SoCalZ

Hi Everyone,

I recently purchased a '97 Z28 and I love it. Problem is with the current setup I can't pass smog here in CA. Has Pacesetter headers and Y pipe into a magnaflow exhaust. I need help from other fellow CA Z owners..what is the best CARB legal exhaust setup?

Thanks!

Injuneer

Probably the stock manifolds. To be CARB legal, the headers can not cause relocation of the cats. That's why the long tubes are not CARB legal. I don't know if anyone still makes CARB-OE certified headers for the dual-cat cars. SLP used to. AS&M made them for a while, but discontinued them because the heat from the driver's side header, wrapping up over the valve cover, was melting everything in the engine compartment.

There is a CARB website where you can go and search for CARB approved aftermarket auto components.

pgerst

Hooker and Edelbrock both make CARB-OE shorties. They are 4 into 1 style. SLP is no longer available but you see them on e-Bay; SLP is a tri-Y style. There is a lot of debate whether the shorties are better then stock (IMO they have to be, just by eyeballing they have to flow better.)

I have the SLPs and only have seat of the pants versus stockers (have never done the math on the primary/secondary lengths), but it is an improvement. The tri-y design is phyically smaller than 4 into 1 and fits in the engine bay easier. A shorty 4-1 may flow a bit better but there are instances of heat problems as the tubes come up above the engine (little wrap/heat shield would probably solve that.) Also I still have plug access with the tri-Ys (though 2 is a bee-atch due to the a/c) versus partial to non-existentant on the 4-1 shorties.

If you are willing to do the bi-annual hassle, swap the stock exhaust in and out for the test as long tubes are the way to go for max hp.

pkincy

I have the SLPs and am running into a similar problem now that I am back in Kalifornia. Mine were bought for my 93 very early on (94-95) when SLP was selling them but before vendors were putting part number plates on with the EO number.

I got my 93 Corvette smogged by pulling a hi res image from Hooker's website (I have the 2061HKRs) but can't find an image for the SLPs on a website that has a part number and a reference to the EO number. I do have the EO paperwork from the California database, but these days you have to prove to the Smog place what your part is.

pgerst

Call SLP. They will send you stickers that you can put in the engine bay/glove box with the EO numbers.

cheapchevy

I have to swap my stock cats back up to my SLP headers every two years for smog. Shorties definitely flow much better than stock but not as good as long tubes. SLP Part Number 30017 CARB EO # D-187-7.