpv has good resistance when you push on it to check the ?? Diaphragm?? I 2x checked mine and found it may even be aftermarket as mine had ALOT of resistance on it , more than what would seem normal from all I've read and I see the screws n clamps have all been removed too.

 

I've been researching the fixed tensioner since you mentioned it and I've seen alot of comments about how the engine wasnt designed for that because the stress on the pulleys changes dynamically but like so many things in life who knows the truth..maybe I'll try it . How long have you had yours? You said it's almost fixed. I thought it was 100% fixed.
EDIT I'm such a dummy I thought it replaced everything not just the damper part
As far as a belt I like the continental brand because it is alot heavier duty than the gates so I called them and I'm going to try a continental elite part# 4060545 at 1384mm .
Smoke test tomorrow or thurs .
I checked the BPV when I had everything apart and it closes completely but how can I really tell what's enough tension without something to compare it to or some measurement

 

I picked up a set of "holies" cheap which I'm going to paint gunmetal . Cant wait to lose 5lbs unsprung weight per wheel .

0 to 60 !!! Love it .

 

my engine has had it since I've owned the car and I've run it HARD befor and am by no means easy on it. I've yet to have any issues with it...
for every article I read I read one saying the complete opposite . Imo the extra vibrations in a fixed belt system should be compensated by the dampener our cars have . And I think even with the fixed alta tension rod , the big spring still allows for some travel ..the alta part replaces the strut on the tensioner only .
as long as when you press on the end of the bpv and you feel a decent amount of resistance and you push it in that's good, idk about all either but mines very firm and will spring rite back into position and I can hear it shut .

 

Not to be 'that guy,' but coincidentally, due to COVID I'm moving my engine swap plans up, and have a set of gasket matched and ported manifolds, intake horns, and that Alta tensioner arm (w/ a new tensioner) all for sale currently. Zero miles on all of it because I decided to pull the Iron 1.6 and go with something all-aluminum.

 

Saw all your stuff on sale, and wondered what your "new direction" was.

Looking forward to the build thread.

Sorry for the hijack... back to the topic at hand!