I'm planning to get a HKS Downpipe but I'm not sure what size I should get. What's the difference between size 2.75 and 3" inch?? What are the benefits of having 2.75 and 3"??

 

The diffrence is 0.25", it means better flow, get a 3" DP and a matching 3" exhaust and you'll have a nice setup

 

Definately 3"

 

not really. Bigger is not always better. That down pipe is for quicker spool up. 3inch more power but upstairs (top end) not that much over the 2.75. Hks has been making performance parts for years I think they know what they are doing. By the way I have the Hks dp and Kat back and boost controller and Hks cams and Hks intake. If you are going to use stock turbo then the Hks dp will be good. but if you upgrade to bigger turbo get 3inch dp

 

I have HKS 30 th Anniv cat and I have 2 brands in my mind which is HKS and Helix v2. Which brand is more reliable ??

 

get the Hks Buddy. That cat back is not 3inches. its like 2.9 I feel that the hks dp will complement your cat back

 

Thank you for giving me a good info for the hks dp. So go with the 2.75" hks dp right?

 

It took me a several days to choose for the downpipe. I finally decided to go for the Tanabe Dp since it's $100 bucks cheaper than Hks dp. Since they are 2.75" same size so it won't make any differences, it's just the brand differences which cost more cuz of the brand name. Do you guys think there'll be a slight difference if I go 3" Hks 30th catback with hks dp compare to 3"Hks 30th catback with Tanabe dp??

 

Is there any differences between Tanabe and Hks dp?? I think Hks dp has more good quality since hks is more money but in a performance, any differences?

 

HKS has 2.6 inch diameter DP and helps our turbo spool up faster due to reduced back pressure and better flow. I agree with WRX kila, you will have more high end power with 3 inch DP but will lose some low end torque.