Need a Cobb AP/Tune if I install HFPF internal Upgrades?

[LReyes66]

I have a CPE downpipe on my ms3 with the stock HFPF internals in my 08 MS3. I dont mod, race or go to car meets anymore because I have other things I need to focus on. But this summer I am going to focus on tuning up my car with needed maintence such as replacing the struts/shocks, get new tires, re-tint the windows and get my car professionally detailed (living in a apartment now so detailing myself isnt a viable option). But the main thing after replacing the suspensions I want to take care of is upgrading the HFPF to the autotech internals. I know I may sound ignorant but I didnt do my research back when I was younger before installing the DP that its a bad idea to replace the DP without replacing the HFPF internals which now I want to take care off. I dont have a boost gauge or a monitoring system which I know is a stupid thing to do but ive learned, so flame on if needed.

Questions: Can I replace the HFPF without having to gett a COBB ap or hypertech tune?

I dont wanna spend $500-600 on a Accessport that would get wasted for not being used to its fullest potential.

 

[magicka]

Get a tune. Not for the new HPFP, but for the flow mods (SRI and DP) you already have. It's the best bang you'll get for your buck on this car. I would suggest the AP over the HT because you don't have another monitoring solution, and you desperately need one.

 

[MSMS3]

If you are running an aftermarket downpipe, you NEED (require) the upgrade to your pump internals. You are probably seeing about 2 psi more boost over stock. That increased boost and tge increased flow are really stressing your pump's ability to meet fuel demand. Pressure is probably dropping and you do not know it, because you are probably not monitoring. When pressure drops under heavy load, the ECU tries to maintain AFR by increasing the injector pulse width, the length of time the injector sprays, so that fuel volume per injector cycle remains the same. This protects the engine (up to a point),but the lower pressure does not atomize the fuel as well, so you also lose some power. Worse yet, the unatomized fuel tends to pool up on the top of your pistons. This produces hot spots, which eventually damage the pistons. If that's not enough, you are also spiking boost to 21-22 psi when you first go WOT. That is not healthy for the engine, either.

Short version: if you care about your engine you will not run a 3" downpipe without upgrading the internals. Get them now. This is completely independent of the tuning issue.

Expect to spend about $350. Get the proven AutoTech ones. They are easy to install with basic hand tools and a little common sense. Follow the instructions. It helps to have a bench vice or take the pump somewhere where you can use one for a few minutes. Keep everything spotlessly clean. Flush with lots of clean gasoline. Lube properly. Put a zip tie on the fuel line just below the nut that connects it to the pump, so thar the nut does not slide all the way down the line and become difficult to retrieve.