Finally got one of the last sets of 2nd gen S&S headers installed. I want to stay NA and I think it is finally time for a tune.

Can you guys point me in the right direction? Which aftermarket air/fuel management system should I go with? Do I definitely need one of these aftermarket systems or can the car be tuned using the OEM ECU? I did a search and there is just a ton of info.

Looking for some up to date inputs from CL members who did this recently after S&S install. Is it worth it? What kind of gains were achieved after dyno tune? As most of you know, butt dyno definitely tells a difference after S&S install so I am wondering if air/fuel management system and dyno tune is even necessary. Obvioulsy I have other mods listed below in my signature.

 

Search my previous threads...it will give you ALL the info that you require! IIRC the S&S headers yielded around 14whp and 18wtq WITHOUT a tune! This is basically around the same gains as other have seen. Use the Apexi Neo as your A/F tuner...simple and to the point however, you would need to get rid of your SRT intake setup as it already has a pre-set (and non-tunable) device; many go with either K&N intake or WeaponR intake and combine it with the Neo.

As it stands right now you are probably rolling around 260whp and around 265wtq if you were on the stock 16"/17" wheel setup...heavier, larger wheels definitely slow you down (making less power) as you can see in my signature. FYI...a bone stock GS4XX on average makes around 240-245whp and around 250wtq. GL!

 

What I would recommend in your situation is to pick up a SAFC or SAFC-II as they are pretty much the same and is cheap these days to find. No need to get the latest Neo unit as not much has changed and will still do the same thing. Heck, I still use a SAFC-II to tune my FI GS300.