I'll begin by saying I don't know anything about fuel systems or how to modify rotaries. I bought my car (88 TII) and it has a K&N style air filter and the stock airbox has been removed. I am considering getting an HKS catback exhaust (not sure what kind yet). With these two "modifications" would I need to upgrade the fuel system? I am thinking about the HKS catback because I found a good deal but I have no problem with generic exhaust either. What do you think? Will my car be more reliable with generic exhaust or will this be nearly identical. I don't want to screw up my car so I figured I asked before I did something bad without upgrading the fuel system.

Thanks in advance.

 

Cheap exhausts usually sound like crap. Id rather have the HKS, it will probably last longer. And all you need is a better fuel pump (walbro 255lph are popular) and a fcd, so long as you dont go over 10psi. You can use the search feature in the top right hand corner of the webpage for questions like this. They get asked a lot.

 

I would scratch the cat-back idea, and go with a down pipe and high flow cat. as these are you two biggest bottlenecks. You will barely notice anything (IF anything) with just the cat back.

DEFINITELY go get a Fuel Cut Defensor (FCD) IF these are the mods that you are sticking with, for now the stock fuel pump is fine, but if you upgrade to an aftermarket boost controller you might want to upgrade. For now i would recommend a stock FD fuel pump that will support you to about 255RWHP safely, and you can usually have your hands on one of those for alot less than a Walbro. which brings me to this: I don't like that fuel pump. It makes you run richer at idle, it's noisy, and really won't support 400 RWHP. For a little more you can find fuel pumps that will. I just don't want you to see money poorly spent. Good luck and keep the sticky side down.