i sent my car to get inspected to a shop yesterday and it got knocked down for emissions. the guy said it was due to my holley TB, specifically he said it was too big for the car and it was not creating enough vacuum to make the EGR valve run propperly and, thus, making it spit out NOX. the only thing that makes sense to me is that the day before yesterday, i was looking over the engine and i heard this hissing sound. i had never heard this sound before until that day and i think that's what he's talking about. it was coming from the gasket in between the TB and the plenum. does anyone have a recommendation for fixing this because i don't want to get rid of my nice holley TB.

-GTAman

 

Check the small hard vacuum line that attaches to the small nipple on the bottom of the TB to make sure it's still connected, or the hard line itself is not broke.

 

I find it hard to believe that a 52MM TB would do that.

 

I find it hard to believe that a 52MM TB would do that.

 

ok this is what happened. i picked it up today and they told me it was because of the gasket inbetween the TB and the plenum. yesterday i gave them the box the holley TB came in with the old TB and hardware. they looked through the box and found another gasket that fit the holley TB perfectly leading me to believe the proper gasket was never installed in the first place! so they put this other gasket on and put some stuff called "high tech" on both sides to seal it up good so after 2 days and $220.50 later, my car appeases whoever made these stupid laws up. there goes my new exhaust system =(...for now. atleast my holley is still on =)

 

should have bought the exhaust system instead of the TB... would have made a much bigger difference

 

Just got through reading the "Sticky" on the TB's..... All I can say is that it did make a big difference on my car with the 85 computer in it. No more lug when it hits 3rd, just jams man... Of course my car isn't stock or even a 305 either....

Another thought, larger exhaust pipes without headers won't do anything for your 305 either. I put a 3" mandrel bent ehaust on my car when it still had the 305 and it didn't do a thing for it. In fact, it felt much less responsive and my 1/4 mile ET's didn't improve a bit. I have no doubt that it helped with the 350 when I installed that engine. The headers definitely helped!!!!! the larger TB was probably the last thing I put in and that was only because the stock one was totally worn out. With my 89 computer in the car, I never had that lug going into 3rd gear so the TB may not be of as much benefit to a newer Third Gen

 

i'm not putting in 3" piping because that's too much flow for my rat motor. i'm going to go with a system from dynomax with 2 1/2". my i-pipe on the car now, however is 3" (i think) but after that it's like 2 1/2". i forget what the stock pipe size is on an 88 GTA but the only thing different is the muffler. it's a dynomax super turbo.

as for exhuast, i'm going to invest in the edelbrock tubular exhaust headers mostly because they are a good fit, are smog compatible, and i don't have to mod where my cat is to set things up. actually, i'm going to buy a catco cat and hook it up between the TES and the dynomax exhaust. i'm not going with flowmaster because everyone has them.

edit: oh yeah, the only reason this TB is on here is because GM doesn't make the stock TB anymore.