Supporting Mods For F/I Applications
 

Please use this thread to discuss the supporting mods needed for all types of Forced Induction, such as but not limited to:
- Fueling
- Exhaust
- Tires
- Cooling
- Engine

Please use evidence to support claims and as primary of a source as possible.

Keep it productive and informative!

Straight off the bat, one supporting mod that has become immediately apparent from many tuners is excessive oil temps. Oil cooler a must for FI!

So an oil cooler, larger radiator and a oil temp guage may be things to consider if you plan to run this car, especially on hot summer days.

I wouldn't put in a larger radiator just yet unless you're planning on big power. Oil cooler is definitely number one though. It seems as though even stock cars benefit from it.

oh looord, open the flood gates...

I think it really depends on your performance, driveability, and longevity goals.

Exhaust:
it's going to be 2 different paths depending if you are going turbo or supercharger.

Turbo cars will probably run 3" exhaust systems and what they run will depend on the turbo manifold and down pipe combination and where they connect back up with the oem component locations. Larger diameter exhausts = quicker spool and beefy low end torque especially when you combine VVT tuning.

Supercharged guys can use any exhaust they choose but those that want the most power will run complete systems including headers. Most will probably run 2.5 or 2.75. It's going to depend on power targets. Anything that improves VE will further improve the power produced with a supercharger.

Intakes:
In both cases it will depend on what works with or is provided with the FI kit you choose.

Fuel system:
Not sure here, Perrin is saying SC 14psi at 7500 on stock injectors at 11.2 afr... however higher revs can easily push duty cycles to the point injectors are static so i don't think we have enough info yet on fuel system upgrades.

Instrumentation:
Boost, Oil Pressure, AFR should be mandatory. Oil Temp is almost mandatory on these. EGT is very nice to have for tuning.

Cooling:
Oil cooler should be added for anyone that uses the go pedal a lot, FI or not. I've seen over 212*f just commuting to work and back.

Brakes:
If you more power you should add more ability to scrub off speed.

Traction:
Probably a good application for stagger fitments to deal with added power to the rears. Sticky tires in at least 235's.

Clutch to help put the power down. Different clutch setup for different power goals

Flux Capacitor and mad scientist

There seem to be a lot of people looking for brake upgrades, but they are hardly necessary. A decent pad will perform fine on the track up to 300whp. Amateur drivers may use brakes excessively, and may necessitate an upgrade. But the factory brakes are a very good size for the weight of the car.

Clutch will be a pending upgrade for anyone going FI. The factory clutch won't handle anything more than 275whp for long.

Fuel upgrades for E85, or pushing over 300whp.

Lots and lots of smooth and shiny bits and pieces.

In all serious i need to start my build thread soon.

I personally haven't seen many if any 3" turbo setups on these cars due to the extremely tight fit between the subframe and engine where the over pipe is. I know they can probably fit one but it would be super tricky and would likely require you to lift the engine a bit to wedge it in. As it stands, 2.5 seems to work well on these cars, the Full blown kit is 2.5", P&L is 2.5", AVO is 2.5", etc. I would like to go 3" eventually once i build up the lower end of the block just because I might as well, but for now 2.5" is good for 500+ WHP.

As for other things needed, a clutch is a definite need, the stock will hold 240HP but it gets dodgey and will likely wear quickly. I went to the extreme end of the clutch option spectrum and got a 6 Puck sprung clutch rated to 500lbft (like I'll ever see that).

For wheels and tires...255's are more along the lines you should be looking at, I'm running 7PSI and 255WHP and 255's spin just getting on the throttle in second. Stickier tires will help tremendously, and a properly sorted suspension will help too.

Brakes are a must, with boost 100 mph+ is easy to do and you get there quickly, top of 4th gear is 125mph at 8500rpm. The stock 2 piston calipers can't handle the loads and heat generated trying to slow down from high speeds, they fade super quick. My Wilwoods feel bulletproof at the moment, I'd say they might be too much brake for the car but that's fine by me, more aggressive pads will be a boon with aftermarket calipers.

Oil coolers are a must and I am dying to get mine...just waiting on P&L to finish up theirs.

Radiators aren't a must have item, but can help a lot with track cars, I have my eyes on a Koyorad but i am working out if it will fit with my turbo system.

5W40 or 10W40 oil, don't run the 0W20 stuff, it just gets burnt up and does jack shit for lubrication. The higher stress on the engine will benefit from slightly thicker synthetics, and for those of us running in the desert 10W40 will help keep things lubricated.

I recommend a lightweight crank pulley with the turbo, the lower rotating mass helps spool up the turbo much faster, plus the engine revs super fast so heel toe downshifts are even easier. Paired with a lighter flywheel and clutch and the engine feels very racy.

Suspension in my eyes is a must have, you need to be able to dial in your compression and rebound and spring rates to get the rear end to hook up with any kind of consistency, you need to get the car to transfer weight over the rear wheels, aka squat, under acceleration. Stock struts just aren't made for the violent acceleration of a turbo car, add in the increased braking afforded by an aftermarket brake kit and you have the suspension working twice as hard as it was designed to.

There's a bunch of things i would suggest, but aren't mandatory like a functional rear wing to help keep the rear end planted at speed (get's a little squirrelly back there over 120mph) and a vented hood to help bleed off heat when stuck in traffic (it may help extract heat at speed but no one has proved it to this point, but the heat that would normally be trapped under the hood when in traffic can escape through vents and is very apparent since the heat shimmer is pretty intense). Last thing i would recommend is the most obvious...a good dyno tune or a street tune if you have the opportunity.

Something to catch the blow-by.

From the other thread:

No, that's when you would do something like this instead.

http://i1144.photobucket.com/albums/...pse0b908ab.jpg