Ok, here goes. I may have left something out, but I will add it as I think of it. I am doing this off the top of my head...so bear with me. Also, I can answer any question or clarify anything you need help with.
Before you go adding power, it is highly recommend to upgrade the suspension.
1.) The rear IRS bushings really need replacing. Maximum motorsports has a complete kit to upgrade the cobra IRS. It is ~$750. AC427Cobra on SVTP also has a set just like MM for $450. You can also buy the kit from Steeda for ~$250 for polyurethane bushings (the other kits are derlin bushings, much harder and more durable than poly).
2.) The Billetflow IRS Differencial brace. Don't get the Steeda. Don't get another brand. Get the Billetflow one.
BilletFlow: Home of Premium Billet Pulleys, Throttle Bodies and Accessories to see why.
3.) Full length, weld in sub frame connectors. Especially with a convertible, you don't want to go adding a lot of power without beefing up the chassis some. Mine is slightly twisted due to 470+ ft/lbs of tq with stock sub frames. Yeah, don't do it. lol Maximum motors are very good and beefy. Others like the offerings from steeda and laurel mountain mustang.
General Upgrades that will add minimal power and keep things stock like:
1.) Cat back (I'm partial to Borla Stingers...loud and deep)
2.) H or X pipe with or without cats...your choice. I have a UPR offroad X...my car is defening...it is great.
3.) Cold air intake. Try to avoid anything that will put a bend in the pipe before the MAF. This has caused some tuning issues in some cars. JLT makes a nice setup, either their RAI kit or CAI kit. Avoid the high boost...we couldn't even get it installed in my car...it didn't fit. The CAI has a pipe bend, but it comes AFTER the MAF so it is ok. You could also do just as well getting a drop in K&N Filter.
4.) JLT Pre-filter for the driver side head. This helps keep the amount of oil being recirculated into the system down. When I swapped eatons, I had a puddle of oil in the lower intake....I didn't have a pre-filter.
5.) Short throw shifter. MGW = the best. Period.
Ok, now, before you go adding a ton of power, you are definitely going to want to do some cooling upgrades.
1.) Larger coolant tanks. A lot are doing these to try to keep IAT2 temps down. LFP makes a great one that will do wonders at the track as it allows you to put in a couple pounds of ice directly into the IC resevoir. Canton makes one that will sit like the stocker, hold a little more fluid, and looks a little better in my opinion. The LFP one sticks up about 2" higher than the stock IC resevoir.
2.) The LDC or Even flow cooling mod. Without either of these mods, coolant pools up and can boil with high speed runs = bad joo joo for your motor. The LDC is a T fitting that allows the coolant to flow out of the driver side head and into the heater core. The LDC kit requires you drop the tranny to install it. The evenflow kit routes a hose from the back of the driver head to the coolant crossover and goes directly to the radiator. LDC = ~197, Even Flow = ~120 and requires cutting hoses...does NOT require dropping the trans, just removing of the SC.
3.) Larger Heat Exchanger. The LFP dual pass (~$289) is a great choice. Much larger than stock...nice looking unit.
Ok, now you are thinking about putting down more power:
1.) Upper pulley swap. This is going to net you from 30-60 rwhp depending on which size you go with. I was running a 3.10 with stock lower and custom tune and was able to put down 450 hp/tq to the wheels. With a 2.76" pulley, I put down 454 hp and 476 tq. Heat is the main issue. I had no cooling mods. Many are running 460+ with a 2.76 with cooling mods. (those numbers are all SAE corrected numbers).
2.) Lower Pulley swap. This is a more expensive option, but it is better in a few ways. It lets you run larger pulleys both lower and upper so the amount of belt slip goes way down. With a small upper pulley, you get a lot of belt slip. I am running a combination of large upper and lower (3.1 upper and 6# lower) so my belt slip is a thing of the past. The HP gains here will be equal to doing an upper swap. A 6# lower = the same as a 2.76" upper. 4# = 2.93" upper. 2# = 3.10 upper.
3.) Run a combo of #1 and 2. This is recommended for belt slip issues with running small upper pullies.
4.) Port your supercharger. Stiegemeier is the only source you need to look at. This will add about 50 rwhp to what you are putting down prior to the port. Very recommended not only for power, but it also flows better and runs cooler IAT2 temps.
5.) Upgrade your stock throttle body and plenum. Do one of 3 things: Wait for billetflow later this year, upgrade to an accufab single blade, or get your stock TB and plenum ported with your SC. These will add about 20ish hp to your setup.
6.) Upgrade to a whipple or Kenne bell supercharger. Big bucks here, a ton of power to be had.
You will need some supporting mods depending on how crazy you go with power adders. The details of when what is needed will be in my full write up I am working on...but I can answer any questions you might have on it.
Basically, the fuel system will need upgrading. When you port the supercharger or move to a whipple/kb, you will need to help out your fuel. the Kenne Bell BAP is the econimcal way ~$250. The good way would be a BAP and Dual Ford GT fuel pumps with 2 upgraded FDRM (???) systems. This will hold you for about as much as you might want to run on the street.
You will also need fuel injectors once you go port and upgrade. 60# are the standard, you shouldn't need more than that unless you get real crazy.
You will also need an upgraded MAF sensor. Ported will peg the meter quick. An SCT BA2400 or 2800 will serve the purpose. You could also run a Diablosport MAF.ia which is a piggy back to the stock MAF. Kind of the band aid solution.
When you get up over 500 rwhp, and even below really, you may want to think about upgrading your stock half shafts in the rear end. The stockers can break anytime you get wheel hop. DSS level 2's would be minimal, the level 5s would be the best choice.
