i was thinkin about getting a 3" downpipe for my FD. the question is whether or not i need an ECU. i have heard that you could get boost spikes that could blow out your apex seals. can anyone confirm this? or does anyone run a 3" downpipe without an ECU?

 

You will be fine. Its a reliability mod. You will only have problems if you go with a midpipe also. The downpipe is one of the best and first modifications that should be done.

 

I agree with Dudemaaanownsanrx7. My first mods were downpipe and radiator w/o ECU. Can't go wrong with DP.

 

your answer is in the FAQ just a word of advice not trying to be a dick but if you dont hear it from me youll hear it from somebody else and they'll be doing it to be a dick im just trying to save you some trouble in the future

this is your best friend on the forum

 

thx for the help guys.

about the search i use it as much as i can. maybe ill get the hang of it better in the future. just didnt see it at the time.

 

not tryin to be a dick man, just tryin to save you from some unnecessary bullshit in the future. but like everybody else said, anything before or after the main cat is fair game, its when you get a high-flow or a MP that youll need to be worried about spike/creep

 

I thought only using downpipe with midpipe it causes boost spikes. Is it true that the spikes will occur with high flow cat and downpipe?

 

think of it this way whats the most restrictive thing in the exhaust? the main cat, so regardless of whats before or after it, its gonna have pretty much the same resistance regardless of whats before or after it. remove that resistance and you overload what the stock turbos were meant for, hence creep/spikes

so u can answer your own question by saying how much less resistance am i getting by using a high flow cat vs a MP?


the answer, since nobody on this forum seems to want to work for their answers anymore is that a high flow cat does have less, but not nearly as much less as a MP does, so in turn you need to be watchful of creep/spikes with a high flow cat, but not as much as if you had a MP

 

spikes can def occur with high flow cat and downpipe assuming you also have a cat back system. If you run the stock cat back with high flow cat and DP you should be fine. I have been running a dp, hf cat, and aftermarket cat back system for years with no problems on stock ECU. Of course I had issues with the stock turbo control system but with manual controllers I can set it to have no spike and no creep.