I figured I should have one place to post progress with my car. I initially chose the is350 as I wanted a daily driver that wasn't slow, had four doors and wasn't bad on gass. This car is perfect and even better was the apparrent lack of aftermarket options for the car. I didn't want to dump money into the car as I already have a project car but it seems I like the is350 much more than my mustang. First I wanted to poke at making it faster, the is350 is quick enough for a dd but it really feels like an extra 30-50hp would make it perfect. I have a set goal of 310hp for my car and I believe it is doable. Sometime next year I would like to address the suspension. The car came with lowering springs which are ok however I would really like to at least swap out the sway bars and get it on some coilovers. After that id like to fix the biggest problem I have with the car which is the open differential. I don't really know how I will address it, but I really feel like the car needs something else. Of course there are a handful of other things I would like to do, those are just the biggest things in my opinion.

So on the performance side of things I currently have a custom dual exhaust setup and an intake that I have slowly poked at in hopes of finding something that is perfect. I have paid for (not yet received) PPE headers and plan on redoing the rest of my exhaust after installing the headers. I wan't to try a dual x pipe setup and if the noise isn't too bad after the resonators and mufflers I might skip on installing cats. I have debated going to 2.5" exhaust and stepping down to 2.25" but when I run the numbers for flow requirements it looks like ill be just skating by with the 2.25" which will save me the hassle of swapping out the collectors on the headers. After I have my exhaust done I will have a custom tune dialed in for my by the guy at orange virus tuning and with any luck ill be close to or hit my goal. If after this I am unable to hit my goal, I have a spare lower intake that I would like to use to make a short runner intake tailored to the higher RPMs. I believe that the oem upper intake could benefit from splitting up the runners so each inlet has room to breath, so the plan is to give each runner its own velocity stack aimed in a way so that none of the runners compete with each other. If necessary I will then fill the intake with whatever seems appropriate (probably some epoxy) until I find a plenum volume I feel is right for me. At this point I will have to accept whatever the car makes and I should be at the upper end of the extra 30-50hp I thought the car should have.

 

Redspencer swapped out the open diff for a OG Giken Super Lock TSD and others IIRC have swapped in the BRZ diff.

 

The IS350's open diff can be replaced by an IS-F Torsen LSD, a ATS Carbon LSD, A TOMs LSD, or an OS Giken Super Lock TCD LSD (TY391-HC). The BRZ diff mod is for those with an IS250 rear end only.