Hey guys, I have a 92 Prelude Si and I am probably going to buy a 93 VTEC cat from a member from this board. If I buy his VTEC cat..will I have to order a Thermal exhaust ( I have already decided on getting this exhaust system) for a VTEC car then???

Someone mentioned to me that the difference between the Sis and the VTEC exhaust systems is only the length of the cat. He told me that the Cat on a VTEC is shorter than the ones on Sis.

Anyone know for sure??

 

I'd like to know the answer too, but i don't know man, hopefully someone does.

 

ok, when i swapped mine, the only difference in the cat is the spacing of the connecting studs(bolts) on the side that goes toward the rear. The spacing for the studs on the Si are 1/8-1/4in closer together. So the Si cat wont fit a Vtec exhaust, But if your buying a Vtec cat then you shouldn't have any problems.

The only difference in length i know about is the length of the down pipe, but that is between 4th and 5th gens not 4th gen Si and Vtec.

I personally would buy an aftermarket cat with the free flow design, instead of buying a used cat that might already be plugged up from years of usage.

Or you could just buy a exhaust for a Si and just connect it to you Si cat because it will bolt up to the Vtec header.

*tried to make it easier to understand (i hope)*

 

Don't know if this helps you any but 3 or so years ago I bought the GReddy PE exhaust for my 96 SI prelude. Back then GReddy didn't have an SI application only VTEC(don't know if that has changed). But anyway, I bought the VTEC application and had it installed at a local muffler shop for $90.00. He told me that the differences were minimal and could easily be worked around.

 

The H22A1's cat is longer(about 1") then the H23A1's. So If you buy a H22A1 cat back, the exhaust will be shorter and bang on the heatsheilds, and muffler will bang on the rear swaybar..