Current Set Up:

-89 Si Hatch
-D16y8
-Shorty Intake
-Skunk2 IM
-DC Sports Header

Question 1) Next mod, <U>z6</U> Port and Polished head with Cam (Crower) and Srings/Retainers (Crower)......OR.......High Flow cat and full cat back exhaust?????


Question 2) Is there a difference in Performance from a 2.25 vs. 2.5 inch Cat-Back Exhaust????? More top end from one or other, more mid, etc. etc. etc.

Any and All knowledge on both topics is MUCH appreciated.


Just to add to the mix.....Would the Crower oversized valves help out with the headwork, or a wast of $$? Stock fuel/ignition map will be alright with these mods, correct?

Modified by groundedcivic91 at 3:58 AM 6/10/2004


Modified by groundedcivic91 at 3:02 AM 6/11/2004

 

Get the exhaust first. Then the headwork.
2.25" piping will do the trick.

 

from what I know there isn't much diffrence between the 2.25" and the 2.5" you are talking about a 1/4 of an inch there....not too much diffrence, UNLESS you are running/going to run turbo, as for the next mod..i'd have to say the first..exhaust is minimal HP, port and polish would be better i would think plus you don't get that ricer sound

 

Head work/cams would give a bigger power gain over exhaust work.
2.25 is good for a mild engine, just get high flow cat/muffler w/ no restrictions.

 

Boost will not be in the question, CONSIDERING this is a 150+ mile a day driver

I am thinking that exhaust will compliment the current mods nicely, and a PnP/Cam will as well, but the flow will be hurt do to poor exhaust set up.......

p.s. I beleive this car has original Cat

 

Get the headwork done first, it will make a huge difference.

 

Anyone have a recommended place that provides bare PnP head w/o Valve Train?

This way i can start to compare some prices on this as well

 

ebay my friend, you can usually find them cheep there. also i'd recomend giving JG Engine Dynamics a call up for your springs and retainers, i just build my friend's Z6 head with their parts and they are very high quality at a great price